GOCE orbit analysis

Long-wavelength gravity field determination using the acceleration approach

authored by
O. Baur, T. Reubelt, M. Weigelt, M. Roth, N. Sneeuw
Abstract

The restricted sensitivity of the Gravity field and steady-state Ocean Circulation Explorer (GOCE) gradiometer instrument requires satellite gravity gradiometry to be supplemented by orbit analysis in order to resolve long-wavelength features of the geopotential. For the hitherto published releases of the GOCE time-wise (TIM) and GOCE space-wise gravity field series - two of the official ESA products - the energy conservation method has been adopted to exploit GPS-based satellite-to-satellite tracking information. On the other hand, gravity field recovery from data collected by the CHAllenging Mini-satellite Payload (CHAMP) satellite showed the energy conservation principle to be a sub-optimal choice. For this reason, we propose to estimate the low-frequency part of the gravity field by the point-wise solution of Newton's equation of motion, also known as the acceleration approach. This approach balances the gravitational vector with satellite accelerations, and hence is characterized by (second-order) numerical differentiation of the kinematic orbit. In order to apply the method to GOCE, we present tailored processing strategies with regard to low-pass filtering, variance-covariance information handling, and robust parameter estimation. By comparison of our GIWF solutions (initials GI for "Geodätisches Institut" and IWF for "Institut für WeltraumForschung") and the GOCE-TIM estimates with a state-of-the-art gravity field solution derived from GRACE (Gravity Recovery And Climate Experiment), we conclude that the acceleration approach is better suited for GOCE-only gravity field determination as opposed to the energy conservation method.

Organisation(s)
Institute of Geodesy
External Organisation(s)
Austrian Academy of Sciences
University of Stuttgart
Type
Article
Journal
Advances in space research
Volume
50
Pages
385-396
No. of pages
12
ISSN
0273-1177
Publication date
01.08.2012
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
Aerospace Engineering, Astronomy and Astrophysics, Geophysics, Atmospheric Science, Space and Planetary Science, Earth and Planetary Sciences(all)
Sustainable Development Goals
SDG 7 - Affordable and Clean Energy, SDG 13 - Climate Action
Electronic version(s)
https://doi.org/10.1016/j.asr.2012.04.022 (Access: Unknown)
 

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