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Modeling of the local gravity field in the south pole of the Moon by the Grail satellite data
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Mohsen Feizi *   , Mahdi Raoofian Naeeni , Maryam Miri |
| K.N. Toosi University of Technology |
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Abstract: (463 Views) |
In this study, the ability of local basic functions in static modeling of the Moon's gravity field is investigated by using the local harmonic functions and the artificial observations of the Primary and Extended Missions of GRAIL satellite and GL1500E global model. In this modeling, three months of GRAIL observations are used to form the observational gravity data. The observation used in this research is the gravity difference along the line of sight of the satellite pair (LGD). Due to the supposition that there are ice masses distributed on the moon, analysis and modeling of variations in the gravitational field are crucial. Modeling the moon's gravity field is complicated by the presence of the earth's gravity field and its effect on the dynamic orbit of the GRAIL satellite. In this study, the coefficients of the local gravity model have been obtained by forming the normal equation through adjusted spherical cap harmonic basic functions (ASCH) and solving the inverse problem. In this study, in the first scenario, the modeling of the gravity field using primary mission data (an average altitude of 50 km) is discussed. In the second scenario, due to the different altitude layers of the Primary Mission (average altitude of 50 km) and the Extended Mission (average altitude of 20 km), observations from the Extended Mission are used to provide ASCH coefficients. The observations from the primary mission are used to evaluate the accuracy of the model. The results of the constructed model on the primary mission data at control points was 0.08 micro Gal and the results of the control points on the extended mission observations was 0.15 micro Gal. As a result, the lunar South Pole local geo-potential model's validation is confirmed. By employing fewer coefficients the method we used showed an acceptable spatial precision of the gravity field of the changes compared to the geo-potential models such as GL1500E.
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| Keywords: Adjusted spherical cap harmonic, local gravity field, geopotential model |
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Full-Text [PDF 1134 kb]
(138 Downloads)
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Type of Study: Research |
Subject:
Geodesy
Received: 2022/12/16 | Accepted: 2023/02/12 | Published: 2024/06/20
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