Gene Expression Programming In Fitting Of Gps,

GPS, as a new generation of precision satellite navigation and positioning system, provides precisely three-dimensional coordinates, time and speed for all types because of the capability of navigation, positioning and timing with omnipotency (land, sea, spaceflight and aviation), all weather, global, continuity and availability. It has been integrated into the national economic construction, national defense and social development in various applications as an advanced measurement tool and new productivity. How to get high-precision height by GPS measurement is currently a hot research.Gene Expression Programming is a new genetic algorithm based on the genotype and phenotype. It is developed on the basis of genetic algorithm and genetic programming. It has a very strong function searching capability and high efficiency. It does not require any prior knowledge or type of stored function model when function search, so avoiding the blindness of pre-selected types in modeling algorithm of the traditional function. In this paper, Gene expression programming method is used to improve the fitting accuracy of GPS height.GPS height fitting procedure based on GEP is developed with VC++ 6.0 and Matlab in the study. The experimental results show that the absolute value of maximum residual of GEP fitting is smaller 6.2mm than quadratic surface fitting, The external precision of GEP fitting is larger 3.4mm than quadratic surface fitting. Therefore GEP fitting is better and more uniform distribution of residuals than quadratic surface fitting. A new and effective method is provided for GPS height fitting to improve the fitting precision.