ANSI-C program: init_offset_orbit.c
NAME
init_offset_orbit - Initial registration offset estimation based
on orbit data in the SLC parameter files.
SYNOPSIS
init_offset_orbit <SLC1_par> <SLC2_par>
<OFF_par> [rpos] [azpos] [cflag]
| <SLC1_par> | (input) SLC-1 parameter file |
| <SLC2_par> | (input) SLC-2 parameter file |
| <OFF_par> | (input/output) ISP/offset parameter file |
| [rpos] | range position for offset estimation (enter - for default: center of SLC-1) |
| [azpos] | azimuth position for offset estimation (enter - for default: center of SLC-1) |
| [cflag] |
copy offsets to the range
and azimuth offset polynomials in the OFF_par 0: no (default) 1: yes |
EXAMPLE
init_offset_orbit 19990421.slc.par 19999422.slc.par
19990421_19990422.off 500 500
DESCRIPTION
init_offset reads the
SLC parameter files SLC1_par and SLC2_par,
extracts the oribt data and calculates a registration offset
estimated for the indicated position of SLC-1. The estimation
considers if the SLC images are in deskewed geometry. The
estimated range and azimuth offset are written out to the ISP
offset parameter file.
Examples of ERS data show that the precision of the estimate is often better than 2 pixels. With TerraSAR-X the high precision state vectors usually have sub-pixel accuracy. The precision depends on the accuracy of the orbit data. The initial offset estimate can be refined with a two-dimensional cross correlation analysis, using on of the program init_offset.
OPTIONS
The position of the initial registration offset estimation can be
indicated. As default the SLC-1 image center is used for the
estimate. The user can specify that the initial offset value is
is written to the range and azimuth offset polynomials.
SEE ALSO
typedef_ISP.h, OFF_par, init_offset, offset_SLC, create_offset.