顾及似大地水准面趋势变化的高程异常拟合方法

Fitting method of height anomaly considering variation of quasi-geoid

全球导航卫星系统(GNSS)使用的高程系统为大地高系统,而在我国实际工程中使用的高程系统为正常高系统。为了使GNSS得到的大地高数据直接应用于实际工程中,需要求解出测点的高精度高程异常值,进而将大地高转换至正常高。本文从高程异常曲面拟合过程中的特征点选取角度出发,基于SGG-UGM-2全球重力场模型及移去恢复型曲面拟合方法,提出了一种顾及似大地水准面趋势变化的高程异常拟合方法。经过武汉某沿河实验区实例验证,本文提出的高程异常拟合方法拟合精度损失小,拟合中误差达到±0.014 m,完全满足绝大多数工程测量需求。

The height system used in global navigation satellite system(GNSS)was the geodetic height system,while the height system used in practical engineering in China was the normal height system.To convert geodetic height to normal height and make GNSS geodetic height data applied to practical engineering directly,it was necessary to acquire high-precision height anomaly of measuring points.Based on The SGG-UGM-2 global gravitational model and remove-restore curved surface fitting method,a new height anomaly fitting method that considers the variation of quasi-geoid was proposed in this paper.The method was verified by a practical example in Wuhan.The result showed that the fitting precision loss was small,the fitting error was±0.014m,and the method proposed in this paper could meet a majority of engineering measurements.