ANSI-C program: dispmap.c
NAME
dispmap - Surface displacement map generation form unwrapped
differential phase.
SYNOPSIS
dispmap <unw> <hgt> <SLC_par>
<ISP_par> <disp_map> [mode] [loff]
[nlines]
| <unw> | (input) unwrapped phase (float) |
| <hgt> | (input) height map (float) or - to select constant reference height 0.0 |
| <SLC_par> | (input) SLC parameter file of reference SLC |
| <ISP_par> | (input) ISP/offset parameter file |
| <disp_map> | (output) displacement map |
| [mode] | flag indicating displacement map mode: default=0: along look vector [m] (+:towards sensor) 1: vertical displacement [m] (+:increasing height) 2: horizontal displacement [m] (+:decreasing ground range) |
| [loff] | number of lines offset to starting line (default=0) |
| [nlines] | number of lines to process (default: 0=entire file) |
EXAMPLE
dispmap 8560_9562.unw 8560_9562.hgt 8560.slc.par
8560_9562.off 8560_9562.disp 1
Converts the unwrapped differential interferometric phase to a vertical displacement (subsidence) map.
dispmap 8560_9562.unw - 8560.slc.par 8560_9562.off 8560_9562.disp 1
Converts the unwrapped differential interferometric phase to a vertical displacement (subsidence) map. No heights are provided, 0.0 is used as reference height.
DESCRIPTION
dispmap converts the
unwrapped differential interferometric phase to a surface
deformation map. The differential interferometric phase
corresponds to the displacement along the SAR look vector. As a
consequence the 3-dimensional displacement of a surface element
cannot be completely described. Under the assumption of a
predefined surface displacement direction a conversion to
vertical or horizontal displacement is possible.
To convert the unwrapped phase to displacement along the look vector in meters with positive signs corresponding to displacement towards the sensor dispmap mode 0 is selected. For this conversion no specific assumption on the surface deformation is necessary. To map vertical displacement in meters with positive signs corresponding to increasing surface height and negative signs to subsidence dispmap mode 1 is selected. Vertical displacement can often be assumed in the case of subsidence.
To map the horizontal displacement component in ground range
direction in meters with positive signs corresponding to
decreasing ground range, select mode 2.
OPTIONS
Terrain heights are required for the conversion of the unwrapped
phase to the displacement vectors. As an option the height file
can be avoided and a surface reference height 0f 0.0 m is used
for the conversion. The effect of the terrain height on the
result may in many cases be neglected in comparison to other
error sources.
SEE ALSO
typedef_ISP.h typedef_DIFF.h