Residual Patterns in GRACE Follow-On Laser Ranging Interferometry Post-Fit Range Rate Residuals

verfasst von
Mathias Duwe, Igor Koch, Jakob Flury
Abstract

The novel laser ranging interferometer (LRI) on GRACE Follow-On (GRACE-FO) provides range and range rate measurements for more than 4 years now. Since the launch of the GRACE-FO mission there were few investigations about this measurement system on the level of gravity field recovery and analysis of post-fit residuals. We applied techniques such as along-orbit-analysis or time-argument of latitude diagrams (TAL) to analyse the post-fit range rate residuals as well as the post-fit range acceleration residuals to identify unknown characteristics and systematic effects. The effects are the range rate effect, the panel effect, the Carrier-To-Noise Ratio (CNR) effect and the polar effect. The range rate effect occurs, when the range rate observation ρ̇ of the LRI is around 0 m/s. In the TAL diagram the effect appears as a mesh pattern. The panel effect shows patterns of increased residuals when a specific satellite panel starts or stops being illuminated by the Sun. Increased residuals appear when the laser beam is aligned with the Sun. A CNR drop as well as a fluctuation of the yaw and pitch pointing angles obtained from the LRI steering mirrors is observable. Additionally, when the satellites flying into or out of the Earth shadow this effect coincides with the shadow transition effect. Another effect is the CNR effect which appears as an elliptic shape in the TAL diagram. This pattern occurs when the CNR values drop below the LRI requirements of 70 dB-Hz. All these effects have not been detected in the residuals of the GRACE-FO K-band ranging system (KBR) and therefore further investigation and studies will improve the understanding and applications of LRI technology.

Organisationseinheit(en)
Institut für Erdmessung
Typ
Artikel
Journal
Advances in space research
Band
73
Seiten
5769-5782
Anzahl der Seiten
14
ISSN
0273-1177
Publikationsdatum
15.06.2024
Publikationsstatus
Veröffentlicht
Peer-reviewed
Ja
ASJC Scopus Sachgebiete
Luft- und Raumfahrttechnik, Astronomie und Astrophysik, Geophysik, Atmosphärenwissenschaften, Astronomie und Planetologie, Allgemeine Erdkunde und Planetologie
Elektronische Version(en)
https://doi.org/10.1016/j.asr.2024.03.035 (Zugang: Offen)