Modelling the local geoid of East Kalimantan from combination of airborne and terrestrial gravity data using the KTH method
DOI: https://doi.org/10.3846/gac.2026.21948Abstract
This research aims to determine the gravimetric geoid using the KTH method for East Kalimantan, where Indonesia’s new capital city is located. The geoid of East Kalimantan was calculated from a combination of airborne gravity data, terrestrial gravity data, DTU17 for the sea area, anomalies of EGM2008 degree 2190, SRTM15+, and GGM from EGM2008 degree 360. The geoid modelling is performed using LSMSSOFT software with a grid interval of 0.01˚. The evaluation of capsize variations includes 14 variations: 0.1˚, 0.2˚, 0.3˚, 0.4˚, 0.5˚, 0.6˚, 0.7˚, 0.8˚, 0.9˚, 1˚, 1.2˚, 1.3˚, 1.5˚, and 2˚. The KTH geoid was evaluated using 264 GNSS-Levelling data points. The best accuracy was obtained at a capsize of 0.6˚ with a standard deviation value of 0.0532 m. The accuracy of the geoid model after shifting to the tidal benchmark (BM) is 0.0526 m. A comparison with the recent national geoid model of INAGEOID2020 v.2 obtained using the Remove-Restore method, which has a standard deviation of 0.0588 m, shows that the accuracy of the KTH method geoid model is higher, with a precision improvement of 0.0062 m.
Keywords:
geoid, airbone, terrestrial, gravity, KTH, East KalimantanHow to Cite
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Copyright (c) 2026 The Author(s). Published by Vilnius Gediminas Technical University.

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References
Abbak, R. A. (2020). Effect of a high-resolution global crustal model on gravimetric geoid determination: A case study in a mountainous region. Studia Geophysica et Geodaetica, 64(4), 436–451. https://doi.org/10.1007/s11200-020-1023-z
Abbak, R. A., Erol, B., & Ustun, A. (2012). Comparison of the KTH and remove–compute–restore techniques to geoid modelling in a mountainous area. Computers & Geosciences, 48, 31–40. https://doi.org/10.1016/j.cageo.2012.05.019
Abbak, R. A., & Ustun, A. (2015). A software package for computing a regional gravimetric geoid model by the KTH method. Earth Science Informatics, 8(1), 255–265. https://doi.org/10.1007/s12145-014-0149-3
Abdalla, A., & Tenzer, R. (2011). The evaluation of the New Zealand’s geoid model using the KTH method. Geodesy and Cartography, 37(1), 5–14. https://doi.org/10.3846/13921541.2011.558326
Center for Geodesy and Geodynamics Control Network BIG. (2023). Sistem referensi geospasial Indonesia. https://srgi.big.go.id/page/geoid-model, https://srgi.big.go.id/map/jkg-active
Featherstone, W. E., & Kuhn, M. (2006). Height systems and vertical datums: A review in the Australian context. Journal of Spatial Science, 51(1), 21–41. https://doi.org/10.1080/14498596.2006.9635062
Hofmann-Wellenhof, B., & Moritz, H. (2005). Physical geodesy. Springer. https://doi.org/10.1007/b139113
Işık, M. S., Erol, B., Erol, S., & Sakil, F. F. (2021). High-resolution geoid modeling using least squares modification of Stokes and Hotine formulas in Colorado. Journal of Geodesy, 95(5), 1–19. https://doi.org/10.1007/S00190-021-01501-z
Jalal, S. J., Musa, T. A., Md Din, A. H., Wan Aris, W. A., Shen, W., & Pa’suya, M. F. (2019). Influencing factors on the accuracy of local geoid model. Geodesy and Geodynamics, 10(6), 439–445. https://doi.org/10.1016/j.geog.2019.07.003
Krdžalić, D., & Abbak, R. A. (2023). A precise geoid model of Bosnia and Herzegovina by the KTH method and its validation. Survey Review, 55(393), 513–523. https://doi.org/10.1080/00396265.2022.2163361
Ly, C. A. T., Diene, J. M. L., Diouf, D., Ba, A., Ly, C. A. T., Diene, J. M. L., Diouf, D., & Ba, A. (2021). GNSS technology’s contribution to topography: Evaluative study of gaps between methods topographies. Journal of Geographic Information System, 13(3), 340–352. https://doi.org/10.4236/jgis.2021.133019
Pa’suya, M. F., Din, A. H. M., Yusoff, M. Y. M., Abbak, R. A., & Hamden, M. H. (2021). Refinement of gravimetric geoid model by incorporating terrestrial, marine, and airborne gravity using KTH method. Arabian Journal of Geosciences, 14(19), 1–19. https://doi.org/10.1007/S12517-021-08247-0
Sakil, F. F., Erol, S., Ellmann, A., & Erol, B. (2021). Geoid modeling by the least squares modification of Hotine’s and Stokes’ formulae using non-gridded gravity data. Computers & Geosciences, 156, Article 104909. https://doi.org/10.1016/j.cageo.2021.104909
Sansò, F., & Sideris, M. G. (Eds.). (2013). Geoid determination (Vol. 110). Springer. https://doi.org/10.1007/978-3-540-74700-0
Sjöberg, L. E. (2003). A general model for modifying Stokes’ formula and its least-squares solution. Journal of Geodesy, 77(7–8), 459–464. https://doi.org/10.1007/S00190-003-0346-1
Sylvester, E., Olujimi, O., Sunday, O., & Candidate, P. D. (2018). Procedure for the determination of local gravimetric-geometric geoid model. International Journal of Advances in Scientific Research and Engineering (IJASRE), 4(8), 206–214. https://doi.org/10.31695/IJASRE.2018.32858
Wu, Q., Wang, H., Wang, B., Chen, S., & Li, H. (2020). Performance comparison of geoid refinement between XGM2016 and EGM2008 based on the KTH and RCR methods: Jilin Province, China. Remote Sensing, 12(2), Article 324. https://doi.org/10.3390/rs12020324
Yildiz, H., Simav, M., Sezen, E., Akpinar, I., Akdogan, Y. A., Cingoz, A., & Akabali, O. A. (2021). Determination and validation of the Turkish Geoid Model-2020 (TG-20). Bulletin of Geophysics and Oceanography, 62(3), 495–512. https://doi.org/10.4430/bgta0345
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