*** DRAFT ***
How to Add an Orbit State Type to GMAT
Wendy C. Shoan
Goddard Space Flight Center
Introduction
GMAT provides the capability to model spacecraft orbits. As of R2013a, there are six orbit state representations allowed in GMAT: Cartesian, Keplerian, Modified Keplerian, SphericalAZFPA, SphericalRADEC, and Equinoctial.
This document will first give a brief overview of how GMAT handles these state types. Then it will explain how to add a new orbit state type to GMAT. Due to current design, new state types cannot be added by plugins and so GMAT base code must be modified. The implementation of a new orbit state type will involve, at a high level:
- Modifying the Spacecraft class to handle the new type
- Adding conversions methods in StateConversionUtil
- Adding new parameters to GMAT for the fields associated with your new state type
- Modifying the Orbit tab of the Spacecraft panel
State Type Overview
The user can set a spacecraft's orbital state in any of the above-mentioned representations, via the script or the Orbit tab of the Spacecraft panel.
Adding a State Type
Step 1: Modify Spacecraft.hpp
Step 2: Modify Spacecraft.cpp
Step 3: Modify StateConversionUtil
Step 4: Add the new parameters
Step 5: Update the Orbit Panel