This repository is associated with:

Purinton, B.; Mueting, A.; Bookhagen, B. Image Texture as Quality Indicator for Optical DEM Generation: Geomorphic Applications in the Arid Central Andes. Remote Sensing. 2023. 10.3390/rs15010085.

Please cite that paper:

@Article{purinton2023spot,
	author = {Purinton, B., Mueting, A. and Bookhagen, B.},
	title = {{Image Texture as Quality Indicator for Optical DEM Generation: Geomorphic Applications in the Arid Central Andes}},
	journal = {Remote Sensing},
	volume = {15},
	number = {1},
	article-number = {85},
	doi = {10.3390/rs15010085},
	url = {https://www.mdpi.com/2072-4292/15/1/85},
	year = {2023}
}

BEFORE YOU BEGIN PROCESSING READ ALL INSTRUCTIONS HERE:

Prior to running the Ames Stereo Pipeline on the SPOT6 images, we convert them from their native, tiled format with external Rational Polynomial Coefficient (RPC) files, to a GeoTiff format with the RPC data contained in the file header using the following GDAL command. Since Ames also needs the original *.xml RPC file for processing purposes to be fed into the pipeline at various steps, we also rename this file to match our GeoTiff filename. These commands are run in each of the three directories containing the A, B, and C tristereo images:

cd /path/to/SPOT6-A-image/tiles/
gdal_translate DIM_SPOT6_*.XML A.tif -co TILED=YES
cp RPC_SPOT*_*.XML A.XML

cd /path/to/SPOT6-B-image/tiles/
gdal_translate DIM_SPOT6_*.XML B.tif -co TILED=YES
cp RPC_SPOT*_*.XML B.XML

cd /path/to/SPOT6-C-image/tiles/
gdal_translate DIM_SPOT6_*.XML C.tif -co TILED=YES
cp RPC_SPOT*_*.XML C.XML

Once this is done, you should generate a directory with a shortname for the area you are working in (e.g., for us it was Pocitos), and place the A.tif, B.tif, C.tif and A.XML, B.XML, C.XML files in a subdirectory called merged_tiles (i.e., Pocitos/merged_tiles/).

Prior to running ames_spot_processing.sh you need to place the script in the directory of your SPOT processing (e.g., Pocitos/ames_spot_processing.sh), make sure you are inside this directory at the command line (e.g., cd /path/to/Pocitos), and make sure you have donwloaded and installed the Ames Stereo Pipeline and you can access all commands from your current command line.

Once you have completed these steps, the processing parameters that you may wish to change are on line numbers 12-39 in the ames_spot_processing.sh shell script. Descriptions are provided inline, but we note the alignment DEM at line 18. You will need to make a new subdirectory called Alignment_DEMs (e.g., Pocitos/Alignment_DEMs), and in there you should put a coarse (i.e., 30 m) DEM that will be used for co-registration and map-projection (Steps 5-7 in our publication Section 3.2.3). It is up to the user to source and appropriate DEM for this step, but we recommend the Copernicus.

Once you have completed ALL of the above pre-processing steps you are ready to run the shell script!

Output processing logs will be found in the asp_logs/ subdirectory (e.g., Pocitos/asp_logs/) and all DEM results will be found in the asp_out/ subdirectory (e.g., Pocitos/asp_out/). Both of these subdirectories are generated automatically by the shell script.