Optimal, Data-driven GRACE Accelerometer Calibration and Atmospheric Drag Models
| Autor: | Tzamali, Myrto, Pagiatakis, Spiros |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2023 |
| Zdroj: | XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
| Popis: | For the accurate determination of the Earth’s gravity field and the investigation of the Earth’s upper atmosphere, most of the LEO space missions carry on-board an accelerometer that measures the non-gravitational accelerations primarily caused by the drag, the Solar Radiation Pressure and the Earth Radiation Pressure. For accurate accelerometer measurements, the instrument needs to be calibrated during the post-processing of the measurements, a quite challenging task, since it cannot be calibrated on the ground. This study presents an alternative calibration approach based only on the accelerometer measurements and the GPS POD positions, using the matched filter detection method, widely used in radar applications to identify the presence of known signal pulses injected in the transmitted signal. The total accelerations of the satellite, which play the role of the transmitted signal, are retrieved by a double numerical differentiation of the GPS positions and the penumbra transitions measured from the accelerometer represent the known signal that is to be detected through this optimal detection technique. The calibration factors and their errors are derived for different solar activity periods for GRACE and GRACE-FO missions and a correlation with the β’ angle is presented. The calibrated measurements are then used for the development of a data-driven atmospheric drag model using least squares with weighted constraints based on the physics of the orbit. The 28th IUGG General Assembly (IUGG2023) (Berlin 2023) |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|