Localization Algorithm Optimization Design And Application Of The Second Generation Beidou System

The second generation Beidou satellite navigation system (BD2) is a system designed by China. Compared to GPS which has been built very well, BD2is a navigation system under construction. This situation affects it’s popularization in application filed. AS satellite navigation systems play an irreplaceable and significant role in economic and military, continuous development of BD2system is an inevitable requirement to meet the needs of our national security, economic and technological improvement and others. With the development of BD2, it will gradually change the proportion of modern satellite navigation systems and the monopolization of GPS. It will also enhance our ability to safeguard national interests and increase our national strength.In this thesis, GDOP (Geometric Dilution Precision) is the key clue.As it affects real-time and precision of a satellite navigation system. How the number of satellites, elevation angle and azimuth impact GDOP values are studied. Base on the study, a quick satellite selection optimization algorithm and a satellite selection algorithm about joint navigation are proposed. Then the proposed algorithms are applied in vehicle wireless video surveillance system. The main work includes:1. Satellite selection algorithm optimization of second-generation Beidou systemAnalyze BD2’s navigation equations and get expression of GDOP by formula derivation. From the expression, relationship between the accuracy of satellite positioning is got:The smaller GDOP value, the higher navigation accuracy; In this thesis, the relationship between the number of satellites and GDOP value is analyzed, as also the relationship between satellite elevation angle and azimuth and GDOP value. Base on the relationships, a quick satellite selection optimization algorithm is proposed; Simulation results show that the proposed algorithm is a suboptimal selection algorithm and it’s able to balance accuracy and real-time requirements.2. Joint navigation of BD2and GPSAnalyze the differences between BD2and GPS systems and get the theoretical model of joint navigation. In joint navigation, the number of satellites increases and new variables are introduced a. A satellite selection algorithm of joint navigation base on determinant value is proposed; Simulation results show that joint algorithm is also a suboptimal algorithm. But it can change the number of satellites participated in navigation to meet different accuracy and have a better real-time.3. Design and application of joint receiver of BD2and GPSFirst analyze the design principle and the composition of single receiver. Then use DSP、domestic RF receiver、baseband processing chip to complete the design of joint receiver. The joint selection algorithm and the method of least squares position solution are realized in DSP; Apply the joint receiver to the vehicle wireless video surveillance system and the system’s actual effect is tested and analyzed.