satkit 0.5.5

Satellite Orbital Dynamics Toolkit

Satellite Toolkit with Rust

An accurate, high-performance satellite orbital kinematics toolkit, written in Rust with a sensible interface.
Also includes python bindings for all functions via via pyo3

Github

Crates.io

PyPi

Language Bindings

• Native Rust bindings
• Python bindings for compiled rust code ... speed of Rust with convenience of Python
  Install with pip install satkit
  PyPi includes binary packages for windows, macos (Intel & ARM), and linux. Python documentation is at: https://satellite-toolkit.readthedocs.io/latest/

Features

• High-precision coordinate transforms between:
  • International Terrestrial Reference Frame (ITRF)
  • Geocentric Celestial Reference Frame (GCRF) using IAU-2000 reduction
  • True-Equinox Mean Equator (TEME) frame used in SGP4 propagation of TLEs
  • Celestial Intermediate Reference Frame (CIRF)
  • Terrestrial Intermediate Reference Frame (TIRF)
  • Terrestrial Geodetic frame (latitude, longitude)
• Geodesic distances
• SGP4, and Keplerian orbit propagation
• JPL high-precision planetary ephemerides
• High-order gravity models
• High-precision, high-speed numerical satellite orbit propagation with high-order efficient Runga-Kutta solvers, ability to solve for state transition matrix, and inclusion following forces:
  • High-order Earth gravity with multiple models
  • Solar gravity
  • Lunar gravity
  • Drag (NRL MISE-00 density model)
  • Radiation pressure

ODE Solvers

The high-precision numerical satellite orbit propagation makes use of adaptive Runga-Kutta methods for integration of ordinary differential equations. The pure-Rust ODE solver is included as part of the library.

The methods use Runga-Kutta pairs for ODE integration and error estimation generated by Jim Verner: https://www.sfu.ca/~jverner/

References, Models, and External Software.

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

Data Dependencies

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 in to compute satellite drag
• Gravity Models - http://icgem.gfz-potsdam.de/home
  International Center for Global Earth Models (ICEGM), 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.
• JPL Ephemerides - https://ssd.jpl.nasa.gov/ephem.html
  High-precision ephemerides for solar system bodies (sun, moon, planets) in frame of solar system barycenter

Verification

The package includes rust test modules and python test modules for verification of nearly all calculations, including but not limited to:

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

Getting Started

Rust

Simply include the code in your Cargo.toml file to use. Once installed, make sure you run utils.update_datafiles to download the most-recent data files necessary for many calculations. This only needs to be done once, unless more-recent space weather and Earth orientation parameter data is required (these are updated at least daily).

satkit.utils.update_datafiles()?;

Python

Satkit is available via pypi.org, and can be installed via the pip command:

python -m pip install satkit

Binaries are available for Windows (AMD64), Mac (Intel, Apple Silicon) and Linux (x86_64) for python versions 3.8 through 3.13.

Once installed, make sure you download the most-recent data files necessary for many calculations. This only needs to be done once, unless more-recent space weather and Earth orientation parameter data is required (these are updated at least daily).

import satkit as sk
sk.utils.update_datafiles()

Author

Steven Michael ([e-mail])

Please reach out of you find errors in code or calculations, are interested in contributing to this repository, or have suggestions for improvements to the API.