GPS elevation fitting method and system considering gravity terrain correction

Abstract

The invention provides a GPS elevation fitting method considering gravity terrain correction, which is used for mountain terrain and comprises the following steps of: calculating terrain correction and interlayer correction of Bouguer gravity anomaly at grid points according to a digital elevation model of a measurement area; adding the terrain correction and interlayer correction of the Bouguer gravity anomaly, and performing converting to obtain the influence of terrain factors in the elevation anomaly at the grid points; carrying out gravity terrain correction to deduct the influence of terrain factors in elevation anomaly at a GPS benchmark; performing numerical fitting on the elevation anomaly of the GPS benchmark after the terrain correction to obtain a local quasi-geoid model after the terrain correction; and combining the local quasi-geoid model after the terrain correction with the terrain influence in the elevation anomaly calculated at the corresponding position to obtain a real local quasi-geoid, and taking the real local quasi-geoid as a final GPS elevation fitting result considering gravity terrain correction. The data acquisition cost is lower than that of a gravity measurement method, and the GPS elevation fitting precision of mountainous areas can be effectively improved.

Description

technical field [0001] The invention relates to a method for constructing a high-precision geoid-like model, in particular to a GPS elevation fitting scheme for gravity terrain correction in consideration of the influence of terrain fluctuations in mountainous areas, and belongs to the field of geodesy and surveying engineering. Background technique [0002] The elevation of the measuring points obtained by GPS measurement technology is the geodetic height based on the reference ellipsoid, while the elevation system adopted in my country is the normal height system based on the quasi-geoid. There is a certain gap between the two. If the elevation results measured by GPS are to be applied to In actual engineering, it is necessary to obtain the quasi-geoid model of the survey area, so as to convert the geodetic height into a normal height. The GPS elevation fitting method is one of the methods for constructing a local quasi-geoid model. Its main principle is to use some point d...

AI Technical Summary

Problems solved by technology

[0015] Aiming at the problem that the cost of the gravity measurement method is high and the accuracy of the conventional GPS fitting method is poor in mountainous areas, the present invention proposes a GPS elevation fitting scheme that takes gravity terrain correction into account, and uses a purely numerical fitting method with a lower cost to establish a local approximation. Geoid model for mountainous terrain

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