Software Edition Information

The SGP4/SDP4 implementations are available in three editions: Public, Standard, and Professional.

The Public Edition is true to the original NORAD implementation.  It is available on this website for immediate download.  This version of the software is for non-commercial use only;  commercial users must obtain either the Standard Edition or the Professional Edition.

The Standard Edition is identical to the Public Edition, except it also includes support for WGS-84.  Intended for commercial use, a license fee is required.  License holders may also purchase the optional Track Library.  Contact the author for more information.

The Professional Edition is similar to the Standard Edition, but also incorporates the changes recommended in "Revisiting Space Track Report #3".  This edition of the software provides the next level of accuracy and reliability for the most demanding tracking applications.  Intended for commercial use, a license fee is required. License holders may also purchase the optional Track Library.  Contact the author for more information.

*Implements "Revisiting Space Track Report #3" recommendations.