The OrbitTools Libraries
NORAD SGP4/SDP4 Implementations in C++ and C#
Michael F. Henry
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 and the ECF coordinate system. Intended for commercial use, a license fee is required (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 (contact the author for more information.) Professional Edition license holders may also purchase the optional Track Library.
"Revisiting Space Track Report #3" recommendations.
Copyright © 2009-2020 Michael F.
The author may be reached at firstname.lastname@example.org