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DEM geocoding

Added by Sofia Antonova over 8 years ago

Hi,

does anybody tried to geocode TSX DEM obtained by interferometry? I ended up with the file $1_$2.hgt, then I use commands gc_insar and geocode and then produce tif file which looks good. However, if I convert .hgt file from slant to ground range with the command res_map and then apply the same commands to the transformed file $1_$2.rhgt, the output contains stripes and doesn't look healthy. I wonder what can be a problem and if the geocoding flow is correct, and if the slant-to-ground transformation is necessary at all.

Thanks a lot!
Sonya


Replies (2)

RE: DEM geocoding - Added by Redmine Admin over 8 years ago

Hello Sonya,­

It is not even clear to me what you are trying to accomplish.

res_map is an ancient relic of the early age of Gamma, its pu­poses hidden by mist­and fire, before we had geocoding. in the ­software. res_map resamples the data to ground-range, and permits resampling in both range and azimuth to get the­desired pixel size. So it looks like a map­projected product, but is not.

gc_insar creates the­ lookup table that maps each slant-range pixel into the map coordinates.
You can use the use the program geocode to calculate the new h­eight map in the DEM projection.

Charles

DEM geocoding - Added by Charles Werner over 8 years ago

Hello Sonya,

It is not even clear to me what you are trying to accomplish.

res_map is an ancient relic of the early age of Gamma, its purposes hidden by
mist and fire, before we had geocoding. in the software. res_map resamples the
data to ground-range, and permits resampling in both range and azimuth to get
the desired pixel size. So it looks like a map projected product, but is not.

gc_insar creates the lookup table that maps each slant-range pixel into the map
coordinates.
You can use the use the program geocode to calculate the new height map in the
DEM projection.

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