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)
: Details in the research portal "Research@Leibniz University"

BibTeX

@article{27668097c2514874bc54cfb797e78dc4,
title = "GOCE orbit analysis: Long-wavelength gravity field determination using the acceleration approach",
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 {"}Geod{\"a}tisches Institut{"} and IWF for {"}Institut f{\"u}r 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.",
keywords = "Empirical covariance function, GOCE, GPS, Gravity field, Kinematic positions, Numerical differentiation",
author = "O. Baur and T. Reubelt and M. Weigelt and M. Roth and N. Sneeuw",
year = "2012",
month = aug,
day = "1",
doi = "10.1016/j.asr.2012.04.022",
language = "English",
volume = "50",
pages = "385--396",
journal = "Advances in space research",
issn = "0273-1177",
publisher = "Elsevier Ltd.",
number = "3",
}