G99BM (ASCII format) Download PAGE
The Fortran source code for the interpolation (INTG.FOR) and extraction
& conversion (XNTG.FOR) programs must be downloaded and then compiled
on your platform to generate compatible executable files (presumably named
INTG and XNTG, respectively). The INTG program will interpolate geoid heights
from data files using user-provided coordinates. The XNTG program will
extract sub-grids from the binary data files, as well as convert back and
forth between binary and ASCII, or just give statistics about a data file.
To use G99BM, both the executables and at least one data file must be
present. Once you have downloaded the desired data files that cover your
region, the XNTG program will be used to convert the ASCII data to binary
and the INTG program will recognize which of these files are present.