Comparison of Recent and Former Satellite-Based Gravity Models: A Case Study of Kansas, USA


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Doğru F.

Dokuz Eylül Üniversitesi Mühendislik Fakültesi Fen ve Mühendislik Dergisi, vol.23, 2021 (Peer-Reviewed Journal) identifier

Abstract

Satellite-based gravity models have been used constantly in many different areas recently. The easy accessibility of the data provides great advantages for difficult conditions such as mountainous areas or the ability to calculate directly for inaccessible areas such as Arctic regions. In addition, shallow studies are possible by increasing the spatial resolution over time by using new satellites and new models obtained from these satellite data. Spatial resolution can be increased with the use of terrestrial data and thus the most representative satellite gravity model which has the lowest error may be determined for a region. It is thought that the results obtained from the studies with this lowest error model represent that region in the best way. Within the scope of this study, experiments were conducted for former and current satellite gravity models using terrestrial gravity data that was collected in Kansas state. Besides, comparisons were made at different degree/order using only GOCE satellite gravity models (long wavelengths) and combined models (short wavelengths). As 8.63 mGal lowest error between satellite models and terrestrial data was obtained from XGM2019e_2159 and ERTM2160 combination. In the comparison between GOCE models, GOCE TIM R5 model gave the lowest error with a difference of 9.94 mGal. Although it is observed that the difference between the other combined models and the results obtained from the XGM2019e_2159 model does not exceed 0.4 mGal for degree up to 2190 and these values are not considered as a big difference in geophysical studies, but the sensitivity of these values is much more important in geodetic studies.