ANSI-C program: residue.c,residue_cc.c
NAME
residue - Reads smoothed interferogram, determines phase
residues and writes these into the flag file.
residue_cc - Reads smoothed interferogram, determines phase residues under consideration of low coherence areas and writes these into the flag file.
SYNOPSIS
residue <interferogram> <flagfile>
<width> [xmin] [xmax] [ymin] [ymax]
| <interferogram> | complex image data (smoothed interferogram) |
| <flagfile> | flag filename |
| <width> | number of samples/row |
| [xmin] | offset to starting range pixel (default = 0) |
| [xmax] | offset last range pixel (default = width-1) |
| [ymin] | offset to starting azimuth row (default = 0) |
| [ymax] | offset to last azimuth row (default = nlines-1) |
EXAMPLE
residue 1352_1610.sm 1352_1610.flag 2500
residue_cc 1352_1610.sm 1352_1610.flag 2500
DESCRIPTION
residue and residue_cc read smoothed
interferograms, determine phase residues and write these into the
unwrapping flag file. Residues are important for the phase
unwrapping process. Growing the phase around a residue leads to
an inconsistency of 2PI. There are both positive and negative
residues depending on the sign of the inconsistency. The tree
generation program (e.g. tree_cc or tree_gzw)
connects these changes to create neutral trees that will not
generate large global unwrapping errors. The unwrapping flag file
is generated with the program corr_flag. This file
contains information on the location of the trees, branch cuts,
region unwrapped, regions of low correlation, and neutrons. The
meaning of the individual bits in the bit mask of each pixel is
explained in typedef_ISP.h. The information contained in
the flagfile can be displayed with the programs disflag
and rastree.
residue_cc does not consider the phases of the low coherence areas. As a consequence much fewer residues are found, which will speed up the connection of the residues by brach cuts as done by the program tree_cc. When using residue_cc the branch cuts should be determined with tree_cc rather than with tree_gzw.
SEE ALSO
typedef_ISP.h, corr_flag, tree_cc, tree_gzw,
neutron, disflag, rastree.
© Copyrights for Documentation, Users Guide and Reference Manual by Gamma Remote Sensing, 2000.
UW, CW, last change 28-Jan-2000.