Testing State Transition Matrix Propagation

Conversations pertaining to the testing of GMAT

Testing State Transition Matrix Propagation

Postby shughes » Tue Jun 09, 2009 7:19 pm

To test the state transition matrix, we need to make sure we test all of the dynamics models that have STM implemented, this is not currently true so some of the tests won't run, or will fail. We should still develop scripts for all tests. I checked with the STK rep and STK does not allow you to output the STM. So we can't test against STK in this case. I believe FreeFlyer also does not support this feature. So, I think we will have to compare to finite differenced STM matrices. The alternative is to develop matlab code and compare the Matlab and GMAT. I think this could be too time consuming....

The proposed test approach is to take existing scripts that test dynamics models, copy them to a new file, and modify them to test the STM for that dynamciks model. (Perhaps we should just add STM to some of the existing test scripts, but we should get EGD's opinion on this first). The advantage of modifying existing scripts, is that it will save time in running the tests.

For all default celestial bodies test STM for the following dynamics models.
  • Point Mass Central Body
  • Nonspherical central body
    • Check two different models (e.g. for earth check EGM-96 and JGM2)
  • Solar radiation pressure
  • Point Mass Perturbations
    • Sun pert only
    • All default bodies
  • Tides
  • Drag
  • All Forces

Check STM at earth using all integrators. Use the all forces case.

For user defined celestial bodies. Test the following for a sun-centered and planet-centered body.
  • Point Mass Central Body
  • Solar radiation pressure
  • Point Mass Perturbations
    • Sun pert only
    • All default bodies
  • All Forces
shughes
 
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