The Study On Key Technology Of Gps Receiver;

The GPS (Global Positioning System) has been got the application and development far and wide in the military and civil affairs for its high precision, automation, high efficacies, world wide and round-the-clock, and in the near years, there are many countries to develop their own global positioning system such as the GLONASS of Russia, Galileo system of Europe and our Beidou global positioning system while the key technology of the receiver are being an outstanding problem for various systems. The paper, taking the GPS receiver for example, has studied the key technologies of receiver in the absolute positioning, pseudo-range difference and carrier phase measurement these 3 applications.First, the paper took the SUPERSTAR II single frequency of NovAtel and the MATLAB to introduce the specialty of SUPERSTAR II receiver, the data format of Marconi and the navigation data protocol ICD-GPS-200 describing the algorithms of absolute positioning such as the acquisition and decoding of GPS navigation data, the position calculation of satellite, the fitting of satellite orbit and pseudo-range calculation, meanwhile, it also discussed various error sources to influence the positioning result and some correcting methods such as group delay, the error of satellite clock and its correcting method, ionosphere error and its correcting method, troposphere delay and its correcting method, relativistic effect, the earth rotation effect and the clock error of receiver, which were corrected with MATLAB.Second, facing the current wide application of Differential GPS technology, the paper has studied the key technology of DGPS with pseudo-range. On the foundation of gripping the DGPS principle,the author has done the decoding algorithm of RTCMSC-104; Meanwhile, the author has also realized the positioning algorithm of pseudo-range DGPS in MATLAB with the platform built with SUPERSTAR II GPS receiver and X60 reference station.At last, taking the background of GPS receiver for measuring, the paper has studied the two key problems in carrier and phase measurement: the cycle-slip detecting and the calculation of integer ambiguity. In the cycle-slip detecting and correcting, the author brought up the algorithm making the high-order difference combine the polynomial method to detect and correct the cycle-slip; on the other hand, the author built the single different, double different and triple different step by step on the foundation of relative position principle. Further more, the author has solved the cycle-slip detecting and correcting and the calculation of integer ambiguity these two key problems.