These scripts make it possible to compute the average of the AOD1B over the solution periods of the Swarm gravity field models, which happen to be complete calendar months.

Before that, there is the need to download the AOD1B data with AOD1B/download.sh. Notice that the AOD1B data is very large, 7.2Gb per year uncompressed.

The script aod-mean.awk is where all the work takes place. All input arguments are assumed to be AOD1B files to be averaged. Optionally, the environment variable lmax can be exported before running the awk script to define the maximum degree to consider (defaults to 40).

The script aod-mean-monthly.sh wraps around aod-mean.awk to pick the AOD1B files relevant to a particular calendar month defined by the input arguments:

./aod-mean-monthly.sh <4-digit year> <2-digit month>

As a result, GA[ABCD]_<start_date>_<stop_date>.gfc are produced. The header information is retrieved from the AOD1B files and left unchanged.