GENERATING BOUGUER ANOMALY MAP FROM AIRBORNE GRAVITY DATA (A CASE STUDY IN SOUTH EAST SULAWESI)

*Laode M Sabri  -  Departemen Teknik Geodesi, Fakultas Teknik, Universitas Diponegoro, Indonesia
Bambang Sudarsono  -  Departemen Teknik Geodesi, Fakultas Teknik, Universitas Diponegoro, Indonesia
Jamal Jamal  -  Pusat Survey Geologi, Kementerian Energi dan Sumber Daya Mineral, Indonesia
Sonny Mawardi  -  Pusat Penelitian dan Pengembangan Geologi Kelautan, Kementerian Energi dan Sumber Daya Mieral, Indonesia
Received: 19 Oct 2020; Published: 4 Dec 2020.
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Abstract
Terrestrial measurements can provide accurate gravity data, but it is costly and time-consuming for large and remote area. Airborne gravity measurements have actually been carried out in Indonesia since 2008 by Technical University of Denmark (DTU) in collaboration with the Geospatial Information Agency (BIG). Purpose of the project was to develop a geoid model used for converting elevations from GPS/GNSS measurements that refers to ellipsoid to orthometric elevations that refer to sea level. The data can actually be explored so that it can be used for geophysical and other geoscience purposes, but the data must be carefully treated and extracted into observational gravity data. This study aims to improve the accuracy of gravity airborne data to produce an accurate complete Bouguer anomaly map. The data used in this study were airborne gravity data over Province of Southeast Sulawesi collected on September 29, 2008 to October 1, 2008.  Variation in flight height at the time of consecutive data introduced new horizontal acceleration vector. It must be treated as a noise in the measurement of gravity data. The first stage of processing was to eliminate noise due to aircraft acceleration. Gravity data measured in aircraft conditions accelerating more than 5 m.s-2 were eliminated. In this stage, the gravity data were reduced from 64481 observation points to 4900 observation points. The second stage of processing was low pass filtering to eliminate the remaining surges in gravity data. Airborne gravity data that have been snooped and filtered were then applied to calculate the complete Bouguer anomaly. Visually, a complete Bouguer anomaly map through the enhancement process produced a finer map compared to maps from airborne gravity data without enhancement. Comparison of airborne Bouguer anomaly map and terrestrial Bouguer anomaly maps of Kendari sheet showed a correlation of more than 83%. The conclusion of this study was that the enhancement of the airborne data significantly increases the accuracy and reliability of the airborne gravity data for generating a complete bouguer anomaly map. The results of this study also indicated that the airborne archive data has the potential to be used for geophysical and geosciences purposes in Southeast Sulawesi and Indonesia.

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  1. Supriyanto, Rokhmatuloh, Sobirin, R., & Suhanto, E. (2018). The effect of gravity measurement distribution points on interpretation of gravity data in the Gunung Endut geothermal prospect area, Indonesia. International Journal of GEOMATE, 14(41), 60-67. https://doi.org/10.21660/2018.41.07022
  2. Setyawan A., Y. Fukuda, J. Nishijima and T. Kazama, "Detecting Land Subsidence Using Gravity Method in Jakarta and Bandung Area, Indonesia", Procedia Environmental Sciences 23 ( 2015 ) pp. 17 – 26, doi: 10.1016/j.proenv.2015.01.004
  3. A M Pahlevi, B Bramanto, B Triarahmadhana, S Huda, D Pangastuti, A Nur, D D Wijaya, K Prijatna, M Julianto and A B Wijanarto , “Airborne gravity survey, towards a precise Indonesian geoid model (case study: Sumatera Island)”, IOP Conference Series: Earth and Environmental Science, Volume 389, Geomatics International Conference 2019 21–22 August 2019, Surabaya, Indonesia
  4. R. I. Hackney and W. E. Featherstone, "Geodetic versus geophysical perspectives of the ‘gravity anomaly’," in Geophysical Journal International, vol. 154, no. 1, pp. 35-43, July 2003, doi: 10.1046/j.1365-246X.2003.01941.x
  5. PAHLEVI A., D. PANGASTUTI, N. SOFIA, A. KASENDA, K. PRIJATNA, "Determination of Gravimetric Geoid Model in Sulawesi–Indonesia", FIG Working Week 2015From the Wisdom of the Ages to the Challenges of the Modern WorldSofia, Bulgaria, 17-21 May 2015
  6. Sobari, I., Mirnanda, E., Siagian, H. P. (2007) Bouguer Anomaly Map of The Kendari Quadrangle. Pusat Survey Geologi, Bandung, Indonesia

Last update: 2021-05-05 16:11:49

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Last update: 2021-05-05 16:11:49

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