SSAPy - Space Situational Awareness for Python
SSAPy is a python package allowing for fast and precise orbital modeling.
SSAPy is much faster than other orbit modeling tools and offers:
A variety of integrators, including Runge-Kutta, SciPy, SGP4, etc.
Customizable force propagation models, including a variety of Earth gravity models, lunar gravity, radiation pressure, etc.
Multiple-hypothesis tracking (MHT) UCT linker
Vectorized computations
Short arc probabilistic orbit determination
Conjunction probability estimation
Uncertainty quantification
Monte Carlo data fusion
Support for multiple coordinate frames (with coordinate frame conversions)
Installation
For installation details, see the Installing SSAPy section of the documentation.
Strict dependencies
Python (3.8+)
The following are installed automatically when you install SSAPy:
scipy for many statistical functions;
astropy for astronomy related functions;
pyerfa a Python wrapper for the ERFA library;
emcee an affine-invariant ensemble sampler for Markov chain Monte Carlo;
lmfit a package for non-linear least-squares minimization and curve fitting;
sgp4 contains functions to compute the positions of satellites in Earth orbit;
matplotlib as a plotting backend;
and other utility packages, as enumerated in setup.py.
Documentation
All documentation is hosted at https://LLNL.github.io/SSAPy/.
The API documentation may also be seen by doing:
python3
>>> import ssapy
>>> help(ssapy)
Contributing
Contributing to SSAPy is relatively easy. Just send us a pull request. When you send your request, make develop the destination branch on the SSAPy repository.
Your PR must pass SSAPy’s unit tests and documentation tests, and must be PEP 8 compliant. We enforce these guidelines with our CI process. To run these tests locally, and for helpful tips on git, see our Contribution Guide.
SSAPy’s develop branch has the latest contributions. Pull requests should target develop, and users who want the latest package versions, features, etc. can use develop.
Releases
For multi-user site deployments or other use cases that need very stable software installations, we recommend using SSAPy’s stable releases.
Each SSAPy release series also has a corresponding branch, e.g. releases/v0.14 has 0.14.x versions of SSAPy, and releases/v0.13 has 0.13.x versions. We backport important bug fixes to these branches but we do not advance the package versions or make other changes that would change the way SSAPy concretizes dependencies within a release branch. So, you can base your SSAPy deployment on a release branch and git pull to get fixes, without the package churn that comes with develop.
The latest release is always available with the releases/latest tag.
See the docs on releases for more details.
Code of Conduct
Please note that SSAPy has a Code of Conduct. By participating in the SSAPy community, you agree to abide by its rules.
License
SSAPy is distributed under the terms of the MIT license. All new contributions must be made under the MIT license.
See Link to license and NOTICE for details.
SPDX-License-Identifier: MIT
LLNL-CODE-862420
Basics