Determination of gravity anomalies in Java, Indonesia, from airborne gravity survey

Abstract

The Geospatial Information Agency of Indonesia (BIG) recently carried out an airborne gravity survey mission to support a reliable Indonesian geoid model. The gravity observations covered all the main islands of Indonesia. This paper presents a state-of-the-art for gravity anomalies derivation using airborne gravity mission in Java, Indonesia. The common gravity corrections for deriving the scalar free-air gravity anomalies along the flight trajectory had been estimated using GNSS-derived positions. The corrected data were then filtered using the FIR method in which the cut-off frequency had been predetermined by considering aircraft altitude, geological setting, and instrument’s accuracy. To assess the airborne gravity results, we compared them with the upward continued terrestrial gravity measurements. In addition, we performed crossover analysis and adjusted the estimated biases to the airborne gravity measurements. The accuracy of adjusted airborne gravity anomaly was estimated to 3.37 mGal. In conclusion, the airborne gravity mission provided valuable data needed for further geodesy and geophysics applications