Airborne gravity survey, towards a precise Indonesian geoid model (case study: Sumatera Island)

Abstract

Airborne gravity method for high-resolution geoid model in Indonesia held in Sumatera Island using Lacoste & Romberg Air-Sea Gravity Meter S-130 and Trimble R9S GNSS installed in the cessna grand caravan type C208B. Flight altitude ranging from 3000 to 4000 meters and the aircraft speed is 277 km/h. Processing GNSS are using differential processing which is tied to SRGI2013 with a standard deviation tolerance <7 cm in high position and 90% data fix. The gravity raw data (LCR file) is filtered using the lowpass filtering filter mode with the weight function blackman window, the filter window used is 150-seconds. From crossover analysis, some cross over misfit relatively large difference with more than ±20 mGal difference, the average and standard deviation of crossover misfit were-0.0023 mGal and 9.0214 mGal respectively. The result of spectral analysis, airborne gravity signal has minimum 10 km of wavelength while the EGM2008 degree 2190 has minimum 18 km of wavelength.