Enhancement the Elevations of GNSS Technique Via Calibrating Geoid Separation of Electronic Gravity Model 2008: A Case Study: Maysan, Iraq

Abstract

Global Navigation Satellite System (GNSS) is one of the most common technique in the geodetic survey field over the traditional techniques such as level, theodolite and total station because its time-saving, intervisibility, accuracy and number of operators. advanced GNSS technique introduces ellipsoid height and it has to be transformed orthometric-height for application of surveying. Thus, a geoid model has to be employed for transformation process. On the other hand, there is no specific electronic geoid model in iraq that can be utilized for obtaining an appropriate orthometric-height. Therefore, this research aims to compute the calibrated geoid model separation based on Earth Gravitational Model 2008 (EGM08) via observing the existing of vertical network utilizing GNSS technique. The results revealed that there was difference among the orthometric-height got from EGM08 in comparison with the local mean sea level. This research can aid in enhancing the accuracy obtained from GNSS technique and can significantly support the producing of a new Iraq electronic geoid model. This study concluded that the EMG08 cannot be utilized directly to obtain an accurate orthometric height and it can be used as second-order applications.