Marc Costa Sitja (JPL/NAIF) on "What’s New in the new N0067 SPICE Toolkit".

https://naif.jpl.nasa.gov/naif https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/info/whatsnew.html https://naif.jpl.nasa.gov/naif/webgeocalc.html https://naif.jpl.nasa.gov/naif/cosmographia.html