BOREAS RSS-16 Level-3b DC-8 AIRSAR CM Images

Summary

The BOREAS RSS-16 team used satellite and aircraft SAR data in conjunction with 
various ground measurements to determine the moisture regime of the boreal 
forest.  RSS-16 assisted with the acquisition and ordering of NASA JPL AIRSAR 
data collected from the NASA DC-8 aircraft.  The NASA JPL AIRSAR is a side-
looking imaging radar system that utilizes the SAR principle to obtain high-
resolution images that represent the radar backscatter of the imaged surface at 
different frequencies and polarizations.  The information contained in each 
pixel of the AIRSAR data represents the radar backscatter for all possible 
combinations of horizontal and vertical transmit and receive polarizations 
(i.e., HH, HV, VH, and VV). Geographically, the data cover portions of the 
BOREAS SSA and NSA.  Temporally, the data were acquired from 12-Aug-1993 to 31-
Jul-1995. The level-3b AIRSAR CM data are in compressed Stokes matrix format, 
which has 10 bytes per pixel. From this data format, it is possible to 
synthesize a number of different radar backscatter measurements.  The data are 
stored in binary image format files.

Please note:  In early 1998 a problem was found in the AIRSAR Integrated 
Processor Versions 5.01 and 5.02.  This problem affected the backscatter cross 
section ?? values in some of the BOREAS products.  The data that BORIS has 
archived does not reflect the changes made in the processor software to correct 
the problem.  The corrected data has been delivered to ORNL and will be made 
available.  None of the AIRSAR imagery is contained on the BOREAS CD-ROM series, 
although an inventory listing of the data collected is included.

Table of Contents

   *  1  Data Set Overview
   *  2  Investigator(s)
   *  3  Theory of Measurements
   *  4  Equipment
   *  5  Data Acquisition Methods
   *  6  Observations
   *  7  Data Description
   *  8  Data Organization
   *  9  Data Manipulations
   *  10 Errors
   *  11 Notes
   *  12 Application of the Data Set
   *  13 Future Modifications and Plans
   *  14 Software
   *  15 Data Access
   *  16 Output Products and Availability
   *  17 References
   *  18 Glossary of Terms
   *  19 List of Acronyms
   *  20 Document Information

1. Data Set Overview

1.1 Data Set Identification

BOREAS RSS-16 Level-3b DC-8 AIRSAR CM Images

1.2 Data Set Introduction

The BOReal Ecosystem-Atmosphere Study (BOREAS) Staff Science effort covered 
those activities that were BOREAS community-level activities or required uniform 
data collection procedures across sites and time. These activities included the 
acquisition of the relevant aircraft image data. Data from the Airborne 
Synthetic Aperture Radar (AIRSAR) system onboard the National Aeronautics and 
Space Administration (NASA) DC-8 aircraft were acquired by staff at the Jet 
Propulsion Laboratory (JPL) and provided for use by BOREAS researchers.

1.3 Objective/Purpose

The purpose of this data set is to provide multifrequency and multipolarization 
Synthetic Aperature Radar (SAR) images over the BOREAS Southern Study Area 
(SSA).  This data set supplements other visible and near-infrared remote sensing 
images compiled by BOREAS.  The level-3b AIRSAR data were acquired at three 
frequencies of P-band, L-band, and C-band and for all linear polarization 
combinations (HH, HV, VH, and VV).  The level-3b AIRSAR CM image data products 
contain data from all 12 frequency and polarization combinations.  AIRSAR images 
are used to estimate surface parameters such as canopy water content, soil 
moisture, and stand biomass and density.

1.4 Summary of Parameters

SAR parameters: incidence angle, aircraft altitude, range resolution, azimuth 
resolution, frequency, polarization. 

1.5 Discussion

AIRSAR image data gathering for BOREAS was conducted in 1993 and 1994 over the 
two study areas in Canada.  BOREAS was designed to study regional land surface 
climatology and to develop methods for deriving quantitative information about 
surface variables from remote sensing data.  The AIRSAR experiment was devised 
to provide surface moisture and vegetation variables suitable for the soil-
vegetation-atmosphere interaction models.  In particular, the high-resolution 
data obtained by the AIRSAR system can be used to derive information about the 
variability of the surface parameters, which in turn can be used to address the 
scaling problem.

1.6 Related Data Sets

BOREAS RSS-16 Level-3b DC-8 AIRSAR SY Images

2. Investigator(s)

2.1 Investigator(s) Name and Title

Dr. Sasan S. Saatchi

2.2 Title of Investigation

Estimation of Evapotranspiration Using SAR Derived Parameters

2.3 Contact Information

     Contact 1
     -------------
     Dr. Sasan S. Saatchi
     Jet Propulsion Laboratory
     Pasadena, CA
     (818) 354-1051
     saatchi@bacchus.jpl.nasa.gov

     Contact 2
     ----------------
     Dr. Jakob J. vanZyl
     Jet Propulsion Laboratory
     Pasadena, CA 
     (818) 354-1365

     Contact 3
     -------------
     Jeffrey Newcomer
     Raytheon STX Corporation
     NASA GSFC
     Greenbelt, Maryland 
     (301) 286-7858
     (301) 286-0239 (fax)
     Jeffrey.Newcomer@gsfc.nasa.gov


3. Theory of Measurements

The basic quantity measured by a polarimetric radar is a complex (amplitude and 
phase) scattering matrix for each resolution element of the radar image.  This 
implies that AIRSAR is a multichannel system designed to maintain phase 
coherence between radar antennas and different channels.  The polarization 
states used in the AIRSAR system are based on horizontal and vertical antennas. 
The radar is configured to measure all possible combinations available from the 
horizontal (H) and vertical (V) antennas (i.e., H transmitting, H receiving, and 
so forth).  The complete scattering matrix for a resolution element can then be 
determined.  Knowledge of the scattering matrix permits calculation of the 
received power for any possible combination.

4. Equipment

4.1 Sensor/Instrument Description

SAR refers to a technique used to synthesize a very long antenna by combining 
signals (echoes) received by the radar as it moves along its flight track. NASA 
JPL currently maintains and operates the AIRSAR/Topographic SAR (TOPSAR), which 
flies on the NASA DC-8 aircraft.

The AIRSAR system is an airborne SAR that operates simultaneously in a fully 
polarimetric mode at three frequencies (P-, L-, and C- bands).  JPL operates the 
radar aboard the NASA Ames Research Center DC-8 aircraft.  The data collected by 
the AIRSAR system are processed to polarimetric imagery at JPL and provided to 
the BOREAS Information System (BORIS) in digital and photographic forms.  The 
AIRSAR system provides several output products, including real-time imagery and 
the final processed digital products.  Two of the most common digital products 
are the Compressed Matrix (CM) products and the Synoptic (SY) products.

The real-time imagery is provided to the investigators for a SAR pass. This is a 
low-resolution, black-and-white, single-frequency/polarization (typically LHH) 
image of the entire pass.  No digital data of this type are provided.  
Annotation of the image allows the investigators to select areas for further 
processing.  The information on the data includes run name (name assigned to the 
data acquisition pass, typically the site name), Greewich Mean Time (GMT) (day 
of year followed by GMT), A/C Lat-Lon, frame count, and frequency/polarization.

The standard AIRSAR CM product consists of a 16-look (20-MHz) or 8-look (40-MHz) 
"polarization compressed" digital file on tape for each frequency (for input to 
polarization synthesis software provided by JPL) and a color photo product.  The 
frame product corresponds to about 12 km along-track of imagery by 10-15 km 
across-track. As part of the standard products, the data sets are calibrated by 
the ground SAR processor.

During the 1993 experiment, only limited data were collected over the BOREAS 
study areas.  In 1994, a large amount of imagery was collected and is summarized 
in Section 7 below.  In 1995, a special collection effort was planned to collect 
imagery over an area of the SSA that had been burned the previous season.

4.1.1 Collection Environment

The AIRSAR system operates within the fuselage of the DC-8 aircraft during 
flight.  The AIRSAR was flown at medium altitudes aboard NASAs DC-8 aircraft 
based at NASAs JPL and provided 11-m slant range resolution at an altitude of 
8000 m.

4.1.2 Source/Platform

NASA DC-8 Aircraft

4.1.3 Source/Platform Mission Objectives

The objective was to acquire multipolarization and multifrequency SAR images 
over the BOREAS study areas and transect region.     

4.1.4 Key Variables

Polarization, radar frequency, radar look angle, aircraft altitude, range 
resolution, azimuth resolution, site lat-long coordinates, aircraft geometry.

4.1.5 Principles of Operation

The NASA/JPL AIRSAR is a side-looking imaging radar system that utilizes the SAR 
principle to obtain high resolution images that represent the radar backscatter 
of the imaged surface at different frequencies and polarizations. 

4.1.6 Sensor/Instrument Measurement Geometry

During the BOREAS experiment, the instrument was located in the NASA DC-8 
aircraft approximately 7,800 m above ground.  The antennas are located on the 
port side of the aircraft looking at an angle over the site.  The nominal 
pointing angle was 28 degrees, which covered the ground surface from 
approximately 28 to 72 degrees.

All DC-8 AIRSAR CM level-3b images are produced at 6 m in range and 12 m in 
azimuth resolutions.

4.1.7 Manufacturer of Sensor/Instrument

Jet Propulsion Laboratory
4800 Oak Grove Drive
Pasadena, CA  91109
(818) 354-4321

4.2 Calibration

4.2.1 Specifications

In one mode of operation, this system is capable of simultaneously collecting 
all four polarizations (HH, HV, VH, and VV) for three frequencies: L-band 
(lambda ~ 24 cm), C-band (lambda ~ 6 cm), and P-band (lambda ~ 68 cm). In 
another mode of operation, the AIRSAR/TOPSAR system collects all four 
polarizations (HH, HV, VH, and VV) for two frequencies: L-band (lambda ~ 24 cm), 
and P-band (lambda ~ 68 cm), while operating as an interferometer at C-band to 
simultaneously generate topographic height data.

AIRSAR/TOPSAR also has an along-track interferometer mode that is used to 
measure current speeds. Typical image sizes for AIRSAR/TOPSAR products
are 12 km x 12 km, with 10-m resolution in both dimensions. Topographic map 
products generated by the TOPSAR system have been shown to have a height
accuracy of 1 m in relatively flat areas and 5 m in mountainous areas.

4.2.1.1 Tolerance

Each image contains detailed calibration information in the header information 
area.  

4.2.2 Frequency of Calibration

Much of the data produced by the AIRSAR are now calibrated, so that the radar 
backscatter measurements are in normalized radar cross-section format (m2/m2) or 
?? (sigma zero).  Sigma zero is the radar cross-section (measured in m2) 
normalized by the area of the measurement, which in this case is the pixel area 
in square meters.

4.2.3 Other Calibration Information

Two types of complementary calibration techniques are used for AIRSAR data 
calibration: internal calibration and external calibration.  For the internal 
calibration, the information collected from the system tests that are performed 
regularly during the flight is used to obtain calibration parameters to be used 
in the AIRSAR processor.  This will ensure that all the polarization channels 
are calibrated relative to one another at each frequency.  For external 
calibration, which calibrates the radar cross-section of the scene absolutely 
and removes channel imbalance and the cross-talk, information from the scene and 
dihedral corner reflectors as external targets is used. Investigators who are 
interested in checking the accuracy of the calibration and performing other 
corrections themselves can request a copy of the POLCAL software and the user's 
manual directly from JPL.

5. Data Acquisition Methods

The AIRSAR system acquires data during flights of the DC-8 aircraft.  The 
instrument system acquires the data across the various spatial elements while 
the aircraft motion provides the forward motion for image acquisition.

6. Observations

6.1 Data Notes

None given.

6.2 Field Notes

None given.

7. Data Description

7.1 Spatial Characteristics

7.1.1 Spatial Coverage

The BOREAS AirSAR CM Level-3b images cover sections of the Northern and the 
Southern Study Areas (NSA and SSA).  The SSA and the NSA are located in the 
southwest and northeast portions of the overall BOREAS region.

Each image covers a 12-km along-track and 10-km across-track area.  The images 
contain 1,280 pixels in each of the approximately 5,000 lines.

Most of the BOREAS AIRSAR level-3b CM imagery is over the SSA.  There are two 
early season dates of level-3b SY imagery of the Northern Study Area (NSA).  The 
SSA and the NSA are located in the southwest and northeast portions of the 
overall region.

The North American Datum of 1983 (NAD83) corner coordinates of the SSA are:

                         Latitude     Longitude
                         --------     ---------
            Northwest    54.321 N     106.228 W
            Northeast    54.225 N     104.237 W
            Southwest    53.515 N     106.321 W
            Southeast    53.420 N     104.368 W

The NAD83 corner coordinates of the NSA are:

                         Latitude     Longitude
                         --------     ---------
            Northwest    56.249 N      98.825 W
            Northeast    56.083 N      97.234 W
            Southwest    55.542 N      99.045 W
            Southeast    55.379 N      97.489 W

7.1.2 Spatial Coverage Map

Not available.

7.1.3 Spatial Resolution

Resolution in range: 6.66 m (across-track)
Resolution in azimuth: 12.27 m. (along-track)

7.1.4 Projection

The Remote Sensing Science (RSS)-16 team informed BORIS personnel that the 
images have been resampled into a regular spatial grid; however, the details of 
the projection used are not known.

7.1.5 Grid Description

The RSS-16 team informed BORIS personnel that the images have been resampled 
into a regular spatial grid; however, the details of the gridding are not known.

7.2 Temporal Characteristics

7.2.1 Temporal Coverage

The AIRSAR CM level-3b data were collected during concentrated periods from 12-
Aug-1993 to 31-Jul-1995. 

7.2.2 Temporal Coverage Map

   Date           Study Area
12-AUG-93             SSA
11-JUN-94             SSA
17-APR-94             NSA
17-APR-94             SSA
20-APR-94             NSA
21-JUL-94             SSA
22-APR-94             SSA
23-JUL-94             SSA
26-APR-94             SSA
28-JUL-94             SSA
31-JUL-95             SSA

7.2.3 Temporal Resolution

Most of the SSA Modeling Sub-Area (MSA) was covered by the AIRSAR CM images on 
two or three occasions from 12-Aug-1993 to 31-Jul-1995.

7.3 Data Characteristics

Data characteristics are defined in the companion data definition file 
(airscm3b.def).

7.3.1 Parameter/Variable

The data files contain a mixture of character and binary components.  The user 
is encouraged to contact JPL personnel for detailed format descriptions.  For 
the most part, the actual image data are INTEGER*2 in a format compatible with 
Sun computer systems.


7.3.2 Variable Description/Definition

To translate the integer*2 values supplied in the file to radar cross-sections, 
one has to apply the following calculation:
(DN^2)/(General scale factor)
where the General scale factor is the general scale factor supplied in field 2 
of the calibration header.


7.3.3 Unit of Measurement

The image values are stored as the amplitude, i.e. as the square root of the 
power reflected back from the target.


7.3.4 Data Source

The imagery were collected by the AIRSAR sensor aboard the NASA DC-8 research 
aircraft and were processed and provided by the Radar Data Center at the Jet 
Propulsion Laboratory, Pasadena, California.

7.3.5 Data Range

Typically radar images exhibit a dynamic range less than 30 dB.  Therefore each 
data set is scaled by a single value for all pixels such that the dynamic range 
of the total power elements in the Stokes matrices falls within values between 
2-128 and 2127. The total power for each matrix is then coded into two bytes, one 
for the exponent in the above range and one for the mantissa.  The other eight 
elements stored in the 10-byte sample are then normalized.


7.4 Sample Data Record

Sample data format shown in the companion data definition file (airscm3b.def).

8. Data Organization

8.1 Data Granularity

The smallest unit of data tracked by BORIS was a particular level-3b CM image.

8.2 Data Format(s)

The image inventory data file contains numerical and character fields of varying 
length separated by commas. The character fields are enclosed with a single 
apostrophe marks. There are no spaces between the fields. Sample data records 
are shown in the companion data definition file (airscm3b.def).

Prior to 1998, the AIRSAR data received by BORIS were in a single format.  
Starting in 1998, several scenes were received in a new format.  Both of these 
formats are described in the following sections.  Since detailed format 
information on the AirSAR data is available from JPL, BORIS personnel have not 
provided an exhaustive description of the data here.  Please contact JPL 
personnel for further details.

8.2.1 Pre-1998 Data Format

A level-3b AIRSAR CM image from BORIS is contained in three files, one file for 
each of the P, L, and C frequency bands, respectively.  Each record of a level-
3b AIRSAR CM data file contains 10,240 bytes.  The first three records in each 
file contain header information.  The number of data records in a file varies 
depending on the length of the flight line.  Each data record of 10,240 bytes 
contains a portion of the compressed Stokes matrix data. More specific 
information is as follows:

FILE 1 (10,240-byte records for the P-band)

       -  JPL AIRSAR New Header Record (Record 1)
          *  20 records, each containing 50 American Standard Code for
             Information Interchange (ASCII) characters.
          *  9,240 fill bytes.

       -  JPL AIRSAR Old Header Record (Record 2)
          *  64 records, each containing 50 ASCII characters.
          *  7,040 fill bytes.

       -  JPL AIRSAR Parameter Header Record (Record 3)
          *  87 records, each containing 50 ASCII characters.
          *  5,890 fill bytes.

       -  JPL AIRSAR CM Compressed Stokes matrix data records
          (Record 4 to end of file)

FILE 2 (10,240-byte records for the L-band)

       -  JPL AIRSAR New Header Record (Record 1)
          *  20 records, each containing 50 ASCII characters.
          *  9,240 fill bytes.

       -  JPL AIRSAR Old Header Record (Record 2)
          *  64 records, each containing 50 ASCII characters.
          *  7,040 fill bytes.

       -  JPL AIRSAR Parameter Header Record (Record 3)
          *  87 records, each containing 50 ASCII characters.
          *  5,890 fill bytes.

       -  JPL AIRSAR CM Compressed Stokes matrix data records
          (Record 4 to end of file)

FILE 3 (10,240 byte records for the C-band)

       -  JPL AIRSAR New Header Record (Record 1)
          *  20 records, each containing 50 ASCII characters.
          *  9,240 fill bytes.

       -  JPL AIRSAR Old Header Record (Record 2)
          *  64 records, each containing 50 ASCII characters.
          *  7,040 fill bytes.

       -  JPL AIRSAR Parameter Header Record (Record 3)
          *  87 records, each containing 50 ASCII characters.
          *  5,890 fill bytes.

       -  JPL AIRSAR CM Compressed Stokes matrix data records
          (Record 4 to end of file)

8.2.2 1998 Data Format

During 1998, the following scenes were received in a new file format (described 
below):
       17-APR-94:18:25:49 
       17-APR-94:18:44:45
       20-APR-94:19:38:05
       11-JUN-94:19:58:23
       11-JUN-94:20:11:07        
       31-JUL-95:18:34:00

The physical record length is 1024 or 10,240 bytes; the logical record length 
for one line of data is documented as being variable, but all the scenes in 
these sets of data are 25,600 bytes. Records mentioned below are logical 
records.

FILE 1 (the entire scene, headers and image data, is contained in a single file)
     C-band records:

       -  JPL AIRSAR New Header Record (Logical Record 1)
          *  20 records, each containing 50 ASCII characters.
          *  Remainder of the logical record (24,600 bytes) is filler.

       -  JPL AIRSAR Parameter Header Record (Logical Record 2)
          *  100 records, each containing 50 ASCII characters.
          *  Remainder of record (20,600 bytes) is filler.

       -  JPL AIRSAR Calibration Header Record (Logical Record 3)
          *  20 records, each containing 50 ASCII characters.
          *  Remainder of record (24,600 bytes) is filler.

       -  JPL AIRSAR CM Compressed Stokes matrix data records
          (Logical Record 4 to the end of the band).  The end of the band can
          be determined by using the first five parameters (logical record size, 
          nHeader recs, nLines, nSamples, nBytes per sample) listed in the New
          Header Record:

             logical rec size * (nHeader recs - # already read(3)) +
                    nLines * nSamples * nBytes per sample
             ----------------------------------------------------
                            Physical Record Size

            Example:
                           25600 * (6-3) + 6699 * 2560 * 10
                           --------------------------------
                                          1024

   L-band records:

       -  JPL AIRSAR New Header Record (Logical Record 1)
          *  20 records, each containing 50 ASCII characters.
          *  Remainder of the logical record (24,600 bytes) is filler.

       -  JPL AIRSAR Parameter Header Record (Logical Record 2)
          *  100 records, each containing 50 ASCII characters.
          *  Remainder of record (20,600 bytes) is filler.

       -  JPL AIRSAR Calibration Header Record (Logical Record 3)
          *  20 records, each containing 50 ASCII characters.
          *  Remainder of record (24,600 bytes) is filler.

       -  JPL AIRSAR CM Compressed Stokes matrix data records
          (Logical Record 4 to the end of the band).  The end of the band can
          be determined by using the first five parameters (logical record size, 
          nHeader recs, nLines, nSamples, nBytes per sample) listed in the New
          Header Record:

             logical rec size * (nHeader recs - # already read(3)) +
                    nLines * nSamples * nBytes per sample
             ----------------------------------------------------
                            Physical Record Size

   P-band records:

       -  JPL AIRSAR New Header Record (Logical Record 1)
          *  20 records, each containing 50 ASCII characters.
          *  Remainder of the logical record (24,600 bytes) is filler.

       -  JPL AIRSAR Parameter Header Record (Logical Record 2)
          *  100 records, each containing 50 ASCII characters.
          *  Remainder of record (20,600 bytes) is filler.

       -  JPL AIRSAR Calibration Header Record (Logical Record 3)
          *  20 records, each containing 50 ASCII characters.
          *  Remainder of record (24,600 bytes) is filler.

       -  JPL AIRSAR CM Compressed Stokes matrix data records
          (Logical Record 4 to the end of the band).  The end of the band can
          be determined by using the first five parameters (logical record size, 
          nHeader recs, nLines, nSamples, nBytes per sample) listed in the New
          Header Record:

             logical rec size * (nHeader recs - # already read(3)) +
                    nLines * nSamples * nBytes per sample
             ----------------------------------------------------
                            Physical Record Size

9. Data Manipulations

9.1 Formulae

None.

9.1.1 Derivation Techniques and Algorithms

None given.

9.2 Data Processing Sequence

9.2.1 Processing Steps

BORIS staff makes the AIRSAR CM level-3b images available by:

1) Duplicating the JPL delivered images for backup purposes.
2) Extracting pertinent header information from the images for use in 
   inventorying the level-3b image by date and time in the online data base.
3) Reviewing the content of the extracted header information for potential 
   problems/anomlies.
4) Loading the needed information into the online data base.

9.2.2 Processing Changes

In early 1998, a problem was found in the AIRSAR Integrated Processor Versions 
5.01 and 5.02.  This problem affected the backscatter cross section ?? values in 
some of the BOREAS products.  The data that BORIS has archived does not reflect 
the changes made in the processor software to correct the problem.  The 
corrected data has been delivered to ORNL and will be made available. 

The BOREAS data affected by the problem are identified in the following table.

   Date      Study Area   Product ID
17-APR-94        NSA        CM5163
17-APR-94        NSA        CM5165
17-APR-94        NSA        CM5181
20-APR-94        NSA        CM5182
31-JUL-95        SSA        CM5188
11-JUN-94        SSA        CM5190
11-JUN-94        SSA        CM5193

9.3 Calculations

9.3.1 Special Corrections/Adjustments

None given.

9.3.2 Calculated Variables

None given.

9.4 Graphs and Plots

None.

10. Errors

10.1 Sources of Error

None given.

10.2 Quality Assessment

10.2.1 Data Validation by Source

None given.

10.2.2 Confidence Level/Accuracy Judgment

None given.

10.2.3 Measurement Error for Parameters

None given.

10.2.4 Additional Quality Assessments

None given.

10.2.5 Data Verification by Data Center

BORIS staff reviews the images using developed software that was designed based 
on data product format documents received from JPL.  The software reads through 
the data products on tape and summarizes the contents in ASCII files on disk.  
These files are reviewed visually by BORIS personnel for anomalous items.

11. Notes

11.1 Limitations of the Data

None given.

11.2 Known Problems with the Data

The data are provided in two different formats (see Section 8.2).  See also, 
notes in section 9.2.2.

11.3 Usage Guidance

None given.

11.4 Other Relevant Information

None given.

12. Application of the Data Set

AIRSAR images are used to estimate surface parameters such as canopy water 
content, soil moisture, and stand biomass and density.

13. Future Modifications and Plans

None.

14. Software

14.1 Software Description

BORIS staff developed software and command procedures to:

1) Check and extract information from level-3b AIRSAR CM images on tape and 
write the information to ASCII files on disk for both data formats.
2) Read the ASCII disk file and log the level-3b AIRSAR CM images into the 
Oracle data base tables.

The software mentioned under items 1 and 2 is written in the C language and is 
operational on VAX 6410 and MicroVAX 3100 systems at Goddard Space Flight Center 
(GSFC).  The primary dependencies in the software are the tape input/output 
(I/O) library and the Oracle data base utility routines.

14.2 Software Access

All of the described software is available upon request.  See Section 15.4.  
BORIS staff would appreciate knowing of any problems discovered with the 
software, but cannot promise to fix them.

15. Data Access

15.1 Contact Information

Ms. Beth Nelson
BOREAS Data Manager
NASA GSFC
Greenbelt, MD
(301) 286-4005
(301) 286-0239 (fax)
Elizabeth.Nelson@gsfc.nasa.gov

15.2 Data Center Identification

See Section 15.1.

15.3 Procedures for Obtaining Data

Users may place requests by telephone, electronic mail, or fax.

15.4 Data Center Status/Plans

The RSS-16 level-3b AirSAR CM data are available from the Earth Observing System 
Data and Information System (EOSDIS), Oak Ridge National Laboratory (ORNL), 
Distributed Active Archive Center (DAAC). The BOREAS contact at ORNL is: 

ORNL DAAC User Services
Oak Ridge National Laboratory
Oak Ridge, TN
(423) 241-3952
ornldaac@ornl.gov
ornl@eos.nasa.gov

16. Output Products and Availability

16.1 Tape Products

The AIRSAR level-3b CM data can be made available on 8-mm or Digital Archive 
Tape (DAT) media.

16.2 Film Products

None.

16.3 Other Products

During the data acquisition flight, 35-mm photographs were taken of the areas 
imaged by the AIRSAR system.  Anyone interested in these photographs should 
contact Dr. Sasan Saatchi (See Section 2.3.)

17. References

17.1 Platform/Sensor/Instrument/Data Processing Documentation

NASA JPL.  Date unknown. AIRSAR Data Formats, Chap 4.

NASA JPL, 1995. AIRSAR Integrated Processor Documentation: DATA FORMATS. Version 
0.01.

Freeman, T. 1998.  What is Imaging Radar? JPL Imaging Radar, ().

17.2 Journal Articles and Study Reports

Sellers, P., and F. Hall. 1994. Boreal Ecosystem-Atmosphere Study: Experiment 
Plan. Version 1994-3.0, NASA BOREAS Report (EXPLAN 94). 

Sellers, P., and F. Hall. 1996. Boreal Ecosystem-Atmosphere Study: Experiment 
Plan. Version 1996-2.0, NASA BOREAS Report (EXPLAN 96). 

Sellers, P., and F. Hall. 1997. BOREAS Overview Paper. JGR Special Issue.

Sellers, P., F. Hall, and K.F. Huemmrich. 1996. Boreal Ecosystem-Atmosphere 
Study: 1994 Operations. NASA BOREAS Report (OPS DOC 94). 

Sellers, P., F. Hall, and K.F. Huemmrich. 1997. Boreal Ecosystem-Atmosphere 
Study: 1996 Operations. NASA BOREAS Report (OPS DOC 96). 

Sellers, P., F. Hall, H. Margolis, B. Kelly, D. Baldocchi, G. den Hartog, J. 
Cihlar, M.G. Ryan, B. Goodison, P. Crill, K.J.Ranson, D. Lettenmaier, and D.E. 
Wickland. 1995. The boreal ecosystem-atmosphere study (BOREAS): an overview and 
early results from the 1994 field year. Bulletin of the American Meteorological 
Society. 76(9):1549-1577. 

van Zyl, J.  1992. The AIRSAR System, JPL document.

van Zyl, J.  1995.  AIRSAR Integrated Processor Documentation, Version 
0.01, April 21.

17.3 Archive/DBMS Usage Documentation

None.

18. Glossary of Terms

None.

19. List of Acronyms

    AIRSAR  - Airborne Synthetic Aperture Radar
    ASCII   - American Standard Code for International Interchange
    BOREAS  - BOReal Ecosystem-Atmosphere Study
    BORIS   - BOREAS Information System
    BPI     - Bytes per inch
    CCT     - Computer Compatible Tape
    CM      - Compressed Matrix
    DAAC    - Distributed Active Archive Center
    DAT     - Digital Archive Tape
    EOS     - Earth Observing System
    EOSDIS  - EOS Data and Information System
    GMT     - Greenwich Mean Time
    GSFC    - Goddard Space Flight Center
    JPL     - Jet Propulsion Laboratory
    NAD83   - North American Datum of 1983
    NASA    - National Aeronautics and Space Administration
    NSA     - Northern Study Area
    ORNL    - Oak Ridge National Laboratory
    PANP    - Prince Albert National Park
    RSS     - Remote Sensing Science
    SAR     - Synthetic Airborne Radar
    SSA     - Southern Study Area
    SY      - Synoptic
    TOPSAR  - Topographic SAR
    URL     - Uniform Resource Locator

20. Document Information

20.1 Document Revision Dates

     Written:         31-Jul-1995
     Last Updated:    10-Jun-1998

20.2 Document Review Date

     BORIS Review:    17-Mar-1998
     Science Review:  

20.3 Document ID

20.4 Citation

The AIRSAR data were provided by the Radar Data Center at NASAs Jet Propulsion 
Laboratory.

20.5 Document Curator

20.6 Document URL

Keywords
SAR
Radar
JPL
AIRSAR

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