Gamma ISP: Reference Manual

Programs for generation of parameter files and image files for RADARSAT-1 data

Programs: par_RSAT_SCW.c, par_RSAT_SGF.c, par_RSAT_SLC.c.

par_RSAT_SCW

reads the LEADER, the TRAILER and the DATA file in CEOS format, generating the ISP SLC parameter file and the reformatted image.

SYNOPSIS

par_RSAT_SCW <CEOS_leader> <CEOS_trailer> <CEOS_data> <GRD_par> <GRD> [sc_dB] [dt]

<CEOS_leader>	(input) CEOS leader file file provided by processing facility
<CEOS_trailer>	(input) CEOS trailer file
<CEOS_data>	(input) CEOS SCW or SCN image data file
<GRD_par>	(output) ISP image parameter file (*.grd.par)
<GRD>	(output) ground range image data (short integer format)
sc_dB	intensity scale factor in dB (enter - for default: 0.0)
dt	azimuth image time offset (s) (enter - for default = 0.0)

Description

The image is acquired in Wide Swath mode and is in ground range projection. The reformatted image data are scaled and saved as 4-byte/value floating point values. Absolute calibration constants are applied. The time offset dt in seconds, is subtracted from the image times specified in the CEOS leader and is nominally 0.0. Ouput image values are radar cross section in dB. The sc_dB argument is an additional output scale factor used to adjust the output values and is nominally 0.0.

par_RSAT_SGF

reads the LEADER and the DATA file in CEOS format, generating the ISP SLC parameter file and the reformatted image.

SYNOPSIS

par_RSAT_SGF <CEOS_leader> <CEOS_data> <GRD_par> <GRD> [sc_DB] [dt]

<CEOS_leader>	(input) CEOS leader file file provided by processing facility with SGF or SCW16 data
<CEOS_data>	(input) CEOS image data file
<GRD_par>	(output) ISP image parameter file (*.grd.par)
<GRD>	(output) ground range image data (short integer format)
sc_dB	intensity scale factor in dB (enter - for default: 0.0)
dt	azimuth image time offset (s) (enter - for default = 0.0)

DESCRIPTION

The image can be either in ground range format (SGW) or ScanSAR SCW16 format. If the input data file is provided on the command line, an output SLC data set and parameter file are created that are radiometrically calibrated and flipped as required in range and azimuth such that the earliest azimuth time is the first line of the file and the range samples begin at near range and extend to the far range.

The time offset dt in seconds, is subtracted from the image times specified in the CEOS leader and is nominally 0.0. Ouput image values are radar cross section in dB. The sc_dB argument is an additional output scale factor used to adjust the output values and is nominally 0.0.

par_RSAT_SLC

par_RSAT_SLC - reads the LEADER and the SLC DATA file in CEOS format, generating the ISP SLC parameter file and the reformatted SLC image.

SYNOPSIS

par_RSAT_SLC <CEOS_SAR_leader> <SLC_par> [CEOS_DAT] [SLC] [sc_dB] [dt]

<CEOS_leader>	(input) CEOS SAR leader file (example: lea_01.001)
SLC_par	(output) ISP SLC parameter file (example: yyyymmdd.slc.par)
<CEOS_data>	(input) CEOS data file (example: dat_01.001)
<SLC>	(output) SLC data with file and line headers removed (example: yyyymmdd.slc)
sc_dB	intensity scale factor in dB (enter - for default: 85.0)
dt	azimuth image time offset (s) (enter - for default = 0.0)

DESCRIPTION

This program processes a CEOS format SLC data set and creates the ISP SLC parameter file and the SLC image. Radiometric scaling is applied to the data using the scaling factors stored in the CEOS leader file. The image is flipped in range and azimuth if requred to insure that azimuth line time and slant range are always increasing. This insures that the first image sample in the file was acquired earliest and has the minimum slant-range.

The time offset dt in seconds, is subtracted from the image times specified in the CEOS leader and is nominally 0.0. Ouput image values are pairs (re,im) of short integers (scomplex). The sc_dB argument is an additional output scale factor used to adjust the output values so that the available dynamic range is fully utilized. In the case of scomplex data, the data are scaled such that:

sigma0 = 10.0*log10(re*re + im*im) - sc_dB

SEE ALSO:
typedef_ISP.h