References¶

The equations and many of the unit tests underlying this work are drawn from the following sources:

"Fundamentals of Astrodynamics and Applications, Fourth Edition", D. Vallado, Microcosm Press and Springer, 2013. https://celestrak.org/software/vallado-sw.php
"Satellite Orbits: Models, Methods, Applications", O. Montenbruck and E. Gill, Springer, 2000. https://doi.org/10.1007/978-3-642-58351-3

Models¶

This code makes reference to and relies on models generated by the following:

SGP4 Orbit Propagator — https://celestrak.org/software/tskelso-sw.php NORAD / SGP4 orbit propagator used to generate position and velocity states from orbital ephemerides described by Two-Line Element Sets (TLEs). This code base includes a pure-Rust translation of the SGP4 orbit propagator.
NRL MSISE-00 Density Model — https://ccmc.gsfc.nasa.gov/models/NRLMSIS~00/ NRL model of air density, including density at high altitudes, used to compute satellite drag.
Gravity Models — http://icgem.gfz-potsdam.de/home International Center for Global Earth Models (ICGEM), collection and archive in a common format of all existing global gravity field models.
Space Weather — https://celestrak.org/SpaceData/ Space weather used to modulate the air density used in drag calculations.
Earth Orientation Parameters — https://celestrak.org/SpaceData/ Time-varying Earth orientation parameters used for time epoch conversions and high-precision rotations between the inertial and Earth-fixed coordinate frames.
IERS Conventions — https://www.iers.org/IERS/EN/Publications/TechnicalNotes/tn36.html International Earth Rotation and Reference Systems Service Technical Note 36 for rotation between inertial and Earth-fixed coordinate systems.

The code includes Rust test modules and Python test modules for verification of calculations, including but not limited to:

JPL Ephemeris — Via JPL-provided test vectors for Chebyshev polynomial calculation
SGP4 — Via SGP4 test vectors provided with original C++ distribution