Evaluation of Global Gravity Field Models using GPS and Leveling Data over Ethiopia
| dc.contributor.advisor | Tulu, Besha (PhD) | |
| dc.contributor.author | Muhamed, Melesse | |
| dc.date.accessioned | 2021-09-07T04:51:40Z | |
| dc.date.accessioned | 2023-11-28T13:46:15Z | |
| dc.date.available | 2021-09-07T04:51:40Z | |
| dc.date.available | 2023-11-28T13:46:15Z | |
| dc.date.issued | 2021-07 | |
| dc.description.abstract | This study presents the evaluation of the most recently released global gravity field models. The evaluation method involves the comparison of the geoid undulations and relative differences in heights computed from the model with those computed from the GPS and leveling data. The assumption made here is that the value obtained from the GPS and leveling data consider as a standard to which the value obtained from the model. The results of the geoid undulation differences between the GPS and leveling data, and the global gravity field models include EGM2008, EIGEN-6C4, GECO, and XGM2019e-2159 has a standard deviation of 0.5176m, 0.5024m, 0.5102m, and 0.5243m, with the root mean square error of 1.176m, 1.1871m, 1.1772 m and 2.3058 m respectively. Similarly, the results of the differences between spirits leveling based on relative differences in height and models based on relative differences in height has a standard deviation of 0.172m, 0.172m, 0.1718m, and 0.1722m, with the root mean square error of 0.2617m, 0.2617m, 0.2615m and 0.2619m respectively. The error of the geoid undulation generated by the global gravity field models include EGM2008, EIGEN-6C4, GECO, and XGM2019e-2159 are reach up to 9.04 cm, 3.74 cm, 4.66 cm, and 3.58 cm respectively. The global gravity field models are strongly correlated with the GPS and leveling data. The variances of each model with respect to each other are significantly the same at 95% confidence interval. Based on the attained results, it is concluded that the global gravity field models can be used to prepare a topographical map of 4 meter and 1 meter contour interval, absolutely and relatively. | en_US |
| dc.identifier.uri | http://etd.aau.edu.et/handle/12345678/27814 | |
| dc.language.iso | en_US | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Global Gravity Field Models | en_US |
| dc.subject | EGM2008 | en_US |
| dc.subject | EIGEN-6C4 | en_US |
| dc.subject | GECO | en_US |
| dc.subject | XGM2019e-2159 | en_US |
| dc.subject | GPS | en_US |
| dc.subject | Spirit Leveling | en_US |
| dc.subject | Geoid Undulations | en_US |
| dc.subject | Relative Differences in Height | en_US |
| dc.title | Evaluation of Global Gravity Field Models using GPS and Leveling Data over Ethiopia | en_US |
| dc.type | Thesis | en_US |