ANSI-C program: sub_phase_pt.c
NAME
sub_phase_pt - subtract/add interferogram flat-Earth phase trend
(single record or all records)
SYNOPSIS
sub_phase_pt <plist> <pmask> <pint1>
<rec_num> <punw2> <pdiff> [int_type]
[inverse]
| <plist> | (input) point list (int) |
| <pmask> | (input) point data stack of mask values (uchar, set to - to accept all points) |
| <pint1> | (input) point data stack of interferograms (fcomplex or float) |
| <rec_num> | record number to process (default -: all records) |
| <punw2> | (input) point data stack of unwrapped phases (float) |
| <pdiff> | (output) point data stack of differential interferograms (punw2 subtracted/added, same type as pint1) |
| [int_type] | type of pint1 and pdiff (0: float(i.e. unwrapped phase), default=1: fcomplex) |
| [inverse] | subtract/add flag (default=0: subtract punw2, 1: add punw2) |
EXAMPLE
sub_phase_pt testsite.plist testsite.pmask testsite.pint 3
testsite.psim testsite.pdiff 1 0
Subtracts the unwrapped simulated phase from the complex valued interferogram for record 3 of the input and output point data stacks.
sub_phase_pt testsite.plist testsite.pmask testsite.pint - testsite.psim testsite.pdiff 1 0
Subtracts the unwrapped simulated phase from the complex valued interferogram for all records of the input and output point data stacks.
sub_phase_pt testsite.plist - testsite.pdiff.unw - testsite.psim testsite.pdiff 0 1
Adds for all records of the input and output point data stacks the unwrapped simulated phase to the unwrapped differential interferogram to obtain the unwrapped phase of the original interferogram.
INSTALLATION
Source code sub_phase_pt.c in ./IPTA/src, executable version
sub_phase_pt in ./IPTA/bin
DESCRIPTION
sub_phase_pt subtracts or adds unwrapped phase images for
interferograms in point data format. This can be done for complex
valued interferograms or unwrapped (real valued) interferograms
and for a single record of the stack of interferograms or all
records.
The coordinates of the points considered are defined in the point list. The optional mask file indicates for each point if it is valid (1, i.e. considered) or not volid (0, excluded).
The input interferograms are provided as a point data stack. This stack is of fcomplex type for complex valued interferograms and of float type for unwrapped interferometric phase images. The type of the output stack of "differential" interferograms is of the same type as the input stack.
The "differential" interferogram (or more generally speaking the output interferogram) is calculated for each valid point of the point list. Valid points are points with a non-zero input interferogram value, a non-zero subtraction-phase value, and a non-zero mask value (if provided). For each valid point the provided real valued phase is either subtracted from the input interferograms ("flattening") or added to the input interferogram ("reramping"). Such a real valued phase image can result from a simulation (*e.g. using the program phase_sim_pt), or from scaling unwrapped phases of real interferograms (as supported by the program scale_base_pt).
If a new output stack name is indicated the stack is created. Indicating a record number larger than the highest record number of the indicated stack results in an increase of the stack size.
To display the complex or real valued input or output interferograms contained in the point data stack the programs pt2data or pt2d can be used to convert the point data to raster data format which can then be displayed using conventional display programs.
OPTIONS
none.
SEE ALSO
phase_sim_pt, scale_base_pt, pt2data, pt2d,
ipta.h.
© Copyrights for Documentation, Users Guide and Reference Manual by Gamma Remote Sensing, 2003.
UW, CW, TS, last change 20-Feb-2003.