### GMAT orbit propagators compared to SGP4 propagator

Posted:

**Thu Aug 11, 2016 8:19 pm**What is the difference between the GMAT orbit propagators and the SGP4 propagator used by NORAD?

Kind regards

Klaus

Kind regards

Klaus

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Posted: **Thu Aug 11, 2016 8:19 pm**

What is the difference between the GMAT orbit propagators and the SGP4 propagator used by NORAD?

Kind regards

Klaus

Kind regards

Klaus

Posted: **Fri Aug 19, 2016 10:59 am**

Hi,

In short, an SGP4 propagator uses a simplified mathematical model of an object's orbit to predict its position in the future. GMAT numerically solves the equations resulting from all forces acting on an object in space at discrete time time intervals. The results from SGP4 predictions are less accurate and become worse the further you predict into the future, while the results from GMAT will be much more accurate and should remain accurate irrespective of the prediction period. It does, however, take much longer to solve the equations than to use the SGP4 model, so it is slower.

Regards,

Niki

In short, an SGP4 propagator uses a simplified mathematical model of an object's orbit to predict its position in the future. GMAT numerically solves the equations resulting from all forces acting on an object in space at discrete time time intervals. The results from SGP4 predictions are less accurate and become worse the further you predict into the future, while the results from GMAT will be much more accurate and should remain accurate irrespective of the prediction period. It does, however, take much longer to solve the equations than to use the SGP4 model, so it is slower.

Regards,

Niki