椭球膨胀法在地面实际球面面积计算中的应用

Application of ellipsoid expansion method in actual spherical area of ground calculating

针对由于大地高所引起的地面区域实际球面面积与其在参考椭球面上的面积不一致的问题,采用椭球膨胀法对以地面作为投影面计算地面区域实际球面面积进行研究.得到以地面区域的平均大地高为参数将其在参考椭球面上的面积改化为地面实际球面面积的实用方法.研究结果表明:该方法计算简便、精度高,面积修正的相对误差达百万分之一量级.

In view of the problem that there is a discrepancy between the actual spherical area on the ground and the area on the reference ellipsoid caused by geodetic height, this paper calculated the actual spherical area on the ground when considering the ground as the projection plane according to the ellipsoid expansion method, and obtained the applicable method which changes the area on the reference ellipsoid to the actual spherical area on the ground according to the average geodetic height of ground. The results of study show that the method is simple and of high accuracy, and the relative error of the area after corrected can reach the magnitude of a millionth.