ATI Parameter Summary for at0049 processed with interferometric baseline laf_laa Mon Sep 6 17:03:25 PDT 2004 FILESET: Filename: at0049.laf_laa_par Description: This parameter summary file. (ASCII) Filename: at0049.lppp Description: Complete list of processing parms. (ASCII) Filename: at0049.laf_laa_intf1x7 Description: Slant-Range Interferogram Records: 1826 C*8 samples, 11112 lines Filename: at0049.laf_laa-uwScc1x7 Description: Slant-Range Correlation File Records: 1826 R*4 samples, 11108 lines Filename: at0049.laf-az1x7 Description: Slant-Range Multilook Image laf Records: 1826 R*4 samples, 11112 lines Filename: at0049.laa-az1x7 Description: Slant-Range Multilook Image laa Records: 1826 R*4 samples, 11112 lines Filename: at0049.laf_laa-uwWrp-sc10x10 Description: Ground-Projected Velocity Map and Image Records: 2x882 R*4 samples, 3880 lines Filename: at0049.laf_laa-uwScc-sc10x10 Description: Ground-Projected Correlation File and Image Records: 2x882 R*4 samples, 1940 lines Filename: at0049.laf_laa-uwWrp-sc10x10-inc Description: Ground-Projected Incidence Angle Map and Image Records: 2x882 R*4 samples, 1940 lines ============================================================================== Slant-Range Projection Information: 7987.125 meters average platform altitude 8865.539 meters range to first slant-range sample 0.242257 meters radar wavelength 3.331027 meters sample spacing 3.897523 meters record spacing 0.046220 seconds interferogram repeat time interval 0.417096 meters/(seconds*radians) phase to velocity component conversion Ground Map Projection Information: 10.00 meter sample (C) spacing, 10.00 meter record (S) spacing -22172.0 meters: minimum S-coordinate in ground projected output 21218.0 meters: maximum S-coordinate in ground projected output 3832.0 meters: minimum C-coordinate in ground projected output 12642.0 meters: maximum C-coordinate in ground projected output Ground Map Coordinates Map Corner Latitude Longitude First Sample of First Record 17.151 -91.336 Last Sample of First Record 17.506 -91.509 First Sample of Last Record 17.118 -91.411 Last Sample of Last Record 17.473 -91.584 Caveats: This is the first flight season for which we are delivering ATI data. The processor is still under development, and the calibration is not final. The current status of the processor is that only some of the calibration parameters have been adequately determined. In particular, there is an arbitrary phase offset for each interferogram, and therefore an arbitrary velocity offset in the velocity map. There is evidence of inadequate motion measurement and compensation, as well as interferometric phase center alignment: phase variations along-track and a residual phase-ramp across the scene are seen in some of the ATI data sets. Note that phase variations over land are expected due to topography: along-track interferometric processing makes use of an elevation reference for motion compensation. Where this reference is not constant, there will be motion compensation phase variations introduced. The elevation reference is constant over the ocean surface, so this artifact is unique to the land. There is no radiometric calibration for these data.