Terrain corrections for airborne gravity gradiometry
Terrain correction is a critical part for airborne gravity gradient data processing,the quality of which is not only de-pends on elevation resolution and accuracy,but also related to the correction model.Based on the prism integration method,this paper studies the effects of terrain accuracy and resolution,and survey height error on the terrain correction results,then derived an evaluation model.To accelerating calculation of terrain correction without any approximations that may lead to a loss of accuracy,the prism method was parallelized on Nvidia's GPU card based on CUDA interface.Our model and paralleled algo-rithm were validated in both moderate and rugged terrain.The result shows that a 10 m resolution terrain dataset with accuracy better than 0.5 m can guarantee the terrain correction accuracy better than 1 E when survey altitude is higher than 40 m.Mean-while,the parallel algorithm achieves speedup of a factor of 15 on consumer GPU and a factor of 150 on professional GPU,which helps to quickly accomplish terrain corrections even in large survey areas.We confirm that our model,a simple analytic formula,presents a clear guideline for both position and terrain requirements in gravity gradient survey,our parallel algorithm proves to be practical and dramatically reduce the calculation cost while retaining the accuracy.
万方数据
维普
