Improved star camera attitude data and their effect on the gravity field


Autoria(s): Bandikova, Tamara; Meyer, Ulrich; Klinger, Beate; Tregoning, Paul; Flury, Jakob; Mayer-Gürr, Torsten
Data(s)

01/09/2014

Resumo

Efforts are ongoing to decrease the noise of the GRACE gravity field models and hence to arrive closer to the GRACE baseline. The most significant error sources belong the untreated errors in the observation data and the imperfections in the background models. The recent study (Bandikova&Flury,2014) revealed that the current release of the star camera attitude data (SCA1B RL02) contain noise systematically higher than expected by about a factor 3-4. This is due to an incorrect implementation of the algorithms for quaternion combination in the JPL processing routines. Generating improved SCA data requires that valid data from both star camera heads are available which is not always the case because the Sun and Moon at times blind one camera. In the gravity field modeling, the attitude data are needed for the KBR antenna offset correction and to orient the non-gravitational linear accelerations sensed by the accelerometer. Hence any improvement in the SCA data is expected to be reflected in the gravity field models. In order to quantify the effect on the gravity field, we processed one month of observation data using two different approaches: the celestial mechanics approach (AIUB) and the variational equations approach (ITSG). We show that the noise in the KBR observations and the linear accelerations has effectively decreased. However, the effect on the gravity field on a global scale is hardly evident. We conclude that, at the current level of accuracy, the errors seen in the temporal gravity fields are dominated by errors coming from sources other than the attitude data.

Formato

application/pdf

Identificador

http://boris.unibe.ch/69222/1/GSTM2014-A1-21-Bandikova.pdf

Bandikova, Tamara; Meyer, Ulrich; Klinger, Beate; Tregoning, Paul; Flury, Jakob; Mayer-Gürr, Torsten (September 2014). Improved star camera attitude data and their effect on the gravity field. In: GRACE Science Team Meeting. Potsdam, Germany. 29.09.-01.10.2014.

doi:10.7892/boris.69222

Idioma(s)

eng

Relação

http://boris.unibe.ch/69222/

http://www.bernese.unibe.ch/publist/2014/post/GSTM2014-A1-21-Bandikova.pdf

Direitos

info:eu-repo/semantics/openAccess

Fonte

Bandikova, Tamara; Meyer, Ulrich; Klinger, Beate; Tregoning, Paul; Flury, Jakob; Mayer-Gürr, Torsten (September 2014). Improved star camera attitude data and their effect on the gravity field. In: GRACE Science Team Meeting. Potsdam, Germany. 29.09.-01.10.2014.

Palavras-Chave #520 Astronomy
Tipo

info:eu-repo/semantics/conferenceObject

info:eu-repo/semantics/publishedVersion

NonPeerReviewed