GPS Navigation System Rapid Positioning Method Research

The global positioning system (GPS) are widely used in various fields. How to make a quick and accurate positioning has always been a hotspot in research of engineering application. In this paper, the fast and exact location technology GPS navigation system on the following aspects of research:In terms of rapid positioning, GPS intermediate frequency signal quickly capture key to solve the problem, the introduction of GPS code phase and carrier frequency signal based on the principle of capture, expounds the parallel GPS intermediate frequency signal quickly capture method based on FFT. In coherent accumulation, receiving signal to noise ratio, at the same time using ephemeris information forecast doppler frequency shift, etc, analyzed the increase the possibility of intermediate frequency signal rapid capture, finally using a set of GPS measurement data to capture the above analysis. Capture results show that the intermediate frequency signal based on FFT technology rapid capture method has anti-interference and capture efficiency and the ability to detect low SNR signals, and can meet the requirements of GPS receiver to increase the speed of positioning for the first time.To improve positioning accuracy and system stability, this article obtains from the GPS/INS integrated navigation, using the theory of extended kalman filter for integrated navigation of loose coupling and tight coupling algorithm is deduced, and using Matlab software for editing. Finally the GPS receiver and MTi inertial navigation device in the vehicle experiment data import procedures for calculating. Calculating results show that the integrated navigation system based on extended kalman filtering can effectively improve the system in precision, tight coupling of GPS/INS integrated navigation positioning precision and velocity precision than loose coupling, but loose coupling to realize easy, precision positioning accuracy and speed with the need of most engineering application.To improve positioning accuracy, this paper introduces another method:differential positioning. Through the analysis of several differential positioning methods, the pseudorange difference of single base station are proposed positioning method. Using GPS satellite signal simulator and receiver to form experiment platform for pseudorange difference experiment, analyze the results show that using the pseudorange differential positioning can effectively eliminate the public received signal receiver error, improve the positioning accuracy.