Comparing Precision Orbit Solutions of Geodetic Satellites Given Several Ocean Tide and Geopotential Models.

摘要

The ability to successfully perform many aspects of a satellite mission is directly impacted by the ability to precisely determine and predict the satellite's orbit through high precision orbit determination. The orbit determination process relies on numerical procedures, satellite measurements, and force modeling to generate the orbit solution and prediction. As a foundation for detailed force modeling, gravity forces due to the distribution of the Earth's mass must be accurately modeled. In prior research, a number of geopotential models and ocean tide models have been developed for use in orbit determination. This paper examines current and historically recommended geopotential and ocean tide models using the Naval Research Laboratory's Orbit Covariance Estimation and ANalysis tool. Geodetic satellites with high precision satellite laser ranging measurements are used as test cases to evaluate the solution accuracy and predictive capabilities of the geopotential and ocean tide models. Orbit fit and prediction comparison metrics are generated for multiple geopotential and ocean tide model combinations. Results show that use of the EGM2008 geopotential model combined with the GOT4.8 ocean tide model generally results in predictive orbit solutions that more closely follow the definitive orbit solution. However, these results vary for different satellite orbits and time past the initial fit span.