After creating a DEM file using SRTM.py script, now say we need to convert it to a GMT .grd file.
1. convert the binary file to a grd file:
xyz2grd [binary file] -G[output_grd_file] -Zh -I[pixel_size] -R[west]/[south]/[east]/[north]r
- don't forget the r at the end.
- in the -Zh, h is for 2 byte integer. change if needed
2. Sample to a different pixel size and sub-region:
grdsample [input_grd_file] -G[output_grd_file] -I[new_pixel_size] -R[west]/[south]/[east]/[north]r
- if a known number of pixels is desired, say in east-west, use: east = west+[needed_pixel_number - 1]*[new_pixel_size]
3. put zeros instead of null values -9999:
grdmath [input_grd_file] -9999 GT [input_grd_file] MUL = [output_grd_file]
- note that if you sample some of the null pixels will be with different values so use say -500 instead of -9999 as a threshold.
