山区GPS高程转换的探讨

 GPS高程转换的核心问题就是高程异常计算，本文指出了现有算法的不足，推导出更加完善的连续型积分计算公式。该公式在计算过程中无须人工干预，避免了人为误差的影响，并通过试验分析了山区、高山区不同参考面高程对高程异常计算值的影响。在高程拟合方面，对普通的高程拟合进行了改进，给出了一个附加参数的高程拟合模型，试验结果显示这个改进显著提高了高程拟合精度，更加适用于山区GPS高程转换，并把该理论模型用于现场GPS高程测量与实际高程比较。

Discussions on GPS Height Transformation in Mountain Area

The key issue of GPS height transformation is the calculation of the height anomaly. In this paper an improved method for GPS height transformation in mountain area is presented. First, the weakness of the existing formula for height anomaly calculation is pointed out. Then, a continual integral formula (called CIFHAC) is derived. Because human's interference is not needed, the formula proposed in this paper is free of artificial errors. The influence of different reference heights in mountainous and/or huge mountainous areas on the calculation values of height anomaly is analysed by means of trials.Furthermore, a new height fitting model with additional parameters is proposed. The result of the trials shows that, due to the mentioned improvement, the precision of the height fitting is enhanced and that the new model is more suitable for GPS height transformation in mountain areas. The theoretical model is used in GPS height surveying in the job site and comparison is made with the actual height.