Wide-area Multipoint Positioning System Key Technology Analysis

The multilateration which is widely used in navigation system, communication system and aerospace system has attracted more and more attention in aviation system with the introduction of the new navigation system. Passive multilateration system can receive the TDOA (time difference of arrival) and TO A (time of arrived) signal from the same target. And it can get the SSR (secondary surveillance radar) signal through distributed ground receiving locations.One method is TDOA(time difference of arrival) or RD(range difference) which is also called hyperbolic positioning method. Another method is TO A (time of arrived).This paper is based on the algorithm theory and error approach of passive multilateration. Firstly, we study the architecture of Multilateration, including the TO A detection unit,the clock synchronization unit and the central processing station unit. The focus of this paper is multilateration algorithm which is used to central processing station unit.Then, we derive Taylor Algorithm and Chan Algorithm. After this,we make the simulation Taylor algorithm in case of the ideal initial point and get the MSE(mean square error) of Taylor and Chan, according the different SNR(signal noise ratio).By studying the simulation and the MSE table, we analyze the performance of Taylor and Chan algorithm.Thirdly, we derive the Bancroft Algorithm and make its simulation. Based on this algorithm, we propose a new algorithm, which is R-LS (range-based least squares) and SR-LS (squared-range-based least squares). Most position methods for passive localization are TDOA (time difference of arrival) based, mainly because the TOE (time of emission) is generally not known. Different from the TDOA position methods, this paper applies Bancroft’s algorithm which was developed for GPS single-point position to the solution of multilateration TOA (time of arrived) equations. Based on Bancroft’s algorithm, the TOA least squares (TOA-LS) estimation algorithm for passive multilateration is proposed. The closed-form solution to the TOA-LS is derived, and the geometric interpretation of the LS solution by the modified TOA is given. Simulation experiments have demonstrated that the TOA-LS estimator is near optimal and can attain the theoretical lower bound for targets in different geometric positions.In the end, we make a contrast of these algorithms, based on Taylor Algorithm Chan Algorithm Bancroft Algorithm and TOA-LS Algorithm. Under different condition of SNR and receive locations, we make the simulation and get the different suited conditions, and further verify the feasibility of R-LS and SR-LS Algorithm.