- The user manual (more or less) up to date with the latest version is available the same place as the source package, see downloads.
- Otherwise, here is a direct link to the Open Office document in hte source code repository.
- Various tech notes that might be of interest are also available in the source tree.
If you are interested in learning how satellite tracking programs such as Gpredict work, we can suggest the following reading:
- SpaceTrack Report number 3 describes the SGP, SGP4, SDP4, SGP8, and SDP8 propagation models used by satellite tracking programs and provides source code exmaples in FORTRAN. The document also contains references to the original publications.
- The Keplerian Elements Tutorial by Franklin Antonio, N6NKF, explains the two-line file format used for distribution of Keplerian Elements (TLE data).