The new COST-G deterministic signal model

Meyer, Ulrich; Peter, Heike; Lasser, Martin; Jäggi, Adrian (May 2022). The new COST-G deterministic signal model (Unpublished). In: EGU General Assembly 2022. Vienna, Austria. May 23-27, 2022. 10.5194/egusphere-egu22-1614

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The precise orbit determination (POD) of Low Earth Orbiters (LEO), e.g. the Copernicus Sentinel Earth observation satellites, relies on the precise knowledge of the Earth gravity field and its variations with time. The most precise observation of time-variable gravity on a global scale is currently provided by the GRACE-FO satellites. But the monthly gravity field solutions are released with a latency of approx. 2 months, therefore they cannot be used for operational POD. We present a deterministic signal model (DSM) that is fitted to the time-series of COST-G combined monthly gravity fields and describe the differences with respect to the available long-term gravity models including seasonal and secular time-variations. To validate the DSM, dynamic POD of the Sentinel-2B, -3B and -6A satellites is performed based on long-term or monthly gravity field models, and on the COST-G DSM. We evaluate the model quality on the basis of carrier phase residuals, orbit overlap analysis and independent satellite laser ranging observations, and study the limitation on orbit altitude posed by the reduced spherical harmonic resolution of the monthly models and the DSM. The COST-G DSM is updated quarterly with the most recent GRACE-FO combined monthly gravity fields. It is foreseen to apply a sliding window approach with flexible window length to allow for an optimal adjustment in case of singular events like major earthquakes.

Item Type:

Conference or Workshop Item (Speech)

Division/Institute:

08 Faculty of Science > Institute of Astronomy

UniBE Contributor:

Meyer, Ulrich, Lasser, Martin, Jäggi, Adrian

Subjects:

500 Science > 520 Astronomy

Language:

English

Submitter:

Pierre Fridez

Date Deposited:

17 Mar 2023 17:46

Last Modified:

21 Mar 2023 23:27

Publisher DOI:

10.5194/egusphere-egu22-1614

BORIS DOI:

10.48350/180289

URI:

https://boris.unibe.ch/id/eprint/180289

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