Goce precise non-gravitational force modeling for POD applications
Year: 2014
Type: article
Abstract: GOCE was launched in 2009 at 250 km altitude to recover Earth’s static gravity field. As part of the GOCE-Italy project, we carried out the precise modeling for the radiation pressure and the aerodynamic effects on this satellite. This analysis has been performed to reduce the mismodeling of the non-gravitational forces, in order to be able to estimate the ocean tides parameters from the LEO satellites orbital perturbation. A new software ARPA (Aerodynamics and Radiation Pressure Analysis), which takes advantage of the raytracing technique, has been designed and developed to accurately model the non-gravitational perturbations. ARPA can compute the Solar Radiation Pressure (SRP), Earth Radiation Pressure (ERP), the spacecraft Thermal Re-Radiation (TRR) and the aerodynamic forces and torques acting on any satellite with a high level of accuracy. The adopted methodologies and procedure are presented in this thesis, and the results of the tests on GOCE are illustrated and discussed. The NAPEOS (NAvigation Package for Earth Observation Satellites) software, developed and maintained at ESA/ESOC, was upgraded to make use of the new ARPA inputs and adopted to perform the tests on GOCE. The tests were performed on 30 consecutive daily arcs, starting at the beginning of the GOCE science phase on 1st November 2009. The results for the radiation test cases show a significant reduction of the empirical accelerations, especially in the cross-track direction, of about the 20% for the SRP, 12% for the ERP albedo, 13% for the ERP infrared and 20% for the TRR with respect to the standard NAPEOS force modeling (cannon-ball). For the aerodynamics, an important reduction of the post-fit RMS from 7.6 to 7.3 mm has been observed with the new ARPA model, and the a reduction from 4.6 to 4.2 cm of the distance of the orbits computed with ARPA from the official reduced-dynamics GOCE orbits (Precise Science Orbit) has been computed. The obtained results confirm the goodness of the modeling and techniques of ARPA for all the non-gravitational perturbations computed for GOCE. Even though the results are presented for the GOCE satellite, the new technique and software are adaptable to satellite of any shape, whether in Earth-bound orbit, or orbiting another planet, or cruising in interplanetary space.
Author: Francesco Gini
Language: English
Subfield: Geophysics
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2284662381