Study on the impact of calculation radius on IDW gravity modelling

Gravity modelling is a necessary process of applying gravity data to practice, and a vital research area in resource exploring and geodesy. Inverse distance weighted (IDW) interpolation is a widely used algorithm in gravity modelling and many other griding procedures. Based on the gravity anomaly data acquired from the airborne gravimetry over a region in the Northwest of China, IDW method is analysed and implemented with varying calculation radius in gravity modelling. The results show that over the study area, with a proper calculation radius, the IDW can give a more precise prediction than quadric surfaces fitting (QSF) method. The distances between sampled points and unsampled points are the only information taken into consideration in the IDW interpolation, so the analysis of the influence by changing the calculation radius of the unsampled points in this test provides a new research direction of error eliminating when using IDW.