Pseudo-Stochastic Orbit Modeling Techniques for Low-Earth Orbiters

摘要: The Earth’s non-spherical mass distribution and atmospheric drag cause the strongest perturbations on very low-Earth orbiting satellites (LEOs). Models of gravitational non-gravitational accelerations are utilized in dynamic precise orbit determination (POD) with GPS data, but it is also possible to derive LEO positions based point positioning without dynamical information. We use reduced-dynamic technique for POD, which combines geometric strength observations force models, investigate performance different pseudo-stochastic parametrizations, such as instantaneous velocity changes (pulses), piecewise constant accelerations, continuous linear accelerations. estimation empirical parameters a standard least-squares adjustment process observations, together other relevant parameters, strives highest precision computation trajectories. used procedures CHAMP satellite found that orbits may be validated by means independent SLR measurements at level 3.2 cm RMS. Validations accelerometer data revealed correlations 95% along-track direction. As expected, compensate certain extent deficiencies models. analyzed capability deriving information about mismodeled part field evidence resulting recover if number large enough. Results simulations showed significantly better acceleration-based gravity recovery than pulse-based orbits, quality comparable direct unconstrained set up every 30 s.