Research On The Algorithms Of Absolute Positioning And Its DSP Implementation

Global Positioning System (GPS) is a precise positioning system of new generation. It has the potentials of application and development due to its advantages of all-global, all-weather and high accuracy. The point positioning (both stationary and dynamic) is highlighted in research and application.Based on the principles of GPS system, the Doppler Frequency-shift Estimation of GPS and absolute positioning algorithms have been studied in this thesis. Main works of this thesis are as follows:1. The Doppler Frequency-shift Estimation of GPS is discussed and the mathematics models of satellite movement parameters are established. Then the algorithm of visibility and the model of doppler frequency-shift estimation are presented. The above models are simulated with MATLAB.2. The principles of pseudo-range measurement absolute positioning are studied. The models of the least square are described, and Kalman filtering algorithms are studied in detail. Based on research on the principle of standard Kalman filter and analysis of dynamic models which describes the motion of the user, general models in GPS positioning are established. In order to improve dynamic and tracking of filter, adaptive Kalman filtering is used to optimally estimate the true position of target from all kinds of random errors. The models of the least square and Kalman filtering are simulated with MATLAB.3. The absolute positioning algorithms have been partially implemented with DSP.