Application of conical cross-section to terrain correction for gravity reduction

An improved approach for Terrain Correction (TC), named Conical Cross-section method, is demonstrated in this study. Conical Cross-section method directly corrects the effect from gravity attractions between surface surveying-site and geoid. For estimating TC precisely, Conical Cross-section method assumes surveying-site as an original point, and divides surveying-site's neighbor topography into several sector areas with equal central angle to describe the variance of topography. In this paper, four specific points were selected from different features of topography. From the calculated results, we found out the TCs would be into a stable status by using twelve or more equally divided sectors of topography. The compared results between Conical Cross-section method and Hammer's method are within 4 mgal at three specific points except YuSan peak of 12.6 mgal. However, the Conical Cross-section method is more suitable than Hammer's for TCs in complex topography area.