Analysis of topographic correction with half length of square plate

Terrain correction is the most challenging step among all the corrections of gravity data. Usually, it is calculated based on the prism method, and the calculation time consumption increases exponentially with the increase of terrain resolution and integration radius. Workers are often troubled by the value range of the measuring plate. The author elaborately explored the influence of different gauge lengths on the terrain correction algorithm during square area terrain correction based on square gauges. The gravity response algorithm was calculated by selecting an upright rectangular prism, and the rectangular prism model was adopted in the area where the distance between the measurement point and the terrain unit point was less than 10km. The calculation results of terrain correction in the test area show that the terrain undulations beyond 5 kilometers have little influence on the results of terrain correction. This means that for a distance of 5 kilometers, whether a simplified model or a cuboid model is used, the impact on the correction result can be ignored.