Research On The Technology Of High Dynamic GNSS Receiver And Multi-Mode Calculation

The navigation and position technology based on Global Navigation Satellite System (GNSS) are widely used in mapping, telecommunication, military products, astronavigation, electric power, remote sensing and so on. With the expanded application range and developed application quality, we require more higher develops on the navigation and position technology. Such as in the military and astronautic application, the high dynamic vehicle makes the satellite signal have higher Doppler frequency shift, and the Dopller change rapidly, so the acquisition and precise tracking of satellite signal becomes difficult. Otherwise, with the development of GLONASS and BD-2 system, including GPS, how to take advantage of the more visible satellites becomes research focus now. The goal of this thesis is to do research on technology of high dynamic GNSS receiver and mult-mode calculation.The thesis includes:(1). We do a lot of work on the algorithm of parallel correlation in time domain based on match filter, parallel correlation in frequency domain based on FFT and parallel correlation in time domain based on FFT/IFFT in high dynamic environment, of which we analyze the advantage and disadvantage. We propose solution of the problem with computer simulation, and compare the efficiencies of the parallel correlation algorithms by implement complexity.(2). We do research on the frequency locked loop (FLL), phase locked loop (PLL), and delay locked loop (DLL). We analyze the noise and high order response of the tracking loops. We propose a scheme of tracking loop with FLL and PLL in serials and rotating. This scheme has high performances of high order response and its noise performance is good. (3). With the problems that PN code error of different mode satellites is different, and the initial weighed matrix is wrong, we propose a method which can modify the weighed matrix based on posterior estimation. The method can improve the positioning accuracy.(4). We deduce the computation of WGDOP (Weighted Geometry Dilution of Precision), and we analyze the relationship between WGDOP and number of satellites. We propose a new method of selecting satellites based on six order determinant with simulation.(5). We build mult-mode RAIM (Receiver Autonomous Integrity Monitor) model, and we deduce the calculation of the least squares residual method and the parity space method in fault detection with mult-mode satellites and weighted matrix. It is proved that the two methods are equal. We analyze the RAIM availability algorithm and propose two methods of fault isolation which is the subset comparison method and the parity space method. We analyze the performance of the least squares residual method with weighted matrix in fault detection rate and fault isolation rate, comparing the traditional method. We also have performance simulation of the subset comparison method and the parity space method.(6). Due to analysis and simulation above, we design and implement a high dynamic GNSS receiver based on FPGA and DSP.