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Table 3 Statistics of the final gravimetric geoid, quasi-geoid, and their validation [m] modification, which is performed for a specific d/o and then linearly tapered to another higher d/o, all pairs formed from d/o 60 to d/o 300 have been tested. Since FFT needs gridded residual gravity anomalies, the grid was generated based on the irregular residual gravity anomalies over the Kingdom and prediction on a grid with LSC. To evaluate the different gravimetric geoid models resulting from the combination of number of parallels and modification degrees, evalua- tion with a set of available, high-accuracy, GNSS/Leveling dataset by GEOSA was performed. The best results were achieved with a Wong-Gore modification between d/o 80 and 100 and a multiband solution with 3 bands. Figure 3 depicts the final geoid height differences between the final gravimet- ric geoid and the GEOSA GNSS/Leveling geoid heights. In the same processing line, the quasi-geoid over the Kingdom has been determined and from that the geoid was once again estimated using the analytical evaluation of the quasi-geoid to geoid separation by Flury and Rummel (2009). Table 3 tabulates the final gravimetric geoid (see Fig. 2), the quasi- geoid, the difference between the gravimetric geoid and that

Table 3 Statistics of the final gravimetric geoid, quasi-geoid, and their validation [m] modification, which is performed for a specific d/o and then linearly tapered to another higher d/o, all pairs formed from d/o 60 to d/o 300 have been tested. Since FFT needs gridded residual gravity anomalies, the grid was generated based on the irregular residual gravity anomalies over the Kingdom and prediction on a grid with LSC. To evaluate the different gravimetric geoid models resulting from the combination of number of parallels and modification degrees, evalua- tion with a set of available, high-accuracy, GNSS/Leveling dataset by GEOSA was performed. The best results were achieved with a Wong-Gore modification between d/o 80 and 100 and a multiband solution with 3 bands. Figure 3 depicts the final geoid height differences between the final gravimet- ric geoid and the GEOSA GNSS/Leveling geoid heights. In the same processing line, the quasi-geoid over the Kingdom has been determined and from that the geoid was once again estimated using the analytical evaluation of the quasi-geoid to geoid separation by Flury and Rummel (2009). Table 3 tabulates the final gravimetric geoid (see Fig. 2), the quasi- geoid, the difference between the gravimetric geoid and that

Related Figures (5)

Table 1 Land and marine gravity datasets available and data holdings
Table 1 Land and marine gravity datasets available and data holdings
Table 2 Statistics of the original, reduced and residual gravity data in the Aramco database (565,752 point values), GDMS database (5,492 point values) in the shipborne marine database (245,813 point values) and in the altimetry database (771,500 point values). Unit: [mGal] and the removal of the topographic effects. Then we can determine residual geoid heights (N,,;) and restore the con- tribution of the GGM (NGG) and the topography (Njop0), to derive the final gravimetric geoid with RCR as: The FFT evaluation was carried out with GravSoft’s spfour program, during which the number of reference parallels can be selected, as well as the modification of the Stokes kernel. For the number of the of reference parallels used four options were tested (1, 3, 6 and 9). For the Wong-Gore can be selected, as well as the modification of the Stokes
Table 2 Statistics of the original, reduced and residual gravity data in the Aramco database (565,752 point values), GDMS database (5,492 point values) in the shipborne marine database (245,813 point values) and in the altimetry database (771,500 point values). Unit: [mGal] and the removal of the topographic effects. Then we can determine residual geoid heights (N,,;) and restore the con- tribution of the GGM (NGG) and the topography (Njop0), to derive the final gravimetric geoid with RCR as: The FFT evaluation was carried out with GravSoft’s spfour program, during which the number of reference parallels can be selected, as well as the modification of the Stokes kernel. For the number of the of reference parallels used four options were tested (1, 3, 6 and 9). For the Wong-Gore can be selected, as well as the modification of the Stokes
Fig. 2 The final gravimetric geoid model KSA-Geoid21GRA for KSA
Fig. 2 The final gravimetric geoid model KSA-Geoid21GRA for KSA
Fig. 3 Geoid height differences between the final gravimetric geoid and the GEOSA GNSS/Leveling geoid heights
Fig. 3 Geoid height differences between the final gravimetric geoid and the GEOSA GNSS/Leveling geoid heights
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