http://iebkxzjscv4jgaucepdbdf4b7bqmcwd5peulm5cbpoavlsnkfhda5gyd.onion/ddtss/index.cgi/da/translated/da/logs/1710494640/python3-pygac
NOAA-14 and before) or the third
generation (NOAA-15 and onwards) AVHRR instrument by "pygac-run".
This is done by reading the first three bytes of the data set.
If they contain the any of the following values, ["CMS", "NSS", "UKM",
"DSS"], then the KLM reader from "gac_klm.py" file is invoked,
otherwise the POD reader is invoked (gac_pod.py).