Analysis of Determining Geoid Height Values in Urban Areas

Abstract

Floods have a significant impact on human life. To reduce the risk due to flooding, mitigation is needed. Mitigation can be done when information about the flood model has been mapped. Flood modeling requires primary data in height values with reasonable accuracy. The essential data can be obtained through INAGEOID2020. INAGEOID2020 cannot be used optimally due to a lack of information regarding its accuracy. The validation process has been carried out on 5 (five) significant islands. One is the island of Borneo, which focuses on the Kalimantan Barat and Kalimantan Timur Provinces. In the two provinces, the accuracy of 5.88 to 6.43cm. There is no information about the accuracy of INAGEOID2020 in the Kalimantan Selatan Province. So, it is necessary to validate INAGEOID2020 in that province. So, validation activities are needed to get the accuracy of INAGEOID2020 in Kalimantan Selatan. Research requires two types of data, namely primary and secondary data. Preliminary data was obtained by carrying out GNSS observations. In addition, measurements of height differences between validation points were also carried out. In addition, terrestrial gravity data is needed at the validation point as a corrector value for height difference measurements. Secondary data was obtained from the Geospatial Information Agency as validation point gravimetric undulation values. Before carrying out the INAGEOID2020 validation, a geometric undulation calculation must be carried out by utilizing the leveling and GNSS data calculation results. This article shows that the geometric undulation standard deviation value results are 0.368 m, and the RMS value is 0.336 m.