I want to write the results of processing a Rinex file using geodetic heights, and an external geoid from Spain's geographic institute IGN.
I have downloaded the geoid files from their FTP in text format from ftp://ftp.geodesia.ign.es/geoide/ascii/ with .txt and .asc extensions, and in binary GRD format (ftp://ftp.geodesia.ign.es/geoide/GRD/EGM08_REDNAP.grd), but none of them seems to work, and I am getting the exact same results as with RNX2RTKP default's geoid (EGM96, 1ºx1º), while I would expect to see a significant difference in height.
In order to tell RTKLIB that I want to use the external geoid, I run the program as follows:
rnx2rtkp.e -p 0 -k config_file.conf rinex_file.obs brdc_orbits.obs -o output_file.sol
where config_file.conf has only de following lines:
out-height =geodetic file-geoidfile =geoid_filename
and geoid_filename is the .asc, .txt or .grd file.
What am I doing wrong? Am I not providing the file in the correct format, or should I set something else in the config file?