Software Editions

The SGP4/SDP4 implementations are available in two forms: Standard Edition and Professional Edition.

The Standard Edition is true to the original NORAD implementation.  It is available free of charge for non-commercial use.  Commercial users must contact the author to purchase a license agreement.  The software is distributed in source code form.

The Professional Edition incorporates the changes recommended in "Revisiting Space Track Report #3".  Available only  to customers who purchase a license agreement, the Professional Edition of the software provides the next level of accuracy and reliability for the most demanding tracking applications.  Distributed only in compiled form.  Contact the author for licensing information.