GPS高程拟合转换正常高的研究

Research of fitting and transforming GPS height into normal height

通过对GPS测高与水准测量理论及其异同分析的基础上,阐述了确定似大地水准面的原理与方法,分析了用数学模型法,用少量GPS与水准重合点将GPS大地高直接转换为具有cm量级正常高的实现方法。实验结合黑龙江省虎林地区的地形特点,提出了用线性内插法、平面模型法和二次曲面模型法等来转GPS高程,证明在黑龙江省虎林地区可以通过少量且分布合理的水准点来直接求出该地区具有cm量级的正常高,且精度可以达到四等水准测量的精度要求,满足一般工程的需要。

Aiming at the pertinent problems of the Hulin existing elevation systems,technical problems,such as converting ellipsoidal heights to normal heights of the region,are discussed in this paper.After systematically introducing the theory of GPS and leveling measuring height system and their similarities and discrepancies,the principles and methods of determining geoid are emphatically explained.Then using mathematic model,the scheme achieving height transformation with a cm-level precision by a few GPS/leveling points is searched.Finally,an approximate solution of the geoid computation with a cm-level precision in Hulin is proposed based on analyzing the approaches and corresponding errors of computing normal heights in cm-level for different areas.Taking the terrain characteristics of the Hulin region in account,the approaches adapted to different surveying projects are used to realize height transform here.Proved by practice,the normal heights with a cm-level precision for the region can be a-chieved by a few but reasonably distributed leveling points and such precision can meet the demand of general surveying projects.