sgp4

What we today call ‘SGP4’ in fact merges together what in the 1970s were originally two separate satellite propagation routines, but which are now selected automatically: * SGP4 — the ‘Simplified General Perturbations’ model is used for satellites close enough to Earth that their orbit takes less than 225 minutes (3 hours 45 minutes) to complete. * SDP4 — the ‘Simplified Deep Space Perturbations’ model is used for satellites farther from Earth, which take 225 minutes or longer to compete an orbit.

More Information

For more information visit the sgp4 website.

Available Versions

These versions of sgp4 are available on the BEAR systems (BlueBEAR and BEAR Cloud VMs). These will be retained in accordance with our Applications Support and Retention Policy.