Research And Application Of GPS/leveling Height Transformation Model

GPS has become one of the most important methods of measurement in geodetic,primarily because its advantages of three-dimensional positioning velocity, precise timing,real-time throughout the day, free resources highlight. In order to realize the GPS in real sensethree-dimensional, the key lies in how to turn the geodetic height, being no physicalsignificance, into the applied normal height. Generally, we use the abnormal height as theobject of study. According to the different situations, the appropriate mathematical modelsshould be established, while the remove-restore method should be applied too.After concluding some problems relating to GPS/leveling, the paper discuss the methodsof the fitting of GPS/leveling. The paper introduce geometrical fitting model by dividing itinto functional model, statistical model and integrated model. After elaborating their principleand method, the paper compared the accuracy and usefulness of various models by a specificexample. At the same time, the point of distribution and gross errors to the fitting results wereanalyzed. Chapter IV focuses on the GPS/leveling fitting of terrain correction. Its basic idea isto remove the short-wave part of the abnormal height calculated by discrete points beforeusing numerical approximation method. Then the remaining abnormal height was fitted. Atthe interpolation points to restore the short-wave part of the abnormal height. Finally get thepoint of the height anomaly. And also according to the certification of GPS/leveling data as anexample, it has been proved that the size of grid does not significantly affect the finalaccuracy, and therefore there was no need to over-refinement of the grid interconnectiondistance. Additional, this chapter also totally analyses the problems in terrain correction suchas the strange scoring, the impaction of various factors on the fitting accuracy. Finally, thepaper gives some referential conclusions and recommendations.In this paper, considering the terrain correction of the GPS/leveling fitting does not use all data, which is used according to the actual needs. The numerical calculation part usingMatlab7.4completed, and using Surfer10software for grid data processed. It’s very useful forcalculation and analysis.