Detail Airborne vector gravimetry using GPS/INS Bibliografi Author: Kwon, Jay Hyoun ; Jekeli, Christopher (Advisor) Topik: GEODESY|REMOTE SENSING Bahasa: (EN )    ISBN: 0-599-66515-7     Penerbit: THE OHIO STATE UNIVERSITY     Tahun Terbit: 2000     Jenis: Theses - Dissertation Fulltext: 9962419.pdf (0.0B; 0 download) Abstract Compared to the conventional ground measurement of gravity, airborne gravimetry is relatively efficient and cost-effective. Especially, the combination of GPS and INS is known to show very good performances in the range of medium frequencies in the gravity signal and it is relatively cheap and efficient. Conventionally, gravity estimation using GPS/INS was analyzed through the estimation of INS system errors using GPS position and velocity updates. In this case, the complex navigation equations must be integrated to obtain the INS position, and the gravity field must be stochastically modeled as a part of the state vector. The vertical component of the gravity vector is not estimable in this case because of the instability of the vertical channel in the solution of the inertial navigation equations. In this study, a new algorithm using acceleration updates instead of position/velocity updates has been developed. Because we are seeking the gravitational field, that is, accelerations, the new approach is conceptually simpler and more straightforward. In addition, it is computationally less expensive since the navigation equations do not have to be integrated. It is more objective, since the gravity disturbance field does not have to be explicitly modeled as state parameters. An application to real test flight data as well as an intensive simulation study have been performed to test the validity of the new algorithm. The results from the real flight data show very good accuracy in determining the down component, with accuracy better than ±5 mGal. Also, a comparable result was obtained for the horizontal components with accuracy of ±6 to ±8 mGal. The resolution of the final result is about 10 km due to the attenuation with altitude. The inclusion of a parametric gravity model into the new algorithm is also investigated for theoretical reasons. The gravity estimates from this filter showed strong dependencies on the model and required extensive computation with no improvement over the approach without parametric gravity model. Opini Anda Klik untuk menuliskan opini Anda tentang koleksi ini! Lihat Sejarah Pengadaan  Konversi Metadata   Kembali

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