Print Email Facebook Twitter Analysis of star camera errors in GRACE data and their impact on monthly gravity field models Title Analysis of star camera errors in GRACE data and their impact on monthly gravity field models Author Inacio, P.M.G. Ditmar, P.G. Klees, R. Hashemifarahani, H. Faculty Civil Engineering and Geosciences Department Geoscience & Remote Sensing Date 2015-03-03 Abstract Star cameras (SCs) on board the GRACE satellites provide information about the attitudes of the spacecrafts. This information is needed to reduce the K-band ranging data to the centre of mass of the satellites. In this paper, we analyse GRACE SC errors using two months of real data of the primary and secondary SCs. We show that the errors consist of a harmonic component, which is highly correlated with the satellite’s true anomaly, and a stochastic component. We built models of both error components, and use these models for error propagation studies. Firstly, we analyse the propagation of SC errors into inter-satellite accelerations. A spectral analysis reveals that the stochastic component exceeds the harmonic component, except in the 3–10 mHz frequency band. In this band, which contains most of the geophysically relevant signal, the harmonic error component is larger than the random component. Secondly, we propagate SC errors into optimally filtered monthly mass anomaly maps and compare them with the total error. We found that SC errors account for about 18 % of the total error. Moreover, gaps in the SC data series amplify the effect of SC errors by a factor of 5 . Finally, an analysis of inter-satellite pointing angles for GRACE data between 2003 and 2010 reveals that inter-satellite ranging errors were exceptionally large during the period February 2003 till May 2003. During these months, SC noise is amplified by a factor of 3 and is a considerable source of errors in monthly GRACE mass anomaly maps. In the context of future satellite gravity missions, the noise models developed in this paper may be valuable for mission performance studies. Subject star camerasfuture gravity missionsK-band rangingattitude errorsantenna phase centre correction To reference this document use: http://resolver.tudelft.nl/uuid:b4a0a819-c745-4216-807d-769741193ef0 Publisher Springer ISSN 0949-7714 Source https://doi.org/10.1007/s00190-015-0797-1 Source Journal of Geodesy, 89 (6), 2015 Part of collection Institutional Repository Document type journal article Rights © 2015 The Author(s)This article is published with open access at Springerlink.com Files PDF Inacio 2015.pdf 7.22 MB Close viewer /islandora/object/uuid:b4a0a819-c745-4216-807d-769741193ef0/datastream/OBJ/view