A MATLAB library for orbital dynamics, propagation, and filtering in the context of GNSS navigation.
- This library requires installation of NASA JPL's SPICE utility, published through the Navigation and Ancillary Information Facility (NAIF). The MATLAB version can be installed through the JPL NAIF website.
- Many scripts use SPICE to access data and ephemerides of celestial bodies, which stores and accesses information in kernels. Kernels for both generic solar system data and past flight projects are available through the NAIF website as well.
Once the repository is cloned, add the entire GTGNSS directory and its subdirectories to the path. This may be done in MATLAB with the command:
addpath(genpath('path/to/repository'))For use globally, this line can be added to the end of the user's startup.m script -- found in the user's default MATLAB directory.
The script GTGNSS_setup.m can be run during first setup to initialize the library for use (only once is necessary, no need to run on every startup). Currently, this saves the selected absolute path of a common SPICE kernel location so the kernels can be accessed with local paths from within scripts. To run the included examples, contact @mchartigan for a generic subset of SPICE kernels for Earth- and Moon-centered missions; then, the path provided in GTGNSS_setup should be the parent directory of these.
Example implementations of various classes are included in the ex directory. Some require generic SPICE kernels -- see the Installation section for setup info.
Each subdirectory has modules and/or functions that can assist with orbit propagation or navigation filtering. Each module and function has a header describing the inputs (and outputs, if unclear) required to use each utility. Specific data sources are provided in the res directory when applicable, such as spherical harmonic coefficients for the Earth and Moon. For help information, use the command help function-or-module-name. If more specificity is needed, use edit function-or-module-name and peruse the in-line code documentation.
Please notify @mchartigan of any deficiencies in documentation or broken functionality, as this repository is a port from previous codebases.