I .', 

Laboratory for Oceans 

Code 670 

ACTIVITIES REPORT 

FEBRUARY 1986 = APRIL 1988 

(NASA-TH210t257) LABORATORY FOB OCEANS N89-28118 

Activities 3eport, Eel). , - Apr. ,1988 --THB U-- 

Abstracts Only (HASA. Goddard Space Flight N89-28194 

Center) 272 p CSCL zor, Uaclas 

63/48 - 0189856 

NASA GODDARD SPACE FLIGHT CENTER 

Jational Aeronautics and 

;pace Administration GREENBELT, MARYLAND 
LABORATORY FOR OCEANS 

ACTIVITIES REPORT 

- 

February 1986/April 1988 

Space and Earth Sciences Direcbrate 

NASA/Goddard Space Flight Center 

Greenbelt, Maryland 20771 
FOREWORD 

This report has been prepared in response to the need for an 

annual overview of the activities of the Laboratory for Oceans; 

it contains information that is useful to management and to 

colleagues inside and outside of NASA. The activities of the 

Laboratory do reflect the capabilities and interests of its 

staff, as well as the history of the organizational elements that 

were joined to form the Laboratory. Its professional staff is 

nearly evenly divided between engineering and scientific 

personnel, the work in the Laboratory has a corresponding 

distribution of emphasis. The other Earth science laboratories 

in the Directorate of Space and Earth Sciences rely on the 

Laboratory for Oceans for a significant portion of their 

engineering support in aircraft remote sensing projects and 

sensor development. The collaboration with the other Earth 

science divisions also extends into scientific research, since 

the earth sciences tend to be closely related. Among them, 

climate dynamics involves atmospheric, terrestrial and oceanic 

sciences in terms of physics, chemistry and biology. 

This report documents how NASA goals are being supported by work 

in the Laboratory. The introduction gives an overview of 

laboratory capabilities and activities. Short reports on separate 

projects follow, with a list of publications and a listing of 

personnel. 

iii 
ORGANIzATImZu CHAKrS 

RESPDNSIBI- AND UST OF PERsONNEL 

MISSIONS 

OCEAN to^ ExpERlMEKT (Torn) RADARL. C. Rossi, D. W. Hancock, and G. S. Hap 

MARS OBSERVER m ATxDmIm RAD1- (MORAR) 

L. C. Rossi, D. W. Hamock, andG. S. Hap 

BA" -TIC MONIToFUNG (ACEMP) 

C. Vermillion, H. Maurer, M. Williams, J. Kianowski, 

T. Moore, W. Maksimuvich, H. Obler, E. Gilbert 

NASA mma To THE BANGIADFSH -TIC -ALl 

MO"G (ACE") 

C. Vermillion, H. Pkwrer, M. Williams, M. DesJardh, 

E. Mollo-christensen, C. Mason, A. Kerber, J. Gervh, 

J. Elrod 

FLJI SOUTH PACIFIC SEVERE STDRM DEXECTION AND WARNING SYSTEM 

PIMTECT (SPSSD/WS) 

C. Vermillion, H. Maurer, M. Williams, J. -ki, 

T. Moore, W. Makshnvich, A. Hasler 

NASA FoL;L13w-oN To THE FIJI SOUTH PACIFIC SEVERE STDRM WARNING 

SYSTEM FEOJECT (SPSSD/WS) 

C. Vermillion, H. Ma-, M. Williams, J. Kianowski, 

T. Moore, W. Makshovich, A. Hasler 

MONCCWLAR E3XcTm+PrICAL sXEREx3 SCANNER 

C. Vermillion, H. Maurer, V. Salmnson, C. Cote, 

J. catesla, H. Ramapriyan, Dr. J. Smith 

TROPICAL RAINFALL MEASUREMENT MISSION (TRMM) 

T. T. Wilheit 

SPACEBORNE METEDROLCGICAL RADAR SIUDIES 

R. Meneghhi 

ADVANCED AI;TIMETRY 

C. L. Parsons, S. A. Bailey, D. E. Hines, D. W. Shirk, 

C. W. Wright, and A. R. Selser 

PRECEDING PAGE BMGK N6T FILMED 

17 I 

23 I 

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V 
EAKm OBSERVING SYSTEM (Ex) AWANCED 3ATTlmTRY 

C. L. parsons and E. J. Walsh 

WIDE BAND DATA ClXJECI'ION SYSTEM 

J. M. Turkiewicz 

CATJBRATION SUP~RT FDR THE EAKTH OBSERVING SYSTEM PFKUECT 

B. W. Guenther 

-C WIDE FIELD SENSOR 

R. G. Kirk 

"E E2FaT-I RADIAnoN EWCGET EXPERIMENT 

A. T. Ivled~erikunnel 

LLJNAR OBSEHVER LASER ALTnmmR 

J. L. Eufton 

YAG AEw3soL LmYAR 

R. Sullivan 

OCEAN WLOR 

APPLICATIONS OF THE 03STAL ZONE 03LCIR SCANNER IN OCEANOGRAPHY 

C. R. McClah 

OCEAN CDLOR OBSERVATIONS OF ~~ DISTFUBLRTONS AND 

PRIMARY PRomcrIvrIY 

W. Esaias 

O3ASTAL ZONE (XILOR SCANNER SIUDIES 

J. Elrod 

REMYTE SENSING OF OCEAN COLOR IN "E ARCTIC 

N. G. Maynard 

AIRBORNE IN-sm SPECTRAT-I aARAcTERIzATION AND mmTION 

ESTIMATES OF FLIXIRESCENT ORGANICS As A Fu" OF DEPTH 

R. A. Tittle 

mC APPUCATIONS OF LASER TEC"0Lf)GY 

F. E. Hoge 

NASA U-IARGE COUPLED DEVICE (0) S- SYSTEM (NCSS) 

C. W. Wright, S. A. Bailey, and C. R. Piazza 

AlxBoRNE ocEA"IC UIYIR (AOL) FLIGHT MISSION PAR!TICIPATION 

F. E. Hoge 

PAGE 

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vi 
OCEAN DATA ACQUSITICN SYSTEM 

B. Johnson, J. Cavamugh, J. smith, W. ESaias 

COGTAL ZONE CXXOR SCANNER 

B. Johnson 

"E MULTI- OCEAN COIDR SENSOR (MOCS) 

J. D. Okerholtzer and C. R. Vaughn 

SEA ICE 

ARCTIC SEA ICE SIUDIES WITH PASSIVE MIcRckJAvE SATEZLITE OBSERVATIONS 

D. J. Cavalieri 

MI-VE REKYI'E SENSING OF SEA ICE 

J. C. Ccaniso 

ANALYSIS OF SEA ICE DYNAMICS 

J. Zwally 

ICEsHEFTFanARAlmME!mY 

J. Zwally 

SEA ICE/c!lmAlx mm 

C. L. JhMnson 

ICE sHEEr mIEs USING SylmHETIC APEmuRE RADm 

R. Bindscha dler 

PHYSICAL - 

ocEANcwIFTERF€uxEcr 

C. D. Mason 

AIR SEA ICE lxIERAcrICN 

ANALYSIS OF "E WIND-IXUVEN RESPONSE OF TROPICAL OCEANS 

A. J. wlsalac&i 

CLDYAlDLCGICAL ASF!EKTs OF "JS-7 SMMR DATA 

P. Gloersen 

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vii 
R7UNF'AT-L ON MICFKWAm €?EXURN FWJM THE SEA SURFACE 

I L. F. Bliven and J.-P. Giovanaqeli 

WIND-WvE- TANK RESEARCH FACILI'IY USAGE AND STATUS 

L. F. Bliven and S. R. brig 

I ?HE SURFACE WAVE DYNAMICS EWEWMNT (SWADE) 

S. R. mnq, J. D. Chrholtzer, C. W. Wright, 

and H. G. Shirk 

AIMOSPHERIC 

WATER VAPOR PROFILDG USING MICR3WAm -1-Y 

J. R. Wang and T. T. Wilheit 

OZONE - USING BllImoN-BoRNE OZolwSoNDB 

A. L. Torres 

MOBILE LILWI SYS" FOR MERSUREMENT OF WATER VAPOR MIXING RATIO 

AND OZONE NUMBER DENSITY 

I D. Whiteman 

I WRSPHERIC NITRIC OXIDE 

A. L. Torres 

CmUD ABsoRvI?oN rnIoME!mR 

M. G. Strange 

PAGE 

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viii 
DATA UTILIZATION 

THE IAJ3ORAlDRY FOR OCEAN 03MpVIwG FACILXIY 

R. Kao 

03DE 672 OBSERVATIONAL SCIENCE EEG4NU-l coMpElTER NGIWORKS 

D. W. Hancock and H. G. Shirk 

pERsoNALaxmn!ERON~ 

R. Kao 

THIRD l"ATI0NAL SA- DIRECI' BIMADCAST SERVICES USER'S 

CoNFERENCE 

J. Karmwski, C. Vermillion 

Low a36T REAL TIME llVImAIvE ANALYSIS SYSTEM 

F. Steth 

IN-ATION 

NAVIGATIONAL AND -AL SYSTEM ("3) 

T. D. Clem 

AIRBORNE LUlAR GLOm FOSITIONING INVESTIGATIONS 

W. B. Krabill 

MICFUWAVE RENUTE SENSING OF SOIL MOISTURE 

J. C. Shiue and J. R. Wang 

sm1c ApElczuRE MICKMAVE RADIW 

D. M. Le Vine 

RADAR scAm AND SOIL MOIsruRE 

D. M. Le Vine and P. O'Neill 

AwANclED SOUDSI'A!IE ARRAY SPIXXRORADIF. G. Huegel and J. Irons 

AGFacmLmJFE IwErIBAND EXPERIMENT RADIOMETER 

W. H. Jones, J. Schutt, B. Holben 

DIODE-HIMPED LASER RESEARCH 

L. Ramos-Izquierdo, J. wlfton, K. Chan 

LARGE - SCANNING AIRBORNE lxm 

J. Smith, R. Bindscha dler, R. Boers, J. Bufton, 

T. D. Clem, J. Win, S. H. Melfi 

PlUX 

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~ A IWITIPROCESSOR AIRBORNE LIDAR MTA SYSTEM 

C. W. Wright, S. A. Bailey, G. E. Heath, C. R. Piazza 

CALIBRATION 

METEOEQLEICAL SENSOR CALIBRATION FACILITY 

F. J. Schmidlh 

NASA AIRCRAFT-SATELTJTE IN- CALJBRATION PRQSECT 

B. W. Gumther 

€?ADIANcE STD. L. I.tesCXLmRATION CHAMBER OPERATIONS 

D. L. mter 

HJBLZCATIONS 

BOOKS 

PRESENTATIONS 

X 

PAGIZ 

257 

261 

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279 

283 

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301 
GENERAL OVERVIEW 

The strength and character of the Laboratory lies in its 

professional staff, which is made up half of engineers and half 

of scientists. The entire staff contributes to the solution of 

problems in Earth and planetary sciences, working individually 

and directly on scientific problems or as members of teams 

addressing challenges in engineering and science. 

The Laboratory represents an important resource for technology 

within the Earth science divisions at GSFC; one consequence is 

the Laboratory participates in a wide range of terrestrial and 

atmospheric science projects through its engineering support to 

the other Earth science divisions. This deliberate concentration 

of engineering resources allows better utilization of expertise, 

and broadens the range of in-house expertise one can justify and 

maintain. As is apparent from this activities report, the 

Laboratory contributes engineering design skills to aircraft and 

ground-based experiments in terrestrial and atmospheric sciences 

in cooperation with scientists from our sister laboratories in 

the Earth sciences. Space flight instruments are also being 

planned, developed and built in the preview of the Laboratory or 

with significant participation by Laboratory engineers. Examples 

are the TOPEX altimeter, the Mars Explorer Mission altimeter, the 

sensor complement for the Tropical Rainfall Measurement Mission 

as a follow-up to a series of passive microwave sensors that have 

been flown or are destined or intended for future missions. 

1 
Our work in passive microwave radiometry includes a 1.5 Gigahertz 

radiometer for observing soil moisture, the Electronically 

Scanned Thinned Array Radiometer (ESTAR), the High Resolution 

Multi-frequency Microwave Radiometer (HRMMR) and other passive 

radiometers with a variety of combinations of frequencies and 

~ scanning capabilities. 

~ 

Our work in laser altimetry has brought us near flight mission 

readiness, aircraft altimetry is a promising field now that the 

Global Positioning System (GPS) is available. Passive optical 

sensors are also being worked on along many lines for a variety 

of research applications Among the latter are the data system 

for SeaWiFS, the Ocean Color Sensor destined for Landsat-6, and 

Moderate Resolution Imaging Spectrometer (MODIS), for the Eos 

polar orbiter. 

I 

The scientists in the Laboratory do all the research that use 

space technology as a tool of inquiry or satellite data as an 

important source of data. The scientists are recognized members 

of their respective research communities, they are all engaged in 

collaborative efforts with colleagues at universities and 

laboratories in the United States and abroad. The expanded use of 

satellite sensors as a research data source can best be promoted 

through examples of use, efforts at making the data more easily 

accessible and through the development of new methods of data 

interpretation. The modern approach to data analysis is through 

computers, and the combination of numerical modeling of oceanic 

2 
processes and data processing is now under intensive development. 

Scientists from the Laboratory participate in all aspect of this 

work. 

During the period covered by this report, the satellite data 

analysis activities in the Laboratory have been improved 

significantly by the availability of new computer data analysis 

facilities and software. The numerical modeling of oceans, and 

ocean-atmosphere-ice interactions have also made significant 

progress. In aircraft remote sensing, new instruments have been 

built and used in research, our lidar capability has grown, and 

new optical sensors have been used in research. 

The activities of the Standards and Calibration Office is also 

expanding, as its capabilities become known and the importance of 

calibration is demonstrated through flight experience. The 

availability of a group with expertise in optical calibration is 

proving to be advantageous to instrument designers and instrument 

users; they no longer have to go through an independent learning 

experience in the field of calibration, but are able to draw on 

expertise, equipment and facilities that are kept available for 

the purpose and under continual improvement. 

In our research activities, we have increased our participation 

in international observational programs, both as colleagues in 

research and as providers or experts in the use of satellite data 

and space sensor technology. This is valuable preparation for 

participation in future flight missions. 

3 
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5 
670 - LABORATORY FOR OCEANS 

Responsible for a broad program of research in ocean and 

cryospheric sciences, including the role of the ocean in 

climate and the chemical and biological components of the 

global system. The laboratory is also responsible for 

development and exploration in sensor technology, data systems 

and sensor calibration, and carries out aircraft and in situ 

observational programs to improve the fundamental knowledge of 

processes in the ocean, in sea ice and the physics of remote 

sensing. The laboratory collaborates in joint development, 

research and field observations with earth scientists from the 

Goddard Space Flight Center, and from universities and external 

research centers. 

The Laboratory maintains competence through participation in 

research with members of the scientific and engineering I communities and reflects the general needs for development of 

technology applications to research in the earth sciences. 

NPIYE PROFESSIONAL TITLE - CODE PFIONE NUMBER 

Erik Mollo-Christensen Chief (Sc.D., 670 301-286-6171 

Massachusetts Institute of 

Technology) 

Dean S. Smith, 

Lucille Parker 

Dawn Feick 

Assistant Chief for 670 301-286-9869 

Organizations 

(B.s., Kansas State University) 

Secretary 670 301-286-6171 

Secretary 670 301-286-8670 

6 
670.1 OCEAN DATA SYSTEMS OFFICE 

Performs research and development of advanced direct readout 

data acquisition systems directed at meeting the needs of 

ocean, weather, land, climate and hydrology. Plans research 

and technology development, conducts systems studies, develops 

systems, maintains Laboratory for Ocean Color Facility (LOCF), 

and provides consultation and direct assistance to other 

government agencies including foreign government entities. 

Develops and manages major projects for the remote sensing of 

the earth and its environment and implements these projects in 

support of NASA, NOM, or US AID programs. 

NAME 

Charles H. Vermillion 

Terri D. Randall 

John C. Kamowski 

Rosa Kao 

Harold E. Maurer 

Ann T. Mecherikunnel 

Thomas Moore 

Francis L. Stetina 

Margaret Williams 

PROFESSIONAL TITLE 

SUPY., Ground Data Systems 

(University of Maryland) 

Secretary 

Manager, Direct Readout 

Development Laboratory 

Physical Scientist 

(Ph.D., U. of Pittsburgh) 

Ground Data Systems 

(Ph. D. , Purdue University) 

Physical Science Management 

(Ph.D., George Washington 

University) 

Engineering Technician 

Technical Manager 

(M.E.A., George Washington 

University ) 

Earth Sciences Remote Sensing 

(B.S., Villanova Universitv\ 

CODE PHONE NUMBER 

670.1 301-286-5111 

670.1 301-286-5111 

670.1 301-286-5083 

670.1 301-286-8302 

670.1 301-286-8215 

670.1 301-286-5034 

670.1 301-286-6389 

670.1 301-286-5717 

670.1 301-286-6963 

7 
671 - OCEANS AND ICE BRANCH 

Carries out research on oceanic and ice processes, and the 

Develops remote roles of oceans and sensing ice in global methods, weather algorithms and climate. and 

interpretations, to assist in sensor development and to 

demonstrate, throilgh research applications and flight programs, 

the use of remote sensing in research on the Earth community on 

problems in oceanography, air-sea-ice interaction and 

glaciology. Carries out research in climatology in cooperation 

with scientists in meteorology and other neighboring fields. 

Works jointly with engineers and physicists on sensor 

development and the planning and execution of experiments. 

Serves as liaison between NASA and the oceanographic and 

alaciolo~ical research community by collegial interactions and 

Name 

Nancy G. Maynard 

- 

Victoria L. Jenkins 

Robert A. Bindsc3adler 

Antonio J. 8usalacAi 

Donald J. Cavalieri 

Josefino C. Comiso 

Jane A. Elrod 

Daniel E. Endres 

Wayne E. Esaias 

Per Gloersen 

Norden E. Huang 

Frederick C. Jackson 

Robert G. Kirk 

Professional Title - Code 

SUPVY I 67 1 

(Ph.D., Yniv. of Miami) 

S scretary 67 1 

Physical Scientist 67 1 

(Ph.D., Univ. of Washington) 

Oceanographer 67 1 

(Ph.D., Florida State Univ.) 

Physical Scientist 67 1 

(Ph.D., New York Univ.) 

Physical Scientist 671 

(Ph.D., U.C.L.A) 

Oceanographer 67 1 

(Ph.D., Univ. of Rhode Island) 

Mathematician 67 1 

(B.S., Univ. of Minnesota) 

Oceanographer 67 1 

(Ph.D., Oregon State Univ.) 

Senior Scientist 67 1 

(Ph.D., The Johns Hopkins Univ.) 

Oceanographer 67 1 

(Ph.D., The Johns Hopkins Univ.) 

Physicist 67 1 

(Ph.D., New York Univ.) 

Physical Scientist 67 1 

Phone Number 

301-286-4718 

301-286-6662 

301-286-7611 

301-286-9502 

301-286-2444 

301-286-9135 

301-286-9503 

301-286-3434 

301-286-5465 

301-286-6362 

301-286-8879 

301-286-5380 

301-286-7895 

(M.S., U.S. Naval Postgraduate School) 

8 
NAME PROFESSIONAL TITLE CODE PHONE NUMBER 

Antony A.K. Liu Oceanographer 671 301-286-8534 

(Ph.D., The Johns Hopkins Univ.) 

(Ph.D., N.C. State Univ.) 

Charles R. McClain Physical Scientist 671 301-286-5377 

Claire L. Parkinson Physical Scientist 671 301-286-6507 

(Ph.D., Ohio State Univ.) 

Paul S. Schopf Physical Scientist 671 301-286-7428 

(Ph.D., Princeton Univ.) 

Joseph W. Siry Senior Scientist 671 301-286-9013 

(Ph.D., Univ. of Maryland) 

H. Jay Zwally Physical Scientist 671 301-286-8239 

(Ph.D., Univ. of Maryland) 

9 
672 - OBSERVATIONAL SCIENCE BRANCH 

Responsible for theoretical and experimental research of 

observational systems and techniques associated with oceanic 

remote sensing. Performs instrument systems performance 

assessments. Plans and conducts laboratory and field 

measurements to improve the fundamental knowledge of remote 

sensing and to evaluate sensor systems and to quantify their 

performance. Assists other branches with field experiment 

planning, flight platform interfacing and data acquisition. 

Develops, maintains, and operates research facilities (i.e., 

wave tank, laboratory field standards, aircraft remote sensors, 

ground-based ozone and wind sensors) to obtain high quality 

measurements that support the development of new sensors and to 

obtain key scientific data. Establishes agreements for field 

data exchanges in support of scientific studies and satellite 

sensor calibration (i.e., vertical sounding of ozone, 

temperature and humidity, ocean waves and chlorophyll, etc.) . Develops and furnishes algorithms to flight project personnel 

that convert the instrument observations into geophysical 

parameters. 

VAYE P?.CFZSSIONAL TITLZ CODE PYONE NtTBER 

Thomas D. Cle3 SUPVY, Earth Sciences Renote 672 804-824-1515 

Sezsing (B.S.E.E., Purdue Univ.) 

Lisa J. Wood Secretary (A.A.S., Eastern Shore 672 804-824-2527 

Con. College) 

Steven A. Bailey Electronics Engineer (B.S, UMES) 672 804-824-1429 

Larry F. Bliven Oceanographer (?h.D., NCS Univ.) 672 804-824-1057 

David W. Hancock Mathematician 672 804-824-1238 

(B.S., East Carolina Univ.) 

George S. Hayne Xathenatician (Ph.D.,Yale Univ.) 672 304-824-1294 

George E. Heath Electronics Technician 672 804-324-1010 

(X.A.S.,Eastern Shore Com. College) 

Donald E. Hines Electronics Technician 

(Siena College, NY; ESCC) 

Frank E. Hoge optical Physics 672 804-824-1567 

(Ph.D.,West Virginia Univ.) 

William B. Krabill Earth Sciences Remote 672 804-824-1417 

Sensing (B.S., SSC) 
NAME 

Steven R. Long 

John D. Oberholtzer 

Chester L. Parsons 

Laurence C. Rossi 

Francis J. Schmidlin 

Donald W. Shirk 

Helen Shirk 

Robert A. Tittle 

Arnold L. Torres 

Charles R. Vaughn 

Edward J. Walsh 

Charles W. Wright 

PROFESSIONAL TITLE CODE PHONE WBER 

Oceanographer (Ph.D., NCS 672 804-824-1034 

University) 

Optical Physics 672 804-824-1241 

(Ph.D.,Florida State Univ.) 

Earth Sciences Remote 672 804-824-1390 

Sensing (M.S.,Purdue Univ.) 

Engineering & Operations 672 804-824-1590 

Management (B.S.,Northrop 

Institute of Technology) 

Meteorologist 672 804-824-1618 

(B.S.,The Penn State Univ.) 

Electronics Technician 672 804-824-1312 

(computer Science Curriculum, 

SSC) 

Computer Assistant 672 804-824-1405 

Earth Sciences Remote Sensing 672 804-824-1244 

(B.S.,California Tolytechnical 

University) 

Atmospheric Measurements 672 804-842-1553 

(Ph.D.,Univ. of South Carolina) 

Optical Physics 

(M.S., Columbia Univ.) 

672 801-824-1653 

Microwave Physical Electronics 672 303-497-6357 

(Ph.D., Northeastern Univ.) 

Electronics Engineer (M.S.,SSC) 672 804-824-1698 

11 
673 - STANDARDS AND CALIBRATION OFFICE 

The Standards and Calibration Office is a hands on calibration 

activity within the Laboratory for Oceans which specializes in 

visible and near infrared calibration activities. The thrust 

of these activities is to provide Goddard investigators with 

improved radiometric calibrations for their experiments. 

Within the past 2 years the Office personnel have been involved 

in calibration source maintenance and development, flight 

source development and project and mission policy development. 

The Office is beginning an activity of vicarious calibration 

where a well calibrated instrument is used to observe a scene 

simultaneously with a satellite sensor to improve or verify the 

calibration of the satellite sensor. 

NAME PROFESSIONAL TITLF CODE PYONE NUMBER 

Bruce W. Guenther sUPVY, Space optics 673 301-286-5205 

(Ph.D., U. of Pittsburgh) 

Robert Burbage Electronics Technician 673 301-286-7158 

Sol Glicker Optical Physicist 673 301-285-8231 

(?h.D., Poly Tech. Ins. Brooklyn) 

Danny L. Lester Physical Science Technician 673 301-286-6558 

James T. McLean Space Optics (B.S., Central 673 301-286-ai34 

(University) 

12 
674 - EXPERIMENTAL INSTRUMENTATION BRANCH 

The Experimental Instrumentation Branch is organized as a selfcontained instrument development team. Its members have the 

basic skills that are necessary and sufficient for the design, 

project management, fabrication, assembly, and testing of 

electro-optical remote sensing instrumentation. Their skills 

are concentrated in electronic and computer engineering, 

optical and mechanical engineering, instrument design and 

drafting, model-building, and fabrication. They have a wide 

range of experience in instrumentation development for all 

application areas of the Earth sciences. They typically follow 

a task from its inception all the way through initial 

operational missions and data interpretation. This llin-housell 

development team is oriented toward flight pro] ect instrument 

development; primarily for NASA airborne remote sensing 

missions, but also for small spacecraft payloads. They supplement the flight mission development work with sensor 

system research tasks supported by the Director,s Discretionary 

Fund, NASA/Headquarters RTOP tasks, and Small Business 

Innovation Research funding. They specialize in the 

development of lidar sensors, imaging spectrometers, radiometers, and laser altimeters. 

NAME 

Jack L. Bufton 

Carol D. Lundregan 

David L. Carter 

John F. Cavanaugh 

Raymond D. DiSilvestre 

Frederick G. Huegel 

John M. Humphreys 

Bertrand L. Johnson, Jr. 

William H. Jones 

PROFESSIONAL TITLE 

SUPVY, Electronics Engineer 

(Ph.D., Univ. of Maryland) 

Secretary 

Mechanical Engineer 

(B.S., Univ. of Maryland) 

Electronics Engineer 

(B.S., Univ. of Maryland) 

Mechanical Engineering Tech. 

CODE PHONE NUMBER 

674 301-286-8591 

674 301-286-6135 

674 301-286-6319 

674 301-286-5214 

674 301-286-3803 

(Technical Apprentice Program) 

(B.S., Univ. of Cincinnati) 

Mechanical Engineering Tech. 674 301-286-3072 

(Columbia School of Drafting) 

Electronics Engineer 674 301-286-3116 

Electronics Engineer 674 301-286-6179 

(B.S., George Washington Univ.) 

Electronics Engineer 674 301-286-6224 

(B.S., Univ. of Maryland) 

13 
NAME 

Kenneth R. Kirks 

Charles D. Mason 

Luis Ramos-Izquierdo 

James C. Smith 

0. Glenn Staley 

Maxwell G. Strange 

Robert J. Sullivan 

Gunnar J. Sundstrom 

David N. Whiteman 

Edward R. Young 

PROFESSIONAL TITLE 

Mechanical Engineering Tech. 

(Danville Tech. Inst. t 

Naval Weapons) 

Electronics Engineer 

(B.S., Northeastern Univ.) 

Optical and Electronics 

Engineer (M.S., Univ. of 

Rochester ) 

Electronics Engineer 

(B.S., Univ. of Maryland) 

Electronics Technician 

(AAS/ECT Milwaukee School 

of Engineering) 

Electronics Engineer 

(B. S . , Northeastern Univ. ) 

Coos PHONE NUMB ER 

674 301-286-8305 

674 301-286-6609 

674 301-286-6479 

674 301-286-5185 

674 301-286-6117 

674 301-286-6119 

Electronics Engineer 674 301-286-6178 

(B.S., Indiana Inst. of Tech.) 

Mechanical Engineering Tech. 674 301-286-6788 

(Electricity & Electronics Cert.) 

Physical Scientist 674 301-286-3115 

(B.A., Williams College) 

Electronics Technician 674 301-286-5607 

(Electronics Technical Inst.) 

14 
675 - MICROWAVE SENSORS AND DATA COMMUNICATION BRANCH 

The Microwave Sensors and Data Communication Branch (MS&DCB) is 

a vertically integrated branch. The branch conceives sensor 

and system concepts, builds aircraft and ground based 

prototypes, develops interpretation algorithms and tests them 

on the data from the prototypes. After proving the feasibility 

of a given concept, we participate in the development of 

spaceborne missions and in the interpretation of the data from 

these missions. The intended results of all of the MS&DCB 

activities are application of space technology, particularly 

microwave and radio frequency, to advances in various Earth 

Sciences including Meteorology, Oceanography, Hydrology and 

Seismology. In order to be effective over so wide a range, we 

are staffed by technicians, engineers and physicists and we 

collaborate with Earth scientists from other branches, other 

divisions and outside of NASA. 

NAME 

Thomas T. Wilheit 

Stella M. Burress 

John E. Fuchs 

Louis R. Dod 

Richard L. Kutz 

David N. Le Vine 

Robert Meneghini 

James C. Shiue 

Jan M. Turkiewicz 

James R. Wang 

PROFESSIONAL TITLE CODE PHONE NUMBER 

SUPVY. , Physics Engineer 675 301-286-9831 

(Ph.D., Massachusetts Institute of 

Techno 1 ogy ) 

Secretary 67s 301-286-9831 

Electronics Technician 675 301-286-3505 

Electronics Engineer 675 301-286-6720 

(M.S.E.E., George Washington 

University ) 

Electronics Engineer 675 301-286-9114 

(B.S.E.E., Pennsylvania State 

University ) 

(Ph.D., University of Michigan) 

(M.S.E.E., University of Michigan) 

Physicist 675 301-286-8059 

Electrical Engineer 675 301-286-9128 

Electronics Engineer 675 301-286-6716 

(Ph.D., New York University) 

Electronics Engineer 675 301-286-6172 

(B.E.E., George Washington 

University ) 

Physical Scientist 

(Ph.D., University of Chicago) 

675 301-286-8949 

15 
MISSIONS I 

PRECEDING PAGE BLANK NOT FILMED 
OCEAN TOPOGRAPHY EXPERIMENT (TOPEX) RADAR ALTIMETER 

by 

L. C. Rossi, D. W. Hancock, and G. S. Hayne (672) 

Our involvement with the TOPEX Radar Altimeter allows us to 

contribute to the advancement of oceanographic research by 

participating in the NASA TOPEX Mission in the areas of spaceflight hardware and ground data processing algorithm development. 

We are assisting the Jet Propulsion Laboratory's (JPL) TOPEX 

Flight Project Office in the execution of the TOPEX Flight 

Mission relative to the requisite spaceflight hardware and 

supporting data reduction algorithms that will be required. 

Specifically, we are providing a spaceflight qualified Radar 

Altimeter capable of achieving the TOPEX Mission measurement 

precision requirement of 2-centimeters, and will evaluate its 

performance (Engineering Assessment) after launch and 

continuously during its 3-year mission operational period. We 

will be providing to JPL information about the calibration of the 

TOPEX Radar Altimeter. We will provide the specifications for 

the required data processing algorithms which will be necessary 

to convert the Radar Altimeter mission telemetry data into the 

geophysical data. We will participate in the validation of these 

geophysical data prior to their initial release to the TOPEX 

Principal Investigators and at periodic intervals during the 

TOPEX Mission. 

PRECEDING PAGE BLANK NOT FILMED 

19 
The stringent 2-centimeter precision requirement for ocean 

topography determination from space necessitated examining 

existing Radar Altimeter designs for their applicability towards 

TOPEX. As a result, a system configuration evolved using some 

flight proven designs in conjunction with needed improvements 

which include: 1) a second frequency or channel to remove the 

range delay or apparent height bias caused by the electron 

content of the ionosphere; 2) higher transmit pulse repetition 

frequencies for correlation benefits at higher sea states to 

maintain precision; and 3) a faster microprocessor to accommodate 

two channels of altimetry data. Additionally, examination of 

past altimeter programs associated data processing algorithms was 

accomplished to establish the TOPEX-class Radar Altimeter data 

processing algorithms, and the necessary direction was outlined 

to begin to generate these for the TOPEX Mission. 

The Johns Hopkins University Applied Physics Laboratory (JHU/APL) 

over the period FY83-FY86 completed the TOPEX Advanced Technology 

Model (ATM) Radar Altimeter. Since the last Activities Report, 

partial testing of the ATM provided evidence that 2-centimeter 

precision altimetry from space is achievable with the design 

concept chosen for the flight TOPEX Radar Altimeter. The 

necessary administrative arrangements to obtain the support of 

The JHU/APL for the development of this flight Radar Altimeter 

were accomplished during the first half of FY87, and their Flight 

Unit development efforts were initiated in the fourth quarter 

FY87. APL's major emphasis during the remainder of FY87 was the 

establishment of a new Radar Altimeter flight configuration 

20 
compatible with the TOPEX spacecraft selected by the Project and 

the conduct of Radar Altimeter Preliminary design activities. 

Development of the specifications for the flight TOPEX Radar 

Altimeter ground data reduction algorithms was initiated by 

GSFC's Code 672. The TOPEX Project sponsored Data Workshops with 

the TOPEX Science community concerning data processing were 

actively supported during FY87. 

21 
MARS OBSERVER RADAR ALTIMETER RADIOMETER (MORAR) 

by 

L. C. Rossi, D. W. Hancock, and G. S. Hayne (672) 

Our involvement with the Mars Observer Project will permit us to 

contribute to the advancement of the state of the topographic and 

hypsometric knowledge of Mars to a level of 10 meters or better 

over the surface of the planet Mars, to measure the microwave 

surface brightness temperature of Mars with an accuracy of 15 - 

20 degrees KeLvin over the mission lifetime and a repeatability 

of + 2.5 degrees Kelvin over 24 hours, and to measure globally, 

surface returned power related to radar cross section (Sigma 

Zero) with an accuracy of 1 dB and a repeatability of .5 dB. 

We are responsible for accomplishing the MORAR Hardware 

Development, Ground Data Processing, and the Mission Operations 

required by the MORAR Principal Investigator, Dr. David E. 

Smith/Code 620, whose scientific objectives are: a) to define 

globally the topography of Mars at sufficient vertical resolution 

and spatial scale to address both large-scale geophysical and 

small-scale geologic problems, and b) to obtain global surface 

electrical and scattering properties of the upper several 

centimeters of the Martian surface for assessment of the 

composition, physical state, and volatile distribution of the 

surface. 5 t CI \’ 

The MOM instrument development role was assigned to The Johns 

Hopkins University/Applied Physics Laboratory (JHU/APL) via a 

PRECEDING PAGE BUNK NOT FILMED 

23 
NASA Defense Purchase Request to the U.S. Navy, the contracting 

agency for The JHU/APL. The Technical Monitoring of their 

activities is being accomplished by Code 820 personnel. The 

MORAR Ground Data Processing and Mission Operations will be 

accomplished within Code 672. MORAR Project Management is being 

accomplished by Code 672. MORAR Science will be performed both 

within the GSFC and various universities under the leadership of 

I the Principal Investigator. 

During FY87, the MORAR Experiment was confirmed as one of seven 

experiments to be conducted by the Mars Observer Mission. The 

MORAR Experiment Implementation Plan was established and approved 

by JPL. A Letter Agreement was implemented between the GSFC and 

the JPL to effect the MORAR. The MORAR Preliminary Design was 

initiated at The JHU/APL. The Interface Definition with the Mars 

Observer Spacecraft was initiated. The planning documentation 

for the Ground Data Processing System was initiated. The first 

key document defining the activities necessary to convert raw 

MORAR telemetry data into engineering parameters during the first 

of three Ground Data processing steps was established at the 

Preliminary level. Participation in the first MORAR Science Team 

meeting conducted in September 1987 was successfully 

accomplished. During the third and fourth quarters of FY87, the 

necessary replanning was initiated to accomplish the MORAR 

Investigation, in response to a revised Mars Observer launch date 

of 1992, instead of 1990. This replanning is still underway. 

I 24 
BANGLADESH AGRO-CLIMATIC 

I' ' lpd5 L9&lLY 

N 8 9- 2 8 12 1- 

ENVIRONMENTAL 

MONITORING PROJECT 

C. Vermillion, H. Maurer, M. Williams, J. Kamowskj 

T. Moore (670.1), W. Maksimovich (271.1), 

H. Obler (271.3), E. Gilbert (675) 

The Agro-Climatic Environmental Monitoring Project (ACEMP) is 

based on a Participating Agency Service Agreement (PASA) between 

the Agency for International Development (AID) and the National 

Oceanic and Atmospheric Administration (NOAA). The PASA was 

initiated on September 30, 1981, and the Project was completed 

September 30, 1987. A Memorandum of Understanding (MOU) between 

NOAA and NASA established NASA's function as the system 

developer/implementor. 

In FY80, the Asia Bureau and Office of Federal Disaster 

Assistance (OFDA), worked closely to develop a funding mechanism 

which would meet Bangladesh's needs both for flood and cyclone 

warning capability and for application of remote sensing data to 

development problems. In late FY90, OFDA provided $546,000 for a 

High Resolution Picture Transmission (HRPT) receiving capability 

to improve their forecasting accuracy for cyclones, flooding and 

storm surges. While that equipment is highly complementary and 

useful to the development purposes of the ACEM Project, it is 

primarily intended as a disaster prediction and preparedness 

measure. 

The ACEM Project was designed to focus on the development 

applications of remote sensing technology. Through this Project, 

25 
AID provided to the Bangladesh Government (BDG) the equipment, 

I technical assistance, and training necessary to collect and 

employ remote sensing data made available by satellites as well 

as hydrological data obtained from data collection platforms 

- 

placed in major rivers. The data collected will enable the BDG 

~ 

to improve the management of its natural resources. 

I 

A Direct Readout Ground Receiving Station for Satellite data was 

installed at SPARRSO in Dhaka in 1978. This facility was 

substantially augmented in May 1985 to include digital 

processing, user and system operation and maintenance training, 

and a proper operating environment. An Installation Ceremony was l 

held in Dhaka on May 8, 1985. 
NASA FOLLOW-ON TO THE BANGLADESH AGRO-CLIMATIC 

ENVIRONMENTAL MONITORING PROJECT 

by 

C.Vermillion, H. Maurer, M. Williams (670.1), 

M. DesJardins (612), E. Mollo-Christensen (670), 

C. Mason (674), A. Kerber (623), 

J. Gervin (400.6), J. Elrod (671) 

This describes the NASA responsibility and activities for the 

Follow-on to the original Agro-Climatic Environmental monitoring 

Project (ACEMP) which was completed during 1987. The activities 

of the NASA Follow-on to the ACEMP are defined by Amendment 3 of 

PASA BAN-0046-P-CC-1967-00 between the U.S. Agency for 

International Development (USAID) and NOAA, and a Memorandum of 

Understanding (MOU) between NOAA and NASA. These agreements will 

expire November 30, 1988. 

The following schedule is for the five training sessions which 

comprise the NASA ACEMP Follow-on: 

August 29 - September 10, 1987 Agrometeorology 

April 2 - 14, 1988 

June 11 - 26, 1988 

September 17 - 29, 1988 

November 5 - 17, 1988 

Meteorology of Severe 

Storms Using GEMPAK 

Satellite Oceanography 

Hydrology 

Meteorology with TOVS 

The objective of the Follow-on is to train Bangladesh Government 

staff in the use of satellite data for remote sensing 

applications. This activity also encourages the scientific 

connection between NASA/Goddard Space Flight Center and The 

Bangladesh Space and Remote Sensing Organization (SPARRSO). 

27 
FIJI SOUTH PACIFIC SEVERE STORM DETECTION 

AND WARNING SYSTEM PROJECT (SPSSD/WS) 

C. Vermillion, H. Maurer, M. Williams, J. Kamowski, 

T. Moore (670.1), W. Maksimovich (271.1), A. Hasler (612.0) 

In August 1986, a South Pacific Severe Storm Detection and 

Warning System (SPSSD/WS) was installed by NASA at the Fiji 

Meteorological Service (FMS) in Nadi, Fij i. The SPSSD/WS Project 

was funded by the U.S. Agency for International Development (U.S. 

AID) and administered through the National Oceanic and 

Atmospheric Administration (NOAA). 

The system consists of a 6.1 meter parabolic dish antenna, a 

satellite ground station, computer and image processing 

facilities. The system allows tracking of all South Pacific 

tropical cyclones with real-time, high resolution reception of 

visible and infrared cloud images from both the Japanese 

Geostationary Meteorological Satellite (GMS) and the U.S. 

Geostationary Operational Environmental Satellite (GOES-WEST). 

Training was also provided in system usage and operations. A 

course in Satellite Meteorology was also conducted at FMS by 

NASA. On August 19, 1986, the system was formally accepted and 

handed over officially to the Fijian Government. 

In December 1986, the U.S. AID Office of U.S. Foreign Disaster 

Assistance (OFDA) commissioned an evaluation of the SPSSD/WS. 

The report recognized the system as one of the most advanced of 

its kind in the Pacific Basin; that it has functioned 

29 
successfully since installation with only minor interruptions, 

and that it has become the prime tool in supporting the FMS' role 

as the regional tropical cyclone warning center for the Southwest 

Pacific. However, the report also noted that there are needed 

enhancements to the system. This, therefore, led to a follow-on 

program with U.S. AID. 
1y8 9* 2 8 124 

NASA FOLLOW-ON ON THE FIJI SOUTH PACIFIC SEVERE STORM 

WARNING SYSTEM PROJECT (SPSSD/WS) 

BY 

C. Vermillion, H. Maurer, M. Williams, J. Kamowski, 

T. Moore (670.1), W. Maksimovich (271.1), A. Hasler (612.0) 

In December 1987, a Follow-on Participating Agency Service 

Agreement (PASA) was signed directly with the U.S. Agency for 

International Development (U.S. AID). This Follow-on will 

implement needed systems enhancements of the satellite ground 

station installed under the previous SPSSSD/WS project. These 

enhancements include the purchase and installation of an 

Uninterruptible Power Supply (UPS) and lightning protection unit, 

hardware modifications to provide system redundancy and 

increaseddata storage capacity, software modifications for the 

new Japanese GMS digital data, upgrades of the image processing 

software, and both hardware maintenance and tropical cyclone 

analysis training, and a non-renewable grant to provide emergency 

field repairs and replacement/spare parts. 

In March 1988, the UPS and lightning protection unit was 

installed at the Fiji Meteorological Service by NASA personnel. 

A tape recorder and demodulator has been shipped to Fiji to 

record the new digital GMS data. Data tapes are not yet 

available from the Japanese Meteorological Service of the new 

digital format. This data is required to test the GMS digital 

software being developed for the Fiji SPSSD/WS facility. 

31 
I Installa'tion the remaining equipment upgrades, GMS digital 

software, image processing upgrades and maintenance training are 

scheduled for July 1988. 

The tropical cyclone training and Fiji Grant will be implemented 

in FY89 pending provision of remaining funds from U.S. AID. 

I 32 
II 1 

I I II I 

DRY1 1-vn GOEVW 

I 

I 

I 

I 

L 

CUWERTLR 

@Jj BIT 

SYNC. 

I 

I 

BIT 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

I 

1 

I 

I 

I 

I 

I 

I 

I 

I 

i 

I 

I 

Figure 1. SPSSDWS and Enhancement Project Systems Configuration - 

Preliminary Design 

33 
MONOCULAR ELECTRO-OPTICAL STEREO SCANNER ;y-& 

by 

C. Vermillion, H. Maurer (670.1), V.Salomonson (620), 

C. Cote (610), J. Catena (501), 

H. Rampariyan (636), Dr. J. Smith (623) 

The Monocular Electro-Optical Scanner (MEOSS) is an experiment on 

the Indian Space Research Organization (ISRO), Stretched Rohini 

Satellite System (SROSS) two satellites were launched by the ISRO 

Advanced Satellite Launch Vehicle (ASLV) from Shriharikota, 

India. The MEOSS payload is a Federal Republic of Germany (FDR) 

project managed by the Deutsche Forschung-und Versuchsanstalt 

fuer Luft und Raumfahrt (DFVLR) in Oberpfaffenhofen, FDR. 

In November 1986, GSFC Space and Earth Sciences Directorate, Code 

600, responded to an Announcement of Opportunity (AO) from DFVLR 

(German Aerospace Research Establishment) for use of the MEOSS to 

form stereographic images over selected test sites in the Western 

U.S. Formal approval was received in July 1987 in a letter from 

F. Lanzl to V. Salomonson. A rescheduled launch is expected for 

June 1988. The experiment requires the use of the Goldstone 

Facility for data readouts over the U.S. The Goddard Mission 

Operation Manager is John Catena. The Principal Investigator is 

Dr. Vincent Salomonson, and Co-investigators are Charles Cote, 

Charles Vermillion, Dr. H. Ramapriyan, and Dr. J. Smith. 

MEOSS is a single optics and single spectral band camera. Three 

CCD's working in pushbroom mode are mounted perpendicular to the 

flight direction on a common focal plate. Their oblique views of 

plus and minus 23 degrees forwards and backwards as well as nadir 

35 
oriented lead to threefold stereoscopic images. In contrast to 

other stereo scanners like SPOT, this principle allows a nearly 

simultaneous generation of all three images of a stereo triplet. 

The time gap between the forward and aft looking images 

guarantees constant illumination conditions. The ground 

resolution of MEOSS will be 52 by 80 meters ground pixel size, 

height resolution of 55 meters and swath width of 255 kilometers. 

The drifting ground coverage pattern of MEOSS is unique compared 

to polar orbiting satellites and will allow images of an area to 

be taken at different times of the day. A scene will consist of 

3144 scan lines, with each having 3236 pixels. 

The data will be received by the Deep Space Network of JPL 

Goldstone and mailed to Code 670.1 of Goddard. Level 1 data will 

be produced by Code 670.1, i.e, raw data on CCT with appended 

calibration data. Code 636 will receive Level 1 data from Code 

670.1 and will register the scenes and produce bi-directional and 

stereo imagery. Code 630.2 will receive data for storage and 

distribution from a central archive. The Experimenters, i.e., 

Code 623 of GSFC, plus the University of Arizona, and the 

University of California will receive the data from Code 630.2 

for scientific analysis. There is an estimated data volume of 

two/three scenes every 2 to 6 months. This would result in a 

minimum of 12 scenes and a maximum of 54 scenes. Each scene 

represents about 2 minutes of data acquisition time by the 

payload. 

36 
N8 9- 28 126 

TROPICAL RAINFALL MEASUREMENT MISSION 

by 

T. T. Wilheit (675) 

It has long been noted that anomalies in the sea surface 

temperature (sst) in the tropics are strongly correlated with 

climate in the temperate latitudes on a seasonal time scale. The 

best known case is the El Nino-Southern Oscillation (ENSO) 

anomaly which has been correlated with a great many weather 

anomalies in the temperate regions. This correlation is presumed 

to occur because the sst anomaly produces an anomaly in the 

precipitation which, through its release of latent heat, produces 

global scale anomalies in the average atmospheric pressure and 

temperature fields. Our ability to measure the global sst and 

the atmospheric pressure/temperature patterns has made great 

progress. However, at this point, we measure rainfall, the 

putative connection between the two, very poorly. 

The Tropical Rainfall Measurement Mission (TRMM) was conceived to 

fill this gap. The TRMM spacecraft would fly in a low 

inclination, (about 35 degrees), orbit which would concentrate 

the sampling in the very important tropical latitudes. The 

precession of such an orbit would enable observations at all 

times of the day over the span of a month which would permit 

corrections for the diurnal cycle of precipitation which is quite 

marked in parts of the tropics. The payload of the TRMM 

spacecraft, shown in the attached figure, is carefully designed 

to provide accurate measurements of rain. It consists of 

37 
microwave radiometers, a microwave radar and visible/infrared 

radiometer. The two types of microwave instruments provide 

direct measurements of the hydrometeors, each having strengths 

which compensate for weaknesses of the other. The vis/ir 

instrument provides a connection to the long-time series of 

vis/ir measurements from polar and Geosynchronous spacecraft 

which are currently the best available source of global rainfall 

estimates. The accuracy requirement on the measurement is 

estimated to be of the order of 1 mm/day for a 1 month average 

over a 5 degree square. An error model which combined both 

instrumental and sampling error suggests that the TRMM 

measurements will yield an accuracy of about 1.2 mm/day over 

ocean but degrades to about 1.7 mm/day over land. 

The TRMM is currently in a phase A (feasibility) study. The 

principal scenario under consideration is that the government of 

Japan would provide the radar instrument and would launch the 

spacecraft; the United States would provide the remainder. The 

current target is for a FY90 new start approval and a 1994 launch 

date which would permit overlap with the Tropical Oceans Global 

Atmosphere (TOGA) program which ends in 1995. 

The possibility of a Space Station follow-on for TRMM is also 

being studied. Activities are underway to produce three 

instrument proposals and a science proposal which would tie them 

together in response to the Eos Announcement of Opportunity. 

The Microwave Sensors and Data Communication Branch is deeply 

involved in the TRMM. We were part of the team which developed 

38 
the original concept and continue to work on the Phase A study. 

We provide the principal expertise in the microwave measurement 

of precipitation and conduct research to develop algorithms for 

the retrieval of rain rates from the TRMM measurements. 

39 
m 

C 

c 

a, c 

2 

cn 

cn 

CT 

In 

40 

z 

2 

3 

M 
N8 9- 2 8 127 Y.- 

SPACEBORNE METEOROLOGICAL RADAR STUDIES 

by 

R. Meneghini (675) 

The objective of the work is to study various radar designs and 

methods for the estimation of rainfall parameters from space. An 

immediate goal is to support the development of the spaceborne 

radar that has been proposed for the Tropical Rain Measuring 

Mission (TRMM). The TRMM radar, which will be the first 

meteorological radar to be flown in space, has the unique 

capabilities for vertical profiling of the storm cell and for 

quantitative rainfall estimates over land. To take full 

advantage of the radar requires a detailed understanding of its 

performance and the manner in which these data can be combined 

with radiometric measurements. 

The effort is divided into two activities: a cooperative 

airborne rain measuring experiment with the Radio Research 

Laboratory of Japan (RRL), and the modelling of spaceborne 

weather radars. 

An airborne rain measuring experiment was conducted at Wallops 

Flight Facility in 1985-1986 using the dual-wavelength 

radar/radiometer developed by RRL. The data are presently being 

used to test a number of methods that are relevant to spaceborne 

weather radars. An example is shown in Fig. 1 of path-averaged 

rain rates as estimated from three methods: the standard 

41 
reflectivity rain rate method (Z-R), a dual-wavelength method, 

and a surface reference method. The results from the experiment 

have shown for the first time the feasibility of using 

attenuation methods from space. We can also begin to study how 

the various methods can be used to improve the accuracy and 

extend the dynamic range of rain rate estimation. A second phase 

of this experiment is planned for 1989. Toward this end, several 

upgrades of the instrument are being made for its installation in 

a high-altitude aircraft. 

The purposes of the modelling are twofold: to understand in a 

quantitative manner,,,the relationships between a particular radar 

design and its capability for estimating precipitation 

parameters; to help devise and test new methods. The models are 

--.. 

I being used to study the impact of various TRMM radar designs on 

the accuracy of rain rate estimation as well as to test the 

I performance of range-profiling algorithms, the mirror-image 

method, and some recently devised graphical methods for the 

estimation of the drop size distribution. 

I 42 
25 

JUNE 20% 1986 

- SURFACE REF-2 --". Zx-R 

NAOlAlocEAN -- 

0 100 

2o I 

200 300 400 500 600 700 800 900 

NO. OF OBSERVATIONS 

' JUNE 204. 1986 

- DUAL WAVELENGTH-AV 

-.. . -. 2,-R 

NADIWOCEAN 

NO. OF OBSERVATIONS 

Figure 1. Path-Averaged Rain Rates 

43 
N8 9- 28 128 

ADVANCED ALTIMETRY 

by 

C.L. Parsons, S.A. Bailey, D.E. Hines, 

D.W. Shirk, C.W. Wright (672) and A.R. Selser (822.2) 

The radar altimeter being developed for the Ocean Topography 

Experiment (TOPEX) will have an inherent instrument precision of 

2-3 cm. This is smaller than or of the same order of magnitude 

as the effects from other sources of uncertainty in satellite 

altimetry, such as the ionosphere, barometric fluctuations, water 

vapor absorption, etc. While some minor refinements may be 

possible in the future, major geophysical advances could be made 

if altimetric measurements over a wide swath of the Earth’s 

surface were possible. Beginning in January 1986, the NASA 

Headquarters Oceanic Processes Branch is supporting a 3-year 

investigation of the technological issues inherent in the 

precision measurement of topography from spaceborne platforms at 

angles off-nadir. Also, this RTOP, 161-1006, has as an 

additional goal the identification and development of a future 

space mission using the advanced wide swath radar altimetry under 

study. Much progress has been made toward this latter goal, and 

this is described in another activity report in this volume 

entitled ItEos Advanced Altimetry. It 

To explore the off-nadir measurement of topography, a flexible, 

airborne radar instrument system is being developed. Its 

hardware design is now complete, and it consists of the following 

45 
subsystems. The antenna selected is a dielectric lens of .894 m 

diameter. At an operating frequency of 36 GHz, it has a gain of 

I 47.5 dB and a one-way beamwidth of .6 degrees. Most importantly, 

it can be used to transmit and receive at angles up to 12 degrees 

from its axis without major beam pattern degradation from optical 

aberrations. 

The RF subsystem uses phased-locked oscillators, FET solid-state 

amplifiers, and *!times four!! frequency multipliers to develop a 

transmit signal at a frequency of 36.0 GHz and a local oscillator 

signal at a frequency of 35.4 GHz. The transmit signal is 

I switched on and off by a PIN diode switch at a PRF of 200 Hz and 

with a pulse width of 10 ns. RF amplification of the transmit 

pulse is achieved from a 1.5 kw Varian Extended Interaction 

Amplifier, and a waveguide network distributes the transmit and 

I local oscillator signals to five circulator/feed horn/receiver 

assemblies. Each receiver detects the backscattered RF signal 

and downconverts to an intermediate frequency of 600 MHz. 

Lecroy 6880 digitizers under computer control digitize the five \ 

receiver outputs. The digital subsystem consists of six singleboard Heurikon processors. Each has specific responsibilities; 

communication with the other processors is achieved through bus 

interfaces. One executes UNIX and is responsible for 

coordinating the activities of the others, which use VRTX, a 

real-time operating system. With this modularized, highly 

flexible design, the total functioning of the radar system is 

I under computer control. This makes the instrument, the Aircraft 

46 
Multibeam Radar Altimeter (AMRA), a unique tool for studying 

altimetry at angles from nadir to 12 degrees. 

At this time, the instrument construction continues with final 

system integration planned for November 1988. The system Will be 

installed in the Wallops P-3 research aircraft for engineering 

evaluation and test flights in the Spring of 1989. It is hoped 

that the system will be ready for use in field missions by April 

1989. One experiment that the AMRA might support is the spring 

window of SYNOP. Also, the measurement of the backscattering 

cross-section of selected portions of the Earth's surface at 36 

GHz is of considerable -importance to several proposed Eos 

investigations. AMRA should be able to make these needed 

measurements. 

AMRA Desisn Performance Summary: 

RF - 

Antenna - type 

diameter (m) 

gain (dB) 

beamwidth (deg) 

look angles (deg) 

no. of beams 

frequency (GHz) 

power (kw) 

bandwidth (MHz) 

pulse width (nsec) 

pulse rate (Hz) 

samples/wavef orm 

tracker type 

Signal Processor - sampling rate (GHz) 

dielectric lens 

.894 

47.5 

.6 (one-way) 

0-12 

5 

36.0 

1.5 

220 

10 nom.(5 goal) 

200 

1.3 

128 

variable 

47 
EARTH OBSERVING SYSTEM (Eos) ADVANCED ALTIMETRY 

by 

C. L. Parsons and E. J. Walsh (672) 

In the post-TOPEX era, satellite radar altimeters will be 

developed with the capability of measuring the earth's surface 

topography over a wide swath of coverage, rather than just at the 

satellite's nadir. The technological issues inherent in the offnadir measurements are being studied through RTOP 161-10-06. An 

Aircraft Multibeam Radar Altimeter is being developed under this 

RTOP, and it is described in another report in this volume 

entitled "Advanced Altimetry (RTOP 161-10-06).t1 In parallel, the 

identification of potential spacecraft flight missions in the 

future has also been pursued. The best opportunity was found to 

be the Earth Observing System (Eos). Through agency-level 

program initiatives such as Mission to Planet Earth, Eos has 

become the primary platform of opportunity for the earth sciences 

in the 199O's, and the recent Announcement of Opportunity (No. 

OSSA-1-88, January 19, 1988) is convenient and timely. The 

progress in RTOP 161-10-06 makes an Eos proposal at this time 

possible. 

A joint proposal is now in preparation. Participants in this 

activity are from the GSFC, the Jet Propulsion Laboratory, and 

the Federal Republic of Germany. The participants have mutually 

agreed to this collaborative effort because of the interdisciplinary nature of Eos. It is felt that an instrument system 
that has a broad appeal to the earth sciences community stands a 

much better chance of being selected as an Eos instrument. 

Consequently, the Topography and Rain Radar Imager (TARRI) will 

be proposed as a system that has the capability to profile the 

Earth's topography regardless of the surface type. The 

horizontal and height resolutions of interest are obviously 

significantly different over land, ice, and water; but, the use 

of radar to provide an all-weather observation capability is 

I applicable to the whole earth. 

I It is proposed that the instrument development responsibilities 

will be shared by the participants. The Land Mode will use a I 

scanning beam produced by a 12 m x 1 m phased array to measure 

the slant range in the cross-track direction over a 20 km swath. 

The Ocean Mode will use a "parked" beam from the phased array as 

, the transmitter and two parabolic dishes separated by a fixed 

boom as an interferometric receiver. The two-dish interferometric altimeter approach has been described in the 

literature by Bush, al. ("An Analysis of a Satellite Multibeam 

Altimeter,t1 Marine Geodesy, Vol. 8, Nos. 1-4, 1984, pp. 345-384). 

Both modes operate at a frequency of 36 GHz. The Ocean Mode 

dishes have multiple feed horns boresighted in pairs; at present, 

a maximum number of five illuminated spots on the surface is 

envisioned. At a spacing of 25 km, this will yield topographic 

, 

I information over a total swath width of 100 km. 

I 

I The scientific guidance for the design and development of this 
instrument and the eventual scientific utilization of the data 

produced by the TARRI will be provided by seven science teams. 

All are responsible to the Principal Investigator and two Deputy 

Investigators. The teams are formed around scientific 

disciplines and are titled: Geology/Geophysics, Hydrology/Rain, 

Oceanography, Ice/Snow, Geodesy/Orbit/Attitude, Cartography, and 

Surface Properties/Techniques. 

51 
WIDE BAND DATA COLLECTION SYSTEM 

by 

J. M. Turkiewicz (675) 

The Incorporated Research Institutes for Seismology (IRIS) 

approached NASA Headquarters in 1986 about the need to collect 

data daily from seismic stations around the world as part of the 

Earth Observing System (Eos) mission. A typical IRIS Seismic 

Station generates 16 Megabytes of data per day under background 

conditions, and up to 24 Megabytes of data per day when there is 

seismic activity. A competitive contract was won by OR1 to 

perform a preliminary design study which would yield a design to 

the block diagram level, and provide a link analysis, size, 

weight, power and cost estimate. Technical Report No. 2773, IIEOS 

WIDEBAND DATA COLLECTION SYSTEM: BLOCK DIAGRAM, LINK ANALYSIS, 

SIZE, WEIGHT, POWER AND COST ESTIMATES,I1 was delivered on 

September 30, 1987. 

The following is a summary of the Preliminary Design Parameters 

of the Wide Band Data Collection System: 

Concept 

1. Spacecraft 

- WBDCS: fixed earth coverage antenna, 7 GHz receiver, 8.5 GHz 

transmitter, programmable controller for generating 

commands to stations, power converter 

Eos: Data multiplexer, storage for up to 2 orbits (0.4 

Gbytes) of seismic data, communications link to TDRSS 

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md - ~HW~MMILV 

53 
~ 

2. Seismic stations - land based 

Active track antenna, 1.2 m diameter, similar to Marisat 

Tracking and Command Receiver at 8.5 GHz Storage for up to 

24 hours of seismic data (24 Megabytes) Transmitter, 10 

watts, 7 GHz 

3. Operation 

WBDCS: Commands seismic stations in sequence to transmit 

data Receives seismic data, and sends it to Eos Data 

System 

Multiplexes seismic data with Eos data Stores 

multiplexed data 

Transmits multiplexed data to TDRSS 

Eos: 

TDRSS: Relays data to TDRSS ground station 

TDRSS ground station: Strips out seismic data 

Sends data to IRIS Data Center 

~ Note: 

almost 24 hours old before they are received by ~0s. 

Daily collection of data by Eos means some of the data are 

An 

additional maximum delay of 218 minutes (two orbits) may occur 

before the data are transmitted to TDRSS and relayed to a TDRsS 

ground station. There may be additional delay at the TDRSS 

ground station before the seismic data are stripped from the Eos 

data and sent to the IRIS Data Center. 

COMMUNICATIONS LINKS - Summary 

DOWNlink * WBDCS trackina beacon and command transmitter 

frequency 8.5 GHz 

command bit rate 100 bits per second 

margin 20 db 

Uplink * Collect data from seismic stations 

frequency 7 GHz 

bit rate 

modulation quadriphase with rate 1/2 

margin 2 db for 10-7 BER 

1 Megabits per second 

convolutional coding 

Note: 24 hours of data can be collected from each station du :in 

one satellite pass, leaving the second pass during a 24-hour day 

for repeat transmissions as required. * One earth coverage 80 cm diameter antenna for Uplink and DOWNlink 

I 

I 54 
TYPICAL LAND BASED GROUND STATION 

Antenna 1.2 m diameter (similar to Marisat) 

Active tracking at 8.5 GHz 

Transmit at 7 GHz 

Receiver 8.5 GHz: tracking beacon signal from Eos 

commands at 100 bps from WBDCS 

on Eos 

Transmitter 7 GHz, 10 watts 

EIRP 45.4 dbw 

cost Order of magnitude - $100K. 

WIDE BAND DATA COLLECTION SYSTEM - SUMMARY 

Cost, Mass, Volume, Power 

Space Sesment 

RDT & E 

First Unit 

Mass 

Power 

Volume 

Antenna 

$9.17 M 1 19% 

$1.86 M 1 49% 

18.5 kg 

54 watts 

17,641 cm3 0.02 m3 

fixed metal reflector, 

80 cm diameter, with feed horn 

Ground Sesment 

Order of magnitude cost for -$loOK, includes 1.2 m 

land based Uplink and DOWN- diameter active 

link communications with Eos track antenna 

CONCLUSION 

The Wide Band Data Collection System is to be funded by Eos for 

further development to a space qualified system. 

55 
ill 56 
CALIBRATION SUPPORT FOR THE EARTH 

OBSERVING SYSTEM PROJECT 

by 

B. W. Guenther (673) 

The Earth Observing System Project (Eos) program guidelines 

establishes significantly more stringent requirements on 

calibrations of instruments. This requirement is driven by the 

need for long-term continuity of acquired data sets and the use 

of measurements in interdisciplinary investigations. Personnel 

from the Standards and Calibration Office have been supporting 

the Program and Project in interpreting these goals into specific 

requirements. 

Contributions to Eos have included participation in the Panel of 

Experts which produced a List of Consensus Items Necessary for 

Accomplishing an Accurate Calibration and Suggested Eos Project 

Calibration Policy, and drafting the Announcement of Opportunity 

and Bidders Information Package positions on instrument 

calibration and data product validation. We have also provided 

technical staffing to the NASA delegates to the Committee on 

Earth Orbiting Satellites (club of space-faring nations) for the 

standing working group on Calibration and Data Validation. 

57 
OCEANOGRAPHIC WIDE FIELD SENSOR 1- 

by 

R. G. Kirk (671) 

The Oceanographic Wide Field Sensor (SeaWiFS) science project 

will provide measurements of ocean color from space to which will 

support research into: a) the character of ocean physical and 

biological processes; b) to assess the global oceanic biomass; 

and c) to better understand the role of oceanic processes in 

modulating the Earth's biogeochemical cycles, including the C02 

cycle as it is affected by fossil fuel combustion. This research 

will be conducted by NASA as well as the outside scientific 

community through an Announcement of Opportunity process. 

The present work extends previous work to study the feasibility 

of an ocean color mission using the proposed compact Wide-field 

Sensor (SeaWiFS) and the EOSAT Corporation's LANDSAT-6 satellite. 

We conducted a Phase A study which defines a NASA Facility Data 

System and accompanying Science Program for the EOSAT Company's 

commercial ocean color instrument called IlSeaWiFSIl to be launched 

on board LANDSAT-6 in 1991. Codes 670, 630, and 620 participated 

in the study. A current working group chartered jointly by NASA 

Headquarters and EOSAT is providing final baseline 

characteristics. 

Next year a GSFC Project will work with EOSAT and the' Joint 

NASA/EOSAT Working Group to integrate the commercial and science 

59 
baseline and develop a detailed NASA plan for implementation of a 

Science Data System for a FY91 SeaWiFS launch on LANDSAT-6. the 

proposed concept assumes NASA input to the SeaWiFS specification 

and operational scheduling, and the receipt of worldwide, 

continual taped ocean color data from EOSAT, as well as direct 

read out of East Coast real time coverage at GSFC. EOSAT will 

forward taped ocean color data to a data processing system at 

GSFC. GSFC, in turn, will process all received data to 

scientifically useful form on optical disk format and distribute 

it to the research community in conjunction with the NASA Ocean 

Data System. Research community users include: NASA Principal 

Investigators, Announcement of Opportunity participants, and 

other researchers through the NSSDC. 

60 
THE EARTH RADIATION BUDGET EXPERIMENT I 

A. T. Mecherikunnel (670.1) 

DATA ANALYSIS: The Earth Radiation Budget Experiment (ERBE) data 

studied at present are: 

1. The solar data from solar monitors of the ERBE onboard ERBS, 

NOAA-9, and NOAA-10 spacecraft. 

2. Investigation of the colocated satellite altitude irradiances 

from ERBS and Nimbus-7 Earth Radiation Budget measurements. 

3. Analysis of the time- and space- averaged radiation budget 

products from ERBS and Nimbus-7 ERBE. 

1 

A 

1. Solar Data from ERBS, NOAA-9, and NOAA-10. 

The solar total irradiance data obtained by the ERBE solar 

monitors serve as a calibration check on the earth viewing 

radiometers, as well as provide the experimental value of the 

solar constant needed in the net radiation computations. 

Solar data from the ERBE experiments are analyzed, and a 

comparative study of the data with solar measurements made for 

the same period from Solar Maximum Mission Active Cavity 

Radiometer Irradiance Monitor experiment and the Nimbus-7 Earth 

Radiation Budget Measurements. The data sets available from the 

ERBE for a period of 2 years from launch are archived at the 

NSSDC, GSFC, and are available to the scientific community for 

investigations. 

61 
2. 

from ERBS and Nimbus-7 Earth Radiation Budget Measurements. 

Investigation of the colocated satellite altitude irradiances 

The sun-synchronous, near-local-noon Nimbus-7 satellite has 

coincident orbital intersections with the non-sun-synchronous 

ERBS spacecraft. The objective here is to compare the WFOV and 

MFOV (wide and medium field-of-view) observations of the 

ERBS/ERBE, and the Nimbus-7 ERB data sets at the points of their 

orbital intersections. 

3. Globally and zonally averaged ERBE/ERBS data. 

Investigations of the globally and zonally averaged ERB obtained 

from the ERBS scanner, MFOV and WFOV and the Nimbus-7 WFOV is 

being carried out to assess the sensor performance. 

The data analysis is carried out in collaboration with the 

Nimbus-7 ERB processing team, managed by H. Lee Kyle, Code 636. 

These studies have significantly contributed to the ERBE sensor 

calibration and performance evaluation, and data validation. 

Besides, it is useful to assess the relative accuracy of the 

Nimbus-7 ERB data sets (began in 1978), and to establish longterm earth radiation budget data sets for scientific 

investigations. 

I 62 
/7/-5;. a&y I’ N89- 28 134 

LUNAR OBSERVER LASER ALTIMETER 

by 

J. L. Bufton (674) 

The exploration and characterization of the terrestrial planets 

and their satellites requires an accurate understanding of their 

topography. Understanding the global topography of the Moon is 

especially important for answering questions concerning lunar 

origin and evolution. Many outstanding problems in lunar science 

can be addressed with high resolution topographic data. Some of 

these include the precise figure of the Moon, the nature of 

gravity anomalies, and the thermal and loading histories of major 

impact basins. Others are the styles and volumes of volcanic 

eruptions, measurements of modification processes, and problems 

associated with impact catering. The correlation of lunar 

surface geochemical processes and topography has been examined 

only in limited equatorial regions, and requires further 

assessment. Finally, information necessary for the optimal 

placement of lunar bases will require accurate knowledge of the 

local relief of the lunar surface. 

I 

1 

The severe power, mass, size, and data-rate limitations imposed 

by the Lunar Geoscience Observer (LGO) and other Observer-class 

missions are major challenges for all instruments capable of 

measuring topography. A radar altimeter that meets these strict 

requirements could obtain a global perspective of lunar 

topography with a few kilometers spatial resolution and 10 m 

vertical resolution from a lunar orbit of 100 km. Many of the 

63 
problems listed above, however, require topographic data with 

spatial resolution of 100 m or better and vertical resolution of 

1 m. The only means of obtaining such high-resolution data is 

with the small footprints, short pulses, and precise timing 

available with laser altimeters. The instrument heritage and 

scientifically useful data from the three successful missions of 

I 

I the APOLLO Lunar Laser Altimeter provide a solid basis for 

optimizing the technique for KO. Existing laser altimetry 

sensors are simple in design; yet require technological 

improvements in order to provide comprehensive coverage of the 

lunar surface. Laser lifetime, efficiency, and pulse repetitionrate are the key factors. Conventional solid-state, pulsed laser 

~ technology is restricted by flashlamp lifetime to lo6 pulses, 

efficiencies on the order of 1%, and 20 Hz repetition rates. The 

recent breakthroughs in diode-pumping of Nd:YAG crystal lasers 

have dramatically improved all three of these factors by ordersof-magnitude, Now we have available diode-pumped Nd:YAG lasers 

with lifetimes in excess of lo9 pulses, efficiencies of lo%, and 

repetition rates of at least 100 Hz. At the same time, this new 

technology has decreased the size of the laser, eliminated 

closed-cycle liquid cooling systems, and provided a very robust 

all solid-state laser package. Efforts are still required to 

demonstrate the production of nsec-duration pulses with these 

I 

I 

I 

I 

I 

I lasers and then couple the lasers into an altimeter system. 

I We are constructing a prototype model of the Lunar Observer Laser 

Altimeter (LOLA) capable of continuously measuring the range to 

the lunar surface with sub-meter vertical resolution within a 30 

64 
- 300 m diameter surface footprint. This same instrument is also 

designed to provide a direct measure of the surface height 

distribution in the footprint by waveform analysis of the 

backscattered laser pulse. Both these measurements are to be 

made in a continuous, nadir profile across the lunar surface from 

a 100 km orbit. The wavelength of the altimeter is 1064 nm. A 

short-pulse (2 nsec) , diode-pumped Nd:YAG laser combined with a 

25 cm diameter telescope, silicon avalanche photodiode detector, 

ranging electronics, and instrument computer has been designed to 

make these measurements and meet all the requirements of the LGO 

mission. The final LOLA package should weigh less than 15 kg, 

measure less than 35 cm by 25 cm by 25 cm, and consume an average 

power of less than 15 watts. 

The development of the LOLA prototype is being funded at the 

$100K per year level through RTOP Task: 157-30-80 as part of the 

Planetary Instrument Development Program in Code EL at NASA 

Headquarters. The LOLA diode-pumped Nd:YAG laser is being funded 

at the $500K level at Lightwave Electronics, Inc., Mountain View, 

California through a Phase I1 SBIR contract. The completed 

prototype LOLA instrument will be tested during 1988 from NASA 

high-altitude aircraft over planetary analog terrain in Arizona, 

Mexico, and Iceland. The LOLA Project is expected to retain the 

advantages of a small, self-contained in-house effort throughout 

the full-scale development of a spacecraft payload. 

Project Scientists: James Garvin, Code 622 and Maria Zuber, Code 

621. Project Engineers: Jack Bufton, Code 674, Maxwell Strange, 

Code 674, John Dambik, Code 674, and James B. Abshire, Code 723 

65 
N8 9- 28 135 

YAG AEROSOL LIDAR 

by 

R. Sullivan (674) 

The Global Atmospheric Backscattter Experiment (GLOBE) Mission, 

using the NASA DC-8 aircraft platform, is designed to provide the 

magnitude and statistical distribution of atmospheric backscatter 

cross section at lidar operating wavelengths. This is a 

fundamental parameter required for the Doppler lidar proposed to 

be used on a spacecraft platform for global wind field 

measurements. The prime measurements will be made by a C02 lidar 

instrument in the 9 - 10 um range. These measurements will be 

complemented with the Goddard YAG Aerosol Lidar (YAL) data in two 

wavelengths, 0.532 um and 1.06 um, in the visible and nearinfrared. The GLOBE experiment will be conducted over the 

Pacific Basin where there is great interest in the backscatter 

from clean, remote air masses. 

The YAL, being a new activity, is being designed to utilize as 

much existing hardware, as feasible, to minimize cost and reduce 

implementation time. The instrument utilizes a 16-inch telescope 

which is mounted vertically and can be rotated for either an 

uplooking or a downlooking port. This provides aerosol data 

acquisition from the nadir position or aerosol data and inflight calibration data in the zenith position. 

The laser, energy monitor, telescope and detector package will be 

mcclnted on an optical breadboard. The optical breadboard is 

mounted through isolation mounts between two low boy racks. 

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rcmmA1s111- 

67 
The detector package will utilize a photomultipler tube for the 

0.532 urn channel and a silicon avalanche photo detector (APD) for 

the 1.06 urn channel. 

I The data acquisition system is being developed by using a desk 

top PC 386 with a CAMAC crate. The data storage will be provided 

on an optical disk with a tape back-up system. The data 

acquisition system will be located in a separate electronic rack. 

Purchase Orders have been initiated for all major components. 

Some of the items have been received. Design drawings are in 

progress for fabrication of mounting hardware for the optics, 

telescope, energy monitor, and detector package. 

Integration of the instrument into the DC-8 and the flight 

I mission is being scheduled for the Spring of 1989. 

Project Manager: Robert J. Sullivan (674) 

Project Scientist: James D. Spinhirne (617) 

Project Engineer: Fredrick G. Huegel (674) 

I 

I 68 
OCEAN COLOR I 
Applications of the Coastal Zone Color Scanner 

in Oceanography 

C. R. McClain (671) 

Research activities has continued to be focused on the 

applications of the Coastal Zone Color Scanner (CZCS) imagery in 

oceanography. A number of regional studies have been completed 

including investigations of temporal and spatial variability of 

phytoplankton populations in the South Atlantic Bight, Northwest 

Spain, Weddell Sea, Bering Sea, Caribbean Sea and in tropical 

Atlantic Ocean. Also, Frank Muller-Karger who was supported to 

work at GSFC by the NASA Graduate Researchers Assistantship 

Program completed his Ph.D. requirements at the University of 

Maryland. His dissertation research was a study of biological 

variability in the Caribbean Sea and Eastern tropical Atlantic 

Ocean. 

In addition to the regional studies, much work was dedicated to 

developing ancillary global scale meteorological and hydrographic 

data sets to complement the global CZCS processing products (see 

discussion below). To accomplish this, SEAPAK‘s image analysis 

capability was complemented with an interface to GEMPAK (Severe 

Storm Branch’s meteorological analysis software package) for the 

analysis and graphical display of gridded data fields. Plans are 

being made to develop a similar interface to SEAPAK for 

hydrographic data using EPIC (a hydrographic data analysis package developed by NOAA/PMEL). A Director’s Discretionary Fund 

71 
proposal was approved for the support of a dedicated data 

programmer/analyst to be located at the NASA Climate Data System 

(NCDS). He handles the implementation of selected meteorological 

and hydrographic data sets into NCDS. 

Over the last year, a major effort has been the processing of the 

CZCS data set. This is a collaboration among members of the 

Oceans and Ice Branch (Code 671), Code 630, and the University of 

Miami. The Code 671 component has the responsibility of quality 

control of the final products. Finally, during the last year, 

plans for a CZCS follow-on mission, SeaWiFS, have progressed to 

the point where it appears that the mission will be approved for 

a 1991 launch on LandSat-6. 

72 
OCEAN COLOR OBSERVATIONS OF PHYTOPLANKTON DISTRIBUTIONS 

AND PRIMARY PRODUCTIVITY 

\ 

by 

W. Esaias (671) 

The primary goal of this activity is to develop the means to 

assess the mean and variability of phytoplankton biomass and 

primary productivity on global scales. 

There are three major approaches whose goals are to provide 

global scaleobservations. These are 1) processing and analysis 

of the complete CZCS data set in a consistent manner; 2) 

preparing science mission and project implementation plans for 

the Sea-WiFS sensor to be launched on Landsat 6 in 1991; and 3) 

providing guidance to EOS flight projects for ocean color 

observations using the MODIS sensor planned for the Polar 

Platform in the mid 1990's. 

The analysis of the CZCS data set is being conducted in 

collaboration with other ocean color investigators here at GSFC 

and at the University of Miami. This processing presents the 

first consistent view of phytoplankton pigments on global 

scales, and analysis of this temporally undersampled data set is 

proving very instructive in specifying mission requirements for 

Sea-WiFS and future algorithm development. We have begun an 

error assessment of the application of simple satellite pigment 

- primary productivity relationships when used with such 

observations. This is limited to a zonal analysis to overcome 

73 
spatial undersampling on monthly scales. Satellite ocean color 

algorithm refinement and more rigorous quality assessment, while 

keeping the relationship between satellite pigment and primary 

production constant, have increased global estimates of ocean 

productivity to 62 Gigatons carbon per year, an increase of 

nearly 20% over estimates derived from initially processed data. 

Present relationships between satellite ocean color and in-situ 

bio-optical processes will be tested further during the JGOFS 

1989 Spring Bloom Experiment in the North Atlantic. We are 

assisting with the required airborne ocean color remote sensing 

support for this experiment to both provide improved spatial 

sampling for the ship study as well as to begin development of 

ocean color algorithms which make use of the improved Sea-WiFS 

sensor bands. 

I 

Application of the CZCS and future Sea-WiFS data to address 

scientific questions requires close coordination with a number of 

non-NASA research programs. We therefore devote a significant 

fraction of our effort serving on review panels and steering 

committees. These include the NAS C02 Panel, the GOFS Science 

Steering Committee, NSF GOFS Relevancy Review Panels, the Marine 

Pollution Task Force (also known as the Bradley Committee), the 

Science and Technology Advisory Committee Remote Sensing Working 

Group of the Chesapeake Bay Consortium, and the ONR Special 

Research Initiatives Review Panel. 

In coordination with investigators from the Chesapeake Bay 

74 
Consortium, we will conduct remote sensing overflights of 

research and monitoring cruises this summer using the Ocean Data 

Acquisition System (ODAS) on the Virginia Institute of Marine 

Science's aircraft. The ODAS, developed under joint NOAA and 

NASA funding, provides real-time output of chlorophyll pigment 

and surface temperature to a ship station. If the curvature 

algorithm which enables the real time computation is found 

sufficiently accurate for the Bay, the potential for 

I1operational1' use of the sensor by CBC will be established. 

75 
Coastal Zone Color Scanner Studies 

by 

J. Elrod (671) 

Activities over the past year have included cooperative work with 

a summer faculty fellow using the Coastal Zone Color Scanner 

(CZCS) imagery to study the effects of gradients in trophic 

resources on coral reefs in the Caribbean. One paper from this 

project has been submitted for publication and another will be 

presented at a symposium this summer in Australia. Other 

research included characterization of ocean radiances specific to 

an acid-waste plume. Course material for a training course in 

Bangladesh on satellite oceanography was prepared before the trip 

was cancelled, due to strikes in that country. However, the 

course will be presented in June 1988. Other activities include 

involvement in the quality control of imagery produced in the 

processing of the global CZCS data set, the collection of various 

other data global sets, and the subsequent data comparison and 

analysis. 

PRECEDiNG PAGE BLANK NOT FILMED ' 

77 
N8 9- 2 8 139 - 

Remote Sensing of Ocean Color in the Arctic 

by 

N. G. Maynard (671) 

/, 

h 

The main objectives of the research are: 1) to increase the 

understanding of biological production (and carbon fluxes) along 

the ice edge, in frontal regions, and in open water areas of the 

Arctic and the physical factors controlling that production 

through the use of satellite and aircraft remote sensing 

techniques; and 2) to develop relationships between measured 

radiances from the Multichannel Aircraft Radiometer System (MARS) 

and the bio-optical properties of the water in the Arctic and 

adjacent seas. Several recent Coastal Zone Color Scanner (CZCS) 

studies in the Arctic have shown that, despite constraints 

imposed by cloud cover, satellite ocean color is a useful means 

of studying mesoscale physical and biological oceanographic 

phenomena at high latitutdes. The imagery has provided detailed 

information on ice edge and frontal processes such as spring 

breakup and retreat of the ice edge, influence of ice on ice 

effects of stratification on phytoplankton production, river 

sediment transport, effects of spring runoff , water mass 

boundaries, circulation patterns, I and eddy formation in Icelandic 

waters and in the Greenland, Barents, Norwegian, and Bering Seas. 

--. 

.I 

During the past year, a number of images in the Iceland region 

and in the Greenland Sea have been processed on both the SEAPACK 

and Miami systems. These are part of studies on spring blooming 

PRECEDiNG PAGE BUNK NOT FILMED 79 
in Icelandic waters in 1979, 1980, and 1981, the West Spitsbergen 

Current system, and ice edge phytoplankton dynamics in the 

Greenland Sea ice edge. Also in 1987/1988, the MARS sensor was 

completed at the Visibility Lab of Scripps Institution of 

Oceanography (SIO) and deployed during the Greenland Sea 

Experiment in May 1987, making eight successful flights over the 

Polar and Arctic Fronts including overflights of the German 

icebreaking research vessel, the POLARSTERN. Algorithms are 

being developed by J. Mueller at SI0 and San Diego State 

University (SDSU). Data is presently being analyzed and will be 

shared with other participants in the Greenland Sea Experiment 

from the Alfred Wegener Institute, SIO, SDSU, University of 

Tennessee, Lamont Doherty Geological Observatory, and other NASA 

colleagues who participated in coincident overflight in the NASA 

P-3. 

1: 1 

Future plans are to continue to use a combination of historical 

CZCS data and aircraft observations from high latitude study 

areas to help build a long-term data base on the Arctic and 

Antarctic, as well as, to serve as a guide in the selection of 

optimum sampling strategies in upcoming experiments such as GOFS 

and CEAREX. The MARS sensor is scheduled to participate in the 

1989 CEAREX field season to find and investigate eddies in the 

Greenland Sea. 
AIRBORNE IN-SITU SPECTRAL CHARACTERIZATION AND CONCENTRATION 

ESTIMATES OF FLUORESCENT ORGANICS AS A FUNCTION OF DEPTH 

R. A. Tittle (672) 

The primary purpose of many in-situ airborne light scattering 

experiments in natural waters is to spectrally characterize the 

subsurface fluorescent organics and estimate their relative 

concentrations. This is often done by shining a laser beam into 

the water and monitoring its subsurface return signal. To do 

this with the proper interpretation, depth must be taken into 

account. If one disregards depth dependence when taking such 

estimates, both their spectral characteristics and their 

concentrations estimates can be rather ambiguous. 

Figure 1 is a sketch of a simple airborne lidar configuration 

that will detect the subsurface return signal E (Z,X) from a 

particular depth 2 at the wavelength A. While the configuration 

remains unchanged, the depth Z is varied by simply varying the 

height h of the aircraft. Note that by inspection, we see that 

Z = [S - h (tan Aa - tan Ba)] /(tan Aw - tan Bw). 

Now with some algebra, we will find 

2 

K(Z, XL) sec Bw+K(Z,Xf) sec Aw =Lln (z-Az) E(Z-AZrXf) 

where K(Z, Xl) is the diffuse attenuation coefficient at the 

depth Z and the laser wavelength Xl, and where K(2,Xf) is the 

diffuse attenuation coefficient at the depth Z and fluorescent 

AZ 22 Xf) 

81 
wavelength gf. 

calculated. 

Both of these coefficients can be easily 

Now it is well-known that the diffuse attenuation coefficient can 

be expressed as 

K (Z,g) = C(Z) f(g) 

where C(z) is the fluorescent organic concentration as a function 

of Z, and f(g) is the unique proportionality factor, which is 

equal to the absorptivity when very little scattering is 

involved, as a function of g. Hence, one easily sees that if we 

profile K(z,g) as z varies, by analogy, we profile the 

concentration C (z) as a function of depth. 

It should be noted that the monitored collimated return signal 

beam width must be small compared to Z or else the measurements 

lose their meanings. 

Underwater scatterometer have been employed to show that in-situ 

subsurface organics are very sensitive to depth, but they also 

require the use of slow moving boats to cover large sample areas. 

Also, their very entry into the water disturbs the sample it is 

measuring. The method described above is superior to any 

employed thus far. It is the simplest of any employed thus far. 

It will provide accurate characteristic measurements of the 

return signal E(z,g) as a function of depth z and wavelength g. 

It will also provide accurate measurements of the relative 

concentration as a function depth. 

82 
FILTER 

AND LENS 

-7- 

LASER 

/ 

h = HEIGHT 

WATER 

FIGURE 1 

STOPS ~ A , LENS I 

STOP 

RETURN SIGNAL 

FIGURE 2 

83 
OCEANOGRAPHIC APPLICATIONS OF LASER TECHNOLOGY 

by 

F. E. Hoge (672) 

Oceanographic activities with the AOL for the past several years 

have primarily been focussed on using active (laser induced 

pigment fluorescence) and concurrent passive ocean color spectra 

to improve existing ocean color algorithms for estimating primary 

production in the world's oceans. The most significant results 

in this research thrust have been the development of a technique 

for selecting optimal passive wavelengths for recovering 

phytoplankton photopigment concentration and the application of 

this technique, termed active-passive correlation spectroscopy 

(APCS), to various forms of passive ocean color algorithms. 

Included in this activity is use of airborne laser and passive 

ocean color for development of advanced satellite ocean color 

sensors. 

The field missions used to gather the active-passive ocean color 

spectra essential to this research are conducted as part of 

large, multi-institutional, oceanographic field studies. These 

past (and some ongoing) field programs involve numerous 

government agencies, universities, and oceanographic 

institutions. These studies involve the cooperative exchange of 

AOL and shipboard data and information. This exchange of data 

has been mutually beneficial, providing ship truthing 

observations essential to the interpretation of the airborne 

/ 85 
remote sensing chlorophyll and phycoerythrin pigment fluorescence 

data, while furnishing oceanographers on board the ships with 

wide area, nearly synoptic information about the regional 

distribution of the phytoplankton pigments and temperature 

information gathered with the AOL. 

I Airborne laser-induced chlorophyll and phycoerythrin fluorescence 

data are supplied to cooperating investigators shortly after the 

conduct of the field experiments. Corroboration with 

participating scientists in the analysis of the data and 

publication of important findings is an ongoing activity. 

Promising on-wavelength subsurface scattering layer measurements 

were recently obtained and have been submitted for publication. 

A partial summary of these results are shown in figure la. The 

submerged marine scattering layer field experiment was conducted 

3n the Atlantic Ocean southeast of Assateague Island, Virginia. 

NASA's AOL was operated in the bathymetric mode to acquire depthresolved on-wavelength (532 nm) backscatter signals from 

shelf/slope waters. Unwanted laser pulse reflection from the 

air-water interface was minimized by spatial filtering. The 

presence of thermal stratification over the shelf was verified by 

I 

, 

the deployment of airborne expendable bathythermographs. Optical 

beam transmission measurements acquired from a surface truthing 

vessel indicated the presence of a layer of turbid water near the 

sea floor over the inner portion of the shelf. These results 

indicate the ultimate potential for making depth-resolved 

86 
chlorophyll concentration measurements. These measurements would 

involve the use of a second laser operating in the blue spectral 

region. 

It has been shown that significact potential exists for the 

satellite detection of the accessory pigment phycoerythrin using 

recently developed APCS techniques. During the past several 

years, the symmetric three-band (460, 490, 520 nm) spectral 

curvature algorithm (SCA) has demonstrated rather accurate 

determination of chlorophyll pigment concentration using 

low-altitude airborne ocean color data. It has recently been 

shown that the in-water asymmetric SCA, when applied to certain 

recently proposed OCI (NOAA-K and SPOT-3) and OCM (ERS-1) satellite ocean color bands, can adequately recover chlorophyll-like 

pigments. These airborne findings suggest that the proposed new 

ocean color sensor bands are, in general, satisfactorily but not 

necessarily optimally, positioned to allow space evaluation of 

the SCA using high precision, atmospherically corrected, satellite radiances. This analysis indicated that pigment concentration recovery was not as good when existing Coastal Zone Color 

Scanner bands were used in the SCA. The in-water asymmetric SCA 

chlorophyll pigment recovery evaluations were performed using: 

(a) airborne laser-induced chlorophyll fluorescence, and (b) 

concurrent passive upwelled radiances. Data from a separate 

ocean color sensor aboard the aircraft were further used to 

validate these findings. Global satellite detection and mapping 

of phycoerythrin could lead to better primary production 

87 
estimates and improved understanding of phytoplankton species 

variability. A sample of the application of the APCS methodology 

to airborne data for the passive detection of phycoerythrin is 

shown in figure lb. 

88 
ORIGINAL PA,CF 

BLACK AND WHITE P'hOTOGRAPf.( 

Figure la. On-wavelength 532nm laser backscatter profiles obtained from 

beneath the Atlantic Ocean surface southeast of Wallops Island, Virginia. 

Specifically, depth-resolved particulate backscatter was observed in 

she1 f/slope and in inner-sel f waters. 
I90 
N89- 

NASA CHARGE COUPLED DEVICE (CCD) SPECTROMETER 

by 

C. W. Wright, S. A. Bailey (672), and C. R. 

SYSTEM (NCSS) qy 

Piazza (CSC) 

A small lightweight NCSS has been designed, constructed, and is 

now being bench tested at Wallops. The unit provides 256, 2.7 

nanometer wide channels in the visible spectrum from 

approximately 400 to 1100 nanometers. The present input slit 

provides a spectral impulse response of about 10 nanometers. Up 

to five NCSS sensors may be bused to one data system interface. 

This bus interface allows near-simultaneous data capture from 

those sensors. 

The NCSS can output Spectra at a maximum rate of 400 per second. 

The acquired signal amplitude is inversely proportional to the 

read-out rate. The time-between-spectra is the integration time. 

This is the time allowed for a charge to build on each CCD 

element. Longer intervals between spectra yield greater signal 

and background amplitudes. Roughly one-third of a second 

integration (three hertz read-out) is typically used over water 

targets. The host data system controls the integration time. 

The NCSS contains a high speed, 16 bit analog to digital 

converter (ADC) with an integral wide-band sample-and-hold 

amplifier. The CCD sensor array, signal amplifiers, and the ADC 

input are located in close proximity to minimize ground loop and 

EM1 noise. A 280 microcomputer functions as a programmable state 

generator which controls the CCD sensor array, the ADC, the data 

91 
output registers, and data transmission to the host data system. 

The new programmable state generator and ADC combination allow 

new and different CCD sensor arrays to be interfaced with minimum 

engineering. 

The NCSS was developed primarily for use with the Airborne 

Oceanographic Lidar (AOL) . A prototype NCSS is presently 

interfaced to the AOL. This prototype is constructed from an 

extensively modified Spectron Engineering SE590 CCD spectrometer 

head. 

The AOL will use two new NCSS units onboard the Goddard P-3a 

aircraft. They will provide the AOL with high resolution sky and 

ocean spectra. The up-looking NCSS will provide the AOL data 

system (AOLDS) with down-welling solar radiance, and the downlooking NCSS will provide ocean color spectra. The solar 

radiance will be used to correct various ocean color algorithms 

now being researched. 

The NCSS is now interfaced to the AOLDS via a specialized 

parallel high speed Direct-Memory-Access System Expansion Bus 

interface. We plan to interface the NCSS to the IBM-PC/AT bus 

in the near future. The PC interface will allow a small 

portable lightweight ocean/land color data system. 

The NCSS optics consist of: 1) a 1.5cm diameter input lens, 2) an 

entry slit, and 3) a single 2 x 2 cm reflective diffraction 

grating. The sensor and electronics consists of a Reticon 

RL-256 CCD linear array detector digitized by a Analogic 826 ADC. 
I The CCD and the digitizer are controlled by a 280 microprocessor. I 

I For further information on the NCSS contact Wayne Wright at the 

~ GSFC/Wallops Flight Facility. 

93 
94 
AIRBORNE OCEANOGRAPHIC LIDAR (AOL) FLIGHT MISSION PARTICIPATION 

by 

F. E. Hoge (672) 

During this reporting period of February 1986 to the present, the 

AOL participated in six interagency flight missions. These were: 

(1) Shelf Edqe Exchanqe Processes (SEEP 11) (Department of 

Enersv). The SEEP I1 flight experiments were conducted on shelf 

and slope waters east of the Delmarva Peninsula during March and 

April 1988. The SEEP experiments are designed to assess the 

assimilative capacity of the Continental Shelf to absorb the 

energy by-products introduced into the near-shore ocean 

environment from coastal communities and marine activities such 

as energy production plants and offshore oil operations. During 

1985, the AOL had participated in the SEEP I flight missions 

conducted in the New York Bight. 

(2) BIOWATT I1 (Office of Naval Research). The BIOWATT I1 

flights were conducted in a section of the Sargasso Sea east of 

Cape Hatteras. The major objective of this study was to provide 

a better understanding of the relationships between ocean 

physics, biology, bioluminescence, and optics in oligotrophic 

portions of the Atlantic Ocean. During 1985, the AOL had 

participated in the BIOWATT I flight missions conducted in the 

Sargasso Sea south and west of Bermuda. 

(3) Fall Experiment (FLEX) ( Department of Enersv). The FLEX 

missions were conducted over shelf and Gulf Steam waters between 

I 

95 
Charleston, South Carolina, and Cape Canaveral, Florida. The 

FLEX studies were designed to determine the fate of low salinity 

water in the coastal boundary zone that is advected south towards 

the Florida coast during autumn. During 1985, the AOL had 

participated in the Spring Experiment (SPREX). 

(4) Greenland Sea and Icelandic Marine Biolocrical ExDeriments 

(NASA). These flights were conducted in conjunction with the 

NASA Arctic Ice Experiment. The investigations were designed to 

evaluate the distribution of surface layer chlorophyll in the 

Greenland Sea and ,in the coastal waters in the vicinity of 

Iceland. 

(5) Submeraed Oceanic Scatterina Layer ExDeriment (Naval Ocean 

Svstems Center). These flights were conducted over shelf, slope, 

Gulf Stream, and Sargasso Sea watermasses during June 1986. This 

flight experiment demonstrated for the first time the feasibility 

of detecting and metrically measuring the depth to submerged 

layers of particulate matter in the shelf break region and in the 

inner coastal zone. 

(6) Microbial Exchancres and Cour)lincr in Coastal Atlantic Systems 

_/National Science Foundation). These flight investigations were 

conducted in shelf and slope watermasses east of Cape Henry, 

Virginia, during May 1986. This investigation was designed to 

study the transportation and fate of particulates in coastal 

waters and in particular the Chesapeake Bay/coastal Atlantic 

Ocean. 

96 
I Shortly after the conduct of the flight experiments, airborne 

I 

I 

I laser-induced chlorophyll a and phycoerythrin fluorescence data, 

1 as well as sea surface temperature and airborne expendable 

bathythermograph water column temperature profiles are supplied I 

I to cooperating institutions. Corroboration with participating 

1 scientists in the analysis of the data and publication of 

important findings are ongoing activities. During the past 

several years, numerous papers have been published on oceanic 

lidar applications to airborne measurement of chlorophyll, 

phycoerythrin, tracer dye concentration, oil film thickness and 

identification, monomolecular films, front mapping, water depth, 

and sea surface backscatter characteristics. Several papers have 

been recently published on active-passive (laser-solar) airborne 

ocean color methods for phytoplankton pigment concentration 

measurement, chlorophyll algorithm development, and general ocean 

color spectral variability studies. 

Future plans call for AOL participation in the North Atlantic 

Spring Bloom Process Study of the Joint Global Ocean Flux Study. 

This multi-nation experiment is designed to improve the understanding of the spring bloom development in the open ocean. 

Research ships from Great Britain, Germany, The Netherlands, and 

the U.S. will conduct sampling along the 20 W transect in the 

Spring of 1989. It is anticipated that the AOL will conduct its 

overflights from both Iceland and Ireland. 

97 
OCEAN DATA ACQUISITION SYSTEM 

by 

B. Johnson, J. Cavanaugh, J. Smith (674), W. Esaias (671) 

The Ocean Data Acquisition System (ODAS) is a low-cost instrument 

with potential commercial application. It is easily mounted on a 

I small aircraft and flown over the coastal zone ocean to remotely 

1 measure sea surface temperature and three channels of ocean color 

information. From this data, chlorophyll levels can be derived 

for use by ocean scientists, fisheries, and environmental 

offices. Data can be transmitted to shipboard for real-time use 

with sea truth measurements, ocean productivity estimates and 

fishing fleet direction. 

The aircraft portion of the system has two primary instruments: 

an IR radiometer to measure sea surface temperature and a three 

channel visible spectro-radiometer for 460, 490, and 520 nm 

wavelength measurements from which chlorophyll concentration can 

be derived. The outputs of both instruments is fed into a data 

system where they are digitized to 12-bit resolution, formatted, 

recorded on-board, and transmitted to a receiving (shipboard) 

system for processing. The aircraft package contains a L0RAN-C 

unit for aircraft location information, clock, on-board data 

processor and formatter, digital data storage, packet radio 

terminal controller, and radio transceiver for data transmission 

to a ship. From the measurement altitude of 500 feet, the line 

of sight transmitter range to a ship is about 30 miles. The VHF 

transceiver can also be used for voice communication and 

I 

PAGE BLANK NOT N~~~~ 99 

I 
coordination between aircraft and ship. 

The shipboard package contains a transceiver, packet terminal 

controller, data processing and storage capability, and printer. 

Both raw data and chlorophyll concentrations are available for 

real-time analysis. 

~ 

To keep down the cost of reproducing the instrument system in the 

I future, commercially available subsystem components are 

I 

I principally used. Good quality camera lenses for the optical 

systems, amateur radio packet controllers, and modified amateur 

transceivers (modified to FCC assigned ODAS frequencies) for the 

data transmission systems, and rack mountable personal computers 

for the data systems are examples. 

I 

FIELD MISSIONS: 

ENGINEERING FLIGHTS AT WALLOPS FLIGHT FACILITY; MAY 13, 1987 

1987 AIRBORNE SCIENCE EXPEDITION TO THE ARCTIC OCEAN NEAR 

BIOWATT FALL EXPEDITION, NOVEMBER 1987 

SEEP I1 (SHELF EDGE EXCHANGE PROGRAM): MARCH 1988. 

SPITSBERGEN; MAY 17 - MAY 30, 1987. 

1. MEASUREMENT TECHNIQUE: NARROW BAND INTERFERENCE FILTERS AND 

SILICON DETECTORS. 

, 2. OBSERVATION WAVELENGTH(S): 460, 490, & 520 nm. 

3. PARAMETER MEASURED: OCEAN COLOR TO DERIVE CHLOROPHYLL. 

4. SENSOR HEAD SIZE: 12" DIAM. X 17" DEEP WEIGHT: 25 POUNDS (EST) 

! 5. DATA SYSTEM: 19"W X 15"D X 9"H (AIRBORNE DATA SYSTEM IS A 

I PERSONAL COMPUTER W/ PLUG-IN A/D CONVERTER & "HARD CARD". 

I SHIPBOARD DATA SYSTEM IS A PERSONAL COMPUTER WITH HARD DISC OR 

CARD. WEIGHT: 30 POUNDS (EST) DATA RATE (BPS): 1200 

I 6. REMOTE SENSING AIRCRAFT USED: WFF P-3 DE HAVILLAND "BEAVER". 

100 
N89= 28 145 

COASTAL ZONE COLOR SCANNER \ 

by 

B. Johnson (674) 

The Coastal Zone Color Scanner (CZCS) spacecraft ocean color 

instrument is capable of measuring and mapping global oceansurface chlorophyll concentration. It is a scanning radiometer 

with multiband capability. It operated successfully for 7 years 

on Nimbus VII. The engineering model of CZCS underwent extensive 

functional testing and some environmental testing during the 

development of the flight instrument at the contractor, Ball 

Brothers. The engineering model is presently in a Code 674 

laboratory. With new electronics and some mechanical, and 

optical re-work, it probably can be made “flight worthy.11 Some 

additional components of a second flight model are also 

available. An engineering study and further tests are necessary 

to determine exactly what effort is required to properly prepare 

the instrument for spaceflight and the nature of interfaces to 

prospective spacecraft (e.g., AEM, BSS, Eos Polar Platform). The 

following is an outline of a proposed preliminary study by our 

branch to assess the value of further pursuing a spaceflight 

opportunity for this instrument. We estimate that this in-house 

study could be completed in 12 months at a cost of about $25K. 

1. Goal 

1.1. Instrument Status 

1.2. Rework Feasibility 

2. Science & Applications 

2.1. Global Ocean Color 

2.2. Ocean Productivity & Currents 

2.3. Global Biogeochemical Cycles (e.g., CARBON) 

101 
2:4. Commercial & Operational Uses 

2.5. Value-Added Industry 

3. 

4. 

5. 

6. 

Engineering Model Status 

3.1. Flt Model History: 7 Yrs Lifetime 

3.2. E/M Previously Tested 

3.3. E/M Available 

3.4. Appears Good Condition 

Study & Test Effort 

4.1. Optical 

4.1.1. Alignment Verification 

4.1.2. Spectral Characteristics 

4.1.3. IFOV 

4.1.4. Detector Sensitivity 

4.1.5. Spectral Characteristics 

4.2.1. Fit on Small Satellite (E.G. AEM, BSS) 

4.2.2. Requirements & Mods to Fly on Scout 

4.2.3. Environmental Considerations 

4.2.4. Materials 

4.3. Electronic 

4.3.1 

4.3.2. Evaluate/update Signal Analog Circuits 

4.2. Mechanical 

Evaluate/update Scan Motor Drive Circuit 

4.3. Define Instrument Parameters (Characteristics 

4.4. RCQA Rationale (e.g., OCE STRATEGY) 

SPECS) 

cost 

5.1. Contractor Mechanical Engineer & Technician 

5.2. "Breadboard" Parts; Mechanical & Electronic 

Milestones 

6.1. Review & Document Test & Study Results 

6.2. Document Recommendations 

The CZCS provides operational instrument capability for 

monitoring of ocean productivity and currents. It could be a 

simple, low cost alternative to developing new instruments for 

ocean color imaging. Researchers have determined that with 

global ocean color data they can: specify quantitatively the role 

of oceans in the global carbon cycle and other major 

biogeochemical cycles; determine the magnitude and variability of 

annual primary production by marine phytoplankton on a global 

102 

I 
scale; understand the fate of fluvial nutrients and their 

possible affect on carbon budgets: elucidate the coupling 

mechanism between upwelling and large-scale patterns in ocean 

basins; answer questions concerning the large-scale distribution 

and timing of spring blooms in the global ocean; acquire a better 

understanding of the processes associated with mixing along the 

edge of eddies, coastal currents, western boundary currents, 

etc., and acquire global data on marine optical properties1. 

The technique for processing and archiving the data from the CZCS 

instrument would utilize the CZCS global data processing and 

archiving system existing at GSFC. Existing algorithms would be 

used. 

--------------- 

'System Concept for Wide-Field-Of-View Observations of Ocean 

Phenomena from Space, August 1987. 

103 
W8 -2 814 

52s -3 5- 

THE MULTICHANNEL OCEAN COLOR SENSOR (MOCS) 

by I 

J. D. Oberholtzer and C. R. Vaughn (672) 

The MOCS is an imaging spectroradiometer with a sensitivity that 

matches the light upwelling from open bodies of water. Twenty 

contiguous spectral channels in the visible are recorded in a 

line scanning mode from an aircraft. The system also supports a 

thermal infrared radiometer and will accept input from a position 

location system. 

1 

The sensor in the MOCS system is an image dissector tube. A line 

from the scene below the aircraft is disbursed onto the face of 

the image dissector through a grating. This is recorded as a 150 

pixel line with 20 spectral channels in each pixel, where the 

spatial extent is 2 by 4 mrad, and the spectral width of each 

channel is about 15 nm. Three scans (or lines) are recorded each 

second; thus, unless the aircraft is quite high, the scene below 

is sampled rather than recorded as a complete image. For most 

ocean color missions, this is a reasonable method of collecting 

data. 

Originally at the NASA Langley Research Center, the spectral 

curvature algorithm was developed during this time. This relates 

the irradiance in Channel 7 of the MOCS normalized by the 

channels on either side to the chlorophyll concentration in the 

water. Channel 7 is centered at 490 nm which is at a chlorophyll 

absorption peak. No atmospheric correction to the data is needed 

105 
for low flying aircraft gathering chlorophyll data using this 

algorithm. I 

Although the MOCS is now about 15 years old, because its response 

has been so stable, we decided to upgrade its data recording 

system from an obsolete computer with a restricted data record. 

We chose to duplicate the system used by the Aircraft 

Oceanographic Lidar where possible. The new MOCS system was 

designed, and while most of the parts were acquired, the cost of 

the total system was more than the available funds. To complete 

the instrument in order to demonstrate the new system, the 

missing pieces were borrowed from other projects. This was flown 

on several BIOWATT I1 missions in 1987 on which data were 

collected, and the system was shown to work. Earlier, the older 

data recording system was used in a mission to support the 

National Science Foundation funded Microbial Exchanges and 

Coupling in Coastal Atlantic Systems project at the mouth of the 

Chesapeake Bay. A report of this mission is in preparation. 

There have been no funds to finish the data recording system; 

however, a proposal to NASA Headquarters for the necessary funds 

will be submitted. 

The MOCS has been a reliable instrument for recording ocean color 

from low flying aircraft. As NASA enters the next period of 

ocean color investigations from space, such a device can play an 

important role in calibration of the space instrument, as well as 

provide support for programs developing the next generation of 

space borne devices. 

106 

I 
SEA ICE I 
ARCTIC SEA ICE STUDIES WITH 1 

PASSIVE MICROWAVE SATELLITE OBSERVATIONS 

by 

D. J. Cavalieri (671) 

The objectives of this research are: (1) to improve sea ice 

concentration determinations from passive microwave space 

observations; (2) to study the role of Arctic polynyas in the 

production of sea ice and the associated salinization of Arctic 

shelf water; and (3) to study large-scale sea ice variability in 

the polar oceans. The strategy is to analyze existing data sets 

and data acquired from both the DMSP SSM/I and recently completed 

aircraft underflights. Special attention will be given the high 

resolution 85.5 GHz SSM/I channels for application to thin ice 

algorithms and processes studies. 

A study relating the fluctuations in the sea ice areas of the 

Bering and Okhotsk seas to changes in the position and intensity 

of quasi-stationary high and low pressure systems associated with 

large-scale standing wave patterns in the atmosphere has 

been completed and published (Cavalieri and Parkinson, 

1987). Other work recently completed include a 

comparison of SIR-B and SMMR Weddell Sea ice concentrations 

(Martin, et al., 1987) and a study of how ice surface conditions, 

imaging geometry and choice of algorithm parameters affect the 

computation of sea ice concentrations using both active and 

passive microwave sensors (Burns, et al., 1987). Most recently, 
and as part of the NASA DMSP SSM/I Sea Ice and Snow Validation 

Program, a series of coordinated aircraft SSM/I underflights with 

three aircraft were completed in March 1988. NASA's DC-8 

airborne laboratory carried both active and passive microwave 

sensors. The DC-8 radiometers with frequencies and polarizations 

that closely match those of the SSM/I were developed and operated 

I by Goddard's Microwave Sensors and Data Communication Branch 

under the direction of Dr. T. T. Wilheit. The active sensors 

on the DC-8 included the JPL P-, L-, and C-band SAR. Two Navy 

research aircrafts also participated in these underflights in 

support of the NASA program and provided additional passive and 

active microwave coverage. 

Analysis of aircraft and satellite data sets is expected to 

provide a basis for determining the potential of the SSM/I high 

frequency channels for improving sea ice algorithms and for 

investigating oceanic processes. Improved sea ice algorithms 

will aid the study of Arctic coastal polynyas which in turn will 

provide a better understanding of the role of these polynyas in 

maintaining the Arctic watermass structure. Analysis of 

satellite and archived meteorological data sets will provide 

improved estimates of annual, seasonal and shorter-term sea ice 

variability. 

I 

110 
SEA ICE AREA I 

- 800 3 

2 - 600- 

w U 

C : 000- 

u 

200 

- 

- 

I ,,,'SEA OF OKHOTSK 

/' BERING SEA dP,7 

01 I 

100 

SLP VARIANCE 

1 7 13 19 25 31 6 12 18 24 30 5 11 17 23 

Doc 1972 Jan 1973 Feb 1973 

Figure 1. Time series of the sea ice covered areas in the Bering 

and Okhotsk seas, percent variance, and the longitudinal phases 

of the first three harmonics of a zonal Fourier analysis of the 

atmospheric sea level pressure for the Winter of 1972-73. The 

phase of each harmonic corresponds to the position of minimum 

amplitude or low pressure. Two midwinter Bering Sea ice retreats 

starting on December 28 and January 27, respectively, are 

preceded by a reduction in the variance explained by harmonic one 

and an increase in the variance explained by harmonics two and 

three. Rapid changes in the phases of these harmonics are also 

observed and are associated with changes in the position of both 

the Aleutian Low and the Siberian High, two wintertime semipermanent circulation features. The direction of the winds 

associated with these two systems determine whether the ice 

advances or retreats these two seas (Cavalieri and Parkinson, 

1987). 

111 
MICROWAVE REMOTE SENSING OF SEA ICE 

by 

J. C. Comiso (671) 

1 

1 

The long term objectives of this research project are as follows: 

a) to understand the physics of the multispectral microwave 

radiative characteristics of sea ice as it goes through different 

I 

I 

phases: b) to improve characterization of sea ice cover using 

satellite microwave sensors: and c) to study ice/ocean physical 

and biological processes associated with polynya formations and 

variability of the marginal sea ice region. 

Two field experiments have been conducted to pursue these 

objectives. One involved measurements of radiative and physical 

characteristics of sea ice from a ship during a 3-month long 

cruise through the Weddell Sea ice pack during the Austral winter 

of 1986. The other involved similar measurements from two 

aircrafts and a submarine over the Central Arctic and Greenland 

Sea region. The latter was done in collaboration with scientists 

from Goddard (Codes 672 and 675), JPL, and Scott Polar Research 

Institute. Both experiments were very successful. Preliminary 

results have already led to an enhanced understanding of the 

microwave signatures of pancake ice, nilas, first year ice, 

multiyear ice and effects of snow cover. 

Coastal and deep ocean polynyas and their role in bottom water 

formation and ocean circulation have been studied using a time 

series of ice images from SMMR. 

polynya similar in characteristics 

f RECEDING PAGE 

@l@J&JrMiUiKmWr - 

A recurring Cosmonaut Sea 

but much smaller in size than 

” f3 T 

113 

BLANK NOT FILMED 
the large Weddell polynyas in mid-1970's was discovered. A 

simple model shows that the size of the polynya is a strong 

factor that keeps it from persisting throughout a winter period. 

An unsupervised cluster analysis of Arctic sea ice using SMMR and 

THIR emissivity and brightness temperature data has been 

implemented in collaboration with Code 636 personnel. The 

analysis indicates the existence of several unique and persistent 

clusters in the Central Arctic region during winter and that the 

sum of the area of these clusters excluding those of first year 

ice is about 20% less than minimum ice cover area inferred from a 

previous summer data. This result is consistent with saline 

surface for some multiyear ice floes as observed during MIZEZ and 

suggests that a significant fraction of multiyear ice floes in 

the Arctic have first year ice signatures. 

Current plans include the completion of analysis of the 1986 

Weddell Sea data and the 1987 Arctic aircraft/submarine data and 

correlation of results with those of SMMR and the recently made 

available SSM/I data. The role of sea ice in the marginal ice 

zone phytoplankton bloom is also being studied using CZCS data in 

conjunction with SMMR data and in-situ observations. This is 

being done in collaboration with scientists from Goddard, 

University of Tennessee, and University of Southern California. 

A field program to measure radiative, electrical, and physical 

characteristics of Weddell Sea Ice is also scheduled to be 

conducted from June through July 1988 as part of the AMERIEZ 

project . These measurements will be utilized to further 

understand radiative characteristics of sea ice data at 85 GHz. 

114 

I 
VERTICAL POLARIZATION 

220 

200 

180 

180 

140 

120 

300 

280 

280 

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220 

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180 

160 

140 

120 

300 

300r 1 I I 1 I I I I I I I I I I I I I I 

-- 2 .. . - .. z -- - Nrw 

- 

- -- DI - 

- -- - a- 

- -- - 

-- - f OonWrr - I I I I I I I I I I 

I I I I I I I I I I I I I I I I I I 

I I I I I I I I 

- CI 18WVI90G& __ dl37GHzvs90GH. - 

- cy IQ -- - 

- -- - Nrw -- la - Now - Ice 

- -- - 

- -- - 'e kWrr 

- -- - ~ ' Oon wa- - -- - 

- -- - I I I I I I I I I I I I I I I I I i I I I I I 1 I I I 

I I I I I I I I I 

el 6 GHt VI 10 GHz nlOGHzvs18GH. 

a1 6 GH. VI 90 GH. 

ruouts. 1w 

818 AM IO 912 

T*-25.2'C 

240 

120 

bl 10 GHx VI 90 GHz t 

-- i -War - - I I I I I I I I I I I I I I I I I I 

t Mia 

180 

160 

140 

M iQ 

t M IC. i 

BRIGHTNESS TEMPERATURE iKl 

Figure 1. 

ice cover in Winter of 1986. 

combinations of different channels at vertical polarization shows ability to 

discriminate new ice from snow covered and thick first year ice. 

a polynya region are presented by distinct clusters which vary in number and 

relative position depending on which microwave channels are used in combination 

with the 90 GHz channel. 

frequency channel also shows large sensitivity to different state and stages of 

snow cover in thick first year ice areas. 

Mu1 tispectral passive microwave in-situ observations of Weddell Sea 

The series of two-dimensional scatter plots using 

New Ice from 

Also, the use of a 90 GHz channel with another 

115 
N89- 28 149 

ANALYSIS OF SEA ICE DYNAMICS 

by 

J. Zwally (671) 

The ongoing work (FY86, FY87, FY88) has established the basis for 

using multiyear sea ice concentrations from SMMR passive 

f microwave for studies of large-scale advection and 

convergence/divergence of the Arctic sea ice pack. Comparisons 

have been made with numerical model simulations and buoy data 

showing qualitative agreement on daily to interannual time 

scales. Analysis of the 7-year SMMR data set shows significant 

interannual variations (15-20%) in the total area of multiyear 

ice. 

The scientific objective is to investigate the dynamics, mass 

balance, and interannual variability of the Arctic sea ice pack. 

The research emphasizes 1) the direct application of sea ice 

parameters derived from passive microwave data (SMMR and SSMI) 

and 2) collaborative studies with John Walsh using a sea ice 

dynamics model. 

The 7-year time series of multiyear sea cover from SMMR is being 

analyzed on an interactive computer and compared with Arctic buoy 

data and sea ice modeling results. SSMI data will be added, as 

it becomes available, and will be used to examine SMMR/SSMI 

modifying his version of the Hibler sea ice dynamics model to 

incorporate the fractional concentrations of multiyear and first 
year ice, so that more direct comparisons can be made with the 

SMMR data. 

The possible causes of observed interannual variations in the 

multiyear ice area are being examined. The relative effects of 

variations in the large-scale advection and convergence/ 

divergence within the ice pack on a regional and seasonal basis 

are investigated. The effects of anomolous atmospheric forcings 

are being examined, including the long-lived effects of synoptic 

events and monthly variations in the mean geostrophic winds. 

Estimates to be made will include the amount of new ice 

production within the ice pack during winter and the amount of 

ice exported from the pack. 

118 I 
Crn 

DAY 

335 

cm 

DAY 

337 

A Crn 

DAYS 

337 

-1335 L 

SHORT-TERM MULTIYEAR CONCENTRATION 

CHANGES 

Figure 1. 

(day 335, top) and 2 December (day 337, center) 1980. 

multiyear concentration between 30 November and 2 Dec:ember is shown at 

bottom. 

SMMR images of multiyear sea-ice concentration for 30 November 

Field of change of 

ORIGINAL PAGE 

BLACK AND WHITE PHOTOGRAPH 

119 
Figure 2. Color Coded Height Contours of the Southern Greenland Ice Sheet. 

120 
ICE SHEET RADAR ALTIMETRY 

by 

J. Zwally (671) 

The surface topography of the Greenland and Antarctic ice sheets 

between 72 degrees north and south is mapped using radar 

altimetry data from the U. S. Navy GEOSAT. The glaciological 

objective of this activity are to study the dynamics of the ice I 

I flow, changes in the position of floating ice-shelf fronts, and 

ultimately to measure temporal changes in ice surface elevation 

indicative of ice sheet mass balance. 

The ongoing activities include extensive processing of the GEOSAT 

radar altimeter data to obtain corrected ice surface elevations 

and to produce validated data sets for glaciological research. 

Data processing techniques have been developed to account for the 

differences in the operation of radar altimeters over sea ice and 

the continental ice sheets, as compared to ocean surfaces for 

which they were designed. In particular, computer retracking is 

required to correct for the range error caused by lags in the 

altimeter's automatic tracking circuit that adjusts for changes 

in the expected range between radar pulses. Each lO/second 

waveform, representing the received radar signal, is fitted with 

a five- or nine- parameter function to determine its shape and 

the position of the mid-point of the ramp with respect to the 

central range gate, which gives a range correction of typically 

several meters. Atmospheric and tidal corrections are also 

applied. 

121 
Preliminary elevation maps have been made of Greenland and parts 

of Antarctica. Crossover analysis shows an overall precision of 

about 1.6 M with a mean ascending-descending orbit bias of -0.5 

M. Procedures have also been developed for editing and smoothing 

SEASAT data over sea ice, to produce ocean surface maps over the 

sea ice regions surrounding the ice sheets. These ocean surfaces 

will be used to reduce the error in the radial component of the 

satellite orbit and tie the data to a common reference level. 

Glaciological studies with the data include definition of ice 

flow directions, the positions of ice divides and drainage 

basins, the locations of ice rises in Antarctic ice shelves, and 

other features of ice shelves and ice sheets. Data from Geos-3, 

SEASAT, and Geosat are being compared to determine whether the 

ice-sheet surface elevations have changed during the 

approximately 10-year period of the measurements. 

I 

~ 

I 

I 

122 
N8 9- 28 151 

SEA ICE/CLIMATE STUDIES 

by 

C. L. Parkinson (671) 

The objectives of this work are to determine and analyze the 

annual cycle of sea ice extents in the Arctic Ocean and 

peripheral seas and bays over the period 1973-1986, looking in 

particular for any long-term trends; to examine the relationship 

between local sea ice covers and the surrounding atmosphere and 

I 

ocean; and to examine sea ice as a potential early indicator of 

climate change. The work, which is being done partly in 

collaboration with D. J. Cavalieri, involves creating regional 

and hemispheric time series of sea ice variables from satellite 

passive microwave data and analyzing these through various 

intercomparisons amongst themselves and with oceanographic and 

atmospheric fields. 

Time series have been generated of monthly averaged sea ice 

extents from 1979 through 1986 for the Northern Hemisphere and 

for each of eight subregions, using the data of the Nimbus 7 

Scanning Multichannel Microwave Radiometer (SMMR). These 1979- 

1986 data are being compared with ice extents for 1973-1976 

previously calculated from the data of the Nimbus 5 Electrically 

Scanning Microwave Radiometer (ESMR) . Yearly averages and trend 

lines have also been generated (see figure) , as well as plots of 

the year-to-year changes in each month. There are no strong longterm trends indicated for the Northern Hemisphere as a whole or 

123 
for any of the eight subregions. However, although not strong, 

the trend lines are upward for the Arctic Ocean, Bering Sea, and 

Baffin Bay/Davis Strait, and are downward for the Sea of Okhotsk, 

Greenland Sea, and Kara and Barents Seas. The facts that the 

region with the strongest upward trend, Baffin Bay/Davis Strait, 

had a decreasing ice extent over the last 3 years of the data set 

and the region with the strongest downward trend, the Kara and 

Barents Seas, had an increasing ice cover over the last 2 years 

(see figure) reemphasize that none of the regions shows a 

convincing long-term trend. 

Because passive microwave technology allows routine monitoring of 

global sea ice distributions, marked changes in the global sea 

ice cover can be readily determined. This is not the case for 

many climate variables and is a characteristic suggesting the 

potential of sea ice as an early indicator of climate change. 

However, the natural variability of sea ice is not yet well 

enough known so that a climate signal could be clearly 

distinguished from the background noise. This is a central reason 

for the current research effort to examine sea ice variability, 

an effort which is covering regional, seasonal, and interannual 

variations. 

124 
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125 
B; 25 2.. J r/- I 

ICE SHEET STUDIES USING SYNTHETIC APERTURE RADAR 

by 

R. Bindschadler (671) 

The objective of this research is to demonstrate the utility of 

synthetic aperture radar in ice sheet studies. The major 

advantage of SAR imagery over visible imagery is the all-weather 

capability of radar and the ability to specify look angle. 

Available digital SAR imagery over ice sheets has been collected 

and examined both qualitatively and quantitatively using 

corroborative data, such as Landsat imagery, to confirm feature 

identification and interpretations. A simple scattering model 

will be developed to assess the relative importance of surface 

topography, composition, and subsurface layering to the intensity 

of radar backscatter. Recommendations of system parameters will 

be made for optimal SAR operation over ice sheets. 

127 
I PHYSICAL 

OCEANOGRAPHY 
Wave/Current Interaction Model 

by 

A. K. Liu (671) 

The objective of the first task is to model the wave-current 1 

interaction for the application to remote sensing data via 

numerical simulations and data comparison. Using the field data 

of surface current shear, wind condition and ambient wave 

spectrum, the numerical simulations of directional wave spectrum 

evolution have been used to interpret and to compare with the 

aircraft data from Radar Ocean Wave Spectrometer (ROWS) and 

Surface Contour Radar (SCR) across the front during Frontal Air 

Sea Interaction Experiment (FASINEX). Depending on the 

wavelength, angle of attack, current speed and the detailed 

current meandering structure, these waves may penetrate the front 

and refract to form a shadow zone in the south side of front. A 

parametric study for various current meandering profiles and 

incident wave spectrum under FASINEX environmental conditions is 

being performed to investigate the sensitivity of wave-current 

interaction. The wave-current interaction model will be used to 

assess the background current effects on the wave evolution for 

the Surface Wave Dynamics Experiment (SWADE) pre-test sensitivity 

study. 

The second task of wave-ice interaction was inspired by the 

observation of large amplitude waves hundreds of kilometers 

inside the ice pack in the Weddell Sea, resulting in breakup of 

131 
the ice pack. The developed analysis of processes includes the 

refraction of waves at the pack edge, the effects of pack 

compression on wave propagation, wave train stability and 

buckling stability in the ice pack. Sources of pack compression 

and interaction between wave momentum and pack compression are 

investigated. Viscous damping of propagating waves in the 

marginal ice zone are also studied. The analysis suggests an 

explanation for the change in wave dispersion observed from the 

ship and the sequence of processes that cause ice pack breakup, 

pressure ridge formation and the formation of open bands of ' water. Surface signatures of swell, wind, and eddies are 

observed in the marginal ice zone by SAR from satellite and 

airborne radars. It will be an excellent opportunity to study 

the ocean-ice interaction processes in the MIZ using Alaska SAR 

Facility. 

I 

I 132 
STREAM FUNCTION 

50 

40 

30 

20 

10 

0 

-10 

-20 

-30 

-40 

-50 - 

km 

RAY TRACE 

WAVES, A= 21 5 M 

- 

- SHADOW ZONE 

50 -40-30 -20-10 0 10 20 30 40 50 60 70 80 

Figure 1. Wave/Current Interaction Model 

133 
OcEANDwIFTERPRaTEcT 

bu 

C. D. Mason (674) 

Using Erik Mollo43ristensen's Director's Discretionary Funding, four 

drifting buoys were fabricated in the Code 674 mechanical laboratory fm 

mostly local plus animal locating transml 'tters made by TelonicS in 

Arizona. The first two working models were dropped from a Wallops 

aircraft, to test the mecham 'a1 integrity and to test the ability of the 

whole system to withstand the drap an3 provide usable data. There are two 

temperature sensors on board, one to measure sea surface temperature and 

the other to measure air temperature. An on board cmputer controls the 

transmissions, sen ah^^ three water temperature readings for each air 

temperature reading in order to differentiate one from the other after data 

reduction. chuck Mason is the project Manager; Pete Leone, mechanical 

engineering; Max Strange, electronic interface; and Bill Jones, data 

System. 

The transrm 'tted signal is picked up by Aryos equipnent on NO- 9 and NQAA 

10 and relayed back to Landover, Maryland where it can be retrieve by any 

CcRnPuter- 1. 'Ihe location of the buoy is provided by Sewiceargos as 

are four 8-bit words which are reduced by a simple formula to give sea 

surface and air temperatures. 

In October 1987, a drifter was dropped fram the Wallops Sky Van, 100 miles 

east of Wallops Island and drifted freely in and out of the Gulf stream 

toward the east. Good data was received until early February, when signals 

weakened and quit, probably due to battery exhaustion, at a location near 

/ 

135 
i 58 degrees west longitude. 

Ttm other Goddard drifters and one made by Metocean were deployed in the 

I Bay of Bengal the last week of March to monitor Bay currents and to provide 

I the Bangladesh Gowmment scientists with temperatures and barmetric 

pressure. This is a feasibility study to prove the capability of small, I 

hexpensive, drifting buoys to send back data to aid in the early detection 

of monsoon weather. 

At the present time, we are working on the design of an optical drifter 

with three sensors in the 430 to 575 nm Spectrum to look at Upwelled 

radiances and three sensors in the 430 to 700 nm Spectrum to look at 

incident Frradiance. An on-board Computer and a photo cell will be used to 

turn on the transnu 'tter for 3 hours either side of local noon to take 

advantage of the higher solar elevation angles. This program will provide 

validation/calibration of the SeaWiFS space-hsed ocean color sensor and an 

optical analog to in-situ sea surface temperature obsewation. Other 

benefits include gaining experience with long-term optical drifters and 

providing a minimal biolcgical/opticalth series. 

Guidelines for the development and test of optical difthg buoys klude: 

air deployable and expendable, reasonable cost for multiple deployment, 1 

I year lifetime, use of existing technology and a minimal validation 

I 

parametes set. 

The attached drawings shuw the construction and ocean track of the Atlantic 

o~ean Drifter and the characterization and typical data of the planned 

optical drifter. 

136 
350 400 450 500 550 600 650 700 750 

WAVELENGTH (nm) 

Figure la. .Water-Leaving Radiance 

\ --NOM 9-10 

a 

-- 

\ I /A 

-m # 

Figure lb. Optical Drifter 

137 
Figure IC. Surface Drifter Track 

40" TUBE 1 a 

(101.5 CM) V 

Figure Id. Air Launched Drifting Buoy 

138 
I 

AIR SEA ICE 

INTERACTION 
/ 

ANALYSES OF THE WIND-DRIVEN RESPONSE OF TROPICAL OCEANS 

A. J. Busalacchi (671) 

Numerical and analytical models are used to study the upperocean response to surface wind stress estimates from the tropical 

Atlantic and Pacific Oceans. These models are used to identify 

regions of important variability in the wind field, analyze the 

oceanic response, and demonstrate the applicability of remotely 

sensed vector wind stress and altimetry data. For example, a 

multi-mode linear model of the tropical Pacific was forced by 

three different wind products for 1979-1983, namely the FSU ship 

winds, the UH cloud motion winds, and the FNOC operational 

product, in order to investigate current capabilities to model 

upper ocean variability given reasonable estimates of the surface 

wind stress. Both model and XBT depictions of the mean seasonal 

cycle, 1979-1981, were analyzed along the major ship tracks in 

the western, central, and eastern tropical Pacific. Model 

solutions were also used to address array design questions in 

observing system simulation experiments. Subsequent analyses of 

the 1982-1983 solutions will be performed with respect to 

differences from the mean seasonal cycle 1979-1981, as well as, 

differences in the three wind products. 

Related activities include participation on the Science 

Definition Team of NSCAT within a project titled "The Impact of 

NSCAT Winds on Tropical Ocean Modeling". In collaboration with 

Mark Cane (LDGO) and Vince Cardone (Oceanweather, Inc.) , the 

objective of this work is to assess the value of NSCAT winds for 

BRECEDlNG PAGE BLANK NOT FILMEd4' 
improving our ability to specify the state of the upper layers of 

the tropical ocean via numerical ocean models. TOPEX project 

activities include "Studies of Tropical Ocean Dynamics Using the 

TOPEX/POSEIDON Altimeter-Derived Sea Surface Topography". 

Together with Roger Lukas, Gary Mitchum, and Klaus Wyrtki (UH), 

studies of tropical dynamics using the TOPEX/POSEIDON altimeterderived sea level will be carried out in conjunction with the 

large sea level dataset available at the TOGA Sea Level Center. 

Another TOPEX project with Eli Katz (LDGO) , "Sea-Level Response 

to Wind Forcing in the Tropical Atlantic," seeks to study 

interannual variations of the seasonal circulation of the 

tropical Atlantic via a combination of in-situ observations, 

satellite observations, and numerical simulations of the sea 

surface height. In collaboration with Joel Picaut 

(ORSTOM/Noumea) , Thierry Delcroix, and Catherine Gautier (SIO) , 

our POSEIDON project, "Application of TOPEX/POSEIDON Altimetry 

Measurements to Observation and Modeling Studies of the LowFrequency Upper Ocean Mass and Heat Circulation in the Tropical 

Pacific,'' will enhance the information content of TOPEX/POSEIDON 

altimetry with in-situ ocean data, satellite-derived surface 

fluxes and numerical ocean models for the purposes of studying 

the 4-dimensional variability of mass and heat in the tropical 

Pacific Ocean. 

Ancillary activities include serving as Co-Editor for the Journal 

of Geophysical Research/Oceans and faculty advisor to graduate 

students within the Department of Aerospace Engineering Science 

at the University of Colorado. 

142 
N89- 28156 

CLIMATOLOGICAL ASPECTS OF NIMBUS-7 SMMR DATA 

P. Gloersen (671) 

An algorithm has been developed for calculating simultaneously 

SSTs, SWs, and TAUS on a global basis using only the 6.6 and 18 

GHz channels of the SMMR. These channels were found to have 

small and easily correctable drifts over the 9-year SMMR 

lifetime. Samples of the retrievals have been calculated in each 

of eight of the SMMR years and found to produce independent 

results, consistent with weather charts and climatic records, 

even in the presence of high winds. Another new algorithm for 

calculating high-latitude scalar winds from Nimbus-7 Scanning 

Multichannel Microwave Radiometer (SMMR) data has been devised 

and tuned with surface observations from a number of documented 

Arctic Polar Low events. The algorithm utilizes the horizontally 

and vertically polarized radiances from the 0.8 and 1.7 cm 

wavelength channels of the ten-channel SMMR to retrieve near 

surface oceanic scalar winds and cloud water in the column, and 

takes advantage of the relatively small fluctuations in 

atmospheric water vapor at high latitudes. An advantage of this 

algorithm for high-latitude winds from SMMR over the global 

algorithm is an inherently better spatial resolution as a result 

of the shorter wavelengths used. Thus retrievals closer to land 

and sea ice margins are possible. Model calculations were used 

to determine the effect of cloud water on the multispectral 

143 
radiances and the surface observations were used for the wind 

effect. Surface data sets used for the tuning included detailed 

weather observations from the 1984 Arctic Polar Lows and the 

Marginal Ice Zone Experiments, and an archive of polar low events 

compiled at the Norwegian Meteorological Service for Northern 

Norway. The estimated standard error of the wind retrievals from 

the algorithm as it now stands is 10 knots, with a correlation 

coefficient of 0.82. Spatial resolution is about 50 km, and the 

sampling interval is about 15 km for the SMMR. 

Data from the Nimbus-7 Scanning Multichannel Microwave Radiometer 

(SMMR) have been used to provide a seven-year record of sea ice 

coverage in the northern and southern polar areas, for the period 

of November 1978-1985 (See Figure 1.). During this period, the 

maximum coverage in the Southern Hemisphere was found to be 

I trendless, and to vary +/- 0.5 X 10E6 sq km about a mean of 15.1 

X 10E6 sq km, with a precision of about 0.1 X 10E6 sq km. The 

maximum coverage in the Northern Hemisphere was also found to be 

trendless with a variation even less than in the Southern, +/0.3 

about a mean of 12.9 X 10E6 sq km. Variations in the minimum sea 

ice coverage were comparable in the Northern Hemisphere, and 

smaller in the Southern. The trendless total global sea ice 

I 

I 

I coverage had maxima and minima of 22.5 +/- 0.5 and 14.6+/- 0.5 X I 

10E6 sq km, respectively. If areal variations of sea ice cover 

I are indeed a significant indicator of global climate change, such 

as an average global temperature change, these data indicate that 

no such change took place during this period. While the 

144 

I 

I 
I 

I variations in the extrema of the hemispherical ice covers show no 

I 

I trends, the phase of the oscillations is not constant, resulting 

in significant changes in the shape of the oscillations of the I 

I total global ice coverage. 

145 
MICROSCALE OCEAN DYNAMICS 

by 

N. Huang (671) 

The main goal of this task is to study the detailed dynamics of 

I 

the micro-scale ocean surface phenomena, and to establish 

relationships among the surface signatures with the underlying 

dynamical processes. Our approach to advance our understanding 

in this area is as follows: 1) Conduct rigorous theoretical 

studies of the ocean surface wave dynamics and statistical 

properties. 2) Conduct process-oriented laboratory experiments 

to verify the theoretical results, and to provide guidance for 

further studies. 3) Prepare testable hypotheses for field 

verifications and comparisons during the ONR/NASA sponsored 

Surface Wave Dynamics Experiment (SWADE). 

I 

I 

I 

I 

In the past year, we have established an analytic model for wave 

breaking probability to study the influence of wave breaking on 

the spectrum shape in both deep and finite-depth waters. We have 

also processed the laboratory data on the wave number spectrum 

and the structures of the water surface under the influence of 

wind and existing waves. A paper is currently under revision for 

publication in the Journal of Fluid Mechanics. 

Based on our plan for the next three-years, we should be able to 

produce the following results at the end of the study period: 1) 

A quantitative assessment on the importance of the KelvinHelmholtz instability in wind-wave generation. 2) A quantitative 

147 

PRECEDING PAGE BLEUVK NOT FIW 
parameterization of the influence of background waves on the 

development of centimeter-range waves. 3) A definition of the 

threshold for wind-wave breaking, and assess the influence on the 

dynamics of the upper ocean layer. 4) A verification of the 

influencs of the concurrent motions on the weakly nonlinear waveI wave interactions. 

148 
N8 9- 2 8 158 

MICROWAVE RADAR OCEANOGRAPHIC INVESTIGATIONS 

by 

F. C. Jackson (671) 

The main thrust of this activity has been, and continues to be, 

the development and demonstration of the Radar Ocean Wave 

Spectrometer (ROWS) technique for measuring ocean wave 

directional spectra from air and space platforms. The 

measurement technique has been well-demonstrated with data 

collected in a number of flight experiments involving wave 

spectral comparisons with wave buoys and the Surface Contour 

Radar (SCR); recent missions include the SIR-B underflight 

experiment (1984) , FASINEX (1986) / and LEWEX (1987) . ROWSrelated activity is presently concentrating on (1) using the 

aircraft instrument for wave-processes investigations and (2) 

obtaining the necessary support (consensus) for a satellite 

instrument development program. Prospective platforms include 

Eos and the Canadian RADARSAT. 

Allied work conducted under this RTOP task includes studies of 

near-nadir, quasi-specular scatter using the ROWS instrument in a 

broad-beam altimeter mode configuration and theoretical and 

empirical studies of the altimeter EM bias. ROWS altimeter mode 

measurements of the surface Mean Square Slope (MSS) parameter 

(i.e./ the Ku-band frequency effective MSS) in MASEX and FASINEX 

have been shown to be consistent with a wind speed dependent 

equilibrium range slope spectrum model. On properly accounting 

149 
for diffraction effects using a two scale scattering model, the 

model spectrum produced MSS in agreement with a consensus of Kuband data and with the classical optical data of Cox and Munk. A 

two scale model of the EM bias has been developed for swell 

dominated conditions that gives a bias in accord with in-orbit 

estimates (Jackson, 1988). 

All LEWEX data have been processed and communicated to the 

Applied Physics Laboratory. Preliminary comparisons with the 

SCR, Canadian SAR, buoys and wave hindcasts are favorable 

according the results of a recent workshop held at APL. The 

wave/current interaction work with A. K. Liu has been reported at 

the AMs meeting in Anaheim, CA in February (Jackson and Liu, 

1988). The refraction of a long (215 m) swell system computed 

I for a simulated flow field in FASINEX (see Liu’s figure) was 

shown to be consistent with both the ROWS (see accompanying 

figure) and SCR observed spectra on both sides of the oceanic 

front . 

Elements of a new data system for the aircraft ROWS, including a 

new streaming tape drive and waveform sampler have been checked 

out. The new data system should be ready for the planned EM bias 

flights in January-February, 1989. The system is, however, 

presently limited by the power of the small PC; a better computer 

is needed to handle the data stream plus the radar housekeeping 

and aircraft data, and to afford a real time data processing and 

display capability. It is hoped to have such a capability for 

150 

I 
I the upcoming Surface Wave Dynamics Experiment (SWADE) in the 

winter-spring of 1990-91. For this experiment, we plan to 

transfer the ROWS to the small T-39 Sabreliner aircraft at WFF. 

Operating on the T-39 at twice the altitude at about 1/10 the 

I cost per spectral degree of freedom relative to the P-3 operation 

with a turn-key data system will make the flight costs trivial; 

I use of the aircraft ROWS in a I@service" capacity also becomes a 

I 

1 

possibility. 
A - NORTH OF FRONT 

I I 

B - SOUTH OF FRONT 

Figure 1. FKW directional waveheight spectra (W) obsenred north and 

south of the fllbtropical front in FASINEX February 21, 1986. Tw mly 

equal energetic swell systems are evident in the (synnnetrical) wavermber 

spectrum of the surface waves on the north side of the front, while on the 

SaCLth side of the front the north-smth dl is greatly diminished in 

anplitude. -use the front has meandered into a mrth-south orientation 

in the region of the observations, the mrth-south swell system, which 

originated in a stom off New England, strikes the front at neiur grazhq 

hidence and hence experiences stmw refraction. A ray trace us- an 

iasalized del of the frontal Currents by A. K. Liu shows a strong wave, 

shadow, zone south of the front that is consistent with these dcrservatims 

(see figure 1. in A. K. Liu's activity report). 

152 
SURFACE CONTOUR RADAR (SCR) CONTRIBUTIONS TO FASINEX f) 

E. J. Walsh (672) 

The SCR was asked to participate in the Frontal Air-Sea Interaction Experiment (FASINEX) to provide directional wave spectra. 

The NASA P-3 carrying the SCR, the Radar Ocean Wave Spectrometer, 

and the Airborne Oceanographic Lidar was one of five aircrafts 

and two ocean research ships participating in this coordinated 

study of the air-sea interaction in the vicinity of a sea surface 

temperature front near 28" N, 70" W. Analysis of data from the 

February 1986 experiment is still ongoing, but results already 

submitted for publication strengthen the hypothesis that 

off-nadir radar backscatter is closely correlated to wind stress. 

The SCR provided valuable information on the directional wave 

spectrum and its spatial variation. The right side of the figure 

shows one of the directional wave spectra measured by the SCR on 

February 18. The wave pattern was complex, and the synoptic 

weather maps on the left of the figure indicate the sources for 

the trimodal system. In addition to the locally generated waves, 

there was westward propagating swell generated by the circulation 

around the high pressure dominating the region on the previous 

day, and southward propagating swell generated 3 days earlier by 

a low pressure region off Nova Scotia. The SCR data indicated 

that the wave height decreased north of the front which was 

consistent with the observed decrease in the neutral drag 

153 
coefficient. The SCR is presently being upgraded so it can 

produce higher quality directional wave spectra and provide them 

in real-time. 

154 
SURFACE CONTOUR RADAR 

DIRECTIONAL WAVE SPECTRUM 

lORtE 

YIlD DRIVLU SEA 

YESTYARD 

?RO?AOATIU 

som 

Figure 1. Frontal Air-Sea Interaction Experiment (FASINEX) 

1986 

155 
N89- 20160 

RAINFALL ON MICROWAVE RETURN FROM THE SEA SURFACE 

L. F. Bliven (672) and J.-P. Giovanangelil 

Our long range goal remains unchanged--conduct experiments and 

develop/test theoretical models to permit useful algorithms to be 

constructed for microwave systems that observe oceanic processes. 

This topic is relevant to altimeters, scatterometers, and rain 

rate measurements. We currently are focusing attention on 

scatterometer wind velocity measurement. In the future, we plan 

to also investigate (a) the modification of altimeter crosssection due to rain--which is relevant to altimeter derived wind 

speed, and (b) bistatic scatter angle modification due to rain-- 

which is significant to radar measurement of rain-rate by sensor 

proposed for the Tropical Rainfall Measurement Mission. 

One component of our laboratory efforts is an experiment 

conducted, in the wind-wave tank at the GSFC/WFF, to quantify the 

effect of rain-generated surface-wave brightening of radar crosssection. Laboratory conditions can be characterized as light 

wind, functional rain rates, a single drop size, and a 36 GHz 

radar system at 30 degrees inclination. This study set a 

standard for future experiments because these are the first 

observations to reveal a possible functional form for modelling 

this process. During the remainder of FY88, we plan to: (1) 

investigate the effect of drop size on the cross-section 

brightening by rain-wave generation, and (2) conduct an 
experimeni at the Institut de Mechanique and Statistique de la 

Turbulence in Marseille, France, to check the feasibility of 

making measurements at azimuthal angles so that scatterometer 

directional response during rain can be quantified. 

Our primary enterprise during FY89 will be to conduct experiments 

I to quantify the effect of rain attenuation on existing wind-waves I 

as observed by scatterometers. This requires construction of a 

15- by 1.5-feet rain simulator. Design and testing of the 

simulator concepts have been conducted so that construction can 

proceed in a timely manner. The completed system will: (a) 

control rain rate by varying pressure on the water supply, (b) 

control drop size by air-jets blowing drops off each water 

nozzle, and (c) provide realistic raindrop distributions by 

microprocessor control of the air-jets. 

The main research topic for FY89 is to conduct experiments to 

test Manton’s 1973 model of rain-attenuation of wind-waves. 

, IInstitut de Mechanique and Statistique de la Turbulence 

158 
N8 9- 2 8 161 

WIND-WAVE-CURRENT TANK RESEARCH FACILITY 

USAGE AND STATUS 

by 

L. F. Bliven and S.R. Long (672) 

This summary is to provide information as to: (a) research 

activities, and (b) facilities status of the wind-wave-current 

tank research facility located at the GSFC/WFF. 

Research Activities: 

Our intention is simply to identify research activities so 

details of particular topics may be obtained from the investigators participating in each activity. 

(1) Wave-Turbulence Interaction: N.E. Huang, S.R. Long, and D. 

Fry [David Taylor Modelling Basin (DTMB) 3. New study for which 

investigatory experiments were conducted to test new turbulence 

generator and laser-Doppler anemometry measurement capability. 

Preprocessing of data was conducted on-site, and post-processing 

is being conducted at DTMB. 

(2) Velocity Structure Below Waves: J. Papadimitrakis (National 

Research Center), N.E. Huang and S.R. Long. A continuing study 

of water velocity in the near surface region, below surface 

waves; laboratory preparation complete. 

(3) Short-Wave Modification by Lonq-Waves: J. Chu and O.M. 

Phillips (both from The Johns Hopkins University), N.E. Huang, 

and S.R. Long. A new study to investigate the effects of a 

packet of long waves on local wind generated wave field. 

159 
Experiments were conducted, and data are being analyzed at WFF. 

(4) Wind-Wave Generation Time Scale: S.R. Long and N.E. Huang. 

ongoing research to determine time scales involved with local 

generation of wind waves as a function of initial surface 

conditions being either a calm water surface or paddle generated 

background waves. Experiments were conducted, and data are being 

analyzed at the WFF. 

(5) Wave-Current Interaction: N.E. Huang, S.R. Long, and R. Lai 

(David Taylor Modeling Basin). Ongoing investigation for which 

experiments were conducted to examine the strong interaction 

between currents and surface waves. Experiments have been 

conducted, and data have been analyzed at the WFF. 

(6) Rain Effects on Microwave Scatterins from the Sea-Surface: 

I 

I L. F. Bliven, G. Norcross (Computer Science Corporation) and 

J.-P. Giovanangeli [Institut de Mechanique and Statistique de la 

Turbulence (IMST) ] . New investigation to measure and model 

modification of microwave signal from sea surface due to rainfall 

I effects. Experiments and data analyses were conducted/scheduled 

for both the WFF and the IMST. 

(7) Gas Exchancre Rates versus Scatterometer Power: R. Wannikohf 

(Lamont-Doherty Geophysical Observatory), D. Glover (Woods Hole 

Oceanographic Institute) and L.F. Bliven. New investigation to 

derive empirical relationships between gas exchange rates and 

sea-surface scattered, radar-power levels. Experiment design was 

agreed upon. 

160 
THE SURFACE WAVE DYNAMICS EXPERIMENT (SWADE) 

by 

S.R. Long, J.D. Oberholtzer, C.W. Wright, and H.G. Shirk (672) 

SWADE was developed to study the dynamics of the wave field 

development in the open ocean with the following specific 

objectives : 

(1) to understand the development of the wave directional 

spectrum under various conditions, 

(2) 

momentum, heat, and mass, 

(3) to determine breaking distributions as a function of sea 

state, wind, and boundary stability, and 

(4) to provide data and analyses for ERS-1 validation. 

to determine the effect of waves on the air/sea transfers of 

\ 

The experiment is designed for the Winter of 1990-1991. Four 

buoys will be deployed for 6 months starting October 1990 and 

ending March 1991. During that time period, three intensive 

periods of 2 weeks duration each will be selected for frequent 

aircraft flights for wave data collection to satisfy scientific 

studies, as well as ERS-1 validation needs. 

Experiment Location 

The buoys will be located at the corners of a square of 

approximately 100 km on each side, and centered at 37" N and 74" 

W. This location is about 200 km due east off the Wallops Flight 

Facility, just off the continental shelf in the deep ocean. 

Based on available statistics, the buoys will be outside the Gulf 

Stream proper, with a slight possibility of encountering. 

161 
occasional meanders and some warm core rings near the conclusion 

of the deployment. 

I 

Manauement and Wallops Personnel 

The Goddard portion of the SWADE project will be under the 

overall direction of Norden E. Huang. He is one of the 

initiators of the SWADE project. His other duties include 

analytic modeling of the probability structures and dissipation 

source function, investigating the possible impact of 

Kelvin-Helmholtz instability on the wind wave generation, and 

assisting the validation of the scatterometry. 

Steven R. Long will be the Chief for the ground operations at 

Wallops. Additionally, he will be the primary investigator for 

the probability structure of the ocean surface wave field and the 

co-investigator with N. E. Huang and A. K. Liu in assessing the 

new possibility of wind-wave generation mechanisms. Erik 

Mollo-Christensen, supported by ONR, will develop the telemetry 

system for all the ground data collection. He will also assist 

and supervise the data archiving and other theoretical 

investigations. 

David Oberholtzer will be responsible for data archiving. He 

I will be assisted by a full-time data technician, Helen Shirk, at 

Wallops, and also by Erik Mollo-Christensen for this duty. Wayne 

Wright will assist Erik Mollo-Christensen in the development of 

I the central on-board computers and telemetry systems. 

I For further information on Project SWADE, contact N.E. Huang at 

I the GSFC or S.R. Long at the GSFC/WFF. 

I 162 
I ATMOSPHERIC 

MEASUREMENTS 
N89- 

WATER VAPOR PROFILING USING MICROWAVE 

by 

RADIOMETRY 

J. R. Wang and T. T. Wilheit (675) 

Water vapor is one of the most important constituents in the 

Earth's atmosphere. Its spatial and temporal variations affect a 

wide spectrum of meteorological phenomena ranging from the 

formation of clouds to the development of severe storms. It 

provides an important input to tropical numerical weather 

prediction and energy budget studies, because the latent heat 

release due to condensation is crucial to the evolution of many 

tropical weather systems and is an important energy source to the 

global scale Hadley and Walker circulation cells. These 

considerations point to the need for effective and frequent 

measurement of the distribution of atmospheric water vapor, and 

therefore, the need for the development of efficient remote 

sensing techniques. The passive microwave technique offers an 

excellent means for water vapor measurements. It can provide 

both day and night coverage under most cloud conditions. 

Two water vapor absorption features, at 22 and 183 GHz, have been 

explored in the past years. The line strengths of these features 

differ by nearly two orders of magnitude. As a consequence, the 

techniques and the final products of water vapor measurements are 

also quite different. At 22 GHz the atmosphere, in clear 

conditions, typically absorbs less than 

radiation propagating through it. Most 

retrieve water vapor by remote measurements 

PRECEDING PAGE 

20 percent of the 

of the attempts to 

near this frequency 
are, therefore, limited to total precipitable water. On the 

other hand, the strong absorption line at 183 GHz offers the 

potential of profiling the atmospheric water vapor. In fact, all 

the past studies of this absorption feature for remote sensing 

application have emphasized the retrieval of atmospheric water 

vapor profiles. Our effort in the early 1980's concentrated on 

the development of both sensor technology and retrieval 

algorithms at 183 GHz for profiling atmospheric water vapor. The 

Airborne Microwave Moisture Sounder (AMMS) was the result of this 

sensor development effort. Using this sensor, retrieval of water 

vapor profiles under clear sky conditions was successfully demonstrated. As a result of this combined science and technology 

program, this approach to the measurement of water vapor profiles 

is currently being implemented for both the NOAA and DMSP 

satellites and is also planned for inclusion in the Eos payload. 

Our research effort in the past few years has been to improve and 

extend the retrieval algorithm to the measurements of water-vapor 

profiles unde'r cloudy conditions. In addition, the retrieval of 

total precipitable water using 183 GHz measurements, but in a 

manner analogous to the use of 22 GHz measurements, to increase 

measurement sensitivity for atmospheres of very low moisture 

content was also explored. A combination of both these 

techniques was used to retrieve the total precipitable water over 

the coastal Atlantic Ocean during a cold air outbreak which was 

observed by the AMMS on board the NASA ER-2 aircraft during the 

1986 Genesis of Atlantic Lows Experiment as shown in figure 1. 

166 
0 

167 
by 

C. L. Parsons (672) 

1987 can legitimately be called the year that ozone trend 

detection became a public issue in the U. S. In the Fall of 

1986, an interagency Antarctic Ozone Expedition Team, known as 

the National Ozone Expedition (NOZE), spent the months of AugustNovember in Antarctica. They conducted a coordinated series of 

ground- and balloon-based observations to study the disappearance 

of stratospheric ozone reported by Farman & al. of the British 

Antarctic Survey. The NOZE results verified the report that the 

ozone level was diminished by as much as 90 percent at some 

altitudes and that the reduction increased every year. At the 

same time, unpublished reports were circulated stating that the 

ozme amounts around the entire globe were decreasing at the rate 

of about 1 percent per year. It is known that an ozone decrease 

can be associated with an increased risk of skin cancer in 

humans. Consequently, the Antarctic and global results 

heightened interest in ozone trend detection. In the Fall of 

1986, NASA, in conjunction with the World Meteorological 

Organization and the United Nations Environment Program, 

initiated a major review on the subject of ozone trend detection 

with a report on the findings due by the end of 1987. 

An Ozone Trends Panel, composed of eminent scientists from 

federal agencies, industry, and universities, was formed. 
Chaired by Dr. R. Watson of the Upper Atmosphere Programs Office 

of NASA Headquarters, the Panel contains Calibrations, 

Algorithms, Intercomparisons, 

Satellite/Ground Intercomparisons, Comparison of Theory and 

Observations, Other Trends in Stratosphere, Source Gases, 

Aerosols, Antarctic Ozone, and Temperature Working Groups. The 

GSFC Correlative Measurements Program (UPN 665-70) at the Wallops 

Flight Facility was represented on the Satellite/Satellite 

Intercomparisons Working Group. The Correlative Measurements 

Program uses the Rocket Ozonesonde (ROCOZ-A) and the 

Electrochemical Concentration Cell (ECC) balloon-borne ozonesonde 

to measure the vertical profile of ozone amount in the 

atmosphere. The balloon work is described in a separate report 

in this volume entitled "Ozone Measurements Using Balloon-Borne 

Ozonesondes, 'I by Arnold L. Torres. The ROCOZ-A instrument has 

been used for many years to provide in situ lltruthll data for 

Various Satellite ozone measuring systems, such as SBW on 

Nimbus-7, SAGE-11, SBW-I1 on the NOAA series of polar orbiting 

satellites, SME, LIMS, etc. The particular data sets of interest 

to the Ozone Trends Panel Working Group were collected at Natal, 

Brazil. 

Sat el 1 it e/Sa t el 1 i te 

During an experiment at Natal in March and April of 1985, it was 

found (Barnes, & al., IIEquatorial Ozone Profiles From the Ground 

to 52 km During the Southern Hemisphere Autumn," Journal of 

Geophvsical Research, Vol. 92, No. D5, May 20, 1987, pp. 5573- 

5583) that the atmospheric variability is negligible. Therefore, 

170 
a small number of ROCOZ-A vertical ozone profiles can be compared 

with high precision with a larger number of satellite ozone 

profiles in that area and in the same time frame without 

requiring time coincidence. This reduces the cost of the field 

experiment and reduces the complexity of the launch schedule. 

This makes the Natal area in March and April an ideal location to 

use the rocket profiles to tie together various satellite 

instruments. 

The major results produced for and used by the Ozone Trends Panel 

are shown in figure 1. The ROCOZ-A average ozone density profile 

is plotted versus altitude on the left. ECC ozonesondes were 

used for the portion of the profile below 20 km, the lower limit 

for ROCOZ-A. In the center graph, the difference between SAGE-I1 

and ROCOZ-A average density profiles is shown. Between 25 and 50 

km, the differences are sometimes negative and sometimes 

positive, they never exceed 5 percent, and average about -1 

percent (ROCOZ-A on average is slightly higher). In the righthand graph, the difference between ROCOZ-A and the SBUV results 

from Nimbus-7 are plotted. This comparison is made in terms of 

ozone layer amount versus Umkehr layer, the primary ozone data 

product from the SBUV. For all layers, the differences are all 

negative. That is, the SBW values are less than ROCOZ-A. The 

difference is 18 percent at layer 9 and 5 percent at layer 6. 

This result is discussed in further detail by Barnes ("Changes in 

SBUV Ozone Profiles Near Natal, Brazil, from 1979 to 1985," 

Journal of Geophysical Research, Vol. 93, No. D2, February 20, 

1988, pp. 1704-1717). 

171 
The implication of the Natal data sets and the analyses by Dr. 

Barnes (Chemal, Inc.) resulting from them is that the SBW 

vertical profile shape is inconsistent with atmospheric behavior. 

Instrumental effects in the SBW that are improperly accounted 

for in the Nimbus-7 data processing may be responsible. The 

recently published report by the Ozone Trends Panel does indeed 

indicate that findings from the other Working Groups agree with 

ours. The report does conclude that an ozone decrease on a 

global scale is real, however. Although the earlier reports of a 

decrease were considerably exaggerated because of the SBW 

instrument problem, the Earth’s ozone amount is decreasing. In 

the future, even more attention will be paid to the close 

monitoring of the global trend. We expect that the ROCOZ-A 

measurement will continue to be of importance in this effort. 

I 

172 
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N8 9- 2 8 165 

OZONE MEASUREMENTS USING BALLOON-BORNE OZONESONDES 

by 

A. L. Torres (672) 

Vertical profiles of atmospheric ozone have been measured for a 

number of years by WFF personnel using small balloon-borne 

ozonesondes. These sondes are interfaced with meteorological 

radiosondes so that both ozone data and meteorological data 

(pressure, temperature, humidity, wind speed and direction) are 

obtained from ground level up to 30-35 km. I 

Efforts at Wallops have been focused in three areas. The first 

involves biweekly launches from two sites (Wallops and Natal, 

Brazil), timed to coincide with overpasses of satellite-borne 

ozone sensors such as the Solar-Backscattered Ultraviolet. The 

resulting data are reported to the World Ozone Data Center and 

are used for satellite correlative support, as well as, for 

studies of both tropospheric and stratospheric ozone. The second 

activity consists of field campaigns in remote locations in 

support of special projects. The third is a continuing activity 

to quantitatively evaluate and improve the sonde's performance 

under stratospheric conditions. 

The most recent field campaign involved measurements of ozone 

over Palmer Station, Antarctica, during August-October of 1987. 

The Wallops effort was part of both NASA's Airborne Antarctic 

Ozone Experiment and the National Science Foundation's National 

175 
Ozone Expedition. Both of these experiments were aimed at 

studying the annual stratospheric ozone depletion that has 

happened each austral spring in recent years. This year, the 

amount of depletion was larger than ever. Total column amounts 

of ozone decreased by more than 50 percent between August and 

early October, while ozone concentrations in the 17 km region 

decreased by over 95 percent. As shown by other investigators, 

the ozone depletion is approximately confined to the polar 

vortex. Because of meteorological distortions in the boundaries 

of this mass of air circling the polar region, Palmer was within 

the region of depleted ozone on some days, and not on others. 

Figure 1 shows the dramatic depletion that had occurred at 50-100 

mb altitudes in air that was within the ozone-depleted region 

(October 9) compared to the more normal profile of October 6. 

I 

Planning is underway for a second trip to Palmer in the austral 

Spring of 1988. This experiment will provide information on 

I whether the ozone tfholett continues to deepen and spread, both in 

horizontal and vertical extent. 

Sensor evaluation studies have involved both flight tests and 

laboratory studies using a flight simulator. The Balloon 

Ozone Intercomparison Campaign flights in 1983 and 1984 provided 

the chance to test small ozonesondes relative to research-grade 

instruments on a large balloon platform. During this same time 

period, a laboratory-based flight simulator was designed and 

constructed at Wallops. The flight simulator exposed a sonde to 
typical vertical profiles of ozone, pressure, and temperature 

while monitoring the sonde's performance. These studies resulted 

in a well-characterized knowledge of the sondes accuracy and 

precision as a function of altitude. Recent efforts have 

concentrated on designing and constructing an improved version of 

the flight simulator. This is now complete, and first 

applications are underway. Planned studies include an evaluation 

of accuracy and precision for the newer model ozonesondes now 

being used at Wallops, tests to higher altitudes, and 

quantitative determinations of how such factors as 

sensing-solution concentration and preparation procedures affect 

sonde performance. 

177 
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178 
Q5 #8 9- 28 166 

MOBILE LIDAR SYSTEM FOR MEASUREMENT OF ! 

WATER VAPOR MIXING RATIO AND OZONE NUMBER DENSITY 

D. Whiteman (674) 

The Code 674 Water Vapor Lidar has been modified and extended by 

Codes 674 and 617 to make differential absorption measurements of 

ozone. The Water Vapor Lidar group consists of project scientist 

Harvey Melfi, meteorologist/data analyst Rich Ferrare, and 

systems engineer/project manager Dave Whiteman. The Ozone Lidar 

group consists of project scientist, Tom McGee, laser physicists 

Jim Butler and John Burris, Rich Ferrare and Dave Whiteman. 

All of the'lidar equipment is housed in a mobile trailer allowing 

relocation of the experiment. Both experiments are nighttime 

operating only. The experimental equipment includes a 70 Hz XeC1 excimer laser (308 nm), 10 Hz Nd:YAG laser (355 nm), 30 inch 

Dahl-Kirkham telescope, custom designed optics package, 

photomultiplier tube detectors and photon counting signal 

measurement system. The system is controlled by a DEC LSI-11/73 

computer providing experiment control and near real-time graphics 4 

output with a vector co-processor used for real-time data 

processing. 

Water vapor measurements make use of a weak molecular scattering 

process known as Raman scattering. It is characterized by a I 

I 

shift in wavelength of the scattered beam of light relative to 

the incident one. Some of the energy of the incident photon is 

179 
converted to vibrational/rotational energy within the molecule 

leaving the scattered photon shifted to a slightly longer 

wavelength. The amount of this wavelength shift depends on the 

vibrational/rotational energy level structure of the particular 

molecule being excited and is unique to it. For a photo of 

certain incident wavelength, therefore, the shifted wavelength of 

the scattered photon is a signature of the molecule. Melfi 

(1972) has shown that the ratio of the Raman backscattered signal 

from water vapor to that of nitrogen is proportional to the water 

vapor mixing ratio, figure l., assuming that the atmospheric 

transmissivity at the two different wavelengths is the same. 

When performing water vapor measurements, we are able to acquire 

profiles of water vapor mixing ratio from near the ground to 

beyond 7 km every 2 minutes. By forming a color composite image 

of the individual profiles, the spatial and temporal evolution of 

water vapor is visible with vertical resolution of 75 - 150 

meters and temporal resolution of 2 minutes. During two 

intensive field missions in 1987, one at Greenbelt, Maryland the 

other at Falmouth, Massachusetts, we successfully measured the 

evolution of the water vapor structure during various 

meteorological significant events such as cold and warm frontal 

passages and atmospheric gravity waves. During both of these 

missions, we acquired at least a week of continuous nighttime 

data. 

The ozone lidar is intended for use as a cross-calibration 

180 
facility for other stationary ozone lidar systems. This new 

system is undergoing testing in anticipation of its first field 

deployment in July 1988, at Table Mountain, California to perform 

intercomparison measurements with a ozone lidar developed by JPL. 

The ozone measurement employs the technique known as differential 

absorption. The backscattered laser radiation from two different 

wavelengths is measured. One of these wavelengths is strongly 

absorbed by ozone while the other is essentially unabsorbed. By 

comparing the two return signals on a height-by-height basis, one 

can determine the absorption due to ozone and thus derive the 

ozone number density, figure 2. 

We have successfully measured 308 nm returns from 80 km with an 

averaging period of 6 hours. Using these data and a standard 

atmosphere density curve, we have derived an ozone number density 

profile which agrees very well with the standard ozone curve 

between 20 and 40 km. We will soon use the Nd:YAG 355 nm data to 

derive the actual density curve implementing the full 

differential absorption technique. 

181 

I 
2200 0o:oo o2:oo 04:OO 

. . . . . . . . 

0-2 4-6 8 - 10 12 - 14 

2-4 6 -8 10 - 12 14 - 16 

Figure 1. Water Vapor Mixing Ratio (g/kg) 

June 6 - 7, 1988 

182 
OZONE NUMBER DENSITY (CM**-3) 

March 28 - 29, 1988 

xl o1 2 

Figure 2. 

183 
ROCKET TEMPERATURE SOUNDINGS 

by 

F. J. Schmidlin (672) 

In situ rocket-borne measurements of temperature and wind 

contribute to a better determination and understanding of 

stratospheric behavior and, hence, to a better understanding of 

processes that control the dynamical and chemical behavior of 

this region. Rocket-borne measurements provide basic data for 

satellite validation and calibration over the short- and longterm, and for evaluation of new ground-based systems, such as 

lidar. Rocketsonde measurements are used for definitive, smallscale studies of atmospheric behavior and permit monitoring of 

changes occurring in the stratosphere. This long-term data set 

is of extreme value for depicting temperature trends and for 

their correlation with possible trends in the Earth's ozone 

shield. During 1986 and 1987, meteorological rocketsonde funding 

was only sufficient to permit a minimum number of launchings 

consistent with maintaining launch range expertise and 

capability. 

Concern over ozone depletion and the difficulty generally 

involved in determining actual ozone trends has generated 

significant interest in temperature behavior, especially trends. 

Recent analysis of rocketsonde acquired temperature data between 

1969 and 1986 contains evidence that the stratosphere may indeed 

be cooling. Preparation of material for contribution in the 

185 
Report of the Temperature Trends Committee estimates that this 

cooling trend is -0.2/0.3'C per year. Because the magnitude of 

this change is small compared to the magnitude of the 

measurement, the measurement system must possess the capability 

to provide high resolution. The precision of the present 

rocketsonde instrument is about 0.6/0.9"C for temperature and 

about 200-300 meters in the vertical between 20 and 55 

kilometers; this presently is better than the resolution of any 

other instrument providing stratospheric measurement data. While 

radiosondes provide more frequent measurements, their altitude is 

limited to below 30 kilometers. 

~ A lidar for measuring density (temperature) between 25 and 100 

kilometers (current capability is about 25 to 80 kilometers) 

under development at the Air Force Geophysics Laboratory was 

compared to meteorological rocketsonde measurements. This 

comparison took place at the Wallops Flight Facility (1985) and 

at the Poker Flat Research Range, Alaska (1986). The tests were 

successful: the comparison showed that substantial agreement 

exists between this lidar and the in situ data. As a result of 

these comparisons, lidar design improvements are expected. The 

lidar Principal Investigator has since moved to The Pennsylvania 

I State University and plans to continue the development of a 

stratospheric-mesospheric lidar. New comparisons are being 

considered. 

I 

I 

It is the intention of the RTOP to continue to provide 

I 186 
I rocketsonde measurements to: 1) maintain the long-term data 

stratospheric-mesospheric data base already established for 

Wallops: 2) provide ground truth for remote measurements; and 3) 

continue studies of atmospheric structure and morphology of 

disturbances and anomalous events as resources permit. 

187 
N8 9- 28 168 

ELECTRODYNAMICS, WIND AND TEMPERATURE 

F. J. Schmidlin (672) 

This RTOP provides for correlative meteorological wind and 

temperature measurements with atmospheric electrodynamic 

measurements. Meteorological rocketsondes have been launched as 

part of a number of electrodynamic investigations in Alaska, 

Norway, Peru, Sweden, and at the Wallops Flight Facility, Wallops 

Island, Virginia. Measurements obtained as part of the 

MAC/Epsilon campaign during October 1987 from Andoya, Norway, 

were in conjunction with electric field, ion mobility, 

conductivity, and energy deposition studies. Experimenters were 

from the GSFC, University of Denver, and The Pennsylvania State 

University. The measurements obtained between 30 and 90 

kilometers are to evaluate and correlate changes in the 

atmospheric electrical structure caused by the neutral wind and 

temperature, or changes in the neutral atmosphere resulting from 

electrical anomalies. Previous measurements have been obtained 

in connection with the occurrence of noctilucent clouds and 

thunderstorms. Future plans are to study neutral or electrical 

structure correlations in the above situations and to make wind 

and temperature measurements in conjunction with studies of polar 

mesospheric clouds. 

PRECEDIIuG PAGE BUNK NOT FlLHU) 

189 
RADIOSONDE INTERCOMPARISON 

by 

F. J. Schmidlin (672) 

NASA hosted Phase I1 of the World Meteorological Organization 

(WMO) International Radiosonde Intercomparison at the Wallops 

Flight Facility in February-March 1985. Phase I had taken place 

in June-July 1984 at Bracknell, United Kingdom. The comparison 

produced the largest amount of material ever collected from a 

radiosonde cornparison. Radiosondes from Australia, Finland, 

India, and the United States were involved. Data were received 

from 100 soundings, each of which was a simultaneous in situ test 

of four different instrument types. A fifth instrument was 

compared on a limited basis. This was the Graw M60 radiosonde 

manufactured in the Federal Republic of Germany and used by the 

United Kingdom. 

The simultaneous temperature comparison of participating 

operational radiosondes in daylight was about 1°C at the 100 hPa 

level and about 4°C at the 10 hPa level, while the corresponding 

comparison for geopotential was about 40 meters at 100 hPa and 

100 meters at 10 hPa. The uncertainty in the observations made 

using operational radiosondes is today at the 10 hPa level, in 

degrees and meters, roughly the same order as it used to be at 

the 100 hPa level 30 years ago. 

achievement are improved sensors, 

and, in particular, removal of, 

The main reasons for this 

receivers, data evaluation, 

or correction for, radiation 

l 

191 I 

PAGE BLANK NOT FILMED 
I errors of some of the instruments. 

I Estimates of the reproducibility of standard level temperatures 

are give in table 1. Table 1 also includes results from Phase I. 

The reproducibility obtained from the in situ comparisons is, in 

general, slightly better than corresponding results from 

monitoring measurements in a real-time mode at analysis centers. 

The Indian radiosonde, however, turned out to be considerably 

better in the instrument comparison than one might infer from 

I 

monitoring results. 

Conclusions from the intercomparison are many: the following call 

for particular attention: 1) fully automated radiosonde systems 

were able to reproduce geopotential measurements better than nonautomated systems, mainly due to a decrease in observer mistakes. 

2) Observed temperature differences between radiosonde 

measurements were as large during the night as during the day. 3) 

Significant inconsistencies still exist between the nighttime and 

daytime measurements, as well as significant bias errors in the 

pressur'e measurements of some radiosonde types. 

In addition, the Final Report recommends that manufacturers 

increase automation in order to minimize errors caused by manual 

treatment of chart records. Also, the automated systems must be 

provided with standardized instrumental correction procedures to 

avoid systematic errors. 

I 192 
Table 1 Estimates of the reproducibility of standard level 

temperature measurement in 'C. The estimates are 

for one standard deviation (Nash and Schmidlin, 

1987). 

Link Radiosonde 

Pressure FIN USA AUS FRG IND UK BEUK GRAW 

Level (hPa) 1,II 1,II 

1000 

900 

850 

700 

600 

500 

400 

300 

250 

203 

150 

100 

70 

50 

30 

20 

15 

10 

0.3 

0.2 

0.2 

0.2 

0.2 

0.2 

0.2 

0.2 

0.2 

0.2 

0.2 

0.2 

0.2 

0.3 

0.4 

0.5 

0.6 

1.0 

0.8,0.4 

0.4,0.2 

0.3,0.2 

0.3,0.2 

0.3,0.2 

0.3,0.2 

0.3,0.2 

0.3,0.2 

0.3,0.2 

0.3,0.2 

0.3,0.2 

0.3,0.2 

0.3,0.2 

0.6,0.3 

0.8,0.4 

1.0,0.5 

1.2,0.7 

1.5,1.2 

0.5 

0.4 

0.4 

0.4 

0.3 

0.3 

0.3 

0.4 

0.6 

0.8 

0.8 

0.8 

1.2 

1.2 

1.4 

1.6 

2.2 

3.0 

0.3 

0.2 

0.2 

0.3 

0.3 

0.3 

0.4 

0.4 

0.4 

0.4 

0.5 

0.5 

0.5 

0.5 

1.0 

1.5 

2.0 

2.5 

0.7 

0.7 

0.7 

0.7 

0.7 

0.7 

0.7 

0.7 

0.7 

0.7 

0.6 

0.6 

0.7 

0.8 

1.0 

1.5 

2.0 

2.5 

0.3 0.4 

0.2 0.3 

0.2 0.4 

0.2 0.3 

0.2 0.3 

0.2 0.4 

0.2 0.4 

0.2 0.5 

0.2 0.6 

0.2 0.7 

0.2 0.8 

0.2 0.9 

0.2 1.0 

0.3 1.2 

0.4 1.4 

0.5 1.6 

0.6 1.8 

1.0 2.0 

0.5 

0.4 

0.4 

0.4 

0.3 

0.4 

0.4 

0.5 

0.5 

0.6 (0.5) 

0.8 (0.5) 

1.0 (0.5) 

1.3 (0.7) 

1.5 (1.2) 

2.0 (1.2) 

2.0 (1.2) 

2.5 (1.5) 

4.0 (1.5) 

Estimates for the USA and Finland reproducibility differ from 

Phase I to I1 as indicated. Bracketed estimates for Graw are 

for nighttime flights only. 

193 
3189-2'8119 

SATELLITE/RADIOSONDE COMPARISON 

F. J. Schmidlin (672) 

Cokocated measurements of radiosonde and TIROS Operational Vertical 

Sounder (TOVS) data are compared to determine whether significant 

latitudinal, seasonal, or instrumental biases exist. Long-wave 

structure determined by each system is being examined for 

correlation. Because US radiosonde data are archived uncorrected, an 

L 

1 

effort to correct the measurements based on the radiative corrections 

being developed under RTOP 146-71-06 is being considered. These 

corrections will be applied to 7 years of measurements. New 

comparisons will then be made using corrected radiosonde and TOVS 

data. A regression method is used to retrieve temperatures, and 

radiosonde zonal means are used to update the regression 

coefficients. Preliminary results of auto-correlation analysis 

indicate that detection of long-wave structure in each set of data is 

slightly different with some levels and locations experiencing 

different wave periods or amplitudes. Scatter diagrams and linear 

regression for each layer show bias in the mean temperatures. 

Winter-time measurements show poorer correlations due to noisy 

measurements. 

Studies planned under this RTOP were delayed over 9 months waiting 

for contract approvals. The contractor began algorithm development 

in January and plans to have an operational analysis program 

completed by late AprilPRECEDiNG PAGE BUNK NOT FILMED 195 
N8 9- 2 8 17 1 

TROPOSPHERIC NITRIC OXIDE MEASUREMENTS 

by 

A. L. Torres (672) 

Nitric oxide (NO) plays a key role in tropospheric photochemistry. The photochemical oxidation of hydrocarbons, for 

example, can serve as either a source or a sink for ozone, 

depending on the local abundance of NO. Nitric oxide also 

helps govern atmospheric concentrations of the hydroxyl (OH) 

radical. The OH radical is the single most important player in 

photochemical transformations because it controls the atmospheric 

lifetimes of so many chemical species. 

Although NO serves as a very effective catalyst in many important 

chemical processes, its concentration is low enough to normally 

be expressed in units of parts per trillion by volume (pptv). 

Consequently, commercially available detectors for NO (with 

detection limits of about one part per billion) have proven to be 

unsuitable for use anywhere except in urban areas and near other 

local pollution sources. Under the sponsorship of NASA's Global 

Tropospheric Experiment (GTE), Wallops has developed an extremely 

sensitive detector with a detection limit of a few pptv. The 

system was specifically designed for aircraft use, with the 

objective of applying it in global aircraft studies of 

-- 

tropospheric chemistry. 

The Wallops instrument has logged several hundreds of flight 

197 
hours on NASA aircraft, primarily through participation in 

various GTE missions. These include the Chemical Instrumentation 

Test and Evaluation (CITE-1) missions aimed at demonstrating NO 

measurement capabilities, the CITE-2 mission to evaluate nitrogen 

I dioxide (NO2) sensors, and the Amazon Boundary Layer Experiments, 

(ABLE-2A and ABLE-2B). 

recent mission 

1987. This 

I The most 

May of 

troposphe 

was ABLE-2B which took place in Aprilmission was designed to investigate 

-ic chemistry c Ter tropical rain forests during the wet 

season, and complemented the results obtained during the ABLE-2A 

dry-season mission. Daytime mixing ratios of NO over the Amazon 

Basin during this mission were among the lowest ever observed 

over continental areas. The NO mixing ratio averaged 12 pptv for 

altitudes below 0.3 km and 6 pptv at higher altitudes. These 

concentrations bracket the level above which tropospheric 

photochemistry is expected to produce rather than consume ozone. 

During the dry season, 25-60 pptv was found at the lower 

altitudes, and 10-12 pptv were common at the higher altitudes. 

The higher values observed during the dry season reflect a 

combination of more biomass burning and more active soilproduction of NO. 

Planning is now underway to develop techniques for measuring 

other nitrogen species such as NO2 and total reactive nitrogen. 

198 
N8 9- 28 172 ‘I 

CLOUD ABSORPTION RADIOMETER 

BY 

M. G. Strange (674) 

The Cloud Absorption Radiometer (CAR) was developed with 

Director’s Discretionary Funding in 1983-84 for Dr. Michael King, 

Code 615, and has been flown successfully many times aboard the 

University of Washington‘s C-131 cloud physics airplane under a 

National Science Foundation grant. Its purpose is to measure 

spectrally how light is scattered by clouds and to determine the 

single scattering albedot1, important to meteorology and climate 

studies, with unprecedented accuracy. This measurement is based 

on ratios of downwelling to upwelling radiation within clouds, 

and so is not strongly dependent upon absolute radiometric 

calibration of the instrument. 

The CAR has a 5-inch aperture and 1 degree IFOV, and spatially 

scans in a plane orthogonal to the flight vector from the zenith 

to nadir at 1.7 revolutions per second. Incoming light is I 

measured in 13 spectral bands, using silicon, germanium, and 

indium-antimonide detectors. Data from each channel is digitally 

recorded in flight with 10-bit (0.1%) resolution. 

The instrument incorporates several novel features. Since it is 

flown through clouds, moisture may occasionally collect on the 

scan mirror, producing an error. To test for water on the 

mirror, a thin beam of light reflected from the edge of the 

mirror is monitored by a photodiode. Any fogging of the mirror 

199 
scatters the light beam, reducing the specular component detected 

by the photodiode and flagging any stretches of faulty data. 

Another feature ensures that a zero-radiance input always 

produces a zero-volt output without the complication of a fast 

radiation chopper. It works by serving the output to zero during 

each backscan while the detectors are all completely darkened by 

means of a shutter. Data taken during the active portion of the 

scan is then measured with respect to this zero reference level. 

A third feature compensates instantaneous scan angle for up to 

5 degrees of aircraft roll by using a vertical gyro to correct 

the scanner’s time-base. 

Papers published to date on the CAR are as follows: 

1. King, M. D., P. V. Hobbs, and L. F. Radke, 1987: 

Determination of Uncertainty Parameters of Clouds from Airborne 

Measurements of Scattered Radiation Within Clouds, Proc. Beiinq 

Intl. Rad Svmp., Bejinq, PRC. 

2. King, M. D., M. G. Strange, P. Leone, and L. R. Blain, 1986: 

Multiwave Scanning Radiometer for Airborne Measurements of 

Scattered Radiation Within Clouds, J. Atmos. and Oceanic Tech., 

513-522. 

3. King, M. D., 1981: A Method for Determining the Single 

Scattering Albedo of Clouds Through Observation of the Internal 

Scattered Radiation Field, J. Atmos. Sci., 38, 2031-2044. 

4. Radke, L. F., M. D. King, and P. V. Hobbs, 1986: 

Preliminary Measurements of the Cloud Single Scattering Albedo 

and Interstitial Aerosol from an Aircraft, Proc. Ninth Intl. 

Cloud Phvs. Conf., Tallinn, Estoria, USSR. 

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N89- 28173 

The Laboratory For Oceans Computing Facility 

by 

R. Kao (670.1) 

The first VAX computer in the Laboratory for Oceans Computing 

Facility (LOCF) was installed in April 1986 and the facility has 

been largely expanded since then. The growth is not only in 

hardware and software, but also in the number of users and in 

supporting R 61 D projects. The LOCF serves as a general purpose 

computing facility for Code 670 projects. These are: ocean color 

research projects, sea ice research projects, processing of the 

Nimbus-7 Coastal Zone Color Scanner data set, real-time ingest 

and analysis of TIROS-N satellite data, study of the Synthetic 

Aperture Radar data, study of LANDSAT data, and many others. 

The physical space and the electrical power layout of the 

computing room were modified to accommodate all the equipment. 

The facility now has one VAX-11/750 computer, three MicroVAX I1 

computers, and a variety of peripherals. All the computers are 

'clustered' using Local Area VAXcluster technology of Digital 

Equipment Corporation for resource sharing such as sharing local 

disk drives and line printers. All the computers are also on the 

SPAN network so that information exchanges with outside 

communities are convenient. The system configuration diagrams 

are shown in Figures 1 and 2. Currently, we are in the process 

of connecting Code 670 investigators' IBM personal computers to 

the network. This provides a rapid means of accessing data on the 

PRECEDING PAGE BLANK NOT FILMED 

-204 jirMdm 

205 
I LOCF computers. 

The LOCF has several image processing stations which include two 

International Imaging Systems (11s) model 75 processors and one 

Adage processor. An IIS IVAS image processing workstation is on 

order. The facility now has disk farms of the capacity of 7.6 

GBytes and more disks will be added to the system. Additionally, 

the LOCF has Sony optical disk drives for large data set storage 

and archival. 

The facility has the capability of ingesting the TIROS-N HRPT 

satellite data on a real-time basis. 

More than 30 software packages have been installed on the 

systems. System software packages, network software, FORTRAN and 

C compilers, database management software, image processing 

software, graphics, mathematics and statistics packages, TAE, 

I Catalog Manager, GEMPAK, LAS and many other software developed on 

the LOCF computers such as SEAPAK have greatly advanced the 

capability of the LOCF. 

The LOCF coordinates vendors to give either a presentation or a 

demonstration of their products should there are interest from 

the user groups. Examples are: Sony optical disks, RCA Domsat 

capability, INMARSAT communication, 11s image processors, SEICO 

color copiers, a VHS data tape unit. The facility also arranges 

courses when needed. A TAE class was held for the LOCF users. 

206 
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~89-28174 ' 

Code 672 Observational Science Branch Computer Networks 

D. W. Hancock and H. G. Shirk (672) 

In general, networking increases productivity due to the speed of 

transmission, easy access to remote computers, ability t.0 share 

files, and increased availability of peripherals. Two different 

networks within Code 672 Observational Science Branch are 

described below. 

The Observational Science Branch Local Area Network (OSBLAN) 

supports a Gould PowerNode 6000 super-minicomputer, two Sun workstations, and a PC network consisting of MS-DOS personal computers (Figure 1). OSBLAN uses the Transmission Control Protocol/ 

Internet Protocol (TCP/IP) on Ethernet cabling and is bridged in 

turn to NFSNET/ARPANET at GSFC via a Proteon gateway machine. 

The Gould and Suns run under Unix operating systems that support 

NFS (Network File Sharing). OSBLAN PC systems use the Sun 

Microsystems PC-NFS network software for DOS. PC-NFS uses the 

central-server approach to networking which means that all 

network PCs share disk space on a central server system, currently the Gould. Users share and exchange files with little 

effort, and remote logins and file transfers to computers on the 

network are easily achieved. Output data can be spooled to one 

of four printers on the OSBLAN. h user does not see the difference between his files being on a local physical hard disk or on 

the file server disk. The files on the server can be easily 

209 
accessed by other users by the permissions given. DOS files can 

be converted to Unix and Unix files to DOS by provided utilities. 

Sun local disk files are backed up using the Gould tape unit. 

The PC local disk can be copied to the Gould and then backed up 

on 9-track tape. From OSBLAN, users can exchange data with computers on the three major Wide Area Networks (WANs) : ARPANET, 

BITNET, and DECNET. Data to the Division 670 Vax computer at GSFC 

can be exchanged over the network. NASAMAIL and GSFCMAIL can be 

sent from any computer on the network. The communication with the 

WANs uses the Proteon gateway with a 9.6 kilobaud direct line. 

A second network, the TOPEX-MORAR Network (TMNet) connects 

MacIntosh and MS-DOS personal computers (Figure 2). TMNet is 

configured in an active star topology and was implemented by 

using the old ATtT phone lines that existed in the E-106 building. The network allows MacIntosh and MS-DOS computers to share 

disk space, transfer and translate files, and use network output 

devices. Network output is currently handled by an Apple 

Laserwriter Plus with a second laser printer on order. The TMNet 

uses TOPS for its network software and AppleTalk cable connection. TOPS is a distributed server network which means any connected system can be a file server with each user deciding what 

files to make available on the network. TOPS works transparently, therefore, the network files look like MacIntosh files on 

the MacIntosh and MS-DOS files on PCs. TOPS comes with translators for the 

In the future, 

using a Kinetic 

21 0 

most popular MS-DOS and MacIntosh file formats. 

plans are to bridge the TMNet to the OSBLAN by 

Fastpath machine. 
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Many researchers in the Division have projects which require 

transferring large files between their personal computers (PC) 

and VAX computers in the Laboratory for Oceans Computing Facility 

(LOCF). Since Ethernet local area network provides high-speed 

communication channels which make file transfers (among other 

capabilities) practical, we have put together a network plan to 

connect IBM and IBM compatible PC's to Ethernet for participating 

personnel of Code 670 in building 22. 

Our design employs Thinwire Ethernet technology. A simplified 

configuration diagram is shown in .figure 1. A DEC multiport 

repeater (DEMPR) is used for connection of Thinwire Ethernet 

segments. One port of DEMPR is connected to a H4000 transceiver 

and the transceiver is clamped onto the Goddard Ethernet 

'backbone' coaxial cable so that the PC's can be optionally on 

the SPAN network. All these 'common' elements have been 

successfully installed and tested. 

The components needed for each PC to access the network are: a PC 

Ethernet controller and communication software. We have put 

together 'mass' buys for these items and have received all the 

components. A few PC stations have been connected to the network 

and have functioned very satisfactorily. In addition to 

providing fast file transferring between two modes, the software 

213 
also supports task-to-task communications, network resource 

sharing, remote file access, and utilities for network file 

operations. We are now in the process of stringing cables to 

connect all other PC stations to the network. 

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N89- 28176 

THIRD INTERNATIONAL SATELLITE DIRECT BROADCAST 

SERVICES USER'S CONFERENCE 

by 

J. Kamowski, C. Vermillion (670.1) 

A workshop titled, IIThe Third International Satellite Direct 

Broadcast Services User's Conference, jointly sponsored by NASA 

and NOAA/NESDIS is scheduled to be held June 20-24, 1988, at the 

International Hotel located at the Baltimore-Washington Airport. 

It is anticipated that attendance will exceed 400 persons from 

many countries throughout the world. A call for papers has been 

issued, with responses from Japan, Poland, England, Canada, and 

Barbados as well as the United States. 

Non-contributing associate sponsors include, European Space 

Agency, Japan Meteorological Agency, U.S. Department of 

Agriculture, U.S. Agency for International Development, U. S. 

Geological Survey, and the World Meteorological Organization. It 

is anticipated that additional sponsors will join, lending their 

names, distribution facilities, and expertise to the conference. 

Well known speakers have consented to address the audience from 

such organizations as, NASA Headquarters; Department of Commerce; 

NOAA/NESDIS; United Nations; European Space Agency; Japan 

Meteorological Agency; World Meteorological Organization; United 

Kingdom; Institute of Meteorology and Water Management; Krakow, 

Poland; Institute of Industrial Science; University of Tokyo; and 

217 

PRECEDING PAGE BLANK NOT FILMED 
Japan Broadcasting Corporation, Japan: University of Dundee, 

United Kingdom; Atmospheric Environment Service, and MacDonald 

Dettwiler, Canada; are but to name a few, in addition to the many 

U.S. organizations. Mr. Adigun Ade Abiodun, an expert on space 

applications from the United Nations in New York will be the 

keynote speaker. 

Several manufacturers of satellite related products have 

exhibited their desires to attend displaying their wares. 

218 
I ii' 

N89-28177 

LOW COST REAL TIME INTERACTIVE ANALYSIS SYSTEM 

F. Stetina (670.1) 

Efforts continue, to develop a low cost real-time interactive 

analysis system for the reception of satellite data. A 

multi-purpose ingest hardware software frame formatter has been 

demonstrated for GOES and TIROS data and work is proceeding on 

extending the capability to receive GMS data. A similar system 

has been proposed as an archival and analysis system for use with 

INSAT data and studies are underway to modify the system to 

receive the planned SeaWiFS (ocean color) data. This system 

has been proposed as the core of a number of international 

programs in support of U.S. AID activities. The following 

systems have been delivered or are nearing final testing: 

o NOAA-SOCC -for the analysis of TIROS instrument 

o GSFC-(612) -real time GOES reception for severe storms 

performance 

research 

0 U.S. AID 

Fiji Islands-GMS real time reception for disaster 

warning system in Southwest Pacific 

0 U.S. AID 

Bangladesh -Agro-Climatic and Economic Development 

Program 

Systems under development 

o NSF/NOAA/NASA-INSAT data archival and analysis system 

o NASA/EOSAT -Real time reception of Seawifs ocean 

0 EOS/NASA -Studies have been initiated for a real 

color data 

time system for EOS polar platform research 

data. 

219 
Software Development: 

A substantial amount of work has been directed toward improving 

software application programs; these have been in support of the 

Bangladesh and Fiji science applications training activities and 

include: Agro-Meteorology, Hydrology, Meteorology (Severe storms 

and TOVS) and Satellite Oceanography. 

In addition, important software packages have been received from 

the National Weather Service (SLOSH) and the Federal Emergency 

Management Agency (IEMIS), and are being integrated into existing 

software systems to become the basis of a disaster warning and 

economic development program spatial analysis and modeling system 

for Third World countries. 

This software development activity will be directly applicable to 

the development of Eos data systems and data exchange programs 

involving the use of Eos real time data from the international 

community. 

I 220 
INSTRUMENTATION I 

I 
NAVIGATIONAL AND ENVIRONMENTAL MEASUREMENT 

by 

T. D. Clem (672) 

SYSTEM (NEMS) 

The NEMS concept and design were initiated from the need to 

measure and record positional and environmental information 

during aircraft flights of developmental science research 

instrumentation. The unit was designed as a stand-alone system 

which could serve the needs of instruments whose developmental 

nature did not justify the cost and complexity of including these 

measurements within the instrument data system. Initially, the 

system was comprised of a Loran-C receiver and a portable IBM 

compatible computer recording position and time. Later, the 

system was interfaced with the Wallops aircraft inertial 

navigation system (INS), and various other sensors were supplied 

and shared by the Goddard science users. Initial development was 

supported by various Code 600 users. During 1986 and 1987, the 

Wallops Aeronautical Programs Branch (Code 831) supported 

development and equipment purchases. Real-time position mapping 

on video monitors was added for investigator's use and 

information. In 1987, the use of a Global Positioning System 

(GPS) receiver was included in some missions. 

General System DescriDtion 

Figure 1 shows a total configuration of the system and the 

various sensors which can be incorporated. These sensors are 

added or deleted as required for a particular mission. The 

223 

PRECEDING PAGE BLANK NOT FILMED 
system and sensors are a single stand-alone unit moved from 

aircraft to aircraft as required. The following information is 

among that which can be sensed and recorded by the system: 

I 

Time - GMT or Local 

Aircraft Latitude and Longitude Loran-C 

Aircraft Latitude and Longitude from the aircraft INS 

Aircraft Latitude, Longitude, and Altitude from GPS 

Aircraft ground speed 

Aircraft Flight track 

Aircraft (or instrument) roll and pitch angle 

Outside total air temperature 

Outside air pressure (with standard altitude calculated) 

10) Outside air dew point 

I 11) Nadir thermal irradiance 

12) Vertical acceleration 

224 
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N89-281181’/”- 

AIRBORNE LIDAR GLOBAL POSITIONING INVESTIGATIONS 

by 

W. B. Krabill (672) 

The Global Positioning System (GPS) network of satellites shows 

high promise of revolutionizing methods for conducting surveying, 

navigation, and positioning. This is especially true in the case 

of airborne or satellite positioning. A single GPS receiver 

(suitably adapted for aircraft deployment) can yield positioning 

accuracies (world-wide) in the order of 30 - 50 m vertically, as 

well as horizontally. This accuracy is dramatically improved 

when a second GPS receiver is positioned at a known horizontal 

and vertical reference. Absolute horizontal and vertical 

positioning of 1 to 2 meters are easily achieved over areas of 

separation of tens of kilometers. If four common satellites 

remain in lock in both receivers, then differential phase 

pseudo-ranges on the GPS L-band carrier can be utilized to 

achieve accuracies of +/- 10 cm and perhaps as good as +/- 2 cm. 

The initial proof of concept investigation for airborne 

positioning using the phase difference between the airborne and 

stationary GPS receivers was conducted at the NASA/GSFC/Wallops 

Flight Facility (WFF) by scientists from the NOAA National 

Geodetic Survey (NGS) and the Airborne Oceanographic Lidar (AOL) 

group. The single flight experiment was conducted in August 1986 

over the Chincoteague Bay located near WFF. The precise laser 

ranging capability of the AOL system was used to measure the 

relative accuracy of the aircraft height determined from tracking 

227 

PtiECU;)fi\fG PAGE BUM# NOT FILMED 
the phase differences between the stationary and aircraft mounted 

GPS receivers. The GPS ellipsoid height estimates are shown 

compared on a gross scale with the AOL altitude measurements in 

figure 1. is 

shown in figure 2 after removal of the obvious bias in figure 1. 

The results from the flight experiment demonstrated that relative 

decimeter positioning is already achievable. 

An expanded view of a portion of the comparison 

Following these initial investigations with aircraft GPS 

receivers, two Motorola Eagle GPS receivers were obtained by the 

Laboratory for Oceans and Ice. The Eagle receivers have an 

improved once per second update rate compared to the once per 

three second update rate of the TI receivers used in the earlier 

NASA/NOAA flight tests. Within a few days of receiving the GPS 

units, they were deployed in the NASA Arctic Ice Experiment 

conducted during May 1987. During this experiment, both of the 

receivers were operated as airborne units and used to ensure that 

the aircraft remained within +/- 1.5 km of the intended flight 

track so that comparisons with contemporaneous SAR (obtained from 

a different aircraft) and submarine up-looking sonar observations 

would be possible. The GPS positional measurements are currently 

being utilized together with aerial photography to register the 

independent data sets. Also, the vertical control afforded by 

the GPS receivers is being used to remove aircraft vertical 

motion from the laser profiling record so that detailed ice 

topographic features can be statistically analyzed. A section of 

the ice topography is shown in figure 3 where first year and 

multi-year ice with obvious ridging can be seen. 

228 
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Figure 1. Figure 2. 

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Figure 3. 

229 
MICROWAVE REMOTE SENSING OF SOIL MOISTURE 

N89-28180 ih 

by 

J. C. Shiue and J. R. Wang (675) 

Knowledge of soil moisture is important to many disciplines, such 

as agriculture, hydrology, and meteorology. Soil moisture 

distribution of vast regions can be measured efficiently only 

with remote sensing techniques from airborne or satellite 

platforms. 

At low microwave frequencies, water has a much larger dielectric 

constant than dry soil. This difference manifests itself in 

surface emissivity (or reflectivity) change between dry and wet 

soils, and can be measured by a microwave radiometer or radar. 

The Microwave Sensors and Data Communications Branch is 

developing microwave remote sensing techniques using both radar 

and radiometry, but primarily with microwave radiometry. Our 

efforts in these areas range from developing algorithms for data 

interpretation to conducting feasibility studies for space 

systems, with a primary goal of developing a microwave radiometer 

for soil moisture measurement from satellites, such as Eos or the 

Space Station. A proposal to develop a synthetic aperture 

radiometer for soil moisture observation from Eos polar platform 

is being prepared from our group. (See separate element under 

ESTAR by D. Levine) 

We started in soil moisture research by making truck-based 

measurements of emissivities of bare and vegetation covered 
I agricultural fields to establish the basic algorithms for data 

interpretation. We studied the synergistic aspects of soil 

moistures as measured by both an L-band microwave radiometer 

(LBMR) and an L-band synthetic aperture radar (SAR) from the 

Space Shuttle. We also conducted airborne experiments of soil 

moisture with an LBMR in the Eastern Shore of Maryland, western 

high plains of Texas, and southern France (HAPEX) *. We studied 

(in cooperation with Hughes Aircraft and G.E.) the feasibility of 

building an LBMR with a 10 meter real-aperture, electronically 

scanning array. 

In 1987, we participated in the FIFE** remote sensing experiment 

over the Konza Prairie in Kansas, and made a time series 

measurement of the area’s soil moisture changes with an LBMR from 

aboard the NASA C-130. We are processing and analyzing the data 

from the flight experiments. Figures 1 and 2 are some 

preliminary results from the FIFE flights. Figure 1 is a 

comparison between soil moistures retrieved from the airborne 

LBMR to soil moistures obtained from direct in-situ probes. This 

figure establishes that, except for a small bias, the retrieved 

soil moisture correlates very well with the ground truth, showing 

the maturity of this obsenration technique. The real power of 

this technique is in its ability to map areal distribution of 

soil moisture. Figure 2 shows soil moisture contours of a small 

water shed, about 1 km by 1.5 km in size. The data represent a 

saturated soil moisture condition, shortly after a storm. 

I 

232 
We will be back to flying over the Konza Prairie again in 1988 to 

study the change in emissivity of the area, after some part of 

the Konza's grassland is burned as a part of the special research 

treatment. During May of 1988, J. R. Wang will be participating 

in an aircraft experiment to study the use of synthetic aperture 

radars to measure soil moisture and vegetation of agricultural 

fields in the San Juanquin Valley of California. 

* : HAPEX = Hydrologic and Atmospheric Pilot Experiment ** : FIFE = First ISCLSCP *** Field Experiment *** : ISCLSCP = International Satellite Land Surface Climatology Program 

233 
0 In 

0 

rt 

0 

(3 

0 

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234 
Figure 2. 

ORIGINAL PAGE 

BLACK AND WHITE PHOTOGRAPH 

235 
SYNTHETI( YU 3 APERTURE MICROWAVE RADIOMETER 

by 

D. M. Le Vine (675) 

Realizing the full potential of microwave remote sensing from 

space requires putting relatively large antennas in orbit. For 

example, in order to measure soil moisture, an important element 

in the global hydrologic cycle, an antenna on the order of 20 

meters on a side would be required in space as part NASA,s Earth 

Observing System (Eos) . Research is being conducted to develop 

synthetic aperture antennas to reduce the physical collecting 

area required of sensors in space, and to possibly open the door 

to new applications of microwave remote sensing. 

The technique under investigation involves using a correlation 

interferometer with multiple baselines and is similar to "earth 

rctation synthesisIf developed in radio astronomy. In this 

procedure the product of the voltages from a pair of antennas is 

measured coherently (amplitude and phase are detected). This 

correlation is proportional to the Fourier spectrum of the scene 

evaluated at a frequency which depends on the spacing between the 

antennas. By making measurements at many spacings, one can "maptf 

the spectrum, and then the scene itself can be obtained by taking 

the inverse Fourier transform. The important consideration for 

remote sensing purposes is that the resolution obtained depends 

on how well the Fourier spectrum has been sampled (i.e., on the 

distribution of baselines at which measurements have been made) 

and not on the size of the antennas actually employed in these 

--- 
measurements. Thus, one can use small antennas with measurements 

at many baselines and achieve the resolution of a single antenna 

with a much larger aperture. 

The Microwave Sensors and Data Collection Branch has been engaged 

in research to develop this technique for applications to remote 

sensing of soil moisture from space. Soil moisture is important 

for agricultural applications and for understanding the global 

hydrologic cycle. 

We now have an aircraft prototype of an instrument suitable for 

making such measurements. This is an L-band radiometer called 

ttESTARtt which we hope will become part of the Earth Observing 

System (Eos). ESTAR is a hybrid instrument which uses both real 

aperture antennas (long sticks to obtain resolution in the alongtrack dimension) and aperture synthesis (correlation between 

sticks to obtain resolution in the cross track dimension). The 

hybrid was chosen as a compromise to increase the sensitivity (T) 

of the instrument. 

ESTAR made its maiden flight in February 1988, aboard the NASA P3 out of Wallops Flight Facility. We hope to be making soil 

moisture measurements over test fields by the end of the Summer 

1988. 

This research is a cooperative effort involving the Goddard Space 

Flight Center, the Microwave Remote Sensing Laboratory at the 

University of Massachusetts and the Hydrology Laboratory of the 

U. S. Department of Agriculture. 

2 38 
~89-28~~' 

RADAR SCATTERING AND SOIL MOISTURE 

by 

D. M. Le Vine (675) and P. 0. Neil1 (624) 

Research is being conducted on microwave scattering from 

vegetation. The objective is to develop techniques for measuring 

parameters of the vegetation canopy (such as biomass) needed for 

understanding global biogeochemical cycles and to develop 

techniques for correcting microwave measurements of soil moisture 

for the effects of the vegetation canopy. Measurements of 

vegetation and soil moisture are important for understanding the 

environment on a global scale. For example, moisture in the soil 

is an important, highly variable, element in the global 

hydrologic cycle. The hydrologic cycle, in turn, is strongly 

coupled to weather and climate through moisture (and energy) 

fluxes at the surface. The amount and distribution of vegetation 

is an important element in biogeochemical cycles; and knowledge 

of both the vegetation canopy and soil moisture is of practical 

importance in agricultural management. 

This research is a cooperative effort involving the Microwave 

Sensors and Data Communication Branch (Code 675) and the 

Hydrological Sciences Branch (Code 624) at Goddard and the 

Hydrology Laboratory at the U. S. Department Agriculture and the 

Department of Electrical Engineering at the George Washington 

University. Significant progress has been made in developing 

theoretical models for propagation and attenuation in the 

239 
vegetation and this theory is being tested using microwave radars 

and radiometers at specially prepared fields at the nearby USDA 

Research Center in Beltsville, Maryland. 

The theoretical work is based on a discrete model for the 

vegetation. In this approach, the vegetation is modelled as a 

random collection of individual objects (e.g., leaves and stems) 

and the solution is expressed in terms of the scattering 

amplitude and the location and orientation of the individual 

objects. The approach depends on having accurate models for the 

scattering amplitude of the individual objects but has the 

advantage that the results are expressed in terms of quantities 

such as plant geometry and orientation statistics which are 

easily related to the biophysical parameters of the individual 

plants. The Goddard research team has had significant success 

using rods and disks to model the plant parts (leaves and stems) 

and employing a distorted Born approximation to treat the 

multiple scattering problem. Inversion algorithms for the plant 

parameters have recently been developed using these solutions. 

The experimental work is designed to test the theory and verify 

the inversion algorithms. This is being done with a three 

frequency radar (L- C- and X-band) which makes measurements at 

several polarizations (HH, W and HV) as a function of incidence 

angle. This radar was designed for GSFC by the Texas A & M 

University and is in its first season of operation. The crop 

most studied to date has been soybeans. Studies have been made 

240 
to determine plant geometry and orientation statistics needed for 

the models and microwave radiometric measurements have been made 

over the canopy and are being compared with theory. Combined 

radar and radiometric measurements are being prepared for the 

coming season (Summer 1988). 

241 
ADVANCED SOLIDSTATE ARRAY SPECTRORADIOMETER 

by 

F. G. Huegel (674), J. Irons (623) 

During the Summer of 1987, the Advanced Solidstate Array 

Spectroradiometer (ASAS) was installed and flown on the NASA Ames 

C130 in support of the First International Field Experiment 

(FIFE) missions. The study site was over the grassland areas of 

the Konza Prairie in Kansas. The data collected with ASAS during 

these flights has been used to produce the first nearly 

simultaneous multiangular/multispectral images of selected 

terrestrial study sites. This data will be valuable in the study 

of surface bidirectional reflectance and albedo. The data will 

also be useful for the development of data analysis algorithms 

for future spaceborne instruments such as the Goddard MODIS-T and 

JPL's HIRIS. 

The ASAS is an airborne imaging spectrometer with 30 spectral 

channels extending from 450 to 880 nm. The sensor is capable of 

pointing up to 45 degrees fore and aft of nadir during flight. A 

conceptional drawing of the ASAS optical system is shown in 

Figure 1. The reflected solar radiance from a line of 512 pixels 

at right angles to the aircraft direction of flight is imaged by 

the collecting optic onto the entrance slit of a spectrometer. 

Located at the focal plane of the spectrometer is a 512 X 32 

element silicon CID detector array. Thus, each of the 512 surface 

pixels is dispersed into 32 spectral channels. The ASAS image is 
formed in the pushbroom fashion. This has the advantage of 

essentially no moving parts and the dwell time for each pixel is 

(in this case) at least 512 times greater than can be achieved 

with a scanning system having a single detector element. The 

I 

, field of view is 25 degrees and the IFOV is 0.85 mr. 

Originally, the ASAS sensor was mounted on a baseplate in a fixed 

nadir viewing position. In 1985, a pointable mount for the sensor 

was developed at GSFC that allows the ASAS to view an area on the 

surface at several angles fore and aft of nadir during a single 

airborne overpass of the site. The ASAS sensor and a color video 

camera are boresighted on a gimballed platform that is driven by 

a DC motor via a worm gear and worm wheel as shown in Figure 2. 

I 

~ 

I Typically, the target site is imaged at seven angles starting at 

I +45 of nadir and ending at -45 with images acquired at 15 degree 

I 

increments. The image size is typically 512 elements by 300 scan 

1 ines . 

In preparation for the FIFE flights, in 1987, a major effort was 

initiated to redesign and rebuild most of the ASAS sensor 

electronics. This was done to improve the stability of the array 

radiometric response and increase the reliability of the 

instrument. As a result of this effort the instrument operation 

was trouble free for the entire five months and 23 flights that 

it was in operation on the C130 and the instrument radiometric 

stability was on the order of 0.3%. Additional flights of the 

ASAS are planned for the summer of 1988 over forest areas in 

Minnesota. 

244 
Figure 1. ASA Optical Concept 

Figure 1. ASA Sensor 

34 5 
AGRICULTURE MULTIBAND EXPERIMENT RADIOMETER 

by 

W. H. Jones (674), J. Schutt, B. Holben (623) 

Agriculture Multiband Experiment Radiometer (Amber) was designed 

and built in 1979-80 and deployed in 1981. It consists of 15 

independent radiometers, 10 with silicon detectors and 5 with 

lead sulfide detectors. The spectral range of the instrument is 

from 250 to 2500 nanometers. The 15 collimators are mounted 

parallel to one another and are contained in a rectangle of 5 by 

18 inches. Amber is suspended from a boom which is mounted on a 

pick-up truck. Amber was designed to simultaneously measure 

sunlight reflected from vegetation in 15 optical bands. In 1982, 

program interest shifted from ground truth to satellite image 

reduction and Amber was retired. Early in 1987, the project 

scientists concluded that Amber, because of its 15 simple and 

independent optical systems, would be ideally suited to study 

polarized light. 

The following changes were made to add polarimeter capability to 

the instrument: 

(1) Amber was designed to down at vegetation, within 45 degrees 

of the vertical. The scientist required upward looking 

capability as well with near 4 pi steradian coverage. The boom 

was modified to allow greater than 3 pi steradian coverage. 

(2) The 5 lead sulfide detectors were not required and were 

removed along with their associated thermoelectric coolers to 

compensate for the added weight of the boom mechanism. 1 

I 

24 7 
(3) Five optical filters corresponding to thematic mapper channel 

3 (690 nm) and five optical filters corresponding to thematic 

mapper channel 4 (820 nm) were installed. 

(4) Mounts to hold two polarizing filters (one linear and one 

circular) for each channel were built, and installed with the 

filters. 

(5) Amber has a 24 degree field-of-view. Since the polarimeter 

is required to look near the sun, a longer collimator was 

,required with a narrower field-of-view. The collimators were 

extended .three inches and the field-of-view reduced to eight 

degrees. 

This work was completed and the instrument deployed in late 

August of 1987. We supported the field effort through late 

November. Presently we are: 

(1) Designing a shutter mechanism so that the detector dark 

current can be measured, allowing greater accuracy at low signal 

levels. 

(2) Selecting and installing new preamplifiers with lower offset 

drift to allow even lower signal levels to be detected. 

This summer after the above work is complete, we plan to design 

an automated data collection system. This system will collect 

and store the data and electronically transfer data to mainframe 

computers at Goddard. Next year, the emphasis will be to 

increase the data acquisition speed of the instrument. Quicker 

collection of 4 pi steradian data sets is desirable. The 

capability to use Amber on aircraft will be a follow on 

requirement. 

248 
L. Ramos-Izquierdo, J. Bufton (674) 

K. Chanl 

The Laboratory for Oceans is currently working on the development 

of compact laser diode array (LD) pumped Nd:YAG lasers for use in 

space-based altimetry and ranging. Laser diode-array pumping \, 

technology promises to increase the electrical to optical 

efficiency of solid state lasers by an order of magnitude with a 

lifetime increase of nearly three orders of magnitude relative to 

today’s conventional flashlamp-pumped laser systems. The small 

size, efficiency, and ruggedness make LD-pumped solid state 

lasers ideal for space based applications. 

\ 

Under SBIR Phase I & 11, OSSA RTOP, and OAST RTOP funding, LDpumped, Q-switched Nd:YAG lasers are being developed by Lightwave 

Electronics of Mountain View, California. In an in-house RTOP 

effort, Ken Chan has designed and is currently testing, a novel 

multiple-pass LD-pumped Nd: YAG laser amplif ierl to increase the 

100 UJ output pulse energy of the Lightwave laser oscillator 

(Figure 1). Preliminary results have yielded a round trip 

amplifier gain of about 15% using 7 mJ LD-pump energy. This 

amplifier gain is mainly limited by the amount of LD pumping 

energy available and should increase when two new 10 mJ laser 

I( +I ,e : 

diode pump arrays replace the current ones. Analytical results 

indicate that with, for example, 40 mJ pump energy, a 4-paSS 

Nd:YAG amplifier could amplify the 100 UJ pulse energy to about 6 

mJ. A Q-switched oscillator with more than a few 100 UJ output 

24 9 
energy', in combination with the multiple-pass amplifier, should 

become a practical laser source for remote sensing applications. 

As a parallel activity, DDF funding has been recently obtained to 

investigate the possible use of custom made fiber optic arrays to 

obtain an efficient optical coupling mechanism between the 

emitting laser diode-arrays and the target solid state laser 

material. Fiber optic coupling arrays would allow for the easy 

manipulation of the spatial emitting pattern of the diode pump 

sources to match either an end or side pumping laser 

configuration. For example, a 1 cm by 1 um typical emitting area 

from a laser diode-array could be coupled into a linear fiber 

array that terminates in a 1.8 mm diameter circle; an ideal 

termination for end pumping of laser rods (Figure 2). Use of 

fiber optic coupling arrays could also allow for the efficient 

multiplexing of pump sources acting on a given laser rod by 

isolating the sensitive and bulky laser diodes from the laser 

rod. This summer both research activities will be merged to 

demonstrate a laser diode-array pumped, fiber optic coupled 

Nd:YAG oscillator and amplifier system. 

khan, K. ttMultiple-Pass Laser-Diode-Pumped Nd:YAG Amplifier: 

Design,It Amlied ODtics, 26, 3177 (1987). 

'Chan, K. "Generation of High-Power Nanosecond Pulses from Laser 

Diode Pumped Nd:YAG Lasers,t8 Applied Optics, 27, (1988). 

250 
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251 
Array consists of 50 fibers 

\--/- 1.75 mm Active Area 

FIBER: 200u core, 230u 

3 

clad, Silica core, Silicone clad 

200~- Center to center (end A - stripped). 

252 Figure 2. Fiber-Optical Coup1 ing Array 
LARGE APERTURE SCANNING AIRBORNE LIDAR 

J. Smith (674), R. Bindschadler (671), R. Boers (617), 

J. Bufton (674), D. Clem (672), 

J. Gamin (622), S. H. Melfi (617) 

A large aperture scanning airborne lidar facility is being 

developed to provide important new capabilities for airborne 

lidar sensor systems. This complete stand-alone lidar facility 

is ear-marked to become a semi-permanent system aboard the NASA 

DC-8 aircraft, contingent upon completion of the proposed 

airframe modifications (forward nadir viewing port-54" x 63"). 

Due to the schedule uncertainty for this viewing port 

installation, the maiden flights will be performed on the NASA P3 at the Wallops Flight Facility. The already installed bombay 

hatch on the P-3 will provide a more than adequate nadir viewing 

portal (80Iv x 154"). Modest internal aircraft modifications will 

be required to accommodate the laser optical bench, data and 

control systems. 

The proposed scanning mechanism allows for a large aperture 

telescope (25" diameter) in front of an elliptical flat (25" x 

36") turning mirror positioned at a 45 degree angle with respect 

to the telescope optical axis. There will be two coincident axes 

of rotation for the turning mirror; +/- 45 degrees side to side 

I 

, (cross-track) and 0 to 30 degrees fore and aft (along-track) 

which will allow viewing from the aircraft platform from nadir 

through 60 degrees forward. Position encoders monitoring both 

253 
excursions will provide location information and feedback data 

for establishing scanning operational parameters. This 

arrangement will allow aircraft lidar systems to be transformed 

into a full three-dimensional data-collection facility. 

The lidar scanning capability will provide opportunities for 

acquiring new data sets for atmospheric, earth resources, and 

The design and construction of this unique scanning mechanism 

presents exciting technological challenges of maintaining the 

turning mirror optical flatness during scanning while exposed to 

extreme temperatures, ambient pressures, aircraft vibrations, 

etc. The proposed drive system will allow the experimenter to 

select any cross-track scanning sector within the range of +/- 45 

degrees from nadir and/or along-track sector from nadir to 60 

degrees forward. These scanning sectors need not be symmetric 

I 

I 254 
with nadir or any fixed axis. The drive system will also provide 

combined 2-axes scanning capabilities. That is, while scanning 

cross-track the mirror may also be simultaneously tilted. This 

arrangement will, of course, also provide fixed off-axis viewing 

at any point within the range of both axes. 

We are currently completing the design of the scanning mechanism 

and are also in the process of procuring major system components. 

We have received $50K funding to date from the Director's 

Discretionary Fund in FY88 ($200K to follow) and anticipating 

project completion to be around March/April 1989. 

c- y 

255 
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256 
A MULTIPROCESSOR AIRBORNE LIDAR DATA SYSTEM 

by 

C.W. Wright, S.A. Bailey, G.E. Heath (672),and C.R. Piazza (CSC) 

A new multiprocessor data acquisition system has been developed 

for the existing Airborne Oceanographic Lidar (AOL). This 

implementation simultaneously utilizes five single board 68010 

microcomputers, the UNIX system V operating system, and the realtime executive VRTX. Remote sensing data are collected via 

CAMAC, GPIB, RS-232, and specialized data sources. 

The original data acquisition system was implemented on a Hewlett 

Packard HP 21-MX 16 bit minicomputer using a multi-tasking realtime operating system and a mixture of assembly and Fortran 

languages. The constant evolutionary state of the AOL places 

substantial demands on the real-time data acquisition hardware 

and software, as well as the post flight data analysis software. 

As new data sources were added, the original data acquisition 

software eventually required rewriting in assembly language. 

The present collection of data sources produce data at widely 

varied rates and require varied amounts of burdensome real-time 

processing and formatting. It was decided in 1985 to replace the 

aging HP 21-MX minicomputer with a multiprocessor system. Each 

data source or group of related and compatible data sources would 

be connected to a single dedicated microcomputer. To simplify 

the programming task, the IrCtt programming language was chosen to 

replace assembler completely. 

257 
A new and flexible recording format was devised and implemented 

to accommodate the constantly changing sensor configuration. The 

new format allows for the addition, modification, or deletion, of 

data sources with little or no impact on existing acquisition and 

analysis software. 

A central feature of this data system is the minimization of nonremote sensing bus traffic. Therefore, it is highly desirable 

that each micro be capable of functioning as much as possible 

on-card or via private peripherals. The bus is used primarily 

for the transfer of remote sensing data to or from the buffer 

queue. 

At present, the AOL data system (AOLDS) is working as planned and 

has been successfully flown on several missions. A paper titled 

Multiprocessor Airborne Lidar Data System" was presented in 

February of this year at BUSCON-88. The attached drawing is a 

block diagram of the current AOLDS. 

I 

258 
I 

ICI 

U nix n 

System 

RTP 

I 

I 

I 

I 

- . Color 

Monitor 

RTDS 

Figure 1. Data Collection System 

259 
CALIBRATION I 

PRECEDING PAGE BLANK NOT FILMED 

m: : &-IN?EHTXmALLY - 
METEOROLOGICAL SENSOR CALIBRATION FACILITY 

by 

F. J. Schmidlin (672) 

Radiosonde TemDerature Corrections 

The meteorological sensor calibration facility is designed to 

test and assess radiosonde measurement quality through actual 

flights in the atmosphere. United States radiosonde temperature 

measurements are deficient in that they require correction for 

errors introduced by long- and short-wave radiation. This 

situation has existed since the later 1950’s when the present 

radiosonde design was introduced. The effect of not applying 

corrections results in a large bias between daytime and nighttime 

measurements. This day/night bias has serious implications for 

users of radiosonde data, of which NASA is one. Examples are: 1) 

ground truth (satellites such as SAGE, NIMBUS, SME, TIROS N/NOAAseries, etc., lidars, and ST-type radars) ; 2) temperature 

retrieval from satellite remote measurements (operational NOAAseries satellite retrievals depend on a regression scheme that 

uses the world-wide radiosonde temperature; a physical retrieval 

scheme is planned); 3) climatological studies and other upper-air 

research, especially model development; and 4) initialization 

data to tie-on to other measurements systems (e.g.,rocketsondes). 

Adjustments to the temperatures and geopotentials were derived 

for use by analyses centers to compensate for the bias. However, 

these adjustments only are made to daytime measurements making 

them equivalent to nighttime and are not tttruett corrections. The 

3c3 

m PRECEDING PAGE BLANK NOT FiLMED 
day/night difference at 100 hPa is estimated to be -47 meters 

representing a temperature bias of -0.7"C. 

The derivation of corrections for the US radiosonde is quite 

important. Determination of corrections depends on solving the 

heat-transfer equation of the thermistor using laboratory 

measurements of the emissivity and absorptivity of the thermistor 

coating. Because of the presence of other unknowns in the 

equation (e.g., the long-wave and incident radiant short-wave 

powers), simultaneous solutions of three equations is desirable 

using a like number of thermistors. Ninety successful flights 

have been made at solar elevation angles up to 80 degrees. From 

these measurements, a family of temperature correction curves 

versus solar angle as a function of pressure were derived. While 

the daytime correction reaches about 0.8"C, a decrease in the 

magnitude of the daytime correction is observed at levels above 

20 hPa. Other investigators have indicated larger daylight 

errors at these altitudes (mostly theoretical). Although, the 

solar heating of the thermistor increases with decreasing 

density (increasing altitude), it turns out that the emissivity 

from the sensor is large; the long-wave emission cools the 

thermistor at a rapid rate, thus decreasing the daytime 

correction above 20 hPa. 

The United States radiosonde observations from the World 

Meteorological Organization International Radiosonde 

Intercomparison were used as the data base to test whether the 

day/night height bias can be removed. Twenty-five noontime and 

264 
26 nighttime observations were used. Corrected temperatures were 

used to calculate new geopotentials. Day/night bias in the 

geopotentials decreased significantly when corrections were 

introduced. 

The National Weather Service's National Meteorological Center and 

the European Centre for Medium-Range Weather Forecasts have 

offered to test the corrections in their analyses and models, 

respectively. We are in the process of rechecking our data prior 

to releasing the corrections for testing. A few papers have 

already been presented, and formal papers are in preparation for 

submission to the American Meteorological Society Bulletin. 

Because of the small sample, another 100 modified instruments 

have been procured and are to be flown this year. 

Relative Humiditv Sensor Laq 

Some testing of thermal lag attendant with the standard carbon 

hygristor has taken place. Two radiosondes with small bead 

thermistors imbedded in the hygristor have been flown. Detailed 

analysis has not been accomplished; however, cursory examination 

of the data showed that the hygristor is at a higher temperature 

than the external thermistor indicates. Normal reduction 

procedure is to use the external temperature to reduce relative 

humidity for the measurements and also to calculate mixing ratio 

and dew point. Temperature differences of 8 to 10 degrees 

Celsius at 500 hPa were indicated. A further look into the 

seriousness of this problem is planned. 

265 
NASA Aircraft-Satellite Instrument Calibration Project 

by 

B. W. Guenther (673) 

Ground-based prelaunch calibration of satellite instruments 

usually is not adequate to provide an accurate characterization 

of the in-orbit performance of a satellite instrument. This is 

because the ground calibrations may not simulate the in-orbit 

environment observations of the satellite sensor, or because the 

sensor characteristics have changed during launch and in-orbit 

operations. One technique to obtain a meaningful in-orbit 

calibration of satellite sensors is to acquire simultaneous 

observations of an Earth scene with the satellite and a well 

calibrated aircraft or shuttle sensor which has similar 

characteristics to the satellite sensor. This is a direct inorbit calibration technique and is usually called vicarious 

calibration. The experiment with the control instrument must 

occur above the sensible atmosphere as measured by the satellite 

sensor to provide a useful improvement to the calibration of the 

satellite sensor. 

NOAA/NESDIS initiated a vicarious aircraft calibration program in 

the early 1980's. The instrument is used primarily to calibrate 

the AVHRR and VISSR instruments on the NOAA operational 

satellites, but has also been used to check the performance of 

the Coastal Zone Color Scanner (CZCS) instrument on the Nimbus 7 

platform. The program has recently been transferred to the 

Laboratory for Oceans. The primary control instrument is a 

267 
double Ebert monochrometer with a silicon photodiode detector. 

It is currently set to scan from 400 to 1040 nm, and flies on the 

NASA U-2 and ER-2 aircraft from the Ames Research Center. The 

spectrometer has been returned to our laboratories for 

requalification and careful documentation of its configuration 

and performance. The instrument will be tested for calibration 

stability at our large aperture integrating sources, and checked 

for operational integrity in our environmental vacuum chamber. 

An engineering flight is scheduled for the Summer on the Wallops 

Flight Facility T-39 aircraft, and operational vicarious missions 

will be reestablished in the Fall from Ames. ~ 

The project is assigned to Goddard under the terms of a joint 

NASA-NOAA Memorandum of Understanding, and NOAA personnel 

continue to provide the primary interface for the project with 

the Ames flight mission staff. The NASA portion of the mission is 

funded through the NASA Headquarters Flight Projects Branch. 

268 
FLIGHT CALIBRATION SOURCE DEVELOPMENT 

by 

S. Glicker (673) 

T' 

An important element in monitoring the sensitivity of flight 

instrumentation throughout a flight is a reliable reference. 

Tungsten filament quartz halogen and deuterium uv sources have 

been tested for this purpose. All three types were obtained from 

available commercial supplies and were tested against various 

mission requirements, particularly long-term stability 

characteristics. Stability tests were made before and after 

thermal vacuum and vibration tests. 

A lamp assembly for SSBUV flight has been completed. Design of 

an integrating sphere to house the lamps and optics to transfer 

light from the flight sources into the Shuttle-borne SBUV (SSBUV) 

field of view for in-flight stability checks has been completed. 

The transfer optic element is a mirror 4-inches in diameter with 

a 5-inch radius of curvature. The mirror is mounted on the GetAway-Special (GAS) canister lid, and the integrating sphere is 

mounted on the SSBW instrument top deck. Our current analysis 

indicates that a 45-watt tungsten filament lamp mounted in the 

integrating sphere will provide as much energy for instrument 

stability checks as a 100 watt calibrated tungsten filament 

standard lamp in the laboratory provides for system calibrations. 

The lamp assembly was tested in-house, and included a ray trace 

analysis. The multiple lamp sources will provide redundant and 

duplicative measurement to check system degradation. 

269 
N8 9- 28 19 

RADIANCE STANDARDS 

by 

D. L. Lester (673) 

Our Office maintains and operates two radiometric calibration 

sources that are utilized by various groups within Code 600. One 

source is a 6-foot diameter sphere and the other a 4-foot 

diameter hemisphere. Both are internally coated with multiple 

layers of barium sulfate and house an array of 12 tungsten 

filament-quartz iodine lamps that provide a uniform diffuse 

target of radiance traceable to NBS. The lamps are baffled and 

arranged so that they are not part of the scene during 

calibrations. Both systems have a 10-inch viewing aperture. The 

hemisphere is somewhat more versatile in that the aperture can be 

changed and the system is movable so calibrations can be done at 

other sites. 

Together, these systems have supported numerous GSFC projects and 

missions during this review period. They include the First 

International Satellite Land Surface Climatology Project (ISLSCP) 

Field Experiment (FIFE), French SPOT-2 satellite, Acid Rain 

Studies, Forest Canopy Studies, the First International Satellite 

Cloud Climatology Project (ISCCP) Regional Experiment (FIRE), the 

University of Maryland MECCAS project, the Sudan Rangeland 

Project, the Satellite Precipitation and Cloud Experiment 

Microburst and Severe Thunderstorms program (SPACE/MIST), and the 

Arctic Airborne Science Expedition. 
User codes and instruments calibrated are shown below; 

Goddard Code Instrument 

613 Barnes Transmissometer 

617 

623 

673 

674 

Multispectral Cloud Radiometer (MCR) 

Modular Multispectral Radiometer (MMR) 

Integrated Camera and Radiometer (ICAR) 

Portable Field Spectrometer (SE590) 

Bidirectional Reflectance Field Instrument 

(BRFI) 

Exotech Radiometer, Field Polarimeter, MMR 

SPOT-2 in Toulouse, France 

Thematic Mapper Simulator at Ames 

Cloud Absorption Radiometer (CAR) 

Advance Scanning Array Spectrometer (ASAS) 

Biometer 11, MCR, Field Polarimeter 

Ocean Data Acquisition System (ODAS) 

27 2 
273 
274 
ENVIRONMENTAL CALIBRATION CHAMBER OPERATIONS 

by 

D. L. Lester (673) 

The Office has thermal vacuum capabilities that are provided for 

use by Code 600 personnel in the development, calibration, and 

functional operation checks of flight sensors, sources, and 

laboratory and field instruments. Two systems are available. 

The first is a 46 cm diameter diffusion-pumped vacuum chamber of 

the bell jar variety. It has an internal thermal shroud, LN2 

cold trap, two viewing ports, and various electrical and fluid 

feedthroughs. The other, also an oil diffusion-pumped system, 

consists of a 1.8 meter diameter by 2.5 meter long stainless 

steel vacuum tank, associated pumping and control equipment, a 

liquid nitrogen storage and transfer system and internal 

IR/visible calibration sources. This is a two story system with 

the chamber located on one floor and the pumping/cryogenic 

systems located on the floor below. 

ACTIVITY SCHEDULE 

673 SSW Flight Esrvironmental temperature 3/86 

candidate Iamps characterization. 

617 Claud LIDAR Functional test at flight 4/86 

P-. 

674 Multispectral Cloud Pre-flight calibration of 5/86 

Radic3Ete.r (MCR) IR channel. 

616 SSW Horizon Sensor Instnrment devel-t 5/86 

673 SSW Flight m-1 soak in vacuum. 7/86 

Calibration Lamps & 8/86 275 

I 
CODE IN674 MCR 

674 Themalert I1 Sensor 

674 KR 

671 F!lU' 5 (2) 

623 Telatep Tehmmeter Gun 

674 KR 

DESCRIrnrn 

Preflight IR cdlibration 

IR calibration 

Post-flight IR calibration 

and Rst-flight tenp. 

characterization 

IR calibration 

Pre- and =-flight 

IR calibration 

- m 

9/86 

11/86 

12/86 

5/87 

& 6/87 

5/87 

6/87 

& 9/87 

i 276 
CALIBRATION SOURCE MAINTENANCE, 

CHARACTERIZATION,aND DEVELOPMENT 

T' 

J. T. McLean (673) 

The Standards and Calibration Office maintains visible and near 

infrared calibration sources for the use of various GSFC 

organizations instrument calibration needs and related field 

activities. These are large aperture spherical and hemispherical 

integrating sources designed to provide a spatially uniform 

absolute spectral radiance with a well-defined angular uniformity 

characteristic. 

A brief physical description of both the hemisphere and the 6- 

foot sphere is included in section on Radiance Standards. In 

essence, the calibration and characterization efforts involve 

monitoring and documenting the stability and the absolute 

radiance of these calibration sources. These sources are 

recalibrated by Code 673 personnel on a regular basis to both 

document any changes that might occur in the output of the 

sources and to provide the most up-to-date calibration data for 

the source users. Oar efforts included comparing Qur calibration 

numbers with those of a commercial calibration laboratory that we 

engage to do independent calibrations. However, the most recent 

calibrations done by the independent laboratory and those done by 

GSFC personnel show a rather large discrepancy (10 to 15 

percent). Efforts are underway to resolve these differences. 

277 
449 INTEGRATING SPHERE AND HEMISPHERE CALIBRATION UPDATE 

J. T. McLean (673) 

BACKGROUND: 

This background information relates to the conclusions reached 

about the GSFC/Optronic calibrations for the 6-foot sphere. The 

history of these calibrations date back to the year 1978 when 

Optronic first calibrated this sphere. The comparison of the data 

taken then indicated rather close agreement between the 

measurements taken by GSFC and Optronic Labs. This trend 

continued in 1979 and in 1982. The sphere was refurbished in 

terms of repainting and changing the lamps in the Spring of 1985. 

As a result of the refurbishing, the output radiance of the 

sphere nearly doubled going from about 80 to 140 in relative 

numbers as reflected in data taken by both Optronic and GSFC. 

This high output seems to have an effect on the values we 

measure. A comparison of data taken by Optronic and GSFC show 

differences of 12 to 15 percent rather than the 2 to 3 percent 

that we had seen in past measurements. The reasons for the 

differences are not clear. While Optronic has changed their 

calibration equipment and methods somewhat, the changes are the 

types that should tend to improve the measurement. Although the 

GSFC measurement procedure has not changed, the personnel 

performing the measurement has changed, and the results seem to 

be reasonably consistent with previous measurements. 

27 q 

wm-y #.&# PRECEDING f%GE BLANK NOT FILMED 
RECENT DEVELOPMENTS: 

I Both the hemispherical and the spherical integrating sources were 

remeasured in February 1988 by two experimenters and the results 

show a decrease in the output of the sphere. But the discrepancy 

between GSFC data and Optronic Data remains. The decrease in the 

I output can be accounted for by a correction in the current value 

~ of power supplies Number 2 and Number 3. The supplies were 

running about 1.75% high. Minor differences were noted in the 

short wavelength end of the hemisphere. 

The data represents a composite of the average of all the data 

taken by the different detectors, namely, silicon, germanium, 

lead sulfide; different spectrometers, and different operators. 

The estimated uncertainty in the precision of our measurement is 

+/- 3%. However, the uncertainty in absolute accuracy is 

estixated to be somewhat higher, probably 5% to 10%. 

i 

Efforts to resolve the discrepancy between GSFC and Optronic Labs 

as well as improve our ability to make more accurate and precise 

measurements are underway. Arrangements are being made for a 

meeting between GSFC personnel and Optronic Laboratory people to 

make some comparison measurements and discuss the measurement 

techniques involved. Design of new fixtures to position and 

align the calibration test equipment to improve precision has 

been initiated. Updating the measurement equipment to make it 

I more computer compatible is being considered. 

Our recommendation is that these calibration constants be used as 

I GSFC's best estimates within the uncertainties noted above. The I 

280 
values given for the hemisphere are considered as being more 

reliable than those of the 6-foot sphere since the precision of 

measurement for the hemisphere is somewhat higher than that for 

the sphere. However, the uncertainties in the absolute values of 

each device are probably comparable. 

281 
PRECEDlNG PAGE BLANK NOT NLMED 

PUBLICATIONS I 
ARTICLES IN PROFESSIONAL JOURNALS AND SYMPOSIA PROCEEDINGS: 

Andreae, M. O., E. V. Browell, M. Garstang, G. L. Gregory, R. C. 

Harriss, G. F. Hill, D. J. Jacob, M. C. Pereira, G. W. Sachse, A. 

W. Setzer, P. L. Silva Dias, R. W. Talbot, A. L. Torres, and 

S. C. Wofsy, lfBiomass Burning Emissions and Associated Haze 

Layers Over Amazonia,ll Journal of Geophysical Research, 93, pp. 

1509-1527, 1988. 

Atlas, R., A. J. Busalacchi, M. Ghil, S. Bloom, and E. Kalnay, 

IIGlobal Surface Wind and Flux Fields from Model Assimilation of 

SEASAT Data," Journal of Geophvscial Research, 92, 6477-6487, 

1987. 

Barnes, R. A., and P. G. Simeth, "Design of a Rocket-borne 

Radiometer for Stratospheric Ozone Measurements," Rev. Sci. 

Instrum., 57, No. 4, pp. 544-551, April 1986. 

Barnes, R. A., A. C. Holland, H. S. Lee, "An Improved Rocket 

Ozonesonde (ROCOZ-A). 2. Preparation of Stratospheric Ozone 

Profiles," Journal of Geophysical Research, 9l, No. D13, pp. 

14521-14531, December 20, 1986. 

Barnes, R. A., A. C. Holland, and V. W. J. H. Kirchhoff, 

IIEquatorial Ozone Profiles from the Ground to 52 Km During the 

Southern Hemisphere Autumn,Iv Journal of Geophysical Research, 92, 

No. D5, pp. 5573-5583, May 20, 1987. 

Barnes, R. A., IIChanges in SSBW Ozone Profiles Near Natal, 

Brazil, from 1979 to 1985," Journal of Geophysical Research, 93, 

No. D2, pp. 1704-1717, February 20, 1988. 

Beal, R. C., F. M. Monaldo, D. G. Tilley, D. E. Imine, E. J. 

Walsh, F. C. Jackson, D. W. Hancock, 111, D. E. Hines, R. N. 

Swift, F. I. Gonzalez, D. R. Lyzenga, and L. F. Zambresky, "A 

Comparison of SIR-B Directional Ocean Wave Spectra with Aircraft 

Scanning Radar Spectra,I1 Science, 232, pp. 1531-1535, 1986. 

Beck, S. M., R. J. Bendura, D. S. McDougal, J. M. Hoell, Jr., G. 

L. Gregory, H. J. Curfman, Jr.,. D. D. Davis, J. Bradshaw, M. 0. 

Rodgers, C. C. Wang, L. I. Davis, M. C. Campbell, A. L. Torres, 

M. A. Carroll, B. A. Ridley, G. W. Sachse, G. F. Hill, E. P. 

Condon, R. A. Rasmussen, IIOperational Overview of NASA GTE/CITE-1 

Airborne Instrument Intercomparisons: Carbon Monoxide, Nitric 

Oxide, and Hydroxyl Instrumentation," Journal of Geophysical 

Research, 92, pp. 1977-1985, 1987. 

Bindschadler, R. A.,, K. C. Jezek, and J. Crawford, @IGlaciological 

Investigations using the Synthetic Aperture Radar Imaging 

System," Annals of Glacioloqy, Vol. 9, p. 11-19. 

Bindschadler, R. A., P. L. Vornberger, S. N. Stephenson, E. P. 

Roberts, S. Shabtaie, and D. R. MacAyeal, 811ce-Shelf Flow at the 

285 1 
Boundary of Crary Ice Rise," Annals of Glaciolosv, Vol. 11, 1988, 

(In Press). 

I Bindschadler, R. A., D. R. MacAyeal, and S. N. Stephenson, "Ice 

the West Antarctic Ice Sheet, (C. J. Van der Veen and J. 

Oerlemans, eds.), D. Reidel Publishers Co., pp 161-180, 1987. 

, Stream-Ice Shelf Interaction in West Antarctia," The Dynamics of I 

Bindschadler, R. A., S. N. Stephenson, D. R. MacAyeal, and S. 

Shabtaie, "Ice Dynamics at the Mouth of Ice Stream B, 

Antarctica," Journal of Geophysical Research, 2 (B9), 8885-8894, 

I 1987. 

Bliven, L. F., N. E. Huang, and S. R. Long, "Experimental Study 

of the Influence of Wind on Benjamin-Feir Sideband Instability," 

Journal of Fluid Mech., 162, pp. 237-260, 1986. 

Burns, B., D. J. Cavalieri, M. R. Keller, W. J. Campbell, T. C. 

Grenfell, G. A. Maykut, and P. Gloersen, IIMultisensor Comparison 

of Ice Concentration Estimates in the MIZ," Journal of 

I Geophysical Research, 92, 6843-6856, 1987. 

Busalacchi, A. J., "Atlantic Seasonality: 11. Theory,tv Further 

Prowess in Eauatorial Oceanoqraphv: A Report of the U. S. TOGA 

Workshop on the Dvnmaics of the Equatorial Oceans, Eds., Nova 

Univeristy Press, Ft. Lauderdale, FL, 235-254, 1987. 

, 

, Busalacchi, A. J., and M. A. Cane, !'The Effect of Varying 

Stratification on Low-Frequency Equatorial Motions,Il Journal of 

Physical Oceanoqraphy, l8, 1988, (In Press). 

Busalacchi, A. J., and J. Picaut, "The Wind-Driven Sea-Leave 

Response of the Tropical Atlantic Ocean," Geophysical J. R. Astr. 

SOC., 87, 117, 1986. 

Cane, M. A., A. J. Busalacchi, M. Ghil, S. Bloom, and E. Kalnay, 

gtGlobal Surface Wind and Flux Fields From Model Assimilation of 

SEASAT Data," Journal of Geophysical Research, 92, 6477-6487, 

1987. 

Cavalieri, D. J., "Preliminary Observations of Polar Sea Ice with 

Special Sensor Microwave Imager," International Geoscience and 

Remote Sensins SvmDosium Proceedinss, 1988, (In Press). 

l Cavalieri, D. J.! and C. L. Parkinson, "On the Relationship 

Between Atmospheric Circulation and the Fluctuations in the Sea 

Ice Extents of the Bering and Okhotsk Seas." Journal of 

Geophysical Research, 92, 7141-7162, 1987. 

Cavalieri, D. J.,, B. A. Burns, and R. G. Onstott, IIInvestigation 

of Multi-Dimensional Algorithms using Active and Passive 

Microwave Data for Ice Concentration Determination,tt Proceedinqs 

of IGARSS-87 Svmposium, Ann Arbor, May 1987. 

I 286 
Cavalieri, D. J., P. Gloersen and T. T. Wilheit, !'Aircraft and 

Satellite Passive Microwave Observations of the Bering Sea Ice 

Cover During MIZEX-West,lf IEEE Transactions on Geoscience and 

Remote Sensinq, GE-24, (3), 368-377, 1986. 

Cavalieri, D. J., "Passive Microwave Sea Ice Signatures from the 

Nimbus 7 SMMR," Proceedinas of a Workshop on Microwave Sisnatures 

of Arctic Sea Ice Under Summer Melt Conditions, edited by C. 

Matzler, Institute of Applied Physics, University of Berne, 

Switzerland, June 1986. 

Chan, K., @IMultiple-Pass Laser-Diode-Pumped Nd:YAG Amplifier: 

Design," Applied Optics. 26, 3177 (1987). 

Chan, K., "Generation of High-Power Nanosecond Pulses from LaserDiode-Pumped Nd:YAG Lasers," Amlied Optics, 27, (1988). 

Choudury, B. J., M. Owe, S. N. Goward, R. E. Golus, J. P. Ormsby, 

A. T. C. Chang, and J. R. Wang, "Quantifying Spatial and Temporal 

Variabilities of Microwave Brightness Temperature over the U. S. 

Southern Great Plains,Il Internal Journal of Remote Sensinq, 8, 

(2), 177-191, 1987. 

Clausen, H. B., N. S. Gundestrup, S. J. Johnsen, R. A. 

Bindschadler, and H. J. Zwally "Glaciological Investigations in 

the Crete Area, Central Greenland: A Search for a New Deepdrilling Site," Annals of Glaciolosv, -, 10 10-15, 1988. 

Cohen, S. C., J. J. Degnan, J. L. Bufton, J. B. Garvin, and J. B. 

Abshire, !'The Geoscience Laser Altimetry/Ranging System," IEEE 

Trans. on Geoscience and Remote Sensinq, GE-25, 581-592, 1987. 

Comiso, J. C., and A. L. Gordon, IIRecurring Polynyas over -- the 

Cosmonaut Sea and the Maud Rise," Journal of Geophvsical 

Research, 92, C3, 2819-2834, 1987. 

Comiso, J. C., and C. W. Sullivan, 'ISatellite Microwave and InSitu Observations of the Weddell Sea Ice Cover and its Marginal 

Ice Zone, Journal of Geophysical Research, 91, C8, 9663-9681, 

1986. 

Comiso, J. C., IICharacteristics of Winter Sea Ice from Satellite 

Multispectral Microwave Observations,Il Journal of GeoDhvsical 

Research, 9l, C1, 975-994, 1986. 

Crowley, T. J., and C. L. Parkinson., "Late Pleistocene Variations 

in Antarctic Sea Ice I: Effect of Orbital Isolation Changes," 

Climate Dynamics, 1988, (Accepted/In Press) . 

Crowley, T. J., and C. L. Parkinson, "Late Pleistocene Variations 

in Antarctic Sea Ice 11: Effect of Interhemispheric Deep Ocean 

Heat Exchange, Climate Dynamics, 1988, (Accepted/In Press) . 

287 
Elrod, J. A., and D. R. Kester, "Chemical Anomalies ina Cold Core 

Gulf Stream Ring," Deep-sea Research, 33f101, 1313-1325, 1986. 

Engman, E. T., and J. R. Wang, IIEvaluating Roughness Models of 

Radar Backscatter," IEEE Transaction Geoscience Remote Sensinq, 

GE-25(6), 709-713, 1987. 

Engman, E. T., and J. R. Wang, IIEvaluating Roughness Models of 

Radar Backscatter,II Proceedinss, IGARSS-86, Zurich, Switzerland, 

September 1986. 

Engman, E. T., and J. R. Wang, "Roughness Measurements with 

Multipolarization Aircraft Data," Proceedinss, IGARSS-87, Vol. 1, 

273-275, Ann Arbor, Michigan, 1987. 

Esaias, W. E., G. C. Feldman, C. R. McClain, and J. A. Elrod, 

*#Monthly Satellite-Derived Phytoplankton Pigment Distribution for 

the North Atlantic Ocean Basin," Eos Transactions, 67f441, 835- 

837, 1986. 

' 

I Fedor, L. S., E. J. Walsh, and D. J. Cavalieri, "Observations of 

Sea Ice Using the 36 GHz Surface Contour Radar," IEEE 

Transactions on Geoscience and Remote Sensinq, GE-25, No. 3, 393- 

402, 1987. 

Garstang, M., J. Scala, S. Greco, R. Harriss, S. Beck, E. 

Browell, G. Scachse, G. Gregory, G. Hill, J. Simpson, W.-J. Tao, 

and A. Torres, "Trace Gas Exchanges and Convective Transports 

Over the Amazonian Rain Forest," Journal of Geophvsical Research, 

93, 1528-1550, 1988. 

Gloersen P. , and D. J. Cavalieri, "Reduction of Weather Effects 

in the Calculation of Sea Ice Concentration from Microwave 

I Radiances," Journal of Geophvsical Research, 91, 3913-3919, 1986. 

Gordon, A. L. and J. C. Comiso, IIPolynyas in the Southern Ocean," 

Scientific American, 258, 90-07, 1988. 

Grenfell, T., and J. C. Comiso, IIMultifrequency Passive Microwave 

Observations of First Year Sea Ice Grown in a Tank," IEEE 

Transactions on Geoscience and Remote Sensinq, GE-24, 826-831, 

1986. 

Guenther, B. W., IIPractical Aspects of Achieving Accurate 

Radiometric Field Measurements,n Remote Sensincl of Environment, , 22, 131-143, 1987. 

I 

Hall, D. K., R. A. Bindschadler, J. P. Ormsby, and H. 

Siddalingaiah, "Characterization of the Snow/Ice Density Zones on 

Glaciers Using LandSat Thematic Mapper Data," Annals of 

Glaciolosv, VO~. 9, 1-5, 1987. 

288 
Hayne, G. S., and D. W. Hancock, 111, "Waveform Analysis for 

GEOSAT Day 96," Johns Hopkins APL Technical Diqest, 8, No. 2, pp. 

255-259, 1987. 

Hilsenrath, E., W. Attmannspacher, A. Bass, W. Evans, R. 

Hagemeyer, R. A. Barnes, W. Komhyr, K. Mauersberger, J. Mentall, 

M. Proffitt, D. Robbins, S. Taylor, A. Torres, and E. Weinstock, 

@*Results from the Balloon Ozone Intercomparison Campaign (BOIC)," 

Journal of Geophysical Research, 91, 13137-13152, 1986. 

Hoell, J. M., Jr., G. L. Gregory, D. S. McDougal, A. L. Torres, 

D. D. Davis, J. Bradshaw, M. 0. Rodgers, B. A. Ridley, and M. A. 

Carroll, "Airborne Intercomparison of Nitric Oxide Measurements," 

Journal of Geophysical Research, 92, 1995-2008, 1987. 

Hoge, F. E., R. E. Berry, and R. N. Swift, "Active-Passive 

Airborne Ocean Color Measurement: 1. Instrumentation,vt Applied 

Optics, 2!5, 39-47, 1986. 

Hoge, F. E., R. N. Swift, and J. K. Yungel, "Active-Passive 

Airborne Ocean Color Measurement: 2. Applications,*I Applied 

Optics, 25, 48-57, 1986. 

Hoge, F. E., and R. N. Swift, IlActive-Passive Correlation 

Spectroscopy: A New Technique for Identifying Ocean Color 

Algorithm Spectral Regions,Il Amlied Optics, 25, 2571-2583, 1986. 

Hoge, F. E., and R. N. Swift, IIChlorophyll Pigment Concentration 

Using Spectral Curvature Algorithms: An Evaluation of Present and 

Proposed Satellite Ocean Color Sensor Bands," Applied Optics, 25, 

3677-3682, 1986. 

Hoge, F. E.., and R. N. Swift, "Ocean Color Spectral Variability 

Studies Using Solar-Induced Chlorophyll Fluorescence," Amlied 

Optics, 26, 18-21, 1987. 

Hoge, F. E., C. W. Wright, and R. N. Swift, "Radiance-Ratio 

Algorithm Wavelengths for Remote Oceanic Chlorophyll 

Determination,Il Applied Optics, 26, 2082, 1987. 

Hoge, F. E:, '*Oceanic and Terrestrial Lidar Measurements,Il 

Chapter 6 in "Laser Remote Chemical Analysis,Il Raymond M. 

Measures, Editor, John Wiley and Sons publishers, New York, 1988. 

House, F. B., A. T. Mecherikunnel, A. Gruber, and G. E. Hunt, 

IIHistory of Satellite Missions and Measurements of the Earth 

Radiation Budget (1957-1984),!# Reviews of Geophvsics and Space 

Physics, Vol. 24, No. 2, 357-377, May 1986. 

Huang, N. E., L. F. Bliven, S. R. Long, and C. C. Tung, "An 

Analytical Model for Oceanic Whitecap Coverage,Il Journal of 

Physical Oceanoqraphv, l6, pp. 1597-1604, 1986. 

289 
Huang, N. E. , L. F. Bliven, S. R. Long, and P. S. DeLeonibus, "A 

Study of the Relationship Among Wind Speed, Sea State, and the 

Drag Coefficient for a Developing Wave Fieldttt Journal of 

Geophvsical Research, 91, pp. 7733-7742, 1986. 

Huang, N. E., S. R. Long, and L. F. Bliven, "An Experimental 

Study of the Statistical Properties of Wind-Generated Gravity 

Wavesttt Wave Dvnamics and Radio Probins of the Ocean Surface, ed. 

0. M. Phillips and K. Hasselmann, Plenum Pub. Co., Chap. 7, pp. 

129-144, 1986. 

Huang , N. E. , "Wind-Wave Phenomenon , Encvclopedia of Fluid 

Mechanics, 1988, (In Press). 

Huegel, F. G, ''Advanced solidstate array spectroradiometer: 

sensor and calibration improvements,l! Proceedinqs of the SPIE, 

~ 

Vol. 834, Imaging Spectroscopy 11, 12-15, 1987. 

Huhnerfuss, H., W. D. Garrett, and F. E. Hoge, #!The Discrimination Between Crude Oil Spills and Monomolecular Sea Slicks 

by an Airborne Lidar," Int. Journal of Remote Sensinq, 2, 

Hunt, G. E. R. Kandal, and A. T. Mecherikunnel, "A History of 

Presatellite Investigations of the Earth Radiation Budget," 

Reviews of Geor>hvsics and Space Physics, Vol. 24, No. 2, 351- 

356, May 1986. 

I 

~ 137-150, 1986. 

Ileen, A., and R. A. Bindschadler, "Combined Measurements of 

Subglacial Water Pressure and Surface Velocity of 

Findelenglescher, Switzerland: Conclusions About Drinage System 

and Sliding Mechanism,Il Journal of Glaciolosv, 32 (110), 101-119, 

1986. 

, Imhoff, M., M. Story, C. Vermillion, F. Khan, and F. Polcyn, 

ttForest canopy characterization and vegetation penetration 

assessment with space-borne radar," IEEE Transactions on 

Geoscience and Remote Sensins, GE-24, No. 4, 535-542, 1986. 

Irons, J. R., B. L. Johnson, Jr., and G. Linebaugh, **Multiple 

Angle Observations of Reflectance Anisotropy from a Linear Array 

Sensor,It IEEE Transactions on Geoscience and Remote Sensinq, May 

1987. 

Jackson, F. C., and A. K. Liu, tuROWS Observations of Directional 

Wave Spectra in FASINEX,II Seventh Conference on Ocean-Atmosphere 

Interaction, 107-110, 1988. 

Jackson, F. C., "The Physical Basis for Estimating Wave Energy 

Spectra with the Radar Ocean-Wave Spectrometer, It Measurinq Ocean 

Waves from Space. edited by R. Beal, 70-73, JHU/APL Technical 

Digest, & No. 1, 1987. 

I 290 
Jackson, F. C., "The Radar Ocean Wave Spectrometer," Measurinq 

Ocean Waves from Space, edited by R. Beal, 116-127, JHU/APL 

Technical Digest, & No. 1, 1987. 

Jackson, F. C. and D. L. Lyzenga, "Microwave Techniques for 

Measuring Directional Wave Spectra,tg Surface Waves and Fluxes: 

Current Theorv and Remote Sensins, D. Reidel, 1988. (In Press). 

Jackson, F. C., I1A Two Scale Model of the Altimeter EM Bias," 

Journal of Geophysical Research, 1988, (accepted). 

King, M. D., M. Strange, P. Leone, and L. R. Blaine, 

IIMultiwavelength Scanning Radiometer for Airbrone Measurements of 

Scattered Radiation Within Clouds,I1 Journal of Atmospheric and 

Oceanic Technoloav, 3 (3), September 1986. 

Krabill, W. B., and C. F. Martin, "Aircraft Positioning Using 

Global Positioning System Carrier Phase Data," Navigation: 

Journal of The Institute of Navisation, 34, No. 1, pp 1-21, 1987. 

Lee, H. S., and C. L. Parsons, IIMesoscale Ocean Eddy Measurements 

by Multibeam Altimetry," Journal of Geophysical Research, 91, No. 

C8, pp. 9693-9699, August 15, 1986. 

Lang, R. H., D. M. Le Vine, and S. Seker, Wector Solution for 

the Mean Electromagnetic Fields in a Layer of Random Particlesu1, 

Radio Science, Vol. 21, (5), pp. 771-786, 1986. 

Lang, R. H., S. Saatchi, and D. M. Le Vine, "Microwave 

Backscattering from an Anisotropic Soybean Canopy, Proceedass 

IGARRS-86 Symposium, Zurich, Switzerland, pp. 1107-1112, 1986. 

Le Vine, D. M., T. Wilheit, R. Murphy and C. Swift, "A 

Multifrequency Microwave Radiometer of the Future," Proceedinss, 

IGARSS-87 Svmposium, pp. 661-666, Ann Arbor, Michigan, May 1987. 

Ling, C. H., and C. L. Parkinson, "Arctic Sea Ice Extent and 

Drift, Modeled as a Viscous Fluid," Ocean Science and 

Ensineerinq, 11, 71-98, 1986. 

Liu, A. K., IIAnalysis of Nonlinear Internal Waves in the New York 

Bight," Journal of Geophvsical Research, 1988 (accepted/in 

press). 

Liu, A. K., and E. Mollo-Christensen, "Wave Propagation in a 

Solid Ice Pack, Journal of Physical Oceanosranhy. 1988. 

(accepted/in press) . 

Long, S.R., ##Principles of Remote Sensing for Ocean 

Applications,Il Current Practices and New Technolow in Ocean 

Ensineerinq, OED-Vol. 11, ed. T. McGuinness and H. H. Shih, ASME 

Press, New York, pp. 29-38, 1986. 

291 
MacAyeal, D. R., R. A. Bindschadler, K. C. Jezek, and S. 

Shabtaie, "Can Relict Crevasse Plumes on Antarktic Ice Shelves 

Reveal a History of Ice-Stream Fluctuation?,Il Annals of 

Glociolosy, Vol 11, 1988, (In Press). 

MacAyeal, D. R., R. A. Bindschadler, S. Shabtaie, S. N. 

Stephenson, and C. R. Bentley, "Force, Mass, and Energy Budgets 

of the Crary fce Rise Complex,l# Journal of Glacioloay, 33 (114), 

218-230, 1987. 

Maclean, G. A.! and W. B. Krabill, "Gross-Merchantable Timber 

Volume Estimation Using an Airborne Lidar System,Il Canadian 

Journal of Remote Sensing, 12, No. 1, July 1986. 

Martin, S., B. Holt, D. J. Cavalieri, and V. Squire, "Shuttle 

Comparison of SIR-B and Scanning Multichannel Microwave 

Radiometer Ice Concentrations,## Journal of GeoPhysical Research, -I 92 7173-7179, 1987. 

Imaging Radar-B (SIR-B) Weddell Sea Ice Observations: A 

I Maynard, N. G., "Coastal Zone Color Scanner Imagery in the 

Marginal Ice Zone," Marine Technolosv Societv Journal, 20(2), 14- 

27, 1986. 

Maynard, N. G. and D. K. Clark, "Satellite Color Observations of 

Spring Blooming in Bering Sea Shelf Waters During the Ice Edge 

Retreat in 1980," Journal of Geophvsical Research, x(C7), 7127- 

7140, 1987. 

Maynard, N. G., V. Barale, and J. Svejkovsky, tlSatellite Observed 

Dynamics of Chlorophyll and Suspended Sediments in a Shallow High 

1987. 

I Latitude Embayment,08 Advances in Space Research, 2 (2), 83-88, 

McClain, C. R., J. A. Yoder, L. P. Atkinson, J. 0. Blanton, T. N. 

Lee, and F. Muller-Karger, "On the Variability of Surface Pigment 

I Concentrations in the S6iuth Atlantic Bight," Journal of 

Geophysical Research, 1988, (Accepted/In Press) . 

McPhaden, M. J., A. J. Busalacchi, J. Picaut, and G. Raymond, "A 

Model Study of Potential Sampling Errors Due to Data Scatter 

Around XBT Transects in the Tropical Pacific," Journal of 

Geophysical Research, 93, 1988, (In Press). 

McPhaden, M. J., A. J. Busalacchi, and J. Picaut, IIObservations 

and Wind-Forced Model Simulations of the Mean Seasonal Cycle in 

Tropical Pacific Sea Surface Topography,## Journal of GeoPhvsical 

Research, !33, 1988, (In Press). 

I Mecherikunnel, A. T., et al., ERBE Science Team, IIFirst Data from 

American Meteoroloqical Society, 67, No. 7, July 1986. 

I the Earth Radiation Budget Experiment (ERBE)," Bulletin of the 

292 
Mecherikunnel, A. T., R. B. Lee 111, H. L. Kyle, and E. R. Major, 

lVIntercomparison of Solar Irradiance Data from Recent Spacedraft 

Measurements,Il Journal of Geophysical ResearchL 1988. (In press) 

Meneghini, R., J. A. Jones and L. H. Gesell, I'Analysis of a DualWavelength Surface Reference Technique," IEEE Transactions on 

Geoscience and Remote Sensinq, GE-25, 4, 456-471, 1987. 

Meneghini, R., and D. Atlas, IISimultaneous Ocean Cross Section 

and Rainfall Measurements from Space with a Nadir-Looking Radar," 

Journal of Atmospheric and Oceanic Technolosy, -, 3 400-413, 1986. 

Meyer, W., C. R. Philbrick, J. Rottger, R. Ruster, H.-U. Widdel, 

and F. J. Schmidlin, "Mean Winds in the Winter Middle Atmosphere 

above Northern Scandinavia,Il Journal Atmospheric Terr. Phvs., 49, 

NO. 7/8, pp. 675-688, 1987. 

Mo, T., T. J. Schmugge, and J. R. Wang, ltCa1culations of the 

Microwave Brightness Temperature of Rough Soil Surfaces: Bare 

Field," IEEE Transaction Geoscience Remote Sensinq, GE-25(1)-, 47- 

54, 1987. 

Mo, T., J. R. Wang, and T. J. Schmugge, IIRetrieval of Surface 

Roughness Parameters from Dual-Frequency measurements of Radar 

Backscattering Coefficients," Proceedinqs, IGARSS-87, Vol. 1, 

269-272, Ann Arbor, Michigan, 1987. 

Mollo-Christensen, E., F. C. Jackson, E. J. Walsh, and F. E. 

Hoge, IIOceanographic Measurement Capabilities of the NASA P-3 

Aircraft," ERS-1 Wind and Waves Calibration WorkshoD. 111-121, 

ESA SP-262, 1986. 

Monaldo, F. M., and F. C. Jackson, ItThe Response of SAR Imagery 

to Azimuth-Travelling Ocean Surface Waves as Determined from 

Shuttle SAR Imagery,It Int. Geosci. and Remote Sensins SvmD. 

JIGARSS-87) Diqest, 1565-1568, Ann Arbor, MI, May 1987. 

Monaldo, F. M., J. Goldhirsh, and E. J. Walsh, !'Altimeter Height 

Measurement Error Introduced by the Presence of Variable Cloud 

and Rain Attenuation,It Journal of Geophysical Research, 91, C2, 

pp. 2345-2350, 1986. 

Muller-Karger, F., C. R. McClain, and P. Richardson, "Where Does 

the Amazon Water Go?, It Nature, 1988, (Accpeted/In Press) . 

Offermann, D., R. Gerndt, R. Kuchler, K. Baker, W. R. Pendleton, 

W. Meyer, U. von Zahn, C. R. Philbrick, and F. J. Schmidlin, 

"Mean State and Long-Term Variations of Temperature in the Winter 

Middle Atmosphere Above the Northern Scandinavia," Journal of 

Atmospheric Terr. Phvs., 49, No. 7/8, pp. 655-674, 1987. 

Parkinson, C. L. , "Paradigm Transitions in Mathematics, 

Philosophia Mathematica, 2, 127-150, 1987. 

293 
Parkinson, C. L., J. C. Comiso, H. J. Zwally, D. J. Cavalieri, P. 

Gloersen, and W. J. Campbell, "Seasonal and Regional Variations 

of Northern Hemisphere Sea Ice as Illustrated with Satellite 

Passive Microwave Data for 1974," Annals of Glaciolosy, 2, 119- 

126, 1987. 

Petzoldt, K., R. Lenschow, A. Hauchecorne, G. A. Kokin, W. Meyer, 

A. O'Neill, C. R. Philbrick, F. Schmidlin, and R. Thomas, "Large 

Scale Structure of the Stratosphere and the Lower Mesosphere (20- 

60 km) over the Northern Hemisphere During the MAP/WINE 

Campaign," Journal of Atmospheric Terr. Phvs., 49, No. 7/8, pp. 

621-638, 1987. 

Ruf, C., C. T. Swift, and D. M. Le Vine, IIElectronically Steered 

Thinned Array Radiometer (ESTAR): System Design, Calibration and 

Sensitivity," IGARRS-86, Amherst, Massachusetts, 1986. 

Ruf, C., C. T. Swift, A. Tanner, and D. M. Le Vine, "Interferometric Synthetic Aperture Microwave Radiometry for Remote 

Sensing of the Earth," IEEE Transactions on Geoscience and Remote 

Sensins, 1988, (Accepted). 

Schmugge, T. J., J. R. Wang, and R. W. Lawrence, "Results from 

the Pushbroom Microwave Radiometer Flights over the Konza Prairie 

in 1985," Proceedinss, IGARSS-87, Vol. 2, 877-881, Ann Arbor, 

Michigan, 1987. 

Shiue, J. C., J. R. Wang, and T. J. Schmugge, IIAirborne Remote 

Sensing of Soil Moisture by Microwave, Visible, and Infrared 

Radiometers," Proceedinss, IGARSS-87, Vol. 2, 1435, Ann Arbor, 

Michigan, 1987. 

Smith, W. O., N. K. Keene, and J. C. Comiso, IIPotential 

Interannual Variability in Primary Productivity of the Antarctic 

Marginal Ice Zone,Il Antarctic Ocean and Resources Variability, 

ed. by D. Sahrhage, Springer, New York, 1988, (In Press). 

Stephenson, S. N., and R. A. Bindschadler, tfObserved Velocity 

Fluctuations on a Major Antarctic ice Stream," Nature, 1988, (In 

Press). 

Sullivan, C. W., C. R. McClain, J. C. Comiso, and W. 0. Wood, 

tlPhytoplankton Standing Crops within an Antarctic Ice Edge 

Assessed by Satellite Remote Sensing,l! Journal of Geophvsical 

Research, 1988, (Accepted/In Press). 

Torres, A. L., and H. Buchan, tlTropospheric Nitric Oxide 

Measurements Over the Amazon Basin, Journal of Geophysical 

Research, 93, 1396-1406, 1988. 

Tung, C. C. and N. E. Huang, "The Effect of Wave Breaking on the 

Wave Spectrum,It Journal of Physical Oceanoqraphy, 17, 1156-1162, 

1987. 

294 
Tung, C. C., and N. E. Huang, "The Effect of Wave Breaking on 

Wave Spectrum in Water of Finite Depth," Journal of GeoDhvsical 

Research. 92, 5123-5130, 1987. 

Wang, J. R., E. T. Engman, J. C. Shiue, M. Rusek, and C. 

Steinmeier, @!Microwave Backscatter from Agricultural Fields 

Observed by Shuttle Imaging Radar B," IEEE Trannsaction 

Geoscience and Remote Sensinq, GE-24 (41, 510-516, 1986. 

Wang, J. R., IIMicrowave Emission from Smooth Bare Fields and Soil 

Moisture Sampling Depth," IEEE Transaction Geoscience and Remote 

Sensins, GE-25(51, 616-622, 1987. 

Wang, J. R., E. T. Engman, T. Mo, T. J. Schmugge, and J. C. 

Shiue, "The - Effects of Soil Moisture, Surface Roughness, and 

Vegetation on L-Band Emission and Backscatter," IEEE Transaction 

Geoscience and Remote Sensinq, GE-25(6), 825-833, 1987. 

Wilheit, T. T., "Some Comments on Passive Microwave Measurements 

of Rain," Bulletin of the American Meteorolosical Society, 67,. 

pp. 1226-1232, 1987. 

Willis, T. M., H. Weil, and D. M. Le Vine, IIApplicability of 

Physical Optics Thin Plate Scattering Formulas for Remote 

Sensing," IEEE Transactions Geoscience and Remote Sensinq, Vol. -I 26 (2), pp. 153-160, 1988. 

Whillans, I. M., and R. A. Bindschadler, "Mass Balance of Ice 

Stream B," Annals of Glociolosv, Vol. 11, 1988, (In Press). 

Yoder, J. A., C. R. McClain, J. 0. Blanton, and L.-Y. Oey, 

"Spatial Scales in CZCS-Chlorophyll Imagery of the Southeastern 

U.S. Continental Shelf," Limno. OceanoqraDhy, 32 (41, 929-941, 

1988. 

Zwally, H. J., and J. E. Walsh, ttComparison of Observed and 

136-144, 1987. 

Modeled Ice Motion in the Arctic Ocean,tt Annals of Glaciolosv, -, 9 

Zwally, H. J., S. N. Stephenson, R. A. Bindschadler, and R. H. 

Thomas, "Antarctic Ice-Shelf Boundaries and Elevations from I 

Satellite Radar Altimetry," Annals of Glaciolosv, 2, 229-235, 

1987. 

I 

Zwally, H. J., "Technology in the Advancement of Glaciology,*' 

Journal of Glaciolosv, Special Issue, 66-77, 1987. 

Zwally, H. J., J. A. Major, A. C. Brenner, and R. A. 

Bindschadler, I'Ice Measurements by GEOSAT Radar Altimetry, w EL 

Technical Disest, 8, (2), 251-254, 1987. 

295 
BOOKS : 

Landahl, M. T., and E. Mollo-Christensen, Turbulence and Other 

Random Processes in Fluid Mechanics, Cambridge University Press, 

Cambridge, U. K., 158 pp., 1986. 

Parkinson, C. L., J. C. Comiso, H. J. Zwally, D. J. 

Cavalieri, P.Gloersen, and W. J. Campbell, Arctic Sea Ice, 1973- 

1976: Satellite Passive-Microwave Observations, NASA SP-489, 

National Aeronautics and Space Administration, Washington, D.C., 

296 pp., 1987. 

Washington, W. M., and C. L. Parkinson, An Introduction to 

Three-Dimensional Climate Modelinq, University Science Books, 

Inc., Mill Valley, California, and Oxford University Press, 

Oxford, England, 422 pp., 1986. 

PRECEDING PAGE BLANK NOT FILMED 

297 
OTHER REPORTS AND PAPERS: 

Bell, D., T. C. Grenfell, ant3 3. C. Comiso, IIMicrowave Angular 

Distributions from the Winter Weddell Experiment," University of 

Washington Press, 250 pp., 1987. 

indschadler, R. A., "Antarctic Field Tests of SARSAT personal l/d Locater Beacons,tt NASA Technical Mem. 4008, 16 pp., 1987. BB~/dvu3 

Bliven, L. F., N. E. Huang, and-S. R. Long, tlExperimental Study 

of the Influence of the Wind on Benjamin-Feir Sideband 

Instability,Il Sixth Conference on Ocean-Atmosphere Interaction, 

American Meteorological Society, Bulletin of the American 

Meteorolosical Society, 66, No. 9, 1217, 1986. 

Cavalieri, D. J.,, and C. L. Parkinson, IIArctic Sea Ice 1973- 

1986: Interregional Comparisons,Il Second Conference on Polar 

Meteorology and Oceanography, (preprints), American 

Meteorological Society, Boston, Massachusetts, pp. 8-10, March 

1988. 

avalieri, D. J., and C. T. Swift, "NASA Sea Ice and Snow / Validation Plan for the Defense Meteorological Satellite 

Program, It NASA TM100683 September 1987. ey,t/ 3~~18 

Campbell, €. G., T. H. Vonder Harr, D. L. Bartman, R. Kandel, G. 

E. Hunt, A. Mecherikunnel, F. House, H. L. Kyler, R. Maschhoff, 

L. L. Stowe, ItComparison of Nimbus 7 and ERBE Radiation Budget 

Measurements, It (Preprint) Joint Session of the Sixth Conference 

on-Atmospheric Radiationn and the Second Conference on Satellite 

Meteorology/Remote Sensing and Applications, Williamsburg, 

Virginia, American Meteorological Society, May, 1986. 

Jensen, John R., Michael E. Hodgson, Halkard E. Mackey, Jr., and 

William B. Krabill, "Correlation Between Aircraft MSS and LIDAR 

Remotely Sensed Data on a Forested Wetland,It Geocarto 

International (41, pp. 39-54, 1987. 

Huang, N. E., S. R. Long, and L. F. Bliven, tlVariation of the One 

Dimensional Slope Spectrum in Wave Number with the Wind Stress,Il 

Sixth Conference on Ocean-Atmosphere Interaction, American 

Meteorological Society, Bulletin of the American Meteorolosical 

Society, 66, 9, 1217, 2386. 

Kirk, R. G., "Ocean Color Observations from LANDSAT-6," Goddard 

Space Flight Center, 1987. 

B.! and- R. K. Swift, "Airborne Lidar Experiments at 

River Plant--June 1985,It NASA 'Feehnk21 P~pe r 4007, 

DOE/SR/14075-1, September 1987. 89td //a29 T%? 
Meneghini, R., Nakamura, K., Ulbrich, C.W., Atlas, D., Clem, T. 

D., Kostic, R. K., "Comparisons of Methods Using Data from an 

Air-borne Dual-Wavelength Radar," Bulletin of the American 

Meteoroloqy Society, Sepcember 1986. 

Nash, J. and F. J. Schmidlin, WMO International Radiosonde 

Intercomparison Final Report," WMO Instruments and Observing 

Methods, Report No. 30, 103, 1987. 

Parkinson, C. L., "Sea Ice Issues Related to the WOCE Southern 

Ocean Programme," World Ocean Circulation Experiment Newsletter, 

4, 14-20, 1987. 

Parkinson, C. L., J. C. Comiso, and H. J. Zwally, 

@@Satellite-Derived Ice Data Sets No. 2: Arctic Monthly Average 

Microwave Brightness Temperatures and Sea Ice Concentrations, 

1973-1976,Il NASA Technical Memorandum 87825, Goddard Space Flight 

Center, Greenbelt, Maryland, 39 pp., 1987.87~ 3003/ 

Parkinson, C. L., "Sea Ice as a Potential Early Indicator of 

Climate Change," PreDarinq for Climate Chanqe, Proceedings of the 

First North American Conference, Climate Institute, Washington, 

D. C., 118-124, 1988. 

d' 

I 

, Parkinson, C. L., and D. J. Caualieri, "Arctic Sea Ice 1973- 

1986: Seasonal and Interannual Variability," Second Conference 

on Polar Meteorology and Oceanography, (preprints), American 

Meteorological Society, Boston, Massachusetts, 4-7, March 1988. 

P sons, C. L., et al., Altimetry and Precision Orbit Y' etermination Panel for the Earth Observing System, R. R. P. 

Chase, ed., "Altimetric System Pariel Report," Earth Observing 

System Vol. m, NASA, pp. 61, 1987. 

Picaut, J., M. J. McPhaden, A. J. Busalacchi, S. P. Hayes, G. 

Mouillages Chaines a Thermistances,It IFREMER rep. 19.18.132, 

ORSTOM/Noumea, 117 pp. 

I Raymond, R. Tournier, and J. Marchand, "Validation d'un 

Schmidlin, F. J., "Rocket Techniques Used to Measure the Neutral 

Atmosphere," ICSU Handbook for?P, Vol. l9, pp. 28, 1986. 

Schmidlin, F. J., t*Rocketsonde Techniques Used to Measure the 

Middle Atmosphere,Il Handbook for MAP (Ed. R. A. Goldberg) , Vol. I 19, pp. 1-28, March 1986. 

chmidlin, F. J., J. K. Luers, and P. D. Huffman, IIPreliminary 

' P Estimates of Radiosonde Thermistor Errors, NASA Technical Paper 

I TP2637, 15, 1986. 87~p2~gb 

300 
Shiue, J. C., and L. R. Dod, IIRemote Sensing and Microwave 

Radiometry," Antenna Handbook, Chapter 23, Van Nostrand Reinhold, 

New York, 1988. 

Smith, J. C., ItOpen-loop Servo Controls Shaft Position," EDN 

Masazine, Ideas for Design, November 1987. 

Smith, J. C., IIInterface for Digitial Pots Directs Servomotor 

Positioning,Il Electronic Desisn Mmzine, Design Ideas, March 

1988. 

Smith, J. C., "Serial Data System Uses Four-Wire Distribution 

System,It EDN Masazine, Ideas for Design, March 1988. 

Stetina, F., "Spatial Analysis and Modeling System (SAMs) 

Development, Applications and Training for India," August 1987. 

Stetina, F., IISpatial Image Processing System for Natural 

Resource Management and Economic Development of the Philippines," 

submitted to Director, PAGASA, Manila, Philippines, July 1987. 

Stetina, @INASA/SUPARCO Scientific Technological Development and 

Environmental Applications Program," submitted to Pakistan Space 

and Upper Atmospheric Research Commission (SUPARCO), Karachi, 

Pakistan, June 1987. 

Stetina, F., "A Program to Develop a Disaster Warning and 

Emergency Planning System in Developing and Third World 

Countries, It March 1988. 

301 
PRESENTATIONS: 

Achtor, T., H. Woolf, H. Maurer, and F. Huang, IIInteractive 

Processing of Satellite Radiance Measurements,Il Second 

International Conference on Interactive Information and 

Processing Systems for Oceanography, Meteorology, and Hydrology, 

1986. 

Atlas, D., and R. Meneghini, "Rain Retrieval Algorithms for 

Spaceborne Radar," Proc. Int. Symp. of Tropical Precip., Tokyo, 

1987. 

Bindschadler, R. A., B. Koci, A. Ileean, and S. Shabtaie, 

IIEvolution of Crary Ice Rise, Antarctica," Symposium on Ice 

Dynamics, Hobart, Australia, February 1988. 

Bindschadler, R. A., S. N. Stephenson, P. L. Vorberger, D. R. 

MacAyeal, S. Shabtaie, and E. P. Roberts, "Boundary Flow of Crary 

Ice Rise, Fourth International Symposium on Antarctic 

Glociology, Bremerhavu, West Germany, September 1987. 

Bindschadler, R. A., Wse of the Twin Otler Aircraft for 

Antarctic Field Work,Il National Science Foundation Antarctic 

Orientation Conference, Arlington, VA, September 1987. 

Bliven, L. F., G. Norcross, J.-P. Giovanangeli, "A Study of Rain 

Effects on Radar Scattering from Water Waves, AMs Proceedings, 

Seventh Conference on Ocean-Atmosphere Interaction, Anaheim, 

California, 230-33, 1988. 

Bufton, J. L., "Lasers in Remote Sensing, Communication, and 

Operations on Space Platforms,vv PLENARY LECTURE, Laser-87 OptoElectronics and Microwave, Eighth International Congress, Munich, 

Germany, June 1987. 

Bufton, J. L., and J. B. Garvin, "Performance Testing of the 

Shuttle Laser Altimeter, Paper MA4, Proceedings of the Topical 

Meeting on Laser and Optical Remote Sensing, Sponsored by the 

Optical Society of America, North Falmouth, MA, pp. 13-16, 1987. 

Bufton, J. L., I'Laser Applications in Space, INVITED PAPER, 

Optical Society of America Annual Meeting, Rochester, NY, 1987. 

Comiso, J. C., C. R. McClain, W. 0. Smith, and C. W. Sullivan, 

IIObserved Antarctic Ice Edge Productivity, AGU Spring Meeting, 

Baltimore, Maryland, May 19, 1988. 

Comiso, J. C., C. R. McClain, C. W. Sullivan, and W. 0. Smith, 

"Summer Sea Ice Conditions and Productivity in the Weddell Sea," 

Invited Talk, Ocean Sciences Meeting, New Orleans, January 1988. 

PRECEDING PAGE BLANK NOT FILM€D 303 
~ 

Comiso, J. C., H. K. Ramapriyan, and Y. C. Lu, "Unsupervised 

Classification of Arctic Winter Sea Ice," Contributed Talk, Ocean 

Sciences Meeting, New Orleans, January 1988. 

Comiso, J. C., "Sensible Heat Polynyas over the Cosmonaut Sea and 

the Maud Rise, Invited Talk, International Symposuim on 

Polynyas, McGill University, Montreal, Canada, October 1987. 

Comiso, J. C. "NASA-P3 Observations of Arctic Winter Sea Ice 

Cover," International Arctic Sea Ice Workshop, GSFC, September 

1987. 

Comiso, J. C., T. C. Grenfell, D. Bell, M. Lange, and S. F. 

Ackley, IIPassive Microwave Emissivities of Weddell Sea Ice in 

Winter," San Francisco, AGU Fall Meeting, December 1986. 

Comiso, J. C., tgPassive Microwave Remote Sensing of Sea Ice," 

Science Seminar Series, Polarstern Lecture Room, July 1986. 

Comiso, J. C., 81Multispectral Microwave Remote Sensing of Sea 

Ice,'# Invited Talk, Naval Postgraduate School, Monterey, 

California, May 1986. 

Chan, K., and J. L. Bufton, "C02 Laser Pre-amplifier for Lidar 

Application," Paper WC3, Proceedings of the Topical Meeting on 

Laser and Optical Remote Sensing, Sponsored by the Optical 

Society of America, North Falmouth, MA, pp. 262-265, 1987. 

Clark, D. K. and N. G. Maynard, "Coastal Zone Color Scanner 

Imagery of Phytoplankton Distribution in Icelandic Waters," 

Proceedings of Ocean Otpics and Otpic-Electronics, Orlando, 

Florida, March 22-April 4, 1986, pp. 352-357. 

Dod, L., J. Gagliano, and R. Platt, 1190/180 GHZ Millimeter Wave 

Radiometer for Future Airborne Measurement," Proc. loth., 

International Conference on Infrared and Millimeter Waves, Lake 

Buena Vista, Florida, pp. 92-93, December 9-13, 1986. 

Gamin, J. B., and J. L. Bufton, "Laser Altimetry in the 

Geosciences, It Paper # 108867, Proceedings of the Geological 

Society of America Annual Meeting, pp. 609-610, 1986. 

I Gamin, J. B., M. T. Zuber, J. L. Bufton, and J. B. Abshire, 

"Laser Altimetry in Planetary Geodesy, 'I Proceedings of the XVIII 

Lunar and Planetary Science Conference, pp. 318-319, March 1987. 

Guenther, B. , "Practical Aspects of Achieving Accurate , Radiometric Field Measurements," Workshop on Visible-Near IR 

I Calibration of Earth Observing Satellites, Phoenix, Arizona, 

I 1986. 

I 304 
Guenther, B., L. Ramos-Izquierdo, and E. Hilsenrath, IvIn-Flight 

Calibration System for SSBUV,Il at Eighth Workshop on the Vacuum 

Ultraviolet Radiometric Calibration of Space Experiments, 

Boulder, Colorado, 1987. 

Guenther, B., and B. Markham, "NASA Aircraft-Satellite Instrument 

Calibration Program (NASIC)," at Fall AGU Meeting, San Francisco, 

California, 1987. 

Guenther, B., "Role of Calibrations in the Earth Observing 

Systems, It at the SPIE Technical Symposium, Orlando, Florida, 

1988. 

Guenther, B., M. Leroy, and J. Henry, "Comparison of CNES 

Spherical and NASA Hemispherical Large Aperture Integrating 

Sources, I, as Determined with a Laboratory Spectroradiometer,Il 

at New Developments and Applications in Optical Radiometry, 

Teddington, United Kingdom, 1988. 

Guha, S., and B. Guenther, "LIDAR Detector Calibration," at CLEO, 

Baltimore, Maryland, 1987. 

Henry, J., M. Leroy, and B. Guenther, "Comparison of CNES 

Spherical and NASA Hemispherical Large Aperture Integrating 

Source, 11, As Determined with the SPOT-2 Satellite Instruments," 

at New Developments and Applications in Optical Radiometry, 

Teddington, United Kingdom, 1988. 

Hilsenrath, E., B. Guenther, D. Williams, and R. P. Cebula, 

vlIrradiance Calibration of the Shuttle-Borne SBUV (SSBUV) , at 

IAMAP, Vancouver, British Columbia, 1987. 

Hilsenrath, E., D. Williams, B. Guenther, and R. P. Cebula, 

ItCalibration of the Shuttle-Borne SBUV (SSBUV) , at Eighth 

Workshop on the Vacuum Ultraviolet Radiometric Calibration of 

Space Experiments, Boulder, Colorado, 1987. 

Hoge, F. E., I'Analysis of Ocean Color Spectral Variability Using 

Correlation Spectroscopy Methods," Proceedings IUGG XIX General 

Assembly, Vancouver, Canada, August 20-21, 1987. 

Hoge, F. E., vfOceanic and Terrestrial Airborne Lidar 

Applications,Il Lasers '87 Meeting, Lake Tahoe, Nevada, December 

7-11, 1987. 

Hoge, F. E., R. N. Swift, and J. K. Yungel, "Airborne Laser 

Induced Chlorophyll Fluorescence Observations within the Marginal 

Ice Ozone of the Greenland Sea," Proceedings of 1988 AGU/ASLO 

Ocean Sciences Meeting, New Orleans, Louisiana, January 18-20, 

1988. 

305 
Huegel, F. G., and S. Guha, "An Automated Spectral 

Characterization for Imaging Spectrometers," CLEO, Baltimore, 

Maryland, May 1987. 

Irons, J. R., R. R. Irish, B. Guenther, and F. G. Huegel, "ASAS 

Performance Appraisal," at Second Airborne Science Workshop, 

Miami, Florida, 1987. 

Jackson, F. C., and A. K. Liu, IIROWS Observations of Directional 

Wave Spectra in FASINEX," Seventh Conference on Ocean-AtmosDheric 

Interaction, 107-110, 1988. 

Jensen, J. R., M. E. Hodgson, H. E. Mackey, Jr., and W. B. 

Krabill, t8Correlation Between Aircraft MSS and LIDAR Remotely 

Sensed Data on a Forested Wetland in South Carolina," 1987 ASPRSACSM Fall Convention, Reno, Nevada, October 4-9, 1987. 

Johnson, B. L., Jr., "A Low Cost Airborne Ocean Color Instrument 

System,l! Conference on Lasers and Electro-Optics, Baltimore, 

Maryland, April, 1987. 

Johnson, B. L., Jr., L. Korb, J. Degana, H. Melfi, G. Schwemmer, 

L. Uccellini, P. Flamant, M. Bourdet, and G. Megie, "Advanced 

Lidar for an Atmospheric Temperature Profile Measurements 

Program: an Overview," Laser and Remote Sensing Conference, Cape 

Cod, Massucetts, September 28-October 1, 1987. 

Kao, R., I'Agro-Climatic Environmental Monitoring Project: 

Computer System Users Guide and System DescriptionsInstallation, Operations, Maintenance," Science Systems and 

Applications, SSAI/ACEMP-86/02, 1986. 

Kao, R., IIAgro-Climatic Environmental Monitoring Project: 

Training Program for SPARRSO Personnel,Ir Science Systems and 

Applications, SSAI/ACEMP-86/25, 1986. 

Killinger, D. K., J. L. Bufton, and E. J. McLellan, "Enhanced 

Direct-Detection of C02 Lidar Returns Using a Laser PreAmplifier," Paper WC14, Proceedings of the Topical Meeting on 

Laser and Optical Remote Sensing, Sponsored by the Optical 

Society of America, North Falmouth, MA, pp. 304-307, 1987. 

Krabill, W. B., and R. N. Swift, "Airborne Positioning for Remote 

Sensing in the Arctic Using GPS," Proceedings of 1988 AGU/ASLO 

Ocean Sciences Meeting, New Orleans, Louisiana, January 20-22, 

1988. 

Le Vine, D. M., and R. H. Lang, "Short Pulse Scattering from a 

Layer of Random Media Using the Distorted Born Approximationf1, 

USNC/URSI Radio Science Meeting, Blacksburg, Virginia, June 1987. 

306 
Liu, A. K., and E. Mollo-Christensen, "Wave Propagation in a 

Solid Ice Pack, AGU/ASLO Ocean Sciences Meeting, New Orleans, 

Louisiana, January 1988. 

Liu, A. K., "Wave Propagation in Ice,nt Invited Talk at GLERL/NOAA 

Seminar, / Ann Arbor, Michigan, March 1988. 

Long, S. R. and N. E. Huang, "Observations of the Properties of 

the Water Surface Roughness Structure Under the Action of Wind 

and Waves," Seventh Conference on Ocean Atmosphere Interaction, 

American Meteorological Society, Boston, Massachusetts, pp. 170- 

173, 1988. 

Majors, E., H. L. Kyle, and A. T. Mecherikunnel, IISolar Constant 

Measurements from Nimbus-7 ERB," AGU Spring Meeting, Baltimore, 

Maryland, May 1987. 

Mecherikunnel, A. T., R. B. Lee, and H. L. Kyle, "Intercomparison 

of Solar Constant Data from Recent Space Flight Experiments,Il AGU 

Spring Meeting, Baltimore, Maryland, May 1987. 

Mecherikunnel, A. T., IIAbsolute Radiometry and Solar Constant 

Data,ll 1987 CORM Conference, National Bureau of Standards, 

Gaithersburg, Maryland, May 1987. 

Mecherikunnel, A. T., and H. L. Kyle, llIntercomparison of Two 

Major Earth Radiation Budget Data Sets," AGU Spring Meeting, 

Baltimore, Maryland, May 1988. 

Melfi, S. H., D. Whiteman, and R. Ferrare, "Applications of Raman 

Lidar to Atmospheric Measurementsll AIAA symposium, June 1987. 

Melfi, S. H., D. Whiteman, and R. Ferrare, "Moisture Profiling 

Using Raman Lidar," The Symposium on Lower Tropospheric 

Profiling, Boulder, Colorado, May-June 1988. 

Melfi, S. H., D. Whiteman, and R. Ferrare, IIObservation of 

Frontal Passages using a Raman Lidar" 14th International Laser 

Radar Conference, San Candido, Italy, June 1988. 

Meneghini, R., and K. Nakamura, IISome Characteristics of the 

Mirror-Image Return in Rain," Proc. Int. Symp. of Tropical 

Precip., Tokyo, 1987. 

Meneghini, R., K. Nakamura, C. W. Ulbrich, D. Atlas, T. D. Clem 

and R. K. Kostic, IIComparison of Methods Using Data from an 

Airborne Dual Wavelength Radar, Preprints 23, Radar Meteor. 

Conference, AMs, 1986. 

Mollo-Christensen, E., and A. K. Liu, ItWaves on an Ice Covered 

Ocean," Symposium in Honor of C. C. Lin, Cambridge, 

Massachusetts, June 1987. 

307 
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