GPS Satellite Predictions

Accessed:

• Option on Analyze, Satellite predictions.  It will bring up a map, and form showing positions of the GPS satellites. It will start with the current day, and animate motion of the satellites. You can set the time interval between updates, and whether you want to see a trail from the satellite motions.  Sky map not available in this mode, because you do not have a current location.
• Calculate, Intervisibility, Polar orbiter satellite visibility to show results on the current map, with option for a sky map.  The map must have a DEM, to show your horizon.

https://celestrak.org/  Download file gps-ops.txt, and save it in the program directory for MICRODEM. This file is updated "periodically" with current orbital predictions.  If you want best results, you must update it.

You can get predictions for other groups of satellites.  Click on the TLE/3LE links for the groups of satellites you want (top line in each grouping, with the little table symbol, right click, and save as), and place in c:\microdem.  

• https://celestrak.org/NORAD/elements/supplemental/ 
• https://celestrak.org/NORAD/elements/  .  You will probably have to get and run the download program (http://celestrak.com/SpaceTrack/TLERetriever3Help.php ) and have an account at space-track.org
• Another option, which we have not used: https://www.space-track.org (login required),and you want the three line catalog files.

http://www.heavens-above.com/ will give you predictions to compare with these.

Uses code originally from Dr TS Kelso (downloaded a very long time ago, 1992, and a current version may not be available).

Last revision 11/11/2022