Research On Multi-static Passive Radar Localization With Sensor Position Errors

The multi-static passive radar which detects silent targets using an illuminator has received extensive attention by scholars in the past two decades.By performing correlation between the reference and surveillance signals,the Time Difference of Arrival(TDOA)and Frequency Difference of Arrival(FDOA)can be measured,which can used to estimate target position and velocity.In practice,the radar receivers are usually deployed on the mobile platforms such as aircraft,missiles and ships.The position and velocity of receivers are not exactly,which will affect the performance of the multi-static passive localization.The measurement nonlinearity and observer errors make the existing position method not directly applied to the multi-static passive location.Therefore,this paper studies the multi-static passive localization method in the presence of observer errors.Some effective localization algorithms are proposed according to their algebraic characteristics and error analysis in different multi-static passive localization system.The main work is as follows:1.The single-observer multi-transmitter passive localization problem with observer position errors is investigated.Firstly the influence of the observer position errors on target location is analyzed,and a pseudo-linear estimation equation is derived based on the algebraic characteristics of TDOA measurement.Then two robust localization algorithms are proposed based on the statistical characteristics of the observer position errors: Constrained Total Least Squares(CTLS)and Constrained Weighted Least Squares(CWLS).Finally the theoretical analysis and simulation are given.The target position error of the proposed algorithms are analyzed with different parameters including observer position error variance,Signal Noise Ratio(SNR),the number of illuminators,near-field and far-field target.The simulation verified the theoretical results.2.The moving target passive localization with single-observer multi-transmitter in the presence of observer position and velocity errors is investigated.Firstly the pseudo-linear estimation equation is derived based on the algebraic characteristics of TDOA and FDOA measurement.Then the statistical characteristics of the observer position and velocity errors are used to adjust the weight matrix of target stateestimation error.The CTLS and CWLS algorithm with error correction are proposed.Finally the theoretical analysis and simulation are given.The simulation results show that the modified CTLS and CWLS algorithm can achieve CRLB when the measurement noises are moderate.3.The multi-transmitter multi-receiver passive localization under the observer position errors is investigated.Firstly a pseudo-linear estimation model based on multiple bistatic range measurements is established by introducing auxiliary variables.Then two improved positioning algorithms are proposed: Three-stage Weighted Least Squares(3WLS)algorithm and group CWLS algorithm,which considering the statistical characteristics of multiple observer position errors.Finally the CRLB is derived and simulation results are given.A large number of comparative simulation results show that the position accuracy of the proposed 3WLS and group CWLS are higher than the group 2WLS and 2WLS.4.The moving target localization with multi-transmitter multiple-receiver passive radar system in the presence of multiple observer position and velocity errors is investigated.A pseudo-linear estimation model based on multiple bistatic range and bistatic range rate measurements is established.The modified 3WLS algorithm and modified group CWLS algorithm are proposed for moving target localization incorporating the statistical characteristics of multiple observer position and velocity errors.The theoretical and simulation analysis are given.