PENGUKURAN GAYABERAT MENGGUNAKAN GRAVIMETER ABSOLUT A-10

Prayudha Hartanto, Safirotul Huda, Widy Putra, Irpan Septiawan

Abstract


Pengukuran gayaberat absolut merupakan pengukuran nilai gayaberat dengan mengamati percepatan vertikal benda jatuh bebas. Pada tahun 2017, Badan Informasi Geospasial (BIG) melakukan pengukuran gayaberat absolut di beberapa pilar Gayaberat Utama (GBU) di Indonesia dengan menggunakan gravimeter A-10. Tujuan penulisan makalah ini adalah memaparkan teknik pengukuran dan pengolahan data gayaberat absolut di GBU yang merupakan bagian dari Jaring Kontrol Gayaberat (JKG) dengan menggunakan gravimeter A-10. Titik-titik yang akan dijadikan pembahasan dalam makalah ini adalah GBU018 di Jakarta dan GBU035 di Makassar. Pengukuran di tiap titik dilakukan sebanyak 10 set dengan jumlah drop untuk setiap set sebanyak 120. Hasil yang diperoleh adalah nilai gayaberat absolut (µgal) beserta ketidakpastiannya. Nilai gayaberat (g) hasil pengolahan di lapangan (on-site) untuk GBU018 adalah 978140735,73 ± 11,17 µgal, sedangkan untuk GBU035 adalah 978117560,92 ± 7,16 µgal. Nilai-nilai tersebut diperoleh setelah dilakukan koreksi gradien gayaberat. Koreksi tersebut diperoleh dari pengamatan gradien menggunakan gravimeter relatif dengan besaran -0,296301 mgal/m untuk GBU018 dan -0,32414 mgal/m untuk GBU035.

Keywords


anomali gayaberat, gravimeter absolut, gradien gayaberat

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DOI: http://dx.doi.org/10.24895/JIG.2019.25-1.852

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