NASA Conference Publication 10139, Part 2 

DOT/FAA/RD-94/14-11 

Airborne Windshear Detection and Warning 

Systems 

Fifth and Final Combined Manufacturers’ and Technologists’ 

Conference 

Compiled by 

V. E. Delnore 

Lockheed Engineering 6 Sciences Company e Hampton, Virginia 

Proceedings of a conference sponsox XI by the 

Federal Aviation Administration, Washington, 

D.C., and the National Aeronautics and Space 

Administration, Washington, D.C., and held in 

Hampton, Virginia 

September 28-30,1993 

July 1994 
Foreword 

A dramatic improvement in the flight safety of transport aircraft worldwide has 

become possible through the development of sensor systems that detect hazardous wind 

changes miles ahead of an aircraft. This development--the result of a unique cooperation 

among NASA, the FAA, industry, and academia--involved fundamental breakthroughs in 

the understanding and measurement of commercial aviation’s most lethal weather threat: 

microburst windshear. 

One purpose of the meeting reported in these Proceedings was to spread the word: 

we were challenged with a need, joined forces to meet that need, and were enormously 

successful. U. S. avionics manufacturers small and large have capitalized on the results of 

our research and consulting guidance, and now have mounted independent sensor development efforts in the best entrepreneurial tradition. The technology applications include 

Doppler radar, lidar (laser radar), and infrared systems, each of which required groundbreaking advances in state-of-the-art design and signal processing. Many systems are now 

in the final stages of FAA production certification and commercial sales. 

The meeting had another purpose: to open the next chapter in interagency and 

industry cooperation--this time for the development and application of sensors for wake 

vortices and for synthetic and enhanced vision systems. This too is reported in these Proceedings. 

The windshear research reported here is the result of NASA and the FAA in 1986 

setting a timetable for developing and demonstrating a solution to a problem then responsible for more than half the U. S. commercial aviation fatalities of the preceding decade. 

The success of this research, with flight tests completed two years ahead of schedule, 

ensures that, in the very near future, all airline passengers will travel with the threat of aviation’s worst weather hazard effectively removed. 

i 

Contents 

Part 1* 

Foreword ......................................................... i 

Table of Contents ................................................... iii 

Objectives and Organization .......................................... iX 

Agenda ........................................................... Xi 

... Compiler's Notes, Layout of these Proceedings, andAcknowledgments ....... .XVIII 

Session 1: WINDSHEAR FLIGHT TEST OVERVIEW. .................... 1 

Chair: R. Bowles, NASA Langley Research Center. 

FliPht Test of AWAS 111. B. McKissick, NASA Langley Research Center. . *. . . 3 

Flieht Test Evaluation of a Data Link and Aircraft Integration of TDWR 

Wind- shear Information. D. Hinton, NASA Langley Research Center ......... 23 

A Performance Evaluation of Airborne Coherent Lidar Wind Shear Sensors, 

F? Robinson, Lockheed Engineering and Sciences Co. ....................... 49 

Westinghouse MQDAR 3000 Flight Test Results. W. Patterson and M. Eide, 

Westinghouse Electric Corp. .......................................... 67 

NASA's Airborne Doppler Rad& for Detection of Hazardous Windshear. E. 

Bracalente, NASA Langley Research Center .............................. 81 

Session 2: WINDSHEAR MODELING, FLIGHT MANAGEMENT, 

AND GROUND-BASED SYSTEMS. .................... 103 

Chair: D. Vicroy, NASA Langley Research Center. 

Microburst Avoidance Crew Procedures for Forward-Look SensorWiD-L ' r f D. Hinton and R. Qseguera, NASA Langley Research 

Center ............................................................ 105 

* Part 1 published under separate cover. 

iii Fa 
Prdures. R. Oseguera and D. Hinton, NASA Langley Research Center ........... 125 

Jt!,!,k D. Vicmy, 

NASA Langley Research Center ....................................... 143 

Characten ‘sties of a Dry. Pul- Microburst at Denver Stwleton 

E Proctor, NASA Langley Research Center ............................... 177 

Future Enhancements to G round-Based Microbu rst Detection, M. Matthews, S. Campbell, and T. Dasey, Massachusetts Institute of Technology. ...... 221 

Determining: F-Factor Using Ground-Based DopDler Radar: Validation and 

Results. D. Elmore, D. Albo, and R. Goodrich, National Center for AtmosphericResearch ..................................................... 241 

E> M. Salzberger, R. 

Hansman, and C. Wanke, Massachusetts Institute of Technology. .............. 287 

Session 3: AIRBORNE WINDSHEAR DETECTION SYSTEMS. ........... 307 

Chair: S. Harrah, NASA Langley Research Center. 

Successful Infrared Prediction of Low Level Windshear. F? Adamson, Turbulence Prediction Systems. ........................................... 309 

Overview and Highlights from SuDer-Dosition Testing of the MODAR 

m, B. Mathews, E Miller, K. Rittenhouse, L. Barnett, and W. Rowe, 

Westinghouse Electric Corp. [Because it deals primarily with certification 

issues, the text portion of the material furnished for this presentation has 

been moved to Session 4, under the title “Certification of Windshear Performance with RTCA Class D Radomes.”]. .................................. 351 

Wind Hazard Detection with a CO, Airborne Laser Radar. R. Targ, Lockheed Research and Development &., P. Robinson, Lockheed Engineering 

and Sciences Co., and R. Bowles and P. Brockman, NASA Langley 

Researchcenter .................................................... 367 

CLASS (&he rent Lidar Airbo rne Shear Sensor) Windshear Detection Svstern, P. Forney and L. Celmer, Lockheed Missiles and Space Go., R. Calloway and F? Bmckman, NASA Langley Research Center, and E Austin, 

Lockheed Engineering and Sciences Co.. ................................. 395 

iv 
RDR-4B DoDuler Weather Radar with Windshear Detection CaDab ility% D. 

Kunhnan, Bendix-Allied Signal Co.. ..................................... 417 

The Collins Windshear Promm. R. Robertson, Rockwell-Collins Co. - . . . 429 

Part 2 

Session 4: CERTIFICATION OF PREDICTIVE WINDSHEAR DETECTION AND AVOIDANCE SYSTEMS. ................................. 443 

Chair: D. Hinton, NASA Langley Research Center. 

The FAAView, R. Passman and F. Rock, FAA ............................ 445 

Winw-on Data Base for Forwwk DG. Switzer, Research Triangle Institute, and D. Hinton and E Proctor, 

NASA Langley Research Center. ....................................... 447- 

Certification Methodolo-p lied to t he NASA ExDerimenbl Hu 

tem. C. Britt and G. Switzer, Research Triangle Institute, and E. Bracalente, 

NASA Langley Research Center. ....................................... 463 . 

-cation 1 of Windshear Performance with RTCA CIw D Radomes * BY 

Mathews and L. Barnett, Westinghouse Electric Go.. ........................ 489 - 

M. Hufaker, 

Coherent Technologies, Inc. ........................................... 499 -? 

525 -#pa- 6 :p 

Session 5: FUTURE AERONAUTICS TECHNOLOGY RESEARCH 

PROGRAMS. ....................................................... 

High Speed C ivil TransDorta tion Res& M. Lewis, NASA Langley &- 

Research Center.. ................................................... 526m" 

G. Steinmetz, NASA Langley Research Center, , .... 541 JK/'-'- 

9 ji Session 6: DEVEWPMENTANDAPPLICATIONS OF SENSORS FOR 

AIRCRAFT WAKE VORTEX DETECTION AND AVOIDANCE. ........... 543 

Chair: R. Bo wles, NASA Langley Research Center. 

V 
Characte ristics of Civil Aviation A~~OSD heric Hazards, R. Marshall and J. 

Montoya, Research Triangle Institute, and M. Richards and J. GalIiano, 

Georgia Tech Research Institute ........................................ 545, 

Ground-Based Wake Vortex Monitoring. Prediction. and ATC Interface, S. 

Campbell 569 ":&? and J. Evans, Massachusetts Institute of Technology. ............... 

Aircraft Wake RCS M 

Technology ........ .?.':. ......................................... 60Y 

ment. W. Gilson, Massachusetts Institute of $4 

lepppler R&ar Detection of Vortex J. Nespor, E. Hudson, 

and R. Stegall, Government Electronic Systems, Martin Marietta, and J. e** 

Freedman, MITRE Corp. .............................................. 651"" \ 

Remote Sensing of Turbulence in the Clear Atmosphere with 2-micron 

WR. Martinson, Lightwave Atmospherics, Inc., and J. Flint, Schwartz 

Electro-optics, Inc.. ................................................. 689' 1 

/ 

i 

Session 7: SYNTHETIC AND ENHANCED VISION SYSTEMS. . . . 707 P' 

Chair: T. Campbell, NASA Langley Research Centet. 

/. A. Lambregts, Boeing 

Commercial Airplane Co.. ............................................. 70 

Overview of West inphouse Enhanced V ision Technologv Actl 'vitia W. 

Patterson, Westinghouse Electric Corp.. .................................. 72 

Evaluation of Candidate M illimeter Wave Sensors for Svbtlc Vlslw. N. 

Alexander, J. Echard, and B. Hudson, Georgia Tech Research Institute = 0 - = 747- 

... 

Passive MMW Ca mera for Low V isibilitv La ndina M. Shoucri, TRW 

Synthetic Vision System Flirht Test. L. Jordan, Honeywell Technical Center. - 7876' 

Applications Technology Div.. ......................................... 765 . 

Enhanced Svnthetic Vision Svstems. C. Taylor, Lear Astronics Corp.. .......... 799 

vi 
Transcripts Of The Audio Recordings Made During The Question & 

Answer And Panel Discussions ...................................... 

About these Transcripts .............................................. 806 

Jargon and Acronyms in the Transcripts ................................. 807 

811 

820 

805 

Panel and Question & Answer Discussions. Sessions 1 and 2 ................ 

Panel and Question & Answer Discussions. Sessions 3 and 4 ................ 

Question &Answer Discussion. Session 5 ............................... 

Panel and Question &Answer Discussions. Session 6 ...................... 

Panel and Question & Answer Discussions. Session 7 ...................... 

Closing Remarks ................................................... 858 

844 

845 

851 

APPENDIX: Names. Aoliations. and Addresses of Attendees .............. 859 

vii 
Session 4: 

CERTIFICATION OF PREDICTIVE 

WINDSHEAR DETECTION AND 

AVOIDANCE SYSTEMS. 

Chair: D. Hinton, 

NASA Langley Research Center. 
Session 4: 

CERTIFICATION OF PREDICTIVE WINDSHEAR DETECTION AND AVOIDANCE SYSTEMS. 

Chair: D. Hinton, NASA Langley Reseanh Center. 

The FAA View, R. Passman and F. Rock, FAA 

G. Switzer, Research Triangle Institute, and D. Hinton and E Proctor, NASA Langley Research Center 

. Britt and G. Switzer, 

Research Triangle Institute, and E. Bmcalente, NASA Langley Research Center 

. B, Mathews and L. Bamett, Westinghouse Electric Co. 

Survm M. Hufakez, Coherent Technologies, Inc. 

444 
The FAA View. 

R. Passrnan and E Rock, 

FAA 

[This presentation consisted of comments only; 

no visuals are available for these Proceedings] 

I 

445 

G. Switzer, 

Research Triangle Institute, 

and 

De Hinton and E Proctor, 

NASA Langley Research Center 

N95- 13204- 

447 
cn 

m 

In 

wnw 

cna 
Abstract 

Described is an introduction to a comprehensive database (e.g., Switzer 

et al 1993) that is to be used for certification testing of airborne forward-look 

windshear detection systems. The database was developed by NASA Langley 

Research Center, at the request of the Federal Aviation Administration (FAA), to 

support the industry initiative to certify and produce forward-look windshear 

detection equipment. The database contains high-resolution, three-dimensional 

fields for meteorological variables that may be sensed by forward-looking 

systems. The database is made up of seven case studies that are generated by 

the Terminal Area Simulation System (e.g., Proctor 1987a, 1987b), a state-ofthe-art numerical system for the realistic modeling of windshear phenomena. 

The selected cases contained in the certification documentation represent a 

wide spectrum of windshear events. The database will be used with vendordeveloped sensor simulation software and vendor-collected ground-clutter data 

to demonstrate detection performance in a variety of meteorological conditions 

using NASNFAA pre-defined path scenarios for each of the certification cases. 

Included in the following are a brief outline of the contents and sample 

plots from the database documentation. These plots show fields of hazard 

factor, or F-factor (Bowles 1990), radar reflectivity, and velocity vectors on a 

horizontal plane overlayed with the applicable certification paths. For the plot of 

the F-factor field the region of 0.105 and above signifies an area of hazardous, 

performance decreasing windshear, while negative values indicate regions of 

performance increasing windshear. The values of F-factor are based on l-Km 

averaged segments along horizontal flight paths, assuming an air speed of 150 

knots (-75 m/s). The database has been released to vendors participating in the 

certification process. The database and associated document have been 

transferred to the FAA for archival and distribution and are available from the 

FAA. 

449 
Ref e rences 

Bowles, R. L., 1990: Reducing windshear risk through airborne systems 

technology. The 17th Congress of the CAS, Stockholm, Sweden, 

27 PP* 

Proctor, F. H., 1987: The Termitlal Area Simulation System, Volume I: 

Theoretical formulation. NASA Contractor Rep. 4046, NASA, 

Washington, DC, 176 pp. [Available from the National Technical 

Information Service, Springfield, VA, 221 61 .] 

Proctor, F. H., 1987: The Terminal Area Simulation System, Volume II: 

Verification Experiments. NASA Contractor Rep 4047, NASA, 

Washington, DC, 1 12 pp. [Available from the National Technical 

information Service, Springfield, VA, 221 61 .] 

Switzer, G. F., F. H. Proctor, D. A. Hinton, and J. V. Aanstoos, 1993: 

Windshear Database For Forward-Looking Systems Certification. 

NASA Tech. Mem. 109012,132 pp. 

450 
0 

n 

w 

0 

v) 

0 

Q) 

.c 

e 

- 

E 

8 0 0 0 

5 

E 

E 

3 Cn 

0 

451 
W 

W 

U 

w 

U 

W 

cn 

a 

m 

a 

a 

n 

)I 

3 

v) 

€ 

Q) 

cn 

>+r 

v) 

m 

I 

S 

aI 

v) 

Q) 

==I 

rr 

Q) 

)r 

v) 

3 

73 

c 

L 

L 

I 

mh 

a 

LL 

cd 

= 

Q) 

m 

C 

a 

CD 

Q) 

v) 

cd 

cd 

cd 

73 

C 

0 

c13 

0 

.I..r 

I 

s 

I 

a- - 

am 

I. 

I 

ati 

c) 

0 

452 
I 

S 

0 

v) 

S 

m 

cn 

3 

0 

Icr 

m 

N 

cd 

s 

)r 

cd 

c 

Q) 

0 

L 

L. 

+Ir 

L 

- - 

.I 

+Ir 

I 

e 

453 
W 

cn 

a 

m 

a 

a 

n 

n 

Iz 

W 

)I 

z 

W 

cn 

W 

U 

W 

U 

B 

n 

v) 

)I 

z 

W 

> 

w 

w 

L 

v) 

3 

n 

0 

0 

L 

is 

*m 

454 
c: 

0 

)r 

0 

0 

CI 

m- 

- 

8 

il 

C 

i5 

I 

0 

v) 

C 

Q) 

C 

0 

I 

e 

8 

c3 

Q) 

31 

m 

a 

Q 

L 

.cI 

L 

E 

5 

3. 

0 

m 

L 

s 

L 

CI 

Q) 

5 

L 

3. 

Q) 

P 

.cI 

- a 

Q 

0 

=3 

0 

1J 

3 

"CI 

i!! 

c= 

Q) 

v) 

0 

llr= 

0 

v) 

1J 

c= 

E 

0 

3i. 

.II 

455 
2 

IP 

E 

s a, 

8 

0 m 

C 

>Ir 

mI 

L 

mW 

v 

C 

a 

m 

c: 

v 

a 

Q) 

ma 

I 

a, 

U 

2 

c/) 

cn 

la 

C 

0 

Q 

mw 

- 

a 

0 

m 

0 

oa .I 

* 

0 

Yl 

C 0 

0 

0 

3 

m.111 

w 

S 

0 

a. 

0 

m 

a, 

.I 

.cI 

L 

.- 

n 

3 

L 

a, 

a, 

0- 

6 

a, 

v) 

0 

n. 

3 

CL 

L 

.cI 

0 

P, 

c) 

0 

n 

tu cy) tu 

cu' 

cy) 

cu' 

0 8 

1 

0 

c\i 

0 

16 

0 

ui 

0 

ci 

456 
457 
-r 

0 

S 

(wn) A 

cp 

+-.( 

23 

0 

v) 

ir 

a - 

c 

< 

458 
U 

(D d- cu 0 t 9 op 

zr 

0 

c 

459 
460 
n 

Q) * 

Q 

cd 

tn 

I 

m111 

S 

a v) 

v) 

Q) 

0 

0 

‘e 

- 

a 

> 

9= 

0 

eL 

L - ClCI 

cd 

L 

tn 

1 

Q) 

cd 

tn 

w 

m2 

W 

cd 

0 

L 

w 

a 

a a 

LL v) 

a 

Q 

w 

L 

cd 

cd 

w Q) 

v) 

cd 

Q 

cd 

w 

d 

I 

cd 

0 

LL 

111 

S 

E 

L 

C 

mm Q) 

ms 

w 

I 

S 

E 

3c 

0 

0 = 

0 

w 

L 

w 

Q) 

=I 

0 

0 

a 

a 

cn 

z 

cn Q) 

0 

c 

E L 

* 

0 

)r 8 Q 

Q 

cd 

Q 

cd 

I 

Q) 

.clr B S 

Q) 

=I 

L 

L 

0 

e mII m ema ai 

ixI 

n 

461 

Certification Methodology Applied to 

the NASA Experimental Flight Svtem. 

C. Britt and G. Switzer, 

Research Triangle Institute, 

and 

E. Bracalente, 

NASA Langley Research Center 

OT F 
CERTIFICATION METHODOLOGY APPLIED TO THE 

NASA EXPERIMENTAL RADAR SYSTEM 

Charles L. Britt, E, M. Bracalente & G. F. Switzer 

5th Combined Manufacturers and Technologists 

Airborne Wind Shear Review Meeting 

September 28-30, 1993 

Radisson Hotel 

Hampton, VA 

OVERALL RESEARCH OBJECTIVE: Low altitude wind shear has been 

identified as a major hazard to aircraft safety during landing 

and take-off. The FAA is requiring all commercial carriers to 

install a windshear hazard detection system on all aircraft in 

their fleet by 1995. The FAA, in 1986, in cooperation with NASA 

established a joint program to assess a variety of sensor technologies and develop those with significant potential for commercial application. One of these technologies was an airborne 

Doppler radar. An experimental Doppler wind shear radar was 

developed by NASA and flight tested during 1991 and 1992. 

: The specific objective of the research is to apply 

selected FAA certification techniques to the NASA Experimental 

wind shear radar system. 

the NASA system, the procedures developed may prove useful for 

manufacturers that plan to undergo the certification process. 

The certification methodology for forward-looking windshear 

detection. radars will require estimation of system performance in 

several FAA-specified microburst/clutter scenarios as well as the 

estimation of probabilities of missed and false hazard alerts 

under general operational conditions. Because of the near-impossibility of obtaining these results experimentally, analytical 

and simulation approaches must be used. 

Although there is no intent to certify 

: Hazard detection algorithms were developed 

that derived predictive estimates of aircraft hazard from basic 

radar measurements of weather reflectivity and radial wind velocity. These algorithms were designed to prevent false alarms due 

to ground clutter while providing accurate predictions of hazard 

,to the aircraft due to weather. 

probability of missed and false hazard alerts has been developed 

that takes into account the effect of the various algorithms used 

in the system and provides estimates of the probability of missed 

and false alerts per microburst encounter under weather condiA method of calculation of the 

tions found at Denver, Kansas City, 

techniques have been developed that 

radar ground clutter data (obtained 

and Orlando. Simulation 

permit the proper merging of 

from flight tests) with simu464 
lated microburst data (obtained from microburst models) to estite system performance using the microburst/clutter scenarios 

fined by the FAA. 

SIGNIFICANCE: The methodology described is specific to the 

detection techniques and algorithms used in the NASA experimental 

system. 

other systems proposed for certification by various manufacturers 

of windshear detection systems. The methodology for calculation 

of false and missed alert probability will be included as an 

Appendix in the "General Certification Methodology and System 

Level Requirements for Airborne Windshear Predictive Systemsg1 

document published by the FAA. 

However, it will serve as a guide for calculations on 

FUTURE PLANS: A technical report will be issued documenting the 

techniques developed and the predicted performance of the NASA 

experimental system using the FAA-defined microburst/clutter 

certification scenarios. 

465 
Certification Methodology Applied to the NASA Experimental Radar 

system 

Charles L. Britt 

E. M. Bracalente 

G. F. Switzer 

VIEWGRAPH TITLES 

Slide 1 - Title of the Presentation. NASA and Research Triangle 

Institute personnel participated with the FAA and interested 

manufacturers in the development of techniques for certification 

methodology for forward-looking windshear detection systems. 

The certification process presents unique problems because of the 

near-impossibility of testing the proposed systems in a realistic 

environment. While the NASA tests of the experimental system 

demonstrated the possibility of observing numerous hazardous 

windshears in flight tests, the windshears observed were not 

generally located in areas of severe ground clutter as may be 

encountered on a landing approach or takeoff. Also, safety and 

operational factors prohibit flight tests through hazardous 

windshear at low altitudes and slow aircraft speeds. 

Slide 2 - Objective of the Study. The methodology finally 

developed by the FAA and NASA for certification of predictive 

windshear systems is being applied to the NASA experimental radar 

system to test the methodology. 

Slide 3 - Sketch of the general methodology used to evaluate 

system performance using real and simulated data. The success of 

the NASA system and microburst simulation approach led to a 

certification methodology consisting of a combination of flight 

tests and simulation. In this concept, illustrated in the slide, 

ground clutter data will be collected by the manufacturers of 

systems being considered for certification at several severe 

clutter locations (e.g., Washington National, Newark, and Denver) 

and will be merged with simulated microburst data generated by 

the NASA TASS weather model. 

subjected to the signal, data processing, display, and alert 

algorithms of the proposed system (using actual hardware) to 

determine the success of the system in meeting the FAA-specified 

performance goals. 

The merged data will then be 

'Slide 4 - Illustration of the technique used by NASA in 

developing the computer code for merging real clutter data with 

simulated weather data. Modules from the NASA windshear 

simulation program (ADWRS) are incorporated into the radar flight 

data processing software. 

466 
Slide 5 - Example of a radar reflectivity map of case 2-37 of the 

FAA certification test cases. This map shows the lltrUe*l 

reflectivity from the TASS microburst database at a particular 

instant of time with no radar processing and no ground clutter 

incorporated. 

Slide 6 - Radar reflectivity map similar to slide 5 (case 2-37) 

except the TASS data has been processed by the algorithms used in 

the NASA experimental radar system. This map shows the 

reflectivity from the TASS microburst database at a particular 

instant of time with normal radar clutter filtering but with no 

ground clutter incorporated. 

Slide 7 - Radar reflectivity map similar to slide 6 (case 2-37) 

except the real ground clutter data from Philadelphia has been 

merged with the TASS data and has been processed by the 

algorithms used in the radar system. This map shows the 

reflectivity from the merged databases at a particular instant of 

time with normal radar clutter filtering. 

Slide 8 - Hazard (F-factor) map of merged data (case 2-37) taken 

at the same time as the reflectivity map of slide 7, 

hazardous areas have been detected with a maximum averaged Ffactor of 0.14, The windshear alert is given at a distance of 

approximately 8 km. from the hazard. 

Two 

Slide 9 - Plots of wind velocity and hazard factor calculated 

from the merged data sets (case 2-37) as a function of radar 

range, The calculation is made along-a azimuth line that passes 

through the hazardous windshear area shown on the radar F-factor 

map of slide 8, Radar calculated and lltruel' values are shown for 

comparison.. 

Slide 10 - Example of a radar reflectivity map of case 5-40 of 

the FAA certification test cases. This map shows the 81true*1 

reflectivity from the TASS microburst database at a particular 

instant of time with no radar processing and no ground clutter 

incorporated. 

Slide 11 - Radar reflectivity map similar to slide 10 (case 5-40) 

except the TASS data has been processed by the algorithms used in 

the NASA experimental radar system. This map shows the 

reflectivity from the TASS microburst database at a particular 

,instant of time with normal radar clutter filtering but with no 

ground clutter incorporated. 

Slide 12 - Hazard (F-factor) map of merged data (case 5-40) taken 

at the same time as the reflectivity map of slide 12. 

hazardous areas has been detected with a maximum averaged Ffactor of 0.14. The windshear alert is given at a distance of 

approximately 3 km. from the hazard. 

A 

467 
Slide 13 - Plots of wind velocity and hazard factor calculated 

from the merged data sets (case 5-40) as a function of radar 

range. The calculation is made along a azimuth line that passes 

through the hazardous windshear area shown on the radar F-factor 

map of slide 13. Radar calculated and Yruegt values are shown 

for comparison. Because of the low reflectivity of this 

microburst, the true and measured values do not compare as 

favorably as those shown for the wet microburst case of slide 9. 

Slide 14 - Hazard Index definitions used in calculating the 

probability of false and missed hazard alerts. 

Slide 15 - Probability density functions showing areas of the 

density corresponding to probabilities of false alerts, missed 

alerts and detection. 

Slide 16 - Outline of the procedure used to estimate the 

probabilities of missed and false alerts. 

Slide 17 - Methods of reducing false alerts used in the NASA 

experimental system. These methods must be considered when 

calculating the various probabilities. 

Slide 18 - Plots of the standard deviation of the hazard (Ffactor) measurement for the NASA system as a function of the 

radar range for three values of weather reflectivity. 

Slide 19 - Probability density functions for F-factor and 

reflectivity (at three locations) used in the calculations. 

Slide 20 - Averaged cumulative probabilities (log scale) of a 

missed detection of a hazardous windshear at Denver, Kansas City, 

and Orlando for microbursts with reflectivity exceeding 0 dBZ. 

The probabilities of false hazard alerts is estimated to be less 

than when using the algorithms implemented in the NASA 

system. 

468 
I 

I I 

469 
Z 

0 

F 

a 

0 

ii 

i= 

a 

W 

0 

8 LL 

Q 

W 

#- 

v) 

W 

(3 

c3 

1 

v) 

>. 

I 

n 

P, 

a 

0 

)I 

I 

Iz 

W 

z 

U 

W 

n 

x 

W 

a 

a 

- 

uj 

z 

a 

W 

=r 

IO 

I- 

). 

c3 

0 

I 

0 

n 

0 

=e 

IW 

s 

2 

W 

Iv) 

). 

cn 

U 

a 

n 

a 

a 

U 

U 

W 

=e 

v) 

Q 

2 

z 

0 

i= 

a 

v) I_ 

0 

U 

z 

W 

0 

v) 

- 

a 

U 

E 

3 

I 

U 

1 

0 

U 

0 

55 

m 

I 

n ow 

LlL 

nw 

zrr 

a n 

v) 

ir, 

). 

Ii 

m 

a 

m 

0 

U 

n 

W 

I 

ILL 

0 

z 

0 

F: 

z 

i= 

a 

u) 

W 

0 

d 

LL 

n 

a 

n 

5 

2 

W 

v) 

v) 

U 

W 

)Iz 

3 

0 

0 

Z 

W 

470 
471 
v) 

U 

UM 

WC CW 

I 

472 




477 



. I U 

a 

n 

481 
X 

W 

n 

n 

a 

a 

I 

U 

Iv 

z 

n 

W 

u 

z 

a 

[IC 

vi > 

i 

W 

> 

n 

z 

s 

LL 

0 

W 

n 

0 

I 

v) 

P) 

1 

n 

s 

1 

II 

L 

v) 

00 

0 

ov 

vi@ 

482 
m 

.cu 

0 

cu 

‘0 

l-- 

-0 

m 

-0 

0 

483 
II 

0 

v) 

0 

L 

L 

4 

oi 

m 

f 

a 

v) 

a3 

LL 

- 

1 

I 

.)lr 

8- 

0 

I 

0 

8 

% 

N 

m 

I: 5 

m 

Q 

0 

k 

LI 

0 

.I. 

0 

u) 

v) 

3 

Q 

0 

0 

.cI 

L 

L 

s 

d, 

VI 

- 

0 

S 

m 

c 

VI 

c3 ci uj cd r; 

484 
rn 

"CI 

cy) 

A 

I 

0 

F 

a 

a 

11l 

cn 

€ 

00 

V 

=c 

tn 

I 

a 

Fm 

A 

Q 

U 

a 

2 

z 

v) 

E 

c3 

V 

E v) 

A 

W 

U 

Q 

W 

0 

z 

CI a 

W 

a 

0 

c3 

V 

K 

W 

)I 

2 

3 

0 

0 

z 

W 

)I 

6 

uj 

z 

i= 

485 
li 

U 

> 

a 

LL 

0 

w 

U 

n 

n 

v) \ 

E 

cy) 

II 

II 

L 

L 

486 
PROBABILITY DENSITY FUNCTION 

Hazard index (F-factor) 

0 0.05 0.1 0.15 0.2 0.25 0.3 

Hazard index 

PROBABILITY DENSITY FUNCTIONS 

Reflectivity @ Denver, Orlando, & KC 

Oufflow Reflectivity (dBZ) 

' Slide 19 

487 
488 
N95- 13206 

I" 

Certification of Windshear Performance 

with RTCA Class D Radomes. 

B, Mathews and L. Barnett, 

Westinghouse Electric Go. 

489 
Overview and Highlights 

from 

Superposition Testing of MODAR 3000 

Bruce Mathews, Fran Miller, Kirk Rittenhouse, Lee Barnett, 

and William Rowe 

Westinghouse Electric Corporation 

Electronic Systems Group 

Baltimore, MD 

5th (and Final) Combined Manufacturers' 

and 

Technologists' Airborne Wind Shear Review Meeting 

Radisson Hotel, Hampton, VA 

Superposition testing of detection range performance forms a digital 

signal for input into a simulation of signal and data processing equipment and 

algorithms to be employed in a sensor system for advanced warning of 

hazardous windshear. For suitable pulse-Doppler radar, recording of the 

digital data at the input to the digital signal processor furnishes a 

realistic operational scenario and environmentally responsive clutter signal 

including all sidelobe clutter, ground moving target indications (GMTI), and 

large signal spurious due to mainbeam clutter and/or RFI respective of the 

urban airport clutter and aircraft scenarios (approach and landing antenna 

pointing). For linear radar system processes, a signal at the same point in 

the process from a hazard phenomena may be calculated from models of the 

scattering phenomena, for example, as represented in fine 3 dimensional 

reflectivity and velocity grid structures. Superposition testing furnishes a 

competing signal environment for detection and warning time 

confirmation of phenomena uncontrollable in a natural environment 

a7 - 

490 
The range-Doppler power spectral density for clutter along a single, 

instantaneous antenna line of sight is recorded at the output of the FFT along 

with the antenna pointing angle and any other radar configuration and/or 

geometry necessary information. The range gated Doppler power spectral density 

of the microburst is calculated from the radar range equation using a fine 

'three dimensional grid database and descriptions of the radar operation either 

from bench testing characterization and/or in-flight measurements. These plots 

show contours of signal-to-noise from 0 to 50 dB. with contours every 5 dB., 

for an upper bar scan in urban airport clutter. 
The clutter signal recorded should represent the amplitude and phase 

stabilities and amplitude levels of the equipment conditions for the intended 

function and installations. The sensor system includes many other aircraft 

system assets besides the receiver-transmitter-processor unit. A pulse Doppler 

radar is preferably dependent upon INS data for c 

antenna pointing. Furthermore, pulse-Doppler radar perfo ns i t ive to 

the level of returns from antenna sidelobe directions. In a 

level is dependent upon antenna and radome characteristics. 

In response to the practices and wi of the c 

RTCA committee on windshear has revised MOPS for 

Essentially, the airlines have reacted to the introduction of a radar with 

windshear detection capability and a call for better radomes by insuring that 

existing (older) weather radomes and practices are not invalidated by a 

statement of new, improved standards. Especially older aircraft with allegedly 

satisfactorily maintained radomes may exhibit degraded transmissivity and 

antenna sidelobe performance in exception of present standards. A class I'D", 

category 2 radome has been defined as a two way transmissivity of 1.4 dB. loss 

and sidelobe degradations up to -20 dB. relative to the mainlobe, respectively 

(see fig. 2). This has the desired effect of prescribing new standards which 

the practices of the airlines can and apparently do comply with. 

Figures 3 and 4 show the installation configuration of the MODAR 3000 

weather radar with predictive windshear. To support certification, 

Westinghouse has modified a BAC-1-11 radome to conform to the definitions of 

the RTCA class "D", category 2 radome. An otherwise class "A" , category 1 

radome, i.e. a low loss and properly maintained radome of minimal antenna 

pattern distortion was "patched" with coarse fiberglass layers to simulate a 

history of repair producing insertion/dispersion losses and sidelobe 

degradation over the aperture window of the windshear mode operation. The 

repair was non-symetrically located and consisted of three overlapped layers 

of cemented fiberglass near the nose, within the scan area of the windshear 

mode. Layers were applied until the average transmissivity was suitably 

degraded. 

Several attempts were made at achieving the sidelobe levels. As was 

remarked in the RTCA meeting by aircraft and radome companies, class "D", 

category 2 sorts of distortions are difficult to realize from properly and 

purely localized radome repairs. 

First attempts included modification of the antenna amplitude 

distribution by slot taping to raise the sidelobe levels. These first efforts 

produced antenna sidelobe levels which exceeded -20 dB. levels in both azimuth 

and elevation. However, the weather radar performance in either weather or 

windshear introduced continual display of red-yellow reflectivity levels at 

all range scales, even over non-urban clutter areas. That radome degradation 

was judged to be too severe as surely it should have prompted a request for 

maintainence action. The current class "D" , category 2 modifications utilize 

only radome modifications and employ no degradation of the antenna amplitude 

distribution. This has produced azimuth degradations (see fig. 5) raising the 

general sidelobe level 3 to 5 dB. and a pronounced increase in the near 

sidelobes on the side of the I1repair1*, up to -19 dB. In the elevation 
figure 2 Airline ExamPle RTCA Class D.catesorv 2 Radome 

The RTCA class D,category 2 radome states that a degradation in the 

antenna sidelobe levels to within -20 dB. of the mainlobe should be 

acceptable. This also asserts that the dynamic range of weather radars need 

not be 50 dB. This is tantamount to a -40 dB. two way antenna sidelobe 

isolation rather than some -70 dB. min. two way isolation available from the 

phased array antenna. 

493 
figure 3 MOD24R 3000 Installation on the BAC-1-11 

Front View - BAC1-11 MR 3000 Installed With Degraded (Class D) Radome US- CDW 

figure 4 RTCA Class D,catecrorv 2 Radome 

A spare radome for the BAC-1-11 was modified by cementing coarse 

fiberglass asymetrically near the nose. This furnished a decrease in the 

transmissivity and an increase in the antenna sidelobe for antenna pointing 

within the windshear mode window. 

494 
Azimuth Radiation Pattern Comparison 

figure 5 Azimuth Antenna/Radome Pattern 

Plots show a pronounced increase in the antenna first and near sidelobes. 

The degradation varies somewhat over the &30 degree scan window. 

J I U" U" 20" 

Elevation Radiation Pattern Comparison 

figure 6 Elevation Antenna/Radome Pattern 

495 
dimension (see fig. 61, the general sidelobe level has also been raised, but 

the peak distortion is in the azimuth plane. 

In-flight testing with this class "D" radome, most urban airports will 

introduce some sidelobe level leakage, evident on the weather display as 

spurious green spotting and/or smudge. Approaches into Newark, NJ from the 

southwest, however, produced displays with persistent, spatial correlating, 

small red and yellow spotting. 

Westinghouse has been developing the MODAR 3000 to be certified with a 

Class D,category 2 radome. For the more prudent user of better and properly 

maintained radomes, certification to Class D,category 2 levels of radome 

performance would provide a sense of field degradation margin on detectability 

and false alarm performance. For the operator of older aircraft, an 

opportunity to equip with predictive is afforded. 

To date, Westinghouse has collected clutter data for development purposes 

with the Class D,category 2 radome and has been evaluating detection 

performance degradations. Clearly, a class A radome will offer better warning 

time performance, especially against "drier" events, than a class D,category 2 

radome, and, at this time, the prospects for detection certification of the 

class D,category 2 radome must be tentative. However, at the time of this 

paper, Westinghouse has completed flight test in Orlando with the FAA, with 

demonstration of 28 seconds of warning time on a must alert level hazard with 

this radome. Again with the FAA on board, Westinghouse has flown the BAC-1-11 

and class D,category 2 radome into Newark, Washingtion National, and 

Philadelphia for the purposes of simulation path clutter collection. 

Westinghouse will claim FAA certification credit for demonstrating false alert 

free performance with a class D,category 2 radome during those flights. In 

summary, Westinghouse will claim certification credit for the flight test and 

false alert performaace requirements for class D, category 2 or better 

radomes. By definition, a class E, category 2 radome will have the same 

sidelobe specifications but poorer transmissivity. Credit for class E, 

category 2 radome performance for certification might be claimed by using the 

clutter data collected with a class D, category 2 radome with a greater 

insertion loss in the weather return calculation. 

The video shows the outputs from the superposion simulation expected for 

certification run cases. This video shows weather reflectivity and windshear 

hazard icon/anunciation with contours of true hazard against the NASA Denver 

multiple microburst during take-off using BWI class D, category 2 radome 

clutter data with a hazard located at 3 n.mi. The first segment is in the 

absence of clutter. The case begins just prior to brake release. The pilot's 

display initially shows only weak weather reflectivity and truth hazard 

contours. However, after scan-to-scan correlation, the simulation produces 

icons which conform generally to the size and shape of the hazard contours 

before/during brake release, giving the pilot warning well before he would 

have been committed to take-off. As the aircraft rolls down the runway and 

approaches in range, the truth hazard contours and the icon change. The radar 

begins to lose detection ability at nearer range, indicated by a scan without 

an icon, but the subsequent scan does furnish an additional icon. The next 

segment shows the same run with class D, category 2 radome clutter. There are 
additional indications of green and yellow reflectivity due to leakage of 

ground clutter through the antena sidelobes. However, the radar performs 

detection and persistence in a fashion indistinqui e from the clutter free 

run, except the scan of icon recovery at near rang not produced. 

The video also shows the format for certification presentation of results 

(see figure 7). The scenario is depicted in a plan view using N-S or E-W truth 

hazard contours of the dataset at the closest altitude. An in situ trace, 

based on the NASA in situ algorithm, is accumulated from the winds of the 

database at the position of the aircraft as a function of case run time. 

Warning time credit will be claimed from the difference in time at first 

warning (light and sound anunciation) and time of in situ encounter of the 

hazard edge. 

For certification credit of icon scoring, the display will probably 

require modifications for slightly larger icons and coasted or otherwise 

artificial persistence of icons at nearest ranges. 

At what point will airlines find sidelobe degradations unacceptable for 

in-route weather? Operation of an antenna and radome combination with the peak 

degradation only in the azimuth plane produces a weather map display of 

multiple distracting hazardous area portrayal which would seem very 

distracting in a high workload approach environment. A manufacturer of pulse 

Doppler radars and the community regulating their safe use must ultimately 

assume that user airlines will find it in their best interests to comply with 

some minimal standard of radome performence. In the case of a windshear 

detection capability, certification of detection and false alarm performance 

with a radome demonstrating compliance with the transmissivity and sidelobe 

degradations of class "D", category 2, especially with this instance of a BAC1--11 modified radome, suggests that some predictive windshear capability may 

be obtained within the current "art" of radome maintenence . Furthermore , the 

pilots and crew on board aircraft with such radomes would have long been 

monitoring the symptoms of sidelobe degradations and might sense departures in 

the sidelobe performance from weather only observations. 

497 
fig, 7 Certificati 

Each simulation run is summarized by the plan view of the upper right, 

which shows the arrangement of NASA database E-W or N-S path hazard contours 

at the altitude closest to the scenario. The aircraft path will be described 

by a series of arrows, indicating its start and path through the event. The 

lower left furnishes a stripchart of NASA in situ hazard factor calculated 

from the database winds at the aircraft position as a function of time. The 

pilots display will show the weather reflectivity and icon at the time of 

initial position, some simulation runs may include production of a scan-byscan sequence of the display as the event is approached for the judging of 

human factors. Credit for warning time is taken from the time difference of 

anunciation and in situ encounter, as delineated by markers on the in situ 

trace. True hazard contours along the expected flight path may be overlayed 

for observer orientation, but icon scoring will be a separate output. 
a Solid State Coherent Lidar. 

M. Hufaker, 

Coherent Technologies, Inc. 

499 
AIRPORT SURVEILLANCE USING A SOLID-STATE 

COHERENT LIDAR 

R. MILTON HUFFAKER 

STEPHEN M. HANNON 

COHERENT TECHNOLOGIES, INC. 

BOULDER, COLORADO 

FAA - Program Managers: James Rodgers 

Lew Buckler 

CONTRIBUTORS: J. Alex L. Thomson, J.R. Magee, 

G.W. Cox, and S.W. Henderson 

500 
ENERAL WIND PROFlLl 

S DISPLAY DEVELOPMENT 

ONSTRATION MEASUREMENTS 

- EXISTING MOBILE 2.09 pm COHERENT LIDAR SYSTEM 

- KENNEDY SPACE CENTER 

- STAPLETON INTERNATIONAL AIRPORT 

* TASK 3: DATA ANALYSIS AND AS8ESSMENT 

TASK 4: SYSTEM DESIGN SPECIFICATION 

501 

e 

d 

e 

v) 

W 

E 

a 

t 

=> 

n 

Z 

0 

0 

w 

w 

E 

3 

u1 

4 

a 

2 

Q 

(9 

z 

E 

3 

n 

n 

5 

w 

e e e 

503 
% 5 

z 

1 

I \%< 
le+ 

5.3% 

4.30 

3.23 

2.15 

1.0% 

0.00 

1.03 

2.15 

3.23 

4.30 

5.37 

! +o 0 

0 

38 

J .45 

-8 0 8 

I 

RADIAL VELOCITY (mlsec) 

SCAN RATE - SO/sec 

RANGE GATE - 100 rn 

NGATES - 1-28 

NAVG - 3 

PULSE WIDTH - 185 nsec 

PULSE ENERGY - 27 ml 

PRF - 5 HZ 

D-Bcm 
E 

i 

I 

I 

! 

i 

E 

c 

i 

I 

! 

i 

! 

i 

i 

i 

i 

i 

~ . .. -. 

-.- 

i 

0 

0 

0 

0 

F 

0 

0 

0 

ua 

0 

0 

0 * 

0 

0 

0 

cu 

0 

0 

0 

v 

0 

cv 

0' 

506 
H 

2- aZ 

H 

% 

2 '/- 

c 

a 

I Iw 

0 

v1 

a 

507 
w 

25 

508 
0 e 

509 
510 
1 
(+3Om/sec to -30 mlsec) 

W1 

- 

-1 

NEAR RW 

0.7 

0.3 

0.2 

FREpuEWcr (MI. ISM1 

Jun 17 1993 9:52:49 0150 AZIM 270.02 ELN 3.341 

3 

PSD 

.w.. 

MAGNITUDE 

. 

(de) 

/dP 

512 
> x 

0 .*. *, , ..,, 0 ZJffJJJJf" 

+ 

+ * 

0 

+ + ** 

I. 

0 

** 

.* 

513 
I @40° 

MEASURED RADIAL VELOCITY - TIME SLICE 1 

(POSITIVE AWAY FROM LIDAR) I840 

150" 

- 

\ 

lit5 

\ 

1 

1.N 

6oo , I 

12 m/sec HOR1ZOVAL SHEAR LAYER 120° 

\ 

\ 10 m/sec WIND GUST A 

1 I 

-1 0 0 10 

RADIAL VELOCITY (m/sec) 

SCAN RATE = 2"- 

RANGERES = 55m 

PVtSEWR)Tn I 18Snmc 

PULSE ENERGY i 27 mJ 

WlFsSW 

ozsa 'GATES 

)IAvG I3 

514 
c 

2.w 

1.Ob 

l.6? 

H 

E 1.m 

I 

G 

H 1.1~1 

T 

O.¶? 

11 

0.6, 

0.46. 

EASURED RADIAL VELOCITY - TIME SLICE 2 

(POSITIVE AWAY FROM LIDAR) leulo a.ah 

150" \ 

- 

I 

11 

Hat- 09 1993 20:41:59 0357 AZIH 039.999 ELEV 000.760 

1 

-1 0 0 10 

RADIAL VELOCITY (dsec) 

SCAN RATE = 2%~ PULSE moTH = W55nac 

RANGE RES 55 m PULSE ENERGY = 27 IN 

PRF=IW 

D=Ban N~~~~ = '= 'AVGZ3 

515 
2" PPI SHOWING NUMEROUS INHOMOG~NEITI~S 

MEASURED RADIAL VELOCITY 

le41 (POSITIVE AWAY FROM LIDAR) 1.40) I 

'*+.&3 1:lS 0:89 d59 0:30 0:OO 0:30 O:S9 dS9 1:18 

I 

- RANGE (km) 1.41 

Jun 28 1993 15:31:49 1056 AZlM 354.880 ELN 2.000 

,3rY ,> I 1 

-8 0 8 

RADIAL VELOCITY (mlsec) 

516 
MEASURED RADIAL VELOCITY 

5.8 

8 4:80 8:23 2:lS 1:OS I 

RANGE (kr) lea0 

36 

Jun 09-1993 15:26:56 0220 AZIN 030.ao3 ELEV 002.000 

-8 0 8 

RADIAL VELOCITY (Wsec) 

I <A 

517 
350" RHI SHOWING OUTFLOW DIPOLE 

MEASURED RADIAL VELOCITY 

(POSITIVE AWAY FROM LIDAR) I*** 

I 

1200 6oo 

0. 

Jun 09 1993 15:31:33 0132 AZIH 349.773 ELEV 011.232 I hXW" < V+'*. 

RADIAL VELOCITY (mlsec) 9uwRAlE-63ro RILSEWIDW-1~- 

RANQEQATE- tmm PUdEENosGY-Pnrl 

-8 0 8 

0-em * 'ZB 

NAVQ'2 

518 
340" RHI 23 MINUT 

MEASURED RADIAL VELOCITY 

1111 (PostnvE AWAY FROM LIDAR) 

1.U 

1.m 

1.w 

H 

E 0.0 

I 

G 

H o.?t 

T 

k 0.W 

m 

8.W 

0.30 

0.15 

I 

1200 

Jun 28 1993 15:54:43 0264 AZIH 339.993 ELEY 000.472 

I -et '% . -8 0 a 

519 
STAPLETON ~EASURE~E~T~U~~ARY 

0 RELlABLE WAKE VORTEX DETECTION FOR EACH MEASUREMENT 

- LIDAR DETECTS WAKE EVERY TIME (-250+ LANDINGS) 

0 LARGE VORTEX DATABASE IS BEING COMPILED 

- THREE SCAN PLANES (ASPECT ANGLES) 

- LARGE AMOUNT OF METEOROLOGICAL DATA 

- CORRELATIONS BETWEEN ENVIRONMENT AND WAKE PERSISTENCE 

MULTIPLE SCAN PLANES CAN BE USED TO DETERMINE AXIAL FLOW SIGNATURE 

- 

- 

TRANSVERSE FLOW MODEL PREVIOUSLY VERIFIED 

AXIAL FLOW SIGNATURE IMPORTANT TO MAXIMIZE COVERAGE AREA WITH SINGLE-STATION 

LIDAR 

MEASUREMENT GEOMETRY NOT IDEAL 

- MINIMUM ELEVATION ANGLE OF 0.5" (8-1 5 m MINIMUM MEASUREMENT HEIGHT) 

- 

- 

ELIMINATES ASPECT ANGLES BETWEEN 85" AND 45") 

ALTERNATE LOCATION NEAR NWS CONSiDERED FOR JUNE MEASUREMENTS 

520 
z z 

4 

W 

2 

E 

vI 

u! 

0 

521 

INARY PERFORMANCE ASSESS~E~T 

* PULSED SOLID-STATE LIDAR BEST DEVICE FOR DETECTING AND TRACKING WAKE 

VORTICES 

.. PULSE LENGTH 20-75 m TO MATCH WAKE DIMENSIONS 

- HIGH PRF SYSTEMS (A0 Hz) NEEDED TO MEET SPATIAL SAMPLING REQUIREMENTS (2 m) 

- 

- 

PULSED OPERATION PERMITS MEASUREMENT TO RANGES OF A FEW KILOMETERS 

RELIABLE ESTIMATES OF VORTEX LOCATfONS AND PERSfSTENCE CAN BE ACHIEVED 

-. HIGH RESOLUTION WIND PROFILES VALUABLE FOR IN AIRPORT ENVIRONMENT 

(MICROBURST AND WIND GUST DETECTION AND TRACKING) 

- 

- 

- 

LARGE AREA OR SECTOR SCANS ON DEMAND 

VOLUMETRIC SCANNING WITH SUFFICIENT PRF 

VERTICAL WIND PROFILES ON DEMAND 

* MODEST SYSTEM REQUIREMENTS 

- 10-20 mJ PULSE ENERGY; 10-1 5 cm APERTURE; 100-300 Hz PRF 

- EXISTING OR NEAR-TERM DIODE-PUMPED 2 pm TECHNOLO.GY 

- CAPABLE OF FULL AIRPORT COVERAGE 10- 15 km 

3D VELOCITY 'IMAGES' ARE FEASIBLE 

- XYT DEMONSTRATED WITH 5 Hr PRF: AX = 35 m; AT = 10 sec 

- HIGH PRF SYSTEMS PERMIT XYZT WITH AX e 50 m; AT < 10 sec 

523 

Session 5: 

FUTURE: AERONAUTICS 

TECHNOLOGY RESEARCH 

PROGRAMS. 

TF 525 
High Speed Civil Transportation Research. 

M. Lewis, 

NASA LangleyResearch Center 

526 



530 

INTEGRATED HIGH-SPEED CIVIL TRANSPORT PLAN 

The NASA HSR Program is Enabling T8ChnOlogY Development and Validation 

and Not Product Development 

TECHNOLOGY DEVELOPMENT 

($4.9 BILUON) 

t 2o02 2o04 t 2o06 

CERTIFICATION 

1900 1992 1994 1 996 1998 

GO-AHEAD 

532 
c') 

03 

03 

r 

I 

533 
Flight Deck 

Systems 

d flight deck 

systems technologies and 

certification guidelines to enable 

industry development of: 

0 Synthetic vision 

0 Next-generation flight decks 

534 
0 RESTRICTED V1SIBILTTY 

- Approach & Landing 

- Ground Operations 

- Collision Avoidance (VFR, As Well As IFR) 

COCKPIT LOCATION 

- Optimization Of Flight Deck Voiume/Shape 

- Cockpit Motion 

-Taxi Guidance & Control 

0 UNIQUE OPERATING REQUIREMENTS 

- Systems Management (Fuel, Temperature, Radiation) 

- Noise Management 

- ATC Integration 

LACK OF CERTIFICATION GUIDELINES 

- Synthetic Vision 

- Non-Evolutionary Cockpit 

535 
Advanced Subsonic vs. Mach 2.4 HSCT 

1 -11 

1 _-e-- 

. -- 

Improved 

Economics 

536 

)I 

ii 

w 

2 

W 

m 

0 

0 

03 

W 

K 

CI 

I I I I I I I 1 

0 0 0 cu P 

0 0 

d # 0 0 0 

IC CD u) 

538 
0 Addi~io~al Row of Seats 

(2% Gain In Revenue) 

Minimum Special ATC ~an~~ing 

(No T~ro~g~p~ Impact) 

tion Time & Costs 

539 
x 

0 

u 

II 

(3 

3 

LL 

i 

u 

(3 

w 

2 

a 

k 

540 
Terminal Area Productivity. 

G. Steinmetz, 

NASA Langley Research Center 

fThis presentation consisted of comments only; 

no visuals are available for these Proceedings] 

541 

Session 6: 

DEVELOPMENT AND APPLICATIONS 

OF SENSORS FOR 

AIRCRAFT KE VORTEX 

DETECTION AND AVOIDANCE. 

Chair: R. Bowles, 

NASA Langley Research Center. 

F 543 
Session 6: 

DEVELQPMENT AND APPLICATIONS OF SENSORS FOR AIRCRAFT WAKE VORTEX DETECTION AND AVOIDANCE. 

Chair: R. Bowles, NASA Langley Research Center. 

Characteristics of Civil Aviation Amos-Dheric Hazards. R. Marshall and J. Montoya, Research Triangle Institute, and M Richards and J. Galliano, GeorgiaTech Research Institute 

Ground-Based Wake Vortex Monitmine. Prediction. and AX Interface. S. Campbell and J. Evans, Masschusetts Institute of Technology 

mmft Wake RCS Measurement. W. Gilson, Massachusetts Institute of Technology 

Wake Vortex Detection at Denver Staoleton Air~~rt wih a Pulsed 2-micron Coherent Lidar. S. Hannon and 

A. Thomson, Coherent Technologies, Inc. 

Do~~ler Radar Detection of Vortex Hazard Indicators. J. Nespor, E. Hudson, and R. Stegall, Government 

Electronic Systems, Martin Marietta, and J. Freedman, MITRE Corp. 

Remote Sensing of Turbulence in the Clear Amomhere with 2-micron Lidars. R. Martinson, Lightwave 

Atmospherics, Inc., and J. Flint, Schwartz Electro-Optics, Inc. 

544 
Characteristics of Civil Aviation 

Atmospheric Hazards. 

R. Marshall and J. Montoya, 

Research Triangle Institute, 

and 

M. Richards and J. Galliano, 

Georgia Tech Research Institute 

N95- 13208 

545 
Characteristics of Civil Aviation Atmospheric 

Hazards 

R. E. Marshall, M. A. Richards, J. A. Galliano, and J. Montoya 

Abstract 

C/earA/i- Turbu/ence, wake vudicez dryha/;! and vu/canic ash %e 

hazardstu civ/;/av/bf/n thathave nutbeen bruught tu the fmehnt ufp&.c 

attenfibn by a catas&uphic accidenf Huwe ver, these fuurhazards are 

respuns%%e fur majm andm/nur/hjuneG emutiuna/&aum& s/gn/ficant aAzafi 

damages andh mute andtwm/ha/area /hefficiency 

Mustihjuries occur dun2g dear ak furbu/ence. There 1s s/gn/Tcant 

akuafi damage far any vu/canic ash encuuntx Rulshducedby wake vurtices 

occurnear the gruund Cryha/;/u#en appears as an area uf weak echo an the 

weatherradar. 

546 
547 
v3c 

W 

32 

U 

R 

v3 

0 

. 

E 

548 
-03 

W 

kl 

N 

fd 

ZL 

U 

R 

cn 

0 

E 

w 

3: 

Q, 

0 

f 

cd 

# 

W 

c 

m 

L 

E 

E 

m 

c 

Q, 

# 

a 

m 

tl 

0 

# 

(I, 

3 

L= 

0 

c 

CI 

.II 

L 

.- 

.II 

L 

.I 

E 

U 

c 

m 

0 

L 

'3- 

ZE 

a 

a" 

a 

549 
vsr 

W 

N 

ti3 

31: 

c 

RF 

VI 

0 

E 

+Ir 

.I 

# 

0 

U *- # 

$ii 

f'Z3 

.I 0 

0 

550 
# 

W 

c) 

I- 

& 

01 

E Q 

I 

a, 

a, 

13 

# 

Q, 

33 

a 

a 

0 

L 

- 

c, 

8 

-w 

3 

.I 

c 

E 

Q 

CICl 

111 

a 

c 

# 

.I 

+ 

.I 

i2 

a 

551 
U 

03 

'I 

N 

7 

co 

A Er 

552 
v3 

W 

ti3 

N 

(If 

ZT 

c) 

c 

ci 

VI 

0 

E 

w 

(b 

Q, 

0 

cn 

a, 

"(3 

a. 

L. 

0 0 

8 

.- 

(d 

c 

# 

W 

Q, 

r 

tTJ 

W 

c 

73 

c 

(b 

cn 

a, 

0 

73 

(b 

W 

(I, 

u 

(b 

0 

W 

c 

(d 

73 

(I, 

- 

.I 

.I 

s 

E 

L 

L. 

c., 

w 

;iz: 

# 

Qr 

ZT 

# 

m 

u 

0 

Z 

L 

0 0 0 0 0 

553 
v) 

W 

b 

N 

(b 

I: 

U 

mc 

W 

c 

a 

a, 

> 

0 

3 

- 

e 

E 

E 

0 

(D 

0 

m 

0 

ru 

N 

v3 

t 

a, 

m 

c 

m 

v) 

(I, 

t 

0 

cn 

m 

I 

+Ir 

E 

L 

1c 

.I 

.- 

L 

c., 

- .I 

0 

554 
m 

a 

0 

E 

m 

T3 

.- 

.I 

c 

E 

t\j 

Ad 

0 

W 

c 

m 

P 

d 

c: 

Q> 

+-r P 

Q1 

n 

o 

ta 

f 

I 

v) 

.- 

cd 

I 

e 

E 

Ad 

m 

0 

+., 

E 

0 

L 

Yo 

ta 

# 

r 

Q, 

W 

+=J 

n 

a 

8- 

t 

E 

0 

c.' 

UY 

E 

0 

L 

yl 

kj 

a 

.- 

a 

I: 

a 

555 
VI 

W 

ta 

N 

m 

U 

VI 

556 
557 
uc 

0 

. 

E 

558 
VI 

0 

E - 

(b 

V 

v) 

I 

m 

3 

c 

Q, 

CI 

0 

559 
u 

(b 

(b 

mc 

L 

c) 

LL 

E 

m 

c 

'5 + 

w 

m 

V 

v) 

.I 

0 

3i 

m 

[r: 

- 

N 

W 

m 

U 

Q 

c 

v) 

a 

- 

m 

.I 

u 

L 

c.., 

Q, 

E 

E 

+ 

z= 

m 

m 

TZ 

0 

0 

+.lr 

+ 

0 0 0 0 

560 
561 
0 

W 

b 

N 

m 

ZT 

c 

a 

VI 

0 

E 

w 

r= 

Q, 

# 

c, 

0 0 m 0 

562 
ta 

N 

563 
(R 

W 

I: 

cl 

I. 

b 

3' 

03 

564 
*F 

SII, 

m 

> 

'. 

a 

0 

c, 

U 

L 

m 

N 

m 

=L 

m 

v, 

m L 

0 

3 

0 

3 

0 i A 

a a 

565 
v) 

W 

I: 

U 

E: 

m 

U 

- E 

# 

0 

n 

-6 

ki 

c, I 

I. 

-E 

a 

a, 

z 

566 
# 

W 

b 

N 

ed; 

9: 

V 

8 

c 

567 
VI 

0 

E 

3333 

uouv 

wwww 

3333 

uwww 

0000 

.I .I .I .I 

.I 

I.-- 

.I .I .I 

YlYlYlyl 

LLLL 

Q,(1,Q,Q, 

aana sw I. 

568 
Ground-Based Wake Vortex Monitoring,, 

Prediction, and ATC Interface. 

S. Campbell and J. Evans, 

Massachusetts Institute of Technology 

569 
5th (and Final) Combined Manufacturers’ and Technologists’ 

Airborne Wind Shear Review Meeting 

September 28-30’1993 

Hampton, Virginia 

“GROUND-BASED WAKE VORTEX MONITORING, 

PREDICTION AND ATC INTERFACE ”* 

Steven D. Campbell and James E. Evans 

Lincoln Laboratory 

Massachusetts Institute of Technology 

Lexington, Massachusetts 

Telephone: 617/98 1-3386, E-mail: sdc@ll.mit.edu 

This talk will discuss three elements of a proposed Wake Vortex Advisory 

Service: monitoring, prediction and ATC interface. The monitoring element is needed to 

ensure safety by warning controllers of hazardous wake vortex conditions. Such 

conditionsexist when wake vortices persist in the approacWdeparture flight paths due to 

advection or to atmospheric conditions which prevent their decay. The prediction 

element is needed to provide ATC supervisors with advance warning that wake vortex 

separation conditions are about to change (Le., require increased or decreased wake 

vortex separation). The ATC interface element is needed to provide controllers with 

adaptive wake vortex separations. The use of these adaptive wake vortex separations 

would lead to increased airport capacity under most conditions, while maintaining 

safety under conditions of wake vortex hazard. 

’ 

A data gathering program is proposed to begin in the summer of 1994 at a major 

airport. A 10.6 pm Co;! CW lidar system will be developed for characterizing the 

behavior of wake vortices in an operational airport setting. Wide-area weather data will 

be gathered by an Integrated Terminal Weather System (ITWS) testbed. Interface to the 

terminal ATC system will be accomplished using the TATCA (Terminal Air Traffic 

Control Automation) Interface Unit (TIU), which would allow wake vortex separation 

symbology to be inserted onto a TRACON controller’s Full Digital ARTS Display 

System (FDADS) radar screen. 

. 

The proposed program would take advantage of the synergy between the Wake 

Vortex, ITWS and TATCA programs in achieving an integrated Wake Vortex Advisory 

System. An interim product of the program would be a characterization of the wake 

vortex separation requirements for different classes of &craft in an operational setting. 

The ultimate aim of the program would be to achieve fielding of the proposed system. 

* The work described here was sponsored by the Federal Aviation Adminimaion under Air Force 

Contract No.Fl9628-90-C-002. The United States Government assumes no liability for its content or 

use thereof. 

570 
References: 

1. Evans, JB. and J.D. Welch: ”Role of FAA/NWS Terminal Weather Sensors and 

Terminal Air Traffk Automation in Providing a Vortex Advisory Service”, FAA 

International Wake Vortex Symposium, Washington, D.C., October 29-3 1,1991- 

2. Heinrichs, R.M., J.E. Evans and C.A. Primmerman: ”Laser Systems for 

Characterization and Monitoring of Wake Vortices”, FAA International Wake Vortex 

Symposium, Washington, D.C., October 29-3 1,1991. 

571 
II 

II 

W 

m 

e 

s 

a 

0 

ti 

Z 

UI 

=. 

ll.i 

Fv, 

572 
W 

z 

i 

F 

3 

0 

u) 

Z 

0 

i= a 

U 

iz 

W 

u) is 

IU 

0 

> 

Y 

s 

W 

> 

In 

a 

n 

a 

G 

0 

W 

4 

z 

0 

i= 

0 

W 

9 

n 

a 

i3 

a 

n 

1 

u 

z 

z 

n 

b 

W 

- 

3 

a 

3 

5 

a 

a 

v) 

2 

I 

x 

x 

W 

IU 

0 

> 

W 

Y !s 

I 

ci 

4 

a 

.A 

a 

z 

v) 

4 

z 

G 

Ia 

0 

> 

W 

Y 

s 

I 

U 

W 

Iz 

W 

0 

W 

4 

0 

> 

F 

W 

-I 

a 

Z 

4 

a 

a 

v) 

z 

x 

W 

t0 

> 

W 

Y 

W 

a 

s 

4 

0 

t2 

m" 

3 

t 

I 

z 

A 

0 

0 

Z 

7 

573 
n 

S 

cn 

z 

0 

i= 

a 

U 

a e 

W 

v) 

X 

W 

tU 

0 

> 

W 

Y 

f 

w 

s 

0 

0 

0 

0- 

0 

c3 

A 

dc9 

c3 

v) 

z 

0 

F 

a 

a 

4 

Q 

W 

v) 

W 

> 

> 

a: 

W 

v) 

z 

0 

0 

e 

F: 

a 

W 

> 

F: 

e 

a 

n 

Q 

I 

Z 

0 

Z 

574 
U 

Q) 

L 

ic 

rcI 

'5 

0 

& 

E 

Q) 

0 

v) 

Q) 

0 

E 

0) 

U 

Q) 

a 

A 

575 
i 

0 

cn 

? 

576 
v) 

Z 

W 

m 

577 

cn 

4-J 

% 

0 

a, 

0 

1 

Y- CL) 

0 

a, 

cn 

-c 

(d 

Q 

+ -- S 

€ 

I 

0 

c\I 

l-- 

4-J 

0 

1 

T0 

w 

v) 

a, 

0 

-- 

L 

cn 

a, 

cd 

U 

Q 

3 

c: 

-CI 

n 

.I- 

€ 

I 

Tu 

73 

c 

cd .. 

-c-r 

c/) 

a 

0 

a, 

0 

LL 

1 

cb iz 

0 

a, 

0 

LL 

L 

0 

0 

U 

Q 

cd 

oc 

Ia, 

x 

B 

579 
OZQ I 

< I0 

a 

Yn 

Q 

cc 

X 

W 

z 

+ 

9 

n 

IW 

m 

ZI 

cc 

+ 

0 

=I 

U 

0 

Q 

1 

U 

a, 

U 

-- U 

1 

(3 

c/> 

I3 

- 

=c 

c) 

r. 

0 

z 

=c 

0 

W 

Iv) 

0 

Ia, 

Q 

CD 

€ 

I580 

0 

z 

v) 

Io 

u 

0 

e 

Iv) 

Q; 

0 

w 

U 

0 

U 

2 

U 

W 

IU 

0 

I 

v) 

? 

n 

a 

Fc 

3F 

z 

z 

0 

e 

LL 

0 

v) 

cn 

I 

I;; 

a 

z 

Q 

uu 

z 

A 

I 

U 

U 

0 

U 

0 

U 

w 

v) 

3 

w 

z 

0 

* 

I 

n 

m 

a 

Q 

a. 

z 

0 

0 

582 
583 
584 
a 

0 

IZ 

0 

r 

x 

w 

Ia 

0 

> 

I 

Y 

s 

a 

a 

n 

i 

n 

3 

W 

3 

Q 

3 

0 

3 

I 

I 

0 

F: 

cn 

3 

0 

0 

a 

I II 

v) 

W 

3 

iv) 

U 

U 

0 

W 

U 

iiii 

W 

z 

W 

m 

icn 

0 

0 

z 

0 

W 

v) 

E 

n 

a 

\ 

n 

a 

m 

Z 

0 

cn 

W 

I 

_. 

G 

n 

585 
k 

0 

.r( 

3 

3 

P 

f-4 

d 

d 

a 

u 

4 

f 

0 

p9 

2 

W 

5: 4 

9 

9 

4 

d .r( 

? 

*r( 

0 

V 

cd 

586 
a 

0 

> 

a 

I 

W 

m 

x 

W 

Ia 

0 

> 

w 

Y 

- 

s 

2 

I 

k 

a 

0 

u 

c3 

Z 

si 

0 

a 

a 

Ia 

d 

Z 

0 

I0 

W 

- 

II 

h 

a 

I 

0 

I 

W 

Z 

W 

ki 

a 

cn” 

n 

4 

t 

I 

h 

CI: 

I 

W 

IW 

0 

4 

LL 

a 

3 

v) 

cn” 

U 

0 

n 

I 

(3 

Z 

i3 

Z 

3 

0 

v, 

v 

1 

W 

-I 

ii 

0 

U 

n 

U 

W 

5 

W 

.I 

ii 

0 

a 

a. 

W 

0 

z 

W 

-I 

3 

111: 

3 

Irn 

W 

.I 

iT 

0 

rr 

e 

W 

a 

3 

Ia 

a 

W 

e 

I 

W 

I1 

cn 

a 

a 

a 

a 

0 

0 

I2 

a 

n 

a 

a 

a 

zi 

ILL 

0 

n 

a 

w 

n 

I= 

5 

Q 

2 

0 

i= 

E 

0 

e 

W 

W 

v, 

3 

t 

a 

a 

oe 

0 

0 lpt 

I 

z 

0 

i= 

a 

a 

3 

(3 

ii 

Z 

0 

0 

d 

II 

(3 

W 

ILL 

U 

0 

- 

3 

a 

a 

3 

W 

I- a 

I 

i= 

v) 

W 

I 

587 
z 

0 

i= 

4 

U 

3 

(3 

lL 

z 

0 

c) 

U 

- 

a 

n 

i 

x 

w 

IU 

0 

> 

W 

Y 

0 

588 
W 

Y 

a 

3 

589 
z 

0 

i= 

a 

U 

0 

W 

I- 

- Z 

U 

0 

cn 

Z 

W Cn 

X 

W 

IU 

0 

> 

f 

590 
cn 

au 

wa 

cnn 

U 

591 
W 

t3 

2 

U 

a 

W 

n 

f 

W 

(3 

Z 

Pe 

Y 

a 

592 
W 

593 
W 

U 

3 

cn 

W 

E 

0 

Icn 

a 

W 

)I 

W 

2 

a 

a 

a 

n 

a 

a 

x 

W 

)I 

0 

> 

P 

A 

C 

E 

Y 

W 

I 

i= 

0 

cn 

w 

0 

i= 

U 

0 

> 

>. 

U 

a 

z 

0 

i= 

a 

Icn 

n 

z 

4 

Iz 

w 

Icn 

t5 

U 

W 

e 

U 

0 

u, 

m 

U 

3 

0 

0 

0 

P 

U 

a 

M 

a 

r 

e 

594 
0 0 

A1130131A CHZIlVWtlON I 

4 

Y 

K 

IR 

cn 

LL 

0 

IE 

E 

W 

I 

1 I

t 

n 

E 

w 

0 

2 

v) 

w 

(3 

2 

U 

v) 

v) 

0 

0: 

0 

v 

s 

- 

n 

K 

a 

595 

0 u) 

d 'r v! I 

A113013A Cl3ZllVWtlON 

0 

a 

a 
(3 

21 

c) 

cOZI 

2 

0 

F 

c) 

w 

cW 

(3 

x 

UI 

c0 

> 

W 

Y 

1L 

a 

a 

a 

4 a 

a 

[3 

z 

596 
23 

Wv) 

597 
W 

U 

ILL 

0 

v) 

z 

0 

F 

0 

3 

n 

W 

oe. 

a Ia 

n 

s 

a 

598 
13 

z 

Z 

3 

599 
v) 

z 

0 

5 

Iv) 

z 

0 

B 

n 

a 

0 

W 

-I 

z 

c 

W 

a 

0 

2 

600 
II 

M 

w 

c3 

Z 

0 

,.I 

CD 

P 

z: 

ir 

i 

m 

G 

a 

I 

- 

W 

LL 

< 

z 

0 

r= a 

a 

W 

Q 

0 

a 

Z 

IU 

Iv) 

z 

0 

z 

W 

0 

Z 

u 

W 

m 

I 

- 

a 

- 

601 

Aircraft Wake RCS Measurement. 

W. Gilson, 

Massachusetts Institute of Technology 

603 
Radar Measurements of Aircraft Wakes at Kwajalein, RM.I. 

William H. Gilson 

Lincoln Laboratory, Massachusetts Institute of Technology 

244 wood street 

Lexington, Massachusetts 02173-9108 

ABSTRACT 

A series of multi-frequency radar measurements of aircraft wakes at altitudes of 5,000 to 25,000 ft. was 

performed at Kwajalein, R.M.I., in May and June of 1990. Two aircraft were tested, a Learjet 35 and a 

Lockheed C-5A. The cross-section of the wake of the Learjet was too small for detection at Kwajalein. 

The wake of the C-5A, although also very small, was detected and measured at VHF, UHF, L-, S-, and 

C-bands, at distances behind the aircraft ranging from about one hundred meters to tens of kilometers. The 

data suggest that the mechanism by which aircraft wakes have detectable radar signatures is, contrary to 

previous expectations, unrelated to engine exhaust but instead due to turbulent mixing by the wake vortices 

of pre-existing index of refraction gradients in the ambient atmosphere. These measurements were of 

necessity performed with extremely powerful and sensitive instrumentation radars, and the wake crosssection is too small for most practical applications. 

, This work was sponsored by the Office of Naval Technology. The views expressed are those of the 

author and do not reflect the official policy or position of the U.S. Government. 

604 
ILI 

cn 

c) 

a 

W 

Y 

a 

s 

ILL 

U 

c) 

pe 

a 

a 

I 

605 
W 

Iu, 

pc 

0 

CK 

a 

a 

- 

CI 

I 

a 

cn 

P= 

a 

CK 

a 

a 

m 

w 

A 

e 

L 

a 

X 

u 

a I-. a 

n 

U 

a 

n 

a 

U 

<n 

w 

U 

3 

I2 

u 

a 

v) 

W 

Y 

a 

3 

a a a a 

I: 

I- 

(3 

z 

W 

LT 

Iv) 

I 

v) 

z 

a 

z 

a 

I 

0 

W 

=> 

W 

A 

op 

z 

cn 

0 

PL 

I I 

cn 

a 

606 
oc: 

P 

a 

a 

a 

n 

2 

a 

1 

t 

d 

cn 

w 

0: 

3 

I 

c3 

2 

0 

WJ 

E 

Y 

0 

cv 

0 

c0 

c 

0 

3 

0 

r 

I 

60'7 
000000000' Yybc00Q)OrCVm jrrrr 1 I I I I I 

000000000 ~amwmu3b~oa 

I 1 I I I I I I I, 

608 
609 



21 

CC 

0 

0 

W 

M 

- 

n 

a 

n 

IQ: 

n 

2 

I: + 

a 

a 

n 

W 

0 

1 

II- 

- 

a 

CI 

YI 

0 

0 

0 m 

u)' 

CI 

a 

2 

1 

K n 

is 

z 

W 

v) 

CT 

!= 

a 

n 

a 

K 

613 
mW 

UY 

w 

n 

a 

m 

ci, 

z 

f 

c, 

? 

0 

‘0 

cu 

n 

-lo- 

‘W 

(3 

z 

K 

W 

oE 

a 

E 

-8 ii a 

U 

-0 

v) 

-0 

t 

1 

614 
z 

(3 

1 

0 

z 

)I 

a 

w 

t) 

I 

- 

%ll 

MY 

w4 

e 

na 

w 

(3 

2 

M 

z 

m 

a 

n 

a 

ch 

I I I 

n 'ill 

# 

0 

--u) 

cv 

0 m 

'i 5 

615 
v) 

3 

9 

0 

b I 

a 

a 

n 

Ia 

a 

0 

z 

d 

co 

Q, 

.- 

a 

9 

0 

Q) I 

9 

0 

0 

I 7 

0 

CD 

0 

v) 

0 

en 

E 

s 

w 

00 *z 

a I2 

P 0 

cv 

0 

r 

0 

616 
;fi 

z 

v) 

IIa 

a 

a 

n 

a 

3 

Ln 

617 

8 r 

0 

TA 

2 

(3 

). 

W 

i, 

z 

W 

3 

0 

W 

K 

L 

r 

T: 

0 
cn 

LLP 

0 

)I 

U 

a 

1 

cn 

2 

0 

?ii 

3 

ml 

0 

z 

0 

0 

W 

0 

1z: 

W cl 

2 

W 

W 

e 

n 

P[ 

U 

IU 

2 

4 

P 

a 

n 

Z 

w 

=r= + 

E" 

a 

Y 

0 

r 

O 

U 

0 

LL 

t 

8 

LL 

(3 

Z 

i 

J 

LL 

a 

+- 

J 

LL 

a 

I= 

0 

z 

(3 

2 

I- CI 

w 

W 

e 

+ I 

O 

Z 3 3 

-3 e k (3~ a 

U 

W 

n LL a WI- u. 

U v) 

z W Li 

0 W n w+ v) 

s 

W 

Zv) v) 

I 3 ZIJ I a 

n 

k 

s 

z 

W 

U 

+ 

U 

1 

0 + 

u) 

n 

a 

z 

n LL 

LL z -Is 

E a 

0 s 

I: 

+ 

c 0 Y 

U 0 W 0 N r 

.. w UI 

z z 

0 0 z 2 

618 
E 

cn 

z 

a 

I: 

0 

W 

E 

n 

a 

W 

)I 

I 

3 + 

cn 

0 

n 

U 

0 

X 

W 

2 2 

0 

n 

- 

* 

0 

lL 

o W 

K 

W 

n =r: 

e 

v) W 0 e 

n E 

0 

2 

W 

2 

W 

cn 

0 

pe 

- 

L 

(3 

21 

E 

5 

I21 

W 

A 

3 

K 

3 

Im 

v) 

Ia 

U 

(3 

2 

0 

Io 

U 

U 

W 

U 

m 

a 

=I= 

E 

+ 

2 

W + 

cn 

Gi 

2 

0 

0 

I 

w 

I 

III 

>. 

0 

Z 

W 

3 

a 

W 

K 

L 

e a 

W 

> 

>. 

fs 

5 

a 

w 

K 

3 

Icn 

L 

5 

a 

619 
w 

Y 

a 

3 

A 

< 

E 

v) 

). 

U 

W 

> 

a 

n 

w 

Iv) 

W 

(3 

(3 

3 

a 

Y 

[I: 

0 

s 

2 

A 

iii 

a 

a s Y 

W 

ml 

m 

z 

p: 

W 

0 

cn 

c 

El 

0 

2 

I2 

W 

2 

0 

e 

s 

0 

0 

I- in 

a 

3 

I 

X 

Ill 

W 

2 

2 

W 

t5 

2 

0 

F 

3 

m 

E 

t2 

0 

0 

(3 

2 

52 

z 

t2 

2 

z 

0 

a 

n 

.I 

J 

3 

LL 

W 

v) 

3 

W 

0 

2 

W 

n 

2 

W 

e 

W 

n 

W 

I- a 

E 

i 

0 

(3 

2 

0 

U 

Icn 

r 

W 

tcn 

). 

cn 

X 

w 

A 

e 

E 

0 

0 

n 

a 

2 

W 

(3 

a 

a 

ml 

a 

W 

II- 

=> 

ml 

0 

U - 

a 

pc 

W 

mml 

0 

a 

I 

e e 0 

620 
621 
622 
3 

c 

b 

k 

@Z 

3 

623 

Wake Vortex Detection at 

Denver Stapleton Airport with a 

Pulsed 2-micron Coherent Lidar. 

S. Harmon and A. Thomson, 

Coherent Technologies, Inc. 

625 1 FM, 
z 

0 

)I 

I 

W 

n 

5 

)I 

cn 

K 

W 

> 

n 

2 

2 

0 

Io 

W 

IW 

n 

X 

W 

)I 

K 

0 

> 

W 

x 

pc 

zi 

I2 Lu 

pc 

W 

I 

0 

a 

n 

5) 

E 

3. 

a 

I 

is 

cy) 

6) 

L 

m 

m w 

W 

3 

2 

0 

v) 

z 

0 

I 

c 

x 

W 

4 

a 

i 

n 

a 

z 

2 

0 

z 

2 

I 

a 

2 

W 

I 

W 

F 

v) 

e 

0 

z - 

ei 

0 

626 
W 

0 

W 

E 

8 

e 

e 

W 

a 

0 

0 

tu) 

z 

E 

t PI 

z 

z 

3 

u) 

a 

z 

0 

0 

PI 

e 

2 

v) 

w 

0 

W 

7 

m 

0 

f 

c 

Z 

W 

3 

v) 

W 

z 

a 

2 

0 

F= 

e 

z 

0 

u) 

W 

P 

E 

W 

tu) 

ti 

a 

(3 

Z 

3 

u) 

u1 

U 

8 

e 

a 

2 

a 

x 

W 

cU 

0 > 

iij 

u) F 

mJ 

3 

u) 

W 

p1 

W 

IJ 

e 

3 W 

a 0 0 a 0 0 

627 

c-3 - 

Q 

z 

a 

a 
Ei c 

a 

0 

n 

a 

z 

W 

2 

3 

w 

2 

3 

v) 

W 

0 

i= 

a 

0 

> 

W 

2 

3 

c 

2 

W 

c 

v) 

G 

a 

n 

mO be 

-n 

W 

%! 

n 

a 

d 

a 

W 

v) 

m 

z 

3 

0 

c3 

z 

0 

v) 

CI 

0 

W 

LL 

LL 

w 

c 

U 

3 

U 

x 

z 

a 

a 

LL 

2 

v) 

w 

0 

c 

a 

0 

> 

- 

n 

a 

2 

n 

0 

a 

2 

0 

0 

> 2 

w 

x 

5 

U 

0 

v) 

U 

0 

LL 

a 

a 

n 

a 

U 

U 

0 

z 

0 

Fz 

a 

3 

a 

> 

4 

W 

n 

a 

7 

2 

2 

0 

0 

W 

c 

W 

P 

a 

a 

LL 

iz 

Lu 

pc 

U 

3 

01 t I 

0 

n 

w 

W 

z 

c 

z 

W 

c3 

3 

a 

W 

O 

zl 

W 

c 

v) 

5 

a 

W 

Q 

d u1w -0 

Ku 

I01 

Eg 

0 

11 

0 

628 
0 

m 

n 

B >' 

0 

h 0 

E 0 

m x' 

E 

Y 

f YO 

E 

Y 8 

629 
c 

a w 

.................... 

..................... 

....................... ......... 1-11........,., 

...... *..III-----.....*.. 

'.....*.--ZIIIIIIII.*... -rA 3 -......* ~C-LLLeo*~LI-o+..,~. 

....... 0~~~~CCCCC455~.....~.~ 

,- ...*rrr)~cc~e~~~~~~~**.u.~ *d 

...... 

...... ..... -. ..... 

..... 

..... 

...... 

....- 

.... C ....... ....... ...... 

a,....- . 8. ....... #f 8 0 * - q .. -.*-.r*s* 

- ~'.....~~5~~4~CC~~~00..*..- . ...... *\%%s*+++++#@4*** ...... ....... . ...o,~-~~Cm~eLICI~**...r. ti ...... o.---e-~CCC.II...... E .......................... ........................ .................... 

.................... 

d 

d 

? 

a 

d 

9 

E 

W 

00 

00 

N 

F-t 

>r 

9 

W 

v, 

N 

E 

630 
n 

d 

t-. 

v) 

9 

... 

... 

... 

I.. 

.. 

.. 

............................... 

............................... 

............................... 

............................... 

............................... 

............................... 

............................... 

............................... ........ ........... ...... ......... ...... ........ ..... ........ 

..... .... 

.... 

.... 

.... ..... ..... ........ ..... ......... ....... .......... ........ ............ ..$.......*.................... ......................... 

......................... :s: ........................... 

........................... ::2;:::::: ..................... 

..................... .. 83 ............................ t..n ............................ 

n d 

d 

x 

........... .. ...... .. .. ..... .. .. ..... ., .......... 

............. 

............... 

................ 

....... 

...... 

...... 

...... 

...... 

...... 

...... 

...... 

....... 

....... ................ 

............... E ............... vu! ................ 

................ 

................ 

................ 

............... 0 - tz ................. 

OI 

0 

II 

E 

0 

Q 

N 

.CI c 

.-. 

a 

E 

631 
............................... 

............................... 

.......... .*&..........*................. 

E ..Q ............................ '.~.'"'..''......'....'......' 

.. 4 ............................ 

............ 

............ 

............ \

........... 

........... 

........... ui - 

tB ........... 

632 
k 

w elII 

0 

a 

8 

u, 

8 111 

5 

n 

w 

0 

633 
v) 

z 

A 

a 

P, 

2 

4 2 v) 

a 

zf 

Z d 

9 

0 

I 

z 

4 

v) 

n 

s 

2 v) 

v) * 

2 

4 

a 

a 

e 

e 8 

G 

9 

a 

t 

8 

111 

0 

- N 

I 

0 

s 

n 

II 

w 

u, 

n 

n 

3 

4 

w 

u, 

Z 

5 

5 

8 

5 

0 

w 

c 

n 

4 

z 

Ei 

w 

v) 

3 

iz 

0 

p? 

e 

0 

zi 

z 

n 

w 

!iz 

w 

n 

w 

p? 

a 

w 

I 3 

w 

Cr 

3 

p? 

w 

2 

f 

w 

c 

d 

0 

0 

4 

n 

a 

z P 

Z 

i3 

5 

8 

z 

0 

2 

0 

8 c 

f 

0 

2 

5 

w 

- Cr 

n 

v) 

a 

a 

I II 1 I I I 

0 

634 
0 b 

E 

a 

3 

W 

I 

z 

G 

2 

0 

0 

=i 

e 

f 

4 

z 

W 

W 

z 

3 

e 

a 

2 

0 

if 

Z 

0 

z 

=> 

- 

t 

a 

a 

IL 

v) 

8 

a 

8 

z 

z 

e 

IL 

Lx 

Lx 

z 

cn 

I 

2 

n 

6 

w 

I 

cn 

z 

n 

a 

z 

X 

E 

0 

> 

w 

I 

Z 

0 

z! 

a in 

c 

Lu 

n 

a 

z 

0 

3 

I 

a 

u, 

a 

635 
5 

d 

3 

0 

z 

0 

z 

I 

e 

Lu 

9 

8 

a 

S 

k 

CD n 

a z 

l3 

2 

a 

z 

3 

n 

4 

U 

s CD 

Z 

E 

a 

P 

P 

2 

3 

4 

4 

0 

111 + g 

0 

n c 

a 

a 

2 z 

v) m 

m 

Lu 

4 

). 

2 

0 - 

t 

l3 

Lu 

c 

el 

0 

z 

0 

z 

=I: 

e 

d 

s 

Lu 

6 

z 

2 

0 

z 

v) 

a 

I 

s 

0 

0 

U 

I I I I 

636 
). 

mml 

e 

# 

a 

n 

n 

a 

c!j 

5 

- 

2 

z 

# 

w 

0 

0 

e 

a 

LL 

c3 

). 

a 

mm 

0 

I 

IE5 

@ 

z 

0 

U 

3 

u 

IL 

2 

0 

0 

i= 

a 

P 

w 

w 

w 

v) 

0 

c 

n 

2 

D 

@ 

w 

# 

amll 

3 

-a 

e 

E 

\ 

@ 

a 

n 

U 

3 

w 

# 

mml 

3 

e 

0 

m 

2 

u, 

U 

e 

@ 

E 

0 

0 

F 

W 

pc 

3 

c 

a 

w 

n 

a 

I- 

# 

21 

U 

Is 

a 

o 

0 

ln 

u 

0 

ln 

1 

z 

c 

n 

B 

a 

II 

m 

a 

z 

v) 

w 

0 

0 

Ix: 

e 

v) 

0 

- 

I- + 

w 

a 

@ 

637 
638 
si 

LIL 

Lu 

I 

6 

2' 

O 

a 

a cn 

z 

8 6 

G 

n 

v) 

3 

m 

LIL 

;? 

ZI: h e b 

@ 

0. n 8 

a 

z n 

a 

> 

>. 

PP 

0 

3 cn 

3 

z t 

is 

r 

0 

4 

h" 

mv 

rz) 

h 

a 

n 

2 

v 

& 

h 

8 4 v) 

9 

4 

p. 

U 

0 4 

w 

I 

I 

5 

W 

v) 

m 

a 

a z 

n 

z 

P 

A 

3 

m 

c 

Lu 

0 

5 

5 

w 

c. 

w 

2 

z 

a 

w z z 

0 

a 

v) 

a 

2 

n 

0 

c 121 

z 

=r 

a 

c 

t 

t3 

a 

a 

a 

7 

P 

w 

c, 

0 

0 

4 

A 

a 

0 

r 

> 

CIL 

W 

iri 

2 

a 

z 

a 

5 

a 

w 

v) 

e 

A 

a 

0 

0 

A 

8 

2 

f 

c 

3 

Z E 

0 

0 

0 

w 

0 

ao 

d 5 

w 

v) 

e 

w 

N = 

i= 

3 

21 

0 I I I 2 1 I I I 

0 e e 

639 
0 

c 

ab 

z 

0 

i= 

'v 

a 

f 

a 

- N 

8 

f 

5= 

W 

LL 

111 

W 

v) 

p! 

a 

0 

0 

LL 

p! 

e 

3 

0 

111 

0 

640 
n 

)r 

0 

S 

Q) 

S 

CI 

a3 

t 

0 

2 

u, 

cn 

W 

0 

0 

PL 

e 

W 

v) 

1 

3 

e 

W 

(3 

Iv) 

a 

a 

v) 

3 

p. 

m 

L 

a, 

Q 

)r 

06 

Q 

cn 

U 

- 

..I 

z? 

S 

Q) 

3 

w 

a 

t 

6 

0) 

t 

06 

L 

€ 

3 

L 

.Clr 

0 

a 

Q 

cn 

Q) 

3 

[ZI 

a, 

L 

CI 

YI 

i5 

QL 

z 

v) 

0 

z 

v) 

a 

W 

0 

0 

PL 

e 

w 

z 

i= 

8 

W 

0 

cn 

a 

e 

cv 

W 

(3 

Icn 

a 

641 
>.+ 

x4L 

-9 In 

642 
N 

w 

A 

\ 

d 

111 ’ 

A 

LL 

V 

zy 

Q) 

Y 

(A 

s 

0 

S 

m 

> 

a# 

Y 

E 

h 

0 

11 4 

c U 

c 

* 

n 

Y 

’;J 

1 

-4v 

V 

It 

M 

n 

0 

II 

e- 

\ 

4 

J 

cv 

4 

w 

A 

r 

r 

rJ 

gI 

Y 

i3: 

# 

m 

W 

‘ru 

Y 

e 

8 

C 

V 

W .- 

5 + 

II 

.<d 

U I c 

B 

n 

I 

rt 

rtc 

643 
f 

tn 

E a 

Y 

B N 

w 

\ 

m 

cn Y 

Lo 

5 

s 

E 

?i .I

K 

l8 

0 

Y 

Q 

5 

l8 

(P 

0 

U E 

(I) 

Y 

! 

f 

0. 

.I 

PP 

w 

0 

K 

0 

> 

E 

W 

cn 

Q 

(D 

s 

E 

u * 

Ln 

0 

I 

v) 

d - I G 

0 

E 

II 

E 

e 

c. 

0 

Y 

Q) 

e 

- 

.... 

L 

Y 

s 

I I I 

644 
0 0 

645 
cn 

41 

0 

iiI1c: 

0 > 

pe 

0 

u, 

u 

z 

v) 

W 

0 

0 

U 

P, 

Y 

4 

W 

n. 

II 

K 

io 

W 

cn 

a 

a 

E 

v) 

a 

e 

I 

a 

x 

z 

646 
. 

* 

* e 

w f 

E 

F 

a 

P 

E 

f 

H 

:: 

P 

fr 

20 

6 

8 

X 

E 

s 

e -a 

-8 

*+ 

** 

*. 

647 
ra! 

1 

cn 

a 

5 
649 
!s 

a .1 

n 

v) 

55 

1; 

a 

a 

z 

a 

n 

I- < 

650 
J. Nespor, E. Hudson, and R. Stegall, 

Government Electronic Systems, 

Martin Marietta, 

and 

J. Freedman, 

651 
DOPPLER RADAR DETECTION OF VORTEX HAZARD INDICATORS 

J.D. Nespor, B. Hudson, R.L. Stegall and J.E. Freedman* 

Government Electronic Systems 

Martin Marietta MS 108-102 

Moorestown, NJ 08057 

*Current Afffiation: The MITRE Corporation, Mch,VA 

ABSTRACT 

Wake vortex experiments were conducted at White Sands Missile Range, NM using the AN/MPS-39 

Multiple Object Tracking Radar (MOTR). The purpose of these experiments was twofold. The first 

objective was to verify that radar returns from wake vortex are observed for some time after the passage of 

an aircraft. The second objective was to verify that other vortex hazard indicators such as ambient wind 

speed and direction could also be detected. The present study addresses the Doppler characteristics of 

wake vortex and clear air returns based upon measurements employing MOTR, a very sensitive C-Band 

phased array radar. In this regard, the experiment was conducted so that the spectral characteristics could 

be determined on a dwell to-dwell basis. Results are presented from measurements of the backscattered 

power (equivalent structure constant), radial velocity and spectral width when the aircraft flies transverse 

and axial to the radar beam. The statistics of the backscattered power and spectral width for each case are 

given. In addition, the scan strategy, experimental test procedure and radar parameters are presented. 

INTRODUCTION 

The need to provide protection against wake vortex-induced turbulence hazards necessitates imposing large 

separations between heavy jets and other aircraft, resulting in a major constraint on ATC system capacity. 

In truth, an actual wake vortex hazard is rarely present-occurring only when ambient winds along the 

approach path are too weak to rapidly dissipate the vortices. Since today’s ATC system lacks a sensor 

system that can indicate presence or absence of the wake vortex hazard, it must always be assumed that the 

hazard is present and the cost of reduced capacity is borne in the interest of safety. Previous research with 

microwave doppler radar has suggested the potential of this technology to monitor the winds and detect 

turbulence even in clear air conditions. This capability, if combined with the flexibility produced by the 

beam agility of phased array antennas, offers hope for an operational sensor system that can support an allweather fail-safe solution of the vortex problem. This solution could be accomplished in the following 

three ways. First, radar can provide doppler wind field measurements covering the terminal area which, 

when combined with data from other meteorological sensors present, can enable highly accurate 

mesoscale, short-term wind condition forecasts. These forecasts looking 20 to 30 minutes ahead provide 

the lead time needed for air traffic controllers to adjust traffic separations to the vortex hazard as indicated 

by forecasted wind speed and direction in the final approach corridor. Second, the radar could perform 

continuous real-time monitoring of the wind conditions actually occurring along the final approach path, 

providing a means for verifying the forecasted hazard level and if necessary alerting the controller to 

increase separations. Third, for ultimate protection, the radar could provide a means for actually detecting 

the vortices and determining decay rate and motion and, if necessary, alerting the controller to wave-off the 

approaching aircraft. 

652 
The above described possibilities have stimulated interest in including wake vortex protection as a 

functional requirement for the FAA's recently announced Terminal Area Surveillance System ("ASS). 

Encouraged by such interest, the Martin Marietta Co. has conducted an informal series of cooperative 

experiments with the white Sands Missile Range (WSMR) exploring the feasibility of including vortex 

protection functionality in an advanced multifunction terminal radar as envisaged for TASS. The aircraft 

test vehicles were limited to small jet aircraft (A-7), as heavier aircraft were not available. The sensor d 

was the ANMPS-39, a C-Band pulse doppler phased array radar originally developed by MM for the 

WSMR range instrumentation complex. The AN/MPS-39 is an excellent tool for exploring how beam 

agility can be exploited to provide prediction, detection and location of vortex hazards for a multifunction 

airport radar. This paper reports on the experimental results. It first reviews the physical basis underlying 

the application of microwave radar to the vortex problem, then describes the test radar and the experimental 

setup. It then goes on to present results, recommendations for further work, and finally conclusions. 

WAKE VORTEX AND OPTICALLY CLEAR AIR PHENOMENOLOGY 

Scattering from fluctuations in the refractive index of the atmosphere has provided a very powerful tool in 

the application of radars to clear air turbulence (CAT) investigations. It has been clearly established [ 1 ] [2] 

and widely accepted that high powered, very sensitive microwave radars can detect echoes caused by 

backscattering from inhomogeneities of the refractive index in the atmosphere. The backscattered power is 

related to the intensity of the fluctuations in the refractive index within a narrow range of turbulent eddy 

sizes centered at one-half the radar wavelength. This region is known as the inertial subrange of the 

turbulence. 

The theory of scattering of electromagnetic waves from refractive index in homogeneities has been 

developed by Tartarski. [3] For homogeneous and isotropic turbulence, Tartarski has shown 

that the structure constant can be expressed as Dn(r) = Cn2 r2/3. The scattering mechanism from 

homogeneous and isotropic turbulent media is similar to Bragg scatter in that a radar of wavelength h 

scatters from a particular component of turbulence with eddy sizes equal to U2 [4]. Ottersten [5] has 

derived the following expression relating volumetric reflectivity to the intensity of refractive index 

variations: 

n = 0.38 Cn2 h -'I3 

where Cn2 is the structure constant and is a measure of the intensity of the refractive index fluctuations, 

and h is the radar wavelength. It has been established by Chadwick [6] et al. that the scattering model for 

clear air turbulence is applicable to scattering from wake vortex induced turbulence. In other words, the 

vortex induced turbulence is created at scale sizes of 5-10 meters during the wing tip roll-up process and 

,then fractures to smaller sizes as the vortex dissipates. When the vortex induced turbulent scale size 

dissipates to the point where it becomes on the order of half the radar wavelength, the radar backscattered 

power then becomes proportional to the refractive index fluctuations. 

For turbulence associated with wake vortices, the characteristics of the vortex are generated primarily by a 

discontinuity in the air flow traversing the wings. This causes a vortex flow to be shed along the wing 

tips. The velocity gradients that are generated across the width of the vortex core are the primary 

contributor to the refractive index fluctuations. The entrainment of the heat emissions and water vapor 

653 
from the engines leads to increased fluctuations in the refractive index of the vortex as it propagates 

through the atmosphere behind the aircraft producing it 171. 

Continuous real-time monitoring of the low-altitude wind speed and direction has been demonstrated with 

the ANMPS-39 radar. We believe the sensitivity of this radar to monitoring wind speed and direction 

results from refractive index inhomogeneities caused by convective cells produced by the heating of the 

earth’s surface, as well as particulate scatter from small millimeter sized particles such as dust and insects 

which may be lifted by buoyant air parcels rising from the heated surface of the earth. Due to the size and 

nature of these particles, they are accurate tracers of air motion up to the boundary layer. It should be noted 

that the= may be seasonal and geographical variations in the scattering mechanisms that produce the radar 

echoes for mapping the low altitude winds. This is an area that needs to be investigated further. 

DESCRIPTION OF MULTIPLE OBJECT TRACKING RADAR (MOTR) 

Background 

The AN/MPS-39 Multiple Object Tracking Radar (MOTR) is a new precision instrumentation system 

designed to support range safety, weapon development, operational test and evaluation, and training 

exercises involving multiple participants. The first MOTR was delivered to the U.S. Army’s White Sands 

Missile Range (WSMR) in May 1988 where it underwent extensive field testing culminating in final 

government acceptance in December of that year. Since then three other MOTR radars have been delivered 

to various DoD test ranges around the country. A photograph of the radar is shown in Figure 1. 

Technical 

The MOTR’s transmission lens phased array antenna, mounted on an elevation over azimuth pedestal, 

enables it to accurately track up to ten targets while simultaneously processing two surveillance beams. 

Accuracies better than 0.2 mil rrns angle and 1.0 yd rms range are achieved while tracking a 20 dB or 

greater signal-to-noise ratio target. A 5.0 dB or better signal-to-noise ratio is obtained while tracking a 6 

inch diameter sphere with a 1.0 micro-second pulse width at 100 kiloyard range. MOTR is fully coherent 

and has built-in clutter suppression capability. The radar is mobile, and its design is based on Inter-Range 

Instrumentation Group (IRIG) timing, transponder, and frequency standards. Table 1 lists important 

MOTR system parameters. 

As can be seen from Table 1, the radar has the following unique features that make it very well suited for 

vortex detection experiments: 

1) High peak transmit power of 1 MW for high sensitivity. 

2) Antenna beamwidth of 1’ for good angular resolution of targets. 

3) Very low antenna sidelobes -45 dB rms for reduced sidelobe clutter contamination. 

4) Variable pulsewidth between 0.25 psec and 1 psec. This corresponds to variable range 

resolutions of between 37.5 meters to 150 meters. 

654 
5) The ability to electronically steer the beam reduces ground clutter contamination. 

6) High system stability for high doppler resolution. 

Modifications 

MOTR software was extensively modified to support the wake vortex experiments and these changes have 

permanently been made part of all existing systems. MOTR additions consisted of a new mode to enable 

disk recording of 36 range gates of coherent in-phase and quadrature sum channel data and angle scan 

modfications to permit dwells of up to 256 pulse repetition intervals. 

WSMR WAKE VORTEX EXPERIMENTAL OVERVEW 

During January-February of 1991, the AN/MPS-39 MOTR at WSNR, NM was used to conduct wake 

vortex detection experiments. Weather conditions during this time were characterized by mild daytime 

temperatures, rising to 55-60 degrees Fahrenheit on the average, with generally light winds. In general, 

during the winter months, the two dominant type air masses influencing WSMEt weather are modified 

Maritime Polar and Modified Continental Arctic. The modified Maritime Polar was the system that 

dominated the weather patterns during this time. No precipitation in the region occurred during the days 

when fly-bys were being conducted. 

Experiments were conducted using A-7 fighter aircraft flying out of Holloman, Air Force Base. Figure 2 is 

an elevation view of the geometry of the experiment. Figure 3 shows the location of the two space points 

that the aircraft flew through relative to the radar. Space Point 1 was located 3 kyds directly north of the 

radar, and space point 2 was located 3 kyds directly west of the radar. The aircraft flew a clockwise 

racetrack flight pattern and was vectored to the appropriate space point and altitude by the WSMR control 

tower. The experiment was set up such that the radar looked axially behind the aircraft for vortices as it 

flew through space point 2, and looked transverse to the aircraft flight direction as it flew through space 

point 1. The aircraft flew at an approximate speed of 180 knots with both flaps and landing gear down to 

simulate as close as possible a landing configuration. Each mission was composed of three separate data 

collection modes. These consisted of a pre-mission, target mission, and post mission data colIection mode. 

The pre-mission data collection mode was performed approximately 15 minutes before the aircraft arrival. 

The intent was to record data on clear air returns prior to the aircraft’s arrival. Data was then collected for 

at least 30 seconds immediately before the aircraft flew through the beam and for at least one minute after 

the aircraft flew through the beam. Another post-mission data collection mode was then taken for two 

minutes to determine the ambient wind conditions after the fly-by. Before and after each mission, a call 

was placed to the WSMR weather station located a half mile from the radar so that the temperature, 

humidity, pressure, wind speed and direction both at the surface and aircraft altitude could be monitored 

ad used in subsequent data analysis. Visual observations were made of the two space points with 

personnel using binoculars during the entire mission. Two observers were employed; one monitored space 

point 1 and the other space point 2 for birds, insects, etc., flying through or around the beam. 

Figure 4 shows the scan pattern employed by the radar for the axial passes (looking due west to space 

point 2): The radar electronically scanned a 3x3 array, the aircraft was vectored through the top middle 

beam. This scan strategy facilitated vortex detection even when the cross winds were strong enough to 

blow the vortex into the adjacent beams or, as they sank into the lower beams, when the wind conditions 

655 
were calm. Figure 5 shows the scan pattern employed by the radar for the transverse pass when the radar 

was looking due north to space point 1. For this scan, the radar electronically scanned a 6x1 array. The 

aircraft flew through the third beam from the top. This allowed for some uncertainty in the aircraft’s 

altitude as it flew through the beam, and also allowed the vortex to be detected as it sank into the lower 

beams. 

Data collection modes for clear air mapping were very similar to the vortex scan modes discussed above 

except the tests were conducted without an aircraft fly-by. Data was collected for up to three minutes in 

this mode at space points 1 and 2. 

~ 

DATA ANALYSIS AND RESULTS 

Table 2 compares the vortex characteristics of the A-7 aircraft used for this experiment against other well 

known aircraft types. As Table 2 indicates, the circulation strength of the vortex produced by the A-7 is 

significantly less than all the other aircraft presented. This is primarily a function of the lighter weight of 

the A-7 aircraft. With this in mind, this section presents the spectral characteristics of what is believed to 

be a vortex detected when the A-7 aircraft flew through space point 2 (axial to the beam). While severd 

passes were conducted on this day with the A-7 aircraft, the pass presented herein represents the only data 

set collected to date that has been usable. This is because of experimental problems that occurred on the 

other passes on this day. Subsequently, constraints on range or aircraft availability have prevented us from 

reproducing these results. In addition, spectral characteristics from a very windy and a calm clear air day 

are presented. 

Wake Vortex Spectral Processing 

The experiment was set up such that 36 range gates were spread out over a 2 kyd range interval. 

Essentially, there were 18 range gates on either side of the designated space point. The radar was operating 

with a 1 microsecond pulse and a 1280 Hz pulse repetition frequency. For each range gate, 128 I & Q 

samples were recorded for each of the nine or seven beams at a given space point Thus, the dwell time for 

each beam was 0.1 seconds, and each beam was revisited every 0.9 seconds over the course of a given 

data collection period. A 256 point ET was then performed for each of the 36 range gates for all nine 

beams over the entire data collection interval. The time series data was weighted by minimum three-term 

Blackman-Harris weights to push the sidelobes below -70 dB. The periodogram at each range gate was 

then used to estimate the first three central moments such that 

where 

power in dBsm was then converted to an equivalent structure constant Cn2. 

is the estimate of backscattered power and N is the number of spectral lines. The backscattered 

656 
where 9 is the mean velocity estimate and N is the number of spectral lines. 

where G2 is the spectrum width estimate, G is the mean velocity estimate and N is the number of spectral 

lines. 

It should be noted that care was taken to remove the undesired ground clutter spectral components before 

each of the fxst three central moments were computed. This was accomplished by removing four spectral 

lines on either side of the zero velocity component. 

Figures 6(a) through 6(c) show “waterfall” or Doppler history plots of a vortex produced by the A-7 

aircraft as it was flying axially through the top left radar beam. These plots consist of the time history of 

the spectral characteristics for three range gates. For these plots, negative velocities represent motion 

toward the radar and positive velocities represent motion away from the radar. Time increments between 

each spectrum are 0.9 second. On this day at the time of this mission, it was exceptionally calm at the 

surface and winds were reported between 1 - 2 knots at 800 feet, the approximate altitude of the aircraft. 

There were no birds or insect swarms reported from the visual observations made during the course of this 

mission. Figure 6(a) shows no vortex in range gate 14, but it does show the target saturating the receiver 

as it goes through the beam at this range gate. This figure also substantiates the wind conditions reported 

by the WSMR meteorological station. Also note that there were approximately 10 seconds of data collected 

before the aircraft flew through the beam. No spectra induced by vortices shed by .the A-7 are evident after 

the aircraft flies through the beam for this range gate. The dark narrow spectral lines centered around zero 

velocity are ground clutter. However, for Figure 6(b) which is a spectral history for adjacent range gate 

15, vortex induced spectra appear about 8 seconds after the aircraft leaves the beam at 18:07:22 GMT. 

Figure 6(c) which is the spectra1 history for range gate 16, shows a larger amplitude in the spectra and 

again no wind induced spectra before the aircraft flies through this gate. It appears that the vortex is in this 

gate for approximately 10 seconds. The two spectra, one on each side of the zero doppler, may be 

evidence of vortex perturbations in either direction. These have been observed from the axial structure of 

the vortex by other researchers [lo]. In addition, the axial flow perturbations are generally small 

compared with the flight speed. Near the center of the vortex, there may be perturbations on the order of 

15% of the flight speed. For the spectral plots presented here the radial velocities were approximately 5 

657 
hots( about 5 percent of the flight speed). However, we reiterate that relating the complex vortex physics 

to the spectral characteristics is somewhat difficult. The spectra produced by the vortices appear in the 

succeeding range gates 17 and 18 as well for th&s upper beam. 

Figures 7(a) through 7(e) show Doppler History plots for the beam directly below the upper left beam 

considered above. The first range gate where the vortex induced spectral characteristic occurs is number 

13. We believe the vortex produced by the A-7 aircraft is sinking into the lower beams and into the closerin rangegates. This is consistent with results reported by other investigators [8] [9]. For Figure 7(a), the 

first evidence of vortex induced spectra occurs at 18:07:43 GMT approximately 21 seconds after the time 

the vortex appears in the upper beam. It should also be noted that the target returns shown in the plots for 

this beam are caused by the aircraft flying in the angular sidelobes of the antenna. For adjacent range gate 

14 in Figure 7(b), the spectral amplitude is larger. In range gate 15 in Figure 7(c), two sets of spectra 

appear. One set of spectra occure earlier than the spectra in the upper beam and the other occurs later. The 

earlier spectra occur at approximately 18:07:26 GMT. The coherent return appears about 17 seconds 

earlier than it did in the upper beam. It is expected that the vortex returns would occur earlier in time at the 

farther out range gates in the lower beams because the aircraft flew through the lower beams earlier in 

time. In range gate 16 in Figure 7(d), the spectra occurring at the later time begins to decay while the 

spectra occurring earlier in time but at farther out range gates begins to grow. At range gate 17 in Figure 

7(e), the spectra occurring later in time are almost fully dissipated while the spectra occurring earlier is 

larger in amplitude. By range gate 19, the spectra occurring earlier dissipates as well. Both sets of spectra 

lasted for about 10 seconds. 

Figures 8(a) and 8(b) are Doppler History plots for the lowest beam. The first gate where vortex induced 

spectra occur is in range gate 12. The time associated with this spectra is approximately 18:07:45 GMT 

which is about the same time that was observed for the spectra in the beam above. This could be expalined 

by the overlap of the antenna beams at the 3 dB points. Figure 8(b) shows the spectra getting larger in 

amplitude and width, which is indicative of increased backscattered power for that gate. The spectra last 

for about 12 seconds and are spread out spatially over range gates 12 to 17. The apparent radar cross 

sections of the vortices presented for each of the three beams ranged from -65 dBsm to -80 dBsm. The 

equivalent structure constant, Cn2 ranged from -1 16.7 to -135.4 dB. The apparent cross sections tended to 

increase as the vortex dropped into the lower beams. This might mean that the vortex grows spatially as it 

decays and occupies more of the pulse volume as it dissipates with time. The larger spatial extent of the 

vortex within the pulse volume could possibly explain the larger apparant cross sections in the lower 

beams. 

The mean velocities tended to range from 1.1 m/s to 4.5 ds. Spectral width tended to stay relatively 

constant and ranged from 2.75 to 3.7 m/s. We believe the data presented for this A-7 axial case to be 

consistent with what has been generally reported about vortex characteristics. However, specific radar data 

sets of axial looks at aircraft are nonexistent to the best of our knowledge. This makes making definitive 

statements difficult 

Clear Air Spectral Processing 

Figures 9(a) through 9(c) show Doppler History plots of data collected on a very windy day on 5 May 

1991. The wind direction at the surface was from the west at 270 and the wind speed was 15 knots with 

658 
gusts reported to 25 knots by the WSMR meteorological station. At 800 ft., the wind speed was reported 

at 25 lqots with gusts to 30 knots. The radar was pointed due east and scanning a 3 x 3 pattern. The radial 

wind velocities of each of the three time history plots correlate very well with the speed and direction 

reported by the WSMR meteorological station. The plots show that the winds are moving away from the 

radar as one would expect with the prevailing westerly winds and the radar scanning due east. In addition, 

Figures 1O(a) through 1O(c) show the histograms of the fxst three central moments for the data collected 

that day. Figure 1O(b) shows the average radial velocity to be at -428.04 Hz which corresponds to a wind 

speed of 23 knots moving away from the radar. This again correlates quite well with the meteorological 

station's report. Figure 1O(a) shows the average structure constant to be -139 dB for this very windy day. 

In addition Figure ll(c) shows the average spectral width was 91.5 Hz which corresponds to 2.5 m/s or 5 

knots. 

Figures 1 l(a) through 1 l(c) show Doppler History plots of the data collected on a relatively calm morning 

on 6 May 1991. The wind direction at the surface was from the south at 190' and the wind speed was 5 

knots. At 800 ft., the wind speed was reported at 8-10 kts. The radar was pointed due north to space point 

1 and was scanning a 6 x 1 pattern. The Doppler History plots show very little activity for the three highest 

beams except for occasional gusts. Figures 12(a) through 12(c) show histograms of the first three spectral 

moments for the data collected on that day. Figure 12(b) shows the average radial velocity to be at -103.9 

Hz which corresponds to 5 knots away from the radar. Figure 12(a) shows the average structure constant 

to be -143.5 dB, and Figure 12(c) shows the average spectral width to be 95 Hz which corresponds to 5.2 

knots. 

DART Plot Description 

The Doppler History Plot was cumbersome to use when initially examining the data since it only provided 

information on one small segment of the scan volume. Several additional data representations were tried 

for visualizing over a larger volume. We learned that one of the dimensions that was necessary to include 

was time. We finally settled on a representation we called a DART (Doppler-Amplitude-Range-Time) plot. 

Figure 13 shows this plot. Using three axes and color, variations in amplitude and frequency of the 

spectral peak over range and time are easily seen allowing quicker identification of a potential vortex for 

more detailed analysis and a visualization of clear air phenomenon. Color indicates the doppler bin that the 

peak of the power spectrum occurs in. If the velocity is unambiguous, motion toward the radar is indicated 

by blue, motion away from the radar is indicated by red, and near zero velocity is indicated by green. The 

vertical axis is the amplitude of the peak of the power spectrum expressed in dBsddoppler bin, Le., the 

received energy is referenced back to the scattered. Time is shown on the horizontal axis and the 36 range 

bins are shown on the axis coming out of the page. When an aircraft flies through a beam it shows up on 

the DART plot as a high amplitude ridge. The order that the range bins is shown can be reversed so that 

both sides of the ridge can be seen. The DART plot is generated by estimating the power spectrum, as in 

the Doppler History plot, for each range gate. The doppler bin with the peak amplitude is located and the 

doppler bin is color coded. A varying color line is then drawn connecting the peak amplitudes of the 36 

range bins with values less than -100 dBsm being shown at -100 dBsm in black. The processes are 

repeated for each time sample. 

RECOMMENDATIONS FOR FUTURE EXPERIMENTS 

659 
In the course of this experiment, it has become clear that there are a number of useful areas for continued 

investigation. The effort thus far has demonstrated the highly variable and dynamic characteristics of 

vortex induced turbulence and opticaIly clear air returns. We recommend the following areas for future 

investigation: 

1) Carry out a series of experiments that insure the repeatability of the radar vortex returns presented 

in this paper and extend the experiments to include the more representative heavy commercial 

aircraft such as an MD-11 or Boeing 747. 

2) Carry out experiments that will identify wake vortex signatures of heavy commercial aircraft and 

distinguish .them from ambient winds. 

3) Establish the reliability of monitoring wind speed and direction from ambient winds so that the 

conditions for wake vortices stalling can be predicted. A long-term investigation for determining 

wind speed and direction at low altitudes by microwave radar should be compared to a 

meteorological network of wind sensors to validate the reliability of monitoring winds. 

4) The maximum range of detection should be established for heavy commercial aircraft. 

5) A thorough study should be carried out to determine how well microwave radars detect vortices in 

rain, fog and other kinds of precipitation. 

SUMMARY AND CONCLUSIONS 

The experiments reported herein were an exploratory, limited scale feasibility investigation. They were 

performed by piggybacking on other scheduled WSMR missions so that resources could be obtained 

inexpensively. As such, we had to use aircraft that were already at WSMR which limited the aircraft 

population to A-7 jet fighters. Access to a heavy jet capable of producing the hoped-for very strong vortex 

radar echoes could not be provided without a formal testing program. Nevertheless, the tests did show 

definite evidence of detection of weak vortex echoes on an axial view for even the small A-7 aircraft which 

has an expected vortex backscatter cross section two orders of magnitude less than a heavy jet such as a 

MD-Il or Boeing 747. Also, the ability of microwave pulse doppler phased array radar to efficiently 

monitor low-level wind conditions in clear air was demonstrated. We find that these results point toward 

the feasibility of a multifunction radar playing an important role in TASS as a wide area indicator of wake 

vortex hazards. We believe the evidence and ultimate benefits to be substantial enough to warrant a serious 

FAA testing program that would: 1) validate and develop further the role of microwave radar as a vortex 

hazard indicator, and 2) establish appropriate operational concepts. 

ACKNOWLEDGMENTS 

The authors acknowledge the significant contributions to this project made by MM Aerospace engineer L. 

Gereffi. We also are deeply indebted to D. Sammon, T. Stevens, and their personnel for their enthusiastic 

support and cooperation during tests at White Sands Missile Range. 

REFERENCES 

660 
ICR. Hardy, "Studies of the Clear Atmosphere Using High Power Radar", Remote Sensing of the 

Troposphere Symposium, ed. by V. Derr, University of Colorado, 1972. 

K. R Hardy and I. Katz, I' Probing the Clear Atmosphere with High Power High Resolution 

Radars", Proc. IEEE, p.468, April 1969. 

V. I. Tatarski, Wave Propagation in a Turbulent Media, McGraw-Hill, Inc., New York, N.Y., 

1961. 

M. I. Skolnik,.Introduction to Radar Systems, McGraw-Hill, Inc., New York, N. Y., 1980. 

H. Ottersten, 'I Atmospheric Structure and the Radar Backscattering in Clear Air", Radio Science, 

Volume 4, No. 12, Dec. 1969, pp. 1179-1193. 

R B. Chadwick, J. Jordan and T. Detman, "Radar Detection of Wingtip Vortices", 9th Conference 

of Airospace and Aeronautical Meteorology, June, 1983, pp. 235-240. 

J. D. Friedman, "Airborne Wake Vortex Detection", March 1974, pp. 3-7 through 3-9. 

R. B. Chadwick and A. J. Bedard, Jr., Private Communications, April, 1991. 

W. H. Gilson, Private Communications, 199 1. 

[lo] J. N. Hallock and W.R. Eberle, ed., "Aircraft Wake Votices: A State of the Art Review of the 

United States R&D Program, U. S. Department of Transportation, FAA, DOT-TSC-FAA-77-4, 

February 1977. 

661 
Table 1. MOTR System Parameters 

Parameters 

Radar Frequency 

Antenna: 

Directive Gain 

Beamwidth 

Scan Volume 

Transmitter Power: 

Peak 

Average 

Rm7e 

System PRF (Selectable) 

Object PRF (Selectable) 

Pulsewidth (Selectable): 

Non-Chirp 

Chirp (Expanded) 

Chirp (Compressed) 

Position Servo 

Maximum Rate. 

Azimuth 

Elevation 

Pedestal Servo: 

Maximum Acceleration 

Tracking Filters: 

Coordinates 

Tvpes 

Bandwidth 

Value 

C-Band (5.4 to 5.9 GHz) 

45.9 dB 

1.05' 

60' cone plus cusps 

1.0 Mw 

5.0 kW 

0.5 to 8192 kyd 

80,160,320,640,1280 Hz 

20,40,80,160,320,640,1280 Hz 

0.25,0.5, 1.0 ps 

3.125, 12.5,50 ps 

0.25 ps 

Rate-&ded Type 2 

800 nnils/s 

300 dS/S 

200 &/S/S 

Cartesian (XYZ) 

Alpha-Beta, Alpha-Beta-Gamma 

PW/2 to 0.1 Hz 

662 
E 

W 

wv) 

ox 

2:: 

'cc u Oh 

c 

a 

mN 

a& 

w. 

Lc, 

01 * 

X 

0 

0 

N 

T In 

m 

0 

m 

m 

N 

In 

rn 

Q, 

In 

4 

h 

h 

'9 

0 

In - lD 

a0 

0, 

0 

0 

0, 

9 

2 

m 

L 

m 

W 

e 

h 

N 

h 

I 

m 

"1 * 

X 

0 

0 

N 

0 

0 * 

0 

0 

v) 

N 

'd 

v) 

H 

In 

2 

0 

h 

s 

'd 

m 

c.( 

? 

0) 

W 

0 

0 

W 

9 

2 

N 

L 

(II 

a 

CT 

c: 

V 

a 

a? 

v) 

x 

0 

Q, 

4 

v 

b. 

m 

an 

m 

In 

an 

c9 

W 

0 

In 

v) 

re 

In 

Y) 

d 

0 

0 

0, 

2 d 

rrl 

h; 

v) 

x 

In 

N 

N 

CJ 

s 

h 

CI 

z 

In 

e 

lD 

In 

In 

h 

H 

In 

In 

CI 

0 

0 

0 

m 

0 

d 

L 

c1 

v) 

N 

"i 

h 

h 

m 

CJ 

y! 

N 

Q) 

In 

m 

0 

2 

0 

0 

N 

m 

In 

23 

z: 

N 

00 

00 

NO 

NCO 

99 

N 

0 

c) 

L, 

4 

L 

W 

u 

m 

L 

E 

m 

n 

U 

W 

m 

= 

V 

a 

v 

I 

V 

- 

c 

L 

W 

u 

0) 

E 

m 

L 

m 

n 

0 

W 

w 

m 

E 

c, 

v) 

0) 

I 

VI 

.r 
Figure 1. MOTR in Operation (US Army Photograph) 

664 
665 
NORTH 

t 

SPACE POINT 1 

(NORTH) I 

f 1 2 

7 . +- 

3.0 Kyds 

MOTR SN1 I: / 

+- 

SPACE POINT2 

(WEST) \4 

-+ 1- 3.0Kyds -1 

FIGURE 3 

WAKE VORTEX TEST SITE LAYOUT 

666 
Be 

Be 

Alpha Beams 

FIGURE 4 3x3 SCAN PATTERN USED FOR AXIAL PASSES 

Alpha Beams 

FIGURE 5 1 X 7 SCAN PATTERN USED FOR TRANSVERSE PASSES 

667 
640. 320. 0. -320. -640 

I ' 611 ' IO #I' I 

Frequency - & 

-0.5 -0.25 0. 0.25 0.5 

Velocity Fraction 

Plot: (Uncomp. Doppler 1. 

FFT Samples: 

Ill ei g h t: 1 Blac km an-H arris 

Dynamic Range (dB): a 

AmbiguDus Vel. (ydls) = 36.8968 

Peak Spread(&) = 15.01 

P.S. Time: 18: 07: 06.50 

Range Bin = 14 

UBeams = -2 

VBeams = 2 

Signal Peak =-56 87 dBsm/€k 

Display Ceiling =-70.00 dBsm/€k 

PRF 

Frequency = 5690.0 MItz 

tlission: 2/ 6/91 18: 06 

Analysis: 10/23/91 13:25 

Spread(€&) = 10.01 

= 1280.6917 Hz 

Figure qA). Doppler time history plot for A-7 fly-by, 

upper beam, range gate 14, axial case. 

668 
Time I 

Time 

plot: Iuncomo. DODOlef 1 

FFT samples: [ET] 

Dynamic Range (dB): 

Weight:IBlackman-Harris 1 

Ambiguaw Vel. (yd/s) = 36.8968 

Peak Spread(&) = 575.31 

P.S Time: 18:07:14.60 

Range Bin = 15 

UBeams = -2 

VBearns = 2 

Signal Peak 5-56.34 dBsm/& 

Display Ceiling =-70.00 dBsm/& 

Frequency = 5690.0 MHz 015 Ilission: 2/ 6/91 18:06 

Velocity Fraction 0.25 Analysis: 10/23/91 13:34 

Figure 6(B). Doppler time his- plot for A-7 fly-by, 

Spread( Hz) = 10.01 

640 320'Frequency 0. - Hz -320. -640. pw = 1280.6917 Hz 

I * OII a , 81, * 

-0.5 -0.25 0. 

UPP beam, range gate 15, axial -- 

0. -320 -64 0 320'Frequency - Hz 640 

I ' ais ' I "I' I 

-0.5 -0.25 0. 0.25 0.5 

Velocity Fraction 

Plot: IUncomp. Doppler I 

FFT Samples: 1128-1 

Weight:[Blackman-Harris I 

Dynamic Range (dB): 

Ambigunus Vel (yd/s) = 36.8968 

Peak Spread(=) = 415.22 

P.S Time. 18.07.06.50 

Range Ban = 16 

Weans = -2 

VBeams = 2 

Signal Peak =-56.25 dBsrn/R 

Display Ceiling = -70.00 dBsm/R 

PIG = 1280.6917 Hz 

Frequency = 5690.0 

tlzssion: 21 6/91 18:06 

Analysis: 10/23/91 13:48 

Spread(&) = 10 01 

Figure qC). Doppler time history plot for A-7 fly-by, 

upper beam, range gate 16, axial case. 

669 
Time 

~ 

Time 

640. 320. 0. -320. -I Frequency - & 

Plot: [Uncomp. Doppler 1 

FFT samp1es:m 

Ambiguous Vel. (yd/s) = 36.8968 

Spread(&) = 10.01 

Peak Spread(&) = 415.22 18:07:06.30 

P.S. Time: 

Range Bin = 13 

UBeams = -2 VBeams = 0 

Sigrul Peak =-63.24 dBsm/& 

Display Ceiling =-70.00 dBsm/lk 

PRT = 1280.6917 & 

I Frequency = 5690.0 HI& -- 

' ' ' ' ' ' ' ' ' I ' ' o.5 tlission: 2/ 6/91 18:06 -0.5 -0.25 0. 0.25 Analysis: 10/23/91 13:59 Velocity Fraction 

FIGURE 7(A) DOPPLER TIME HISTORY PLOT FOR A-7 FLY-BY, 

MIDDLE BEAM, RANGE GATE 

640. 320. 0. -320. -640. 

I .I' . t ' 'I' ' I 

Frequency - Hz 

-0.5 -0.25 0 0.25 0.5 

velocity fiaction 

13, AXIAL CASE 

plot: Juncomp. Doppler I 

FFT Samptes:F\ 

WeighkIBJackmen-Harris 1 

Dynamic Range (dB): 

Ambigvous Vel. (ydls) = 36.8968 

Spread(&) = 10.01 

Peak Spread(&) = 15.01 

P.S. Time: 18:07:09 00 

Range Bin = 14 UBeaas = -2 VBeans = 0 

Signal Peak 'E-57.27 dBsmffLDisplay Ceiling =-70.00 dBsm/fLPRT = 1280.6917 10 

Frequency = 5690.0 tMz 

tlission: 2/ 6/91 18:06 

Analysis: 10/23/91 14:07 

FIGURE 7(8) DOPPLER TIME HISTORY PLOT FOR A-7 FLY-BY. 

MIDDLE BEAM, RANGE GATE 14, AXIAL CASE 

670 
Time 

Plot: [Uncomp. Doppler 1 

FFT Samples: 11281 

Weight:IBlackman-Harris 1 

Dynamic Range (dBk .- 

Ambimus Vel. fvd/s> 

.. = 36.8968 

Spre&i(&) = 1'0.01 

Peak Spread(&) = 415.22 

P.S. Time: 18 : 07 : 07.20 

Range Bin = 15 

UBeams = -2 

VBeams = 0 

Signal Peak =-56.93 dBsm/& 

Display Ceiling =-7O. 00 dBsm/& 

640. 320'Frequenc]t. 0 - Kz -320. -640. pu = 1280.6917 ZIZ 

frequency = 5690.0 Ilf[z I I' I I' I fission: 2/ 6/91 18: 06 I 

-0.5 -0.2s 0. 0.25 0.5 Analysis: 10/23/91 14: 13 Velocity Fraction 

FIGURE 7(~) DOPPLER TIME HISTORY PLOT FOR A-7 FLY-BY, 

MIDDLE BEAM RANGE GATE 15, AXIAL CASE 

671 
Time I 

Plot: Iuncomg. DoDDIer I 

FFT samples: 1128-1 

Weight:IBleckmen-Harris I 

Dynemic Range (dB): *. 

Ambiguous Vel. (yd/s) = 36.8968 

Peak Spread(*) = 75.04 

P.S. Time: 18:07:26.09 

Range Bin = 16 

UBeams = -2 

VBeams = 0 

Signal Peak =-57.27 dBsm/B 

Display Ceiling = -70.00 dBsm/H; 

Spread( Hz) = 10.01 

= 1280.6917 Hz 640. 320. 0 -320. -640. pm Frequency' - Hz 

Velocity Fraction 

I Frequency = 5690.0 tlHz 

kission: 21 6/91 18: 06 

-0.5 -0.2s 0. 0.2s O.' Analysis: 10/23/91 14:27 

I ,I' I I I ,I' 

FIGURE 7(D) DOPPLER TIME HISTORY PLOT FOR A-7 FLY-BY 

MIDDLE BEAM, RANGE GATE 16, AXIAL CASE 

672 
Time 

k 

640. 320. 0 -320. -640. Frequency.' - Hz I I ,I i I 

-0.5 -0.25 0. 0.25 0.5 

Velocity Fraction 

plot: (Uncomp. Doppler 

FFT Samples: [WJ 

I 

Dynamic Range (dB): 

Ambiguous Vel. (ydls) = 36.8968 

Peak Spread(Hz) = 65.04 

P.S. Time: 

Range Bin = 17 

UBeams = -2 

YBeams = 0 

Signal Peak =-57.53 dBsmlHs 

Display Ceiling = -70.00 dBsm/f[r 

Spread( Hz) = 10.01 

18:07:25.19 

PW Frequency = 5690.0 128.6917 tlHz Hz 

Mission: 21 6/91 18: 06 

Analysis : 1 0 /23/9 1 14 : 33 

FIGURE 7(E) DOPPLER TIME HISTORY PLOT FOR A-7 FLY-BY, 

MIDDLE BEAM, RANGE GATE 17, AXIAL CASE 

673 
Time 

t 

640. 320. 0 -320. -640. 

Frequency',- 4 

-0.5 -0.25 0. 0.25 0.5 

Velocity Fraction 

Plot: [Uncomp. Doppler 1 

FFT Samples: 1'281 

Weigh 1:I Blackman-Harris 1 

Dynamic Range (dB): 

Ambiguous Vel. (ydfs) = 36.8968 

Peak Spread(&) = 415.22 

P.S. Time: 

Range Bin = 12 

UBeams = -2 

VBeams = -2 

Signal Peak =-68.83 dBsrn/H: 

Display Ceiling =-7Q. 00 dBsrn/& 

PW 

Frequency = 5690.0 MHz 

Mission: 2f 6/91 18: 06 

Analysis: 10/23/91 14:48 

Spread(&) = 10.01 

18 : 07 : 08. 50 

= 1280.6917 Hz 

FIGURE 8(A) DOPPLER TIME HISTORY PLOT FOR A-7 FLY-BY, 

LOWER BEAM, RANGE GATE 12, AXIAL CASE 

674 
Time 

~ 

640. 320. 0. -320. -640. 

I 

-0.5 -0.25 0. 0.25 0.5 

Velocity Fraction 

' Frequency - Hz 

I I I' I I,' i 

Plot: [Uncomp. Doppler I 

FFT Samples: [TI 

Weight:(Blackman-Harris 

Dynamic Range (dBk 

Ambiguous Vel. (yd/s) = 36.8968 

Peak Spread(&) = 420.23 

P.S. Time: 18:07:09.40 

Range Bin = 13 

UBeams = -2 

VBeams = -2 

Signal Peak =-67.63 dBsm/H; 

Display Ceiling = -70.00 dBsm/& 

PRF = 1280.6917 Hz 

Frequency = 5690.0 tfKz 

Ilission: 21 6/91 18: 06 

Analysis: 10/23/91 15: 02 

Spread( Hz) = 10.01 

FIGURE 8(B) DOPPLER TIME HISTORY PLOT FOR A-7 FLY-BY, 

LOWER BEAM, RANGE GATE 13, AXIAL CASE 

675 
320. 0. -320. -64 0. 

FrequPmy - HZ 

-0.5 -0.25 0. 0.25 0.5 

640. 

I ,,I I I' I I 

'!!ilt Velocity Fraction 

Plot: [Uncomp. Doppler 

FFT Semples: 1iZ-I 

I 

Weight:IHamming 1 

- 

Dynamic Range (dB): 

Ambiguous Vel. (yd/s'l = 36.8968 

Spread(&) = 10.01 

Peak Spread(&) = 940.51 

P.S. Time: 20:44: 10.31 

Range Bin = 13 

UBeams = 0 

VBeams = 2 

Signal Peak =-86.46 dBsm/& 

Display Ceiling = -70.00 dBsm/Hs 

PRF I: 1280.6917 & 

Freqwncy = 5690.0 tlflz 

tfission: 5/ 2/91 

halysis: 10/22/91 

20:43 

10:31 

'FIGURE 9(~) DOPPLER TIME HISTORY PLOT FOR WINDY DAY, 

UPPER BEAM, RANGE GATE 13, EAST LOOK 

676 
i I 

Dynamic Range (dB): ?. 

Ambiguous Vel. (yd/s) = 36.8968 

Spread( Hz) = 460.25 

Peak Spread(&) = **+++* 

P.S. Time: 20:43:45.02 

Range Bin = 13 

UBeams = 0 

VBeams = 0 

Signal Peak =-77.33 dBsm/& 

Display Ceiling = -70.00 dBsm/& 

= 1280.6917 HZ 640. 320. 0 -320. -640. pw Frequency-- Hz 

Velocity Fraction 

I 1 I' 1 I]' , Frequency = 5690.0 I~Hz 

' o:5 fission: S/ 2/91 20:43 

-0.5 -0.25 0. 0.25 Analysis: 10/22/91 10:41 

FIGURE 9(~) DOPPLER TIME HISTORY PLOT FOR WINDY DAY, 

MIDDLE BEAM, RANGE GATE 13, EAST LOOK 

677 
0. -320. -640. 

640. 320.~requPncy - & 

I I I' 1 81' 1 

-0.5 -0.25 0. 0.25 0.5 

Velocity Fraction 

Plot: 

FFT Samples: 11281 

Weigh t:[Hamming 1 

Dynamic Range (dB): 

Ambiguous Vel. (ydlsl = 36.8968 

Peak Spread(&) = ****** 

P.S. Time: 20:43:45.22 

Range Bin = 13 

UBeams z 0 

VBeams = -2 

Signal Peak 5-76.28 dBsm/Hi 

Display Ceiling = -70.00 dBsm/Hs 

PRF s 1280.6917 Hz 

Spread(&) 5 5.00 

Frequency = 5690.0 W 

Mission: S/ 2/91 20:43 

Analysis: lOl22191 10:50 

FIGURE 9(c) DOPPLER TIME HISTORY PLOT FOR UINDY, 

LOWER BEAM, RANGE GATE 13, EAST LOOK 

678 
500 - 

400 - 

300 - 

200 - 

100 - 

-150 

0- 

-140 -130 

Structure Constant (dB) 

-120 

L 

FIGURE ~O(A) HISTORGRAM OF STRUCTURE CONSTANT FOR WINDY DAY 

-- 1 

-110 

679 
200 - 

0 

a 150- 2 

E 

3 

0 

0 

0 

ccr 

0 

P 

2 100- 

E 

2 

50 - 

"i 

.. 

II L L I 

140422 samdes I 

average = -328.04 

LStcl. Dev. = 82.0818l 

-600 -400 -200 0 200 400 

1 

Spectrum First Moment (Hz) 

. . .. .And - aFIGURE lob) HISTOGRAM OF RADIAL VELOCITY FOR WINDY DAY 

680 
500 

400 

cu 

0 

100 

0 

50 100 150 200 250 300 

Doppler Spread (Hz) 

FIGURE lO(c1 HISTORGRAM OF SPECTRAL WIDTH FOR WINDY DAY 

681 
Plot: Iuncomp. Doppler 1 

Dynamic cRange (dB): a 

Ambiguous Vel. (yd/s\ = 36.8968 

Peak Spread(&) t 415.22 

P.S. Time: 15:48:37.18 

Spread( Hz) = 10.01 

bnge Bin = 28 

UBeams = 0 

VBeams = 6 

Signal Peak r-89.68 dBsm/& 

Display Ceiling = -70.00 dBsm/LCs 

PRF = 1280.6917 Iiz 

Frequency = 5690.0 tlHz 

llission: 51 6/91 15:48 

Analysis: 10/22/91 13: 05 

FIGURE 114~) DOPPLER TIME HISTORY PLOT FOR CALM DAY, 

UPPER BEAM, RANGE GATE 28, NORTH LOOK 

682 
I 

320. 0 -320. -640. Frequency' - Hz 

Velocity Fraction 

I I,, I I 'I, I 

-0.5 -0.25 0. 0.25 0.5 

Plot: IUncomp. Doppler 1 

FFT Samples: 1128) 

weight:(Hamming 1 

Dynamiq Range (dB): 

Ambigwus Vel. (yd/s) = 36.8968 

Spread(&) = 10.01 

Peak Spread(&) = 310.17 

P.S. Time: 15:48:05.40 

Range Bin = 28 

UBeams = 0 

VBeams = 4 

Signal Peak =-80.46 dBsm/fGDisplay Ceiling =-70.00 dBsm/Ht 

PlV = 1280.6917 Hz 

Frequency = 5690.0 tfHz 

Ilission: 5/ 6/91 15:48 

Analysis: 10/22/91 13:26 

FIGURE lib) DOPPLER TIME HISTORY PLOT FOR CALM DAY, 

MIDDLE BEAM, RANGE GATE 28, NORTH LOOK 

683 
640. 320. 0. -320. -640. 

1 

Frequency - Hz 

-0.5 -0.25 0. 0.25 0.5 

Velocity Fraction 

I ,I' I ,I. 1 

Plot: Iuncomp. Doppler . I 

FFT Samples: 1EG-l 

Weight:\Hemming 

Dynamic Range (dB): 

1 

Ambiguous Vel. (yd/sl = 36.8968 

Peak Spread(%) = 10.01 

P.S. Time: 15:48:00.90 

Range Bin = 28 

UBeams = 0 

VBeams = 2 

Signal Peak =-78.11 dBsm/& 

Display Ceiling = -70.00 dBsm/Hi 

Frequency = 5690.0 HHz 

Mission: 51 6/91 15:48 

Analysis: 10/22/91 13~33 

Spread(&) = 10.01 

PIG = 1280.6917 Hz 

FIGURE ll(d DOPPLER TIME HISTORY PLOT FOR CALM DAY, 

LOWER BEAM, RANGE GATE 28, NORTH LOOK 

684 
120 

100 

(D 

a 

0 

c 

E80 e 

0 

0 

Ll 

0 

$60 

I! 

40 

20 

-150 

FIGURE 12(~) HISTOGRAM OF STRUCTURE CONSTANT FOR CALM DAY 

ddaa I 

-140 -130 

Structure Constant (dB) 

-120 

685 
50 

40 

m a2 

2 5 30 0 

0 

0 

G-J 

0 

k 

2 

20 

x 

10 

0 

I 

114180 samples I 

average = -103.943 

IStd. Dev. 141.8331 

-400 -200 0 200 400 600 

Spectrum First Moment (Hz) 

FIGURE 12(~) HISTORGRAM OF RADIAL VELOCITY FOR CALM DAY 

686 
300 

100 

lo0 150 200 250 300 

Doppler Spread (Hz) 

FIGURE 12k) HISTORGRAM OF SPECTRAL k’IDTH FOR CALM DAY 

687 
Point information 

Time : 

IlangeBin: 

Amplitude : 

Location in Ambiguity 

Interval : 

-50, 

dBsm/Hz 

-75, 

-100 

36 

UBeams = 0 

VBeams = 2 

PRF = 1280.6917 

Clutter Suppression:OH fission: 5/ 6/91 16:06 

Analysis: 10/18/91 11:57 Ambiguous Velocity (yd/s) = 36.896 

FIGURE 13 DOPPLER AMPLITUDE RANGE TIME (DART) PLOT 

688 
N95- 1321 3 

Remote Sensing; of Turbulence in the 

R. Martinson, 

Lightwave Atmospherics, Inc., 

and 

J. Flint, 

Schw artz Electro- Optics, Inc. 

689 
690 
r 

Q) 

2 

+! 

8 

2 

0 

13 

d 

f$ 

B 

3 

0 

Q) 

4 

$., 

8 

13 

d a 

13 

d 

f$ 

0 

691 
s 

c, 

c, 

8 

4 

0 

c, 

e e e 

692 
E 

0 

0 

0 

Fl 

0 

0 

Fl 

td 

0 

‘r3 

I 

+I, 

B 0 

u 

*9 

3 

c, 

v) 

ii 

693 
n 

0 

W 

694 
Q) 

8 

4 d 

0 

a 

I! 0 

0 

0 

od 

9 

I 

-I 

9 

00 

AI 

695 
0 

Z 

696 
E E 

E 

Lr 

W Li 

W 

co 

E 

697 
n 

l'l'l'l'l'l'l'l'l' 13 

698 
699 
E 

700 
I w 

.I E 

+n x 

i* la 

P 

z 

u 

k ...I( 

a m 

9 tE 

s 

r! 

e 

701 
< 

702 
m 

s 

0 

0 

\o 

II 

3- 

Y 

24 

Y 

24 

0 0 

0 0 

d N 

2 sr 0 

N 

0 

703 
. 

0 * 

'd 

o 

c, 

$ ('J 

$ 

a 

4 c, 

Ccl 

0 

c, d w Q)

3 c, 

crt 

a 

v) 

2 

Fc 

0 

3 

rclr 

0 

B 

+I 

0 

*!i v) 

704 
0 

- Z 

.,., ,. . 

705 

Session 7: 

SYNTHETIC AND ENHANCED 

VISION SYSTEMS. 

Chair: T. Campbell, 

NASA Langley Research Center. 
Session 7: 

SYNTHETIC AND ENHANCED VISION SYSTEMS. 

Chair: T. Campbell, NASA Langley Research Center. 

ESAS (Enhanced SitUahO n Awareness Sv . stems),A. Lambregts, Boeing Commercial Airplane Co. .. 

Qverview of Wes tinghouse E nbced Vision Technolow Activitia W. Patterson, Westinghouse Electric 

Corp. 

Evaluation of Candidate MI 'Ilimeter Wave Sensors for Syntheh 'c Vision, N. Alexander, J. Echard, and B. Hudson, Georgia Tech Research Insitute 

Passive MMW Camera for Low Wsibilitv Land in& M. Shoucri, TRW Applications Technology Div. 

Svnthetic Vision Svstem Flight Test. L. Jordan, Honeywell Technical Center 

Enhanced SyXIthetI 'c Vision Svstems, C. Taylor, Lear Astronics Corp. 
ESAS (Enhanced Situation 

Awareness Svstems). 

A. Lambregts, 

Boeing Commercial Airplane Go. 

709 
1= 

0 

m 

0 

Q 

L 

2 

2 

s 

0 

m 

a, 

en 

L 

m 

S 

a, 

0 

Q) 

.I 

m 

if 

710 
711 
712 
z 

a 

713 
e. 

fuj 

3- 

714 
\ I 

715 
716 

- ui 

f 
/ 

/ 

I 

719 
m rOr 

0 

c 

as 

18 It 

2 

t a 

720 
CD fa 

Q) 

E 

Q) 

m 

L 

s 

a 

w 

Q) 

0 

S 

m 

_r 

r= 

W 

3 

aa 

> 

- 

0 

Y 

n 

3 

s 

aa 

s 

E 

0 

CI 

eo 

721 
3 

4 

cn 

pb 

0 

E 

a 

c 

w8- 

-w 

3 

L.l 

e 

> 

0 

& 

a 

Q 

0 

L 

a3 

1 

8- 

_F 

0 

w 

0 

U 

.c1 

m 

c. 

E 

ea 

L 

u 

Q) 

L 

=- 

Y 3 

Y 

722 
52 

'a 

C 

Q) 

0 

cn 

CI) 

t 

Ia 

a e e 

fe 0 

723 
23 

OIL 

724 
Overview of Westinghouse Enhanced 

Vision Technology Activities. 

W. Patterson, 

Westinghouse Electric Corp. 

725 
0 

2 

I 

0 

W 

Iv) > W 

W 

v) 

3 

0 

T 

(3 

2 

F 

v) 

5 

LI 

0 

2: 

5 

W 

E 

W 

> 

0 

(3 

2 

F 

W 

W 

z 

9 

5 

UI 

W 

E 

pc 

e9 

0) 

0) 

l0 

cy) 

(3 

726 
cn 

W 

> 

0 

i= 

W 

7 

0 

m 

zf 

0 

a 

0 

a 

n 

n 

a 

n 

W 

i 

W 

!z 

n 

>I W 

727 
cn 

> 

cn 

cn 

> 

W 

1 

3 

(31 

e 

)I 

(3 

0 

4 

0 

Z 

w 

E 

0 

z 

W 

E$ 

E: 

w 

an 

WB 3 

f=l 

WE 

U- 

(3 

a 

e 

LL 

LL 

W 

z 

0 

i= 

v) 

a 

Z 

U 

I- 

>I 

(3 

0 

1 

0 

2 

I= 

0 

W 

l728 

730 
0 

?a 

# 

Q) 

c) 

El 

H 

5 

m" 

4 

.c, 

El 

B 

F 

0 

Q) 

rn si 

cct Y 

731 
e 0 0 e 

732 

734 



Q r88 

Nr 

8 

v) 

i 

0- 

- f 

8 

m 

738 

GI 

CAUTION: BE ALERT TO RUNWAY CROSSING CLEARANCES. 

READBACK OF ALL RUNWAY HOLDING INSTRUOIONS 1s RE 

740 
0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

0 

741 
P 

Z 

P 

I- * 

742 



k 

21 

a 

1 

il 

s 

b 

lr9 

0 

m 

m 

0 g 

c, 

d 

il 

4 

e e e e e e 

746 
N. Alexander, J. Echard, 

and B. Hudson, 

Georgia Tech Research Insitute 

I N95- 1321 4 

Evaluation of Candidate Millimeter Wave 

747 
Evaluation of Candidate MMW Sensors for Synthetic Vision 

Neal T. Alexander, Brian H. Hudson, and Jim D. Echard 

Georgia Tech Research Institute 

7220 Richardson Road 

Smyrna, GA 30080 

The goal of the Synthetic Vision Technology Demonstration (SVTD) Program was to 

demonstrate, and document the capabilities of current technologies to achieve safe &craft 

landing, take off, and ground operation in very low visibility conditions. As part of the 

technology evaluation process, the Georgia Tech Research Institute (GTRI) was a primary 

participant in two of the major thrusts of the program: (1) sensor evaluation in measured 

weather conditions on a tower overlooking an unused airfield and (2) flight testing of sensor 

and pilot performance via a prototype system installed in a test aircraft, 

GTRI supported tower testing of six different millimeter wave (MMW) radar sensor 

configurations and two infrared (IR) sensors at an instrumented tower facility at WrightPatterson AFB in the 1991-1992 time frame. Sensors tested included a Honeywell 35-GHz 

MMW imaging radar, a Norden 95-GHz MMW target detection and tracking radar, a Lear 

Astronics 94-GHz MMW imaging radar, a 3-5 micron Kodak IR imaging camera, and a 3-5 

micron Mitsubishi IR camera. The tower tests were performed under varied meteorological 

conditions including clear, fog, rain, and snow. As tower-test contractor, GTR.I provided 

engineering services, including test planning, equipment preparation, field-test support, 

sensor data analysis, sensor performance modeling, and technical documentation of test 

results. 

Three of the sensors evaluated in the tower tests were subsequently utilized in the flight-test 

evaluation program, which was performed during 1992 using a functional prototype SV 

system mounted in a specially configured Gulfstream II aircraft. During these flight tests, the 

observed performance of the prototype SV system was documented in actual and simulated 

weather conditions. The prototype system evaluated under this program included both a 

MMW radar sensor and an IR imaging sensor to detect and image the runway and 

surrounding area, as well as both a HUD and a head-down display to present the images and 

flight symbology to the pilot. GTRI's primary role in the flight test program was to perform 

analysis of raw radar data fi-ames (snapshots). The effort focused almost exclusively on data 

snapshots captured by the Honeywell MMW radar. GTRI also participated in experiment 

design and test planning, characterization of the radar sensors, radar modeling, radar 

calibration, and weather data analysis. 

The presentation first briefly addresses the overall technology thrusts and goals of the 

program and provides a summary of MMW sensor tower-test and flight-test data collection 

efforts. Data analysis and calibration procedures for both the tower tests and flight tests are 

presented. The remainder of the presentation addresses the MMW sensor flight-test 

evaluation results, including the processing approach for determination of various 

performance memcs (e-g., contrast, sharpness, and variability). The variation of the very 

important contrast metric in adverse weather conditions is described. Design trade-off 

considerations for Synthetic Vision MMW sensors are presented, and the presentation 

concludes with recommendations for future research to address the remaining unresolved 

issues. 

748 
8 

'CJ 

C 

m 

X 

Q) 

3 

S 

0 

v) 

=a 

3 

I: 

S 

cd 

i 

mm 

L 

cn 

d 

)r 

13) 

- 0 

E 

m 

13) 

0 OL 

L 

)r 

m 

0 

0 

S 

s 

0 

II 

I 

0 

c\I 

co 

co 

0 

cy) 

cd 

13) 

a 

m8 

cd 

IZT) 

0 

mL 

8 

co 

6) 

6) 

749 
@E9 a 

n 

lw 

E 

cd 

L 

m 

0 

L 

n 

K 

’0 

C 

m 

750 
n 

d 

b 

Tu 

(I, (I, 

751 
752 
753 
s 

2 

0 

0 

W 

ell 

EO 

u) 

Q) 

U 

ii 9 

0 

0 

d 

754 
13) 

0 

Y755 

@ a 

i 

757 
c 

0 

c) 

758 
CJ 

0 

0 

d 

0 

0 

u) 

c3 

0 

0 

0 

m 

0 

0 

m 

cu 

gth 

oii 

cuz 

0 

0 

u) 

v0 

0 

0 

r 

0 

0 

v) 

0 

759 
n 

c I I 1 1 a 1 I 

1 

0 

0 

0 

-3- 

0 

0 

0 

0 

h 

E 

0- 

od) 

om 

NC 

d 

0 

0 

0 

TO 

760 
L 

0 

v) 

S 

8 

3 

I 

I 

(3 

Lc) 

cy) 

cn 

w 

I 

m 

f 

I 

L 

8 

C 

0 

I 

v) 

0 

a 

II 

II 

W 

n 

0 

Q) 

0 

C 

w 

8 

u 
Q) 

L 

2 

Q) 

Q 

a 

762 
v) 

Q) 

3 

v) 

v) 

u 

II 

0 

Q) 

=o 

c11 

rz: 

+ 

ne 

+ 

763 
0 a 

0 

v) 

m ax6 mm764 
I N95- 1321 5 

Passive MMSV Camera for 

Low Visibilitv Landings. 

M. Shoucri, 

TRW Applications Technology Div. 

765 
766 
'tn 

a, 

a, 

u) 

m 

I 

a, 

E 

a 

m 

C 

& a 

m a 

a 

c 

'b 

.II 

& 

5 

m L. 

C rn 

W I: 

e0 e 

E 

Q) 

v) 

)r 

u) 

r: 

0 

.c1 

767 
a 

E 

1 

0 

0 

.I 

L 

L 

0 

\ 

E! 

E 

v) 

B 

a 

a 

;c 

0 

ce. 

(1 

768 
r=n 

E 

M 

E 

aa 

v) 

mn 

a 

5 

va 

va 

rn 

SI 

a 

+ 

769 
770 


II 

* 

L 

eer 

a3 

E 

0 

L 

L- .- 

a 

773 
- 8 

- 

0 

Ls) 

Ic 

'23 

L. 

a 

0 

c3 

L 

i 

8 * 

8 

s 

8- 

Lu 

4 

E 

2 

> 

z 

W 

4 

E 

2 

> 

774 
N 

77 
776 
aa 

r 

a3 nu II n 

I 

777 
ci5. 

3 

0 

0 

778 
779 

v) 

m 

g, =s? 

). 

m 

E L 

m 

m 

0 

9 

L 

QJ 

> 

0) 

0 

.- 

E? 

781 

783 
3 

784 
785 

Synthetic Vision System Night Test. 

L. Jordan, 

Honeywell Technical Center 

787 F 
w 

t 

L ? 

m > 

a 

3 

3 

TW 

x I- 

€ 

>ri.ii. 

v) 

788 P- 
I... 

t t t 

789 
8 

t f 

L 

7 
7 

.L 

793 



797 
t 

I 44 

79% 
Enhanced Synthetic Vision Systems. 

C. Taylor, 

Lear Astronics Corp. 

799 
t 

0 

w 

Q) 

S 

E 

E 

0 

0 

w 

S 

Q 

a, 

0 

C 

Q 

'c) 

a 

.I 

a 

L 

Q 

Q) 

c 

u) 

rn 

c: 

E 

m 

S 

S 

Q 

9l 

s 

tn 

b 

a, 

e 

Q 

4 

L 

e 

800 
E 

ccz 

P) 

0 

tl 

& 

E 

ccz 

a 

0 

I 

a 

co 

0 

Q) 

I 

S 

Q) 

> 

.I 

6 

t 

E 

0 

v) 

3 

0 

I 

- 

v) 

S 

0 

ra 

S 

m 

m 

S 

v) 

x 

a, 

0 

v) 

a, 

m 

c 

a 

s 

0 

0 

c 

tn 

Q) 

3 

v 

.I 

li, 

111 

i!! 

li, 

li, 

L 

.e 

2 

& 

t 

v 

x 

2 

z 

$ 

2 

t!! 

Q) 

S 

0 

E 

E 

0 

0 

S 

0 

-a 

s 

0 

S 

0 

IO 

IQ) 

0 

S 

a 

-u 

3 

3 

mm 

(3 

I I I 

801 
E 

ccz 

L 

0 

L 

E 

I 

a 

v) 

10 .' 

z=: 

0 

L * 

v) 

a 

L 

ccz 

Q) 

I 

v) 

Q) 

a 

> 

0 

.I 

& 

- 

m 

0 

.I 

t 

E 

E 

0 

0 

ii 

4d 

Q) 

a 

> 

0 

.I) 

& 

r 

S 

3 

c) 

C 

Q) > 

W 

En 

C 

S 

m 

mm 

a- 

)Ir 

0 

S 

Q) 

=I 

L 

L 

0 

I I 

e 

802 
E 

m 

L 

m 

0 

t 

n 

E 

a 

I 

a 

0 

0 

t 

I t2 

L 

w 

Q) 

0 

0 

s 

0 

)r 

m 

0 

0 

S 

x 

0 

Q) 

Io 

v) 

.I 

- 

SI 

A 

v) 

;5 

S 

0 

0 

I 

E 

L 

803 
m 

t 

m 

0 

t 

n 

E 

(3 

I 

a 

v) 

c) 

0 

b 

b 

m 

Q) 

I 

z? 

E 

E 

rn 

3 

cn I 

S 

0 

v) 

S 

LL 

0- 

L 

0 

m 

S 

Q) to 

I 

s 

0 

0 

k 

5 

2 

0 

(II 

3 

m 

- 

2 

-4 

v) 

3 

0 

0 

LL 

L 

E 

0 

v) 

S 

0 

Q) 

3 

CT 

C 

3 

I 

- 

I 

0 0 

I 

804