The impact of common versus separate estimation of orbit parameters on GRACE gravity field solutions

Meyer, Ulrich; Jäggi, Adrian; Beutler, Gerhard; Bock, Heike (2015). The impact of common versus separate estimation of orbit parameters on GRACE gravity field solutions. Journal of geodesy, 89(7), pp. 685-696. Springer 10.1007/s00190-015-0807-3

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Gravity field parameters are usually determined from observations of the GRACE satellite mission together with arc-specific parameters in a generalized orbit determination process. When separating the estimation of gravity field parameters from the determination of the satellites’ orbits, correlations between orbit parameters and gravity field coefficients are ignored and the latter parameters are biased towards the a priori force model. We are thus confronted with a kind of hidden regularization. To decipher the underlying mechanisms, the Celestial Mechanics Approach is complemented by tools to modify the impact of the pseudo-stochastic arc-specific parameters on the normal equations level and to efficiently generate ensembles of solutions. By introducing a time variable a priori model and solving for hourly pseudo-stochastic accelerations, a significant reduction of noisy striping in the monthly solutions can be achieved. Setting up more frequent pseudo-stochastic parameters results in a further reduction of the noise, but also in a notable damping of the observed geophysical signals. To quantify the effect of the a priori model on the monthly solutions, the process of fixing the orbit parameters is replaced by an equivalent introduction of special pseudo-observations, i.e., by explicit regularization. The contribution of the thereby introduced a priori information is determined by a contribution analysis. The presented mechanism is valid universally. It may be used to separate any subset of parameters by pseudo-observations of a special design and to quantify the damage imposed on the solution.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Institute of Astronomy
08 Faculty of Science > Other Institutions > Emeriti, Faculty of Science

UniBE Contributor:

Meyer, Ulrich; Jäggi, Adrian; Beutler, Gerhard and Bock, Heike

Subjects:

500 Science > 520 Astronomy

ISSN:

0949-7714

Publisher:

Springer

Language:

English

Submitter:

Pierre Fridez

Date Deposited:

22 Jun 2015 09:34

Last Modified:

05 Apr 2017 15:54

Publisher DOI:

10.1007/s00190-015-0807-3

BORIS DOI:

10.7892/boris.69655

URI:

https://boris.unibe.ch/id/eprint/69655

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