Modified precise point positioning with ambiguity validation for better performance

For successful GNSS transmission, determination of precise positioning is very important. For better accuracy, two very important concerns are resolving the ambiguities and then improving the precise point positioning algorithm with proper modification. Ambiguities have to be resolved because wrong integer ambiguity estimation may lead us to a fixed positioning solution which will be worse than their float estimates. Then the precise point positioning algorithm for better accuracy has to be modified. In this paper at first a model driven approach for ambiguity resolution which is linked to the theory of integer estimation has been presented and then the basic precise point positioning algorithm aided by three modifications (ionospheric correction, multipath correction, satellite clock correction) has been discussed.