AIRSAR Precision Data Description

AIRSAR precision data contains all of the data channels that were collected during a flight line. The data are calibrated and are processed to full resolution.

Headers

All AIRSAR precision data files start with 3-4 header records a general description of which is included below.

first header: general information about data file including # of lines and samples and offset to the first data record.

parameter header: information specific to the scene

calibration header: information on data calibration

DEM header: only present for TOPSAR data; contains the elevation offset and elevation increment needed to translate the integer*2 values to elevations in meters.

 POLSAR Precision Data

Each POLSAR scene typically contains three data files (see note below for exception) which have the following naming convention:

File Name Data Format File Size (10 km)

CM####_c.dat compressed Stokes matrix data in slant range 15 Mbytes

CM####_l.dat compressed Stokes matrix data in slant range 15 Mbytes

CM####_p.dat compressed Stokes matrix data in slant range 15 Mbytes

 Note: Due to FCC restrictions, since 1994, P-band data are not included for POLSAR datasets collected at 40 Mhz bandwidth over sites in the United States.

The "CM" indicates that the data are in a compressed Stokes matrix format. CM is followed by a four-digit output product number; this number is unique for each scene. All POLSAR data are in the slant range projection. POLSAR CM data will be sent to you on an 8 mm tape or CD-ROM.

TOPSAR Precision Data

Each TOPSAR scene typically contains four (C-band) or eight (if C-band and L-band) DEM and related data files and 1-2 polarimetric data files (see note below for exception) which have the following naming conventions:

File Name Data Description Data Format File Size (10 km)

DEM Data (C-band, maybe L-band)

TS####_c.vvi2 C-band VV polarization only integer2 (signed 16 bit) 2.5 Mbytes

TS####.demi2 C-band DEM integer2 (signed 16 bit) 2.5 Mbytes

TS####.corgr correlation coefficient map byte file 1.2 Mbytes

TS####.incgr local incidence angle map byte file 1.2 Mbytes

Polarimetric Data (collected in a TOPSAR mode)

TS####_l.datgr L-band polarimetry compressed Stokes matrix 15 Mbytes

TS####_p.datgr P-band polarimetry compressed Stokes matrix 15 Mbytes

Note: Due to FCC restrictions, since 1994, P-band data are not included for TOPSAR datasets collected at 40 Mhz bandwidth over sites in the United States.

The "TS" indicates that the data are TOPSAR data. TS is followed by a four-digit output product number that is unique for each scene. All TOPSAR data, including any polarimetric data collected in a TOPSAR mode, will be projected in the ground range (this is indicated by the "gr" in the file extensions shown above).