High Precision Location Technique By Carrier Phase Difference Measurement And Its Application Study

With the economic growth and technological progress，localization precisionbecomes more and more important.Real-time-kinematic, aliased as RTK，which isbased on GPS system is the highest precision positioning system，but there is aunknown value named integer ambiguity. Aimed at this issue，the most popularlysolution is to get a float answer by Markov estimate，whose covariance matrix is illmatrix.Mostly the search domain is weak correlation which is calculated fromambiguity decorrelationConsidering both time-consuming and search timeaim to get the best effect.(1) Experimental analyze three kinds of ambiguity decorrelation algorithms，anddraw conclusions that integer Gaussian transform is lower precision，but less time thanCholesky algorithm.Considering RTK，this articleadopted the less time methd.(2) The research of ambiguity adopted modified PSO arithmetic.Weightingfactor-ωis expressed by the population of maturity.Assimilating genetic algorithmmodification to avoid trapping in local optimum.Using grouping strategy，makeintersection and variation between suboptimal and the worst solution，and makevariation by fixed probability in The optimal particle. The end of the algorithm is asdifference between Faveand Fmaxless than0.001.The research make a detailed analysis processing of ambiguity and come to aconclusion that Lower relevancy is the key to a successful search.The research ofambiguity adopted modified PSO arithmetic and compared with LAMBDAarithmetic.Finally，making a conclusion that modified PSO arithmetic have a sameaccuracy but less time than LAMBDA.The system have two GPS-antenna whoes distance is4meters，and connect to onecomputer The date which is used to analyze lower-relativity meth and the fixedsolution is saved by PC serial port programs.