Vallado/CelesTrak SGP4

SGP4.cpp and SGP4.h are the C++ reference implementation distributed with Revisiting Spacetrack Report #3, AIAA 2006-6753, revision 2020-07-13. They were obtained from CelesTrak’s official software archive:

https://celestrak.org/publications/AIAA/2006-6753/

The upstream permission FAQ states that the source may be used for any purpose with citation and a link to its main page. The files are kept unmodified so published verification vectors remain applicable. Cartofreako compiles this legacy translation unit separately with its upstream warning profile; all adapter code continues to use the repository’s strict warnings.

Captured-file SHA-256 digests:

source archive  3642043b706c76be87cf012db3f22e04da6b80498d00f515e51879e0ffadc115
SGP4.cpp        2ee7ad0e8f201e8251894083fe21e33a7aace2f43c871bf04357eb44a891b06e
SGP4.h          2a5ec44e059a52b3173d78d9a28bda8142b4f6497c1eb16febc2cea4b5006b0c

The adapter initializes SGP4 from CelesTrak OMM fields and uses WGS-72 and AFSPC operation mode, as recommended for compatibility with the published reference results.