Infrared Passive Ranging To A Target At 200km Away

As a passive location method,the infrared search and tracking system can quickly detect the infrared target with a certain temperature difference from the background without transmitting electromagnetic radiation wave.It provides the angle information about the target and has the function of high-precision angle measurement,but it does not have the function of ranging.Therefore,according to the idea of location before ranging,this thesis starts from the related research of airborne single station passive location algorithm,extends to the discussion of passive location algorithm of dual airborne infrared observation platform.The passive ranging of 200 km infrared fixed or slow target is realized by using the angle only parameters obtained from airborne observation platform.The specific research contents are as follows:1.Research on the location algorithm of ground target by single observation platform.Firstly,for the plane target whose relative height of platform and target is known,several traditional typical positioning algorithms are sorted out and analyzed.The least square algorithm based on weighted instrumental variable has better positioning effect,and the error is closer to the lower bound of theoretical error CRLB.Then,aiming at the unknown terrain target whose relative height information of observation platform and target can’t be regarded as known condition,the extended dimension target location algorithm based on weighted instrumental variable is adopted,and on this basis,a two-step weighted instrumental variable algorithm is proposed to obtain the estimated values of target position,relative height between observation station and target and its change rate.For stationary targets,the simulation results show that the RMS error obtained by TS-WIV algorithm is closer to the theoretical error lower bound CRLB,and the ranging error at 200 km detection distance can reach 1.268 km,with a relative error of 0.63%.2.ARIMA-UKF algorithm and optimal maneuver trajectory design of airborne observation platform are proposed.Firstly,aiming at the limitation of the complexity of covariance matrix calculation and the non-stationary term in the system,ARIMA-UKF algorithm is adopted.Under the same simulation conditions,compared with EKF and UKF algorithm,it can converge to the lower bound of theoretical error PCRLB faster and has better tracking effect.Secondly,considering the influence of platform maneuver mode on the performance of target state estimation,the maneuver trajectory design scheme of airborne observation platform is given based on the maximum index of FIM determinant.The experimental results show that the platform has higher positioning accuracy under the maneuver strategy for the target under the three motion models of CA,CV and Singer.When the detection distance is200 km,the ranging error is 0.398 km,and the relative error is 0.2%.3.Research on passive location algorithm of dual airborne observation platform.Firstly,by constructing the mathematical model of bearing only positioning of dual airborne observation platform,a method of dual aircraft cooperative positioning based on weighted nonlinear least squares is studied.Then,aiming at the difficulty of solving the algorithm,the optimization criterion of Gauss Newton descent method is used to get the optimal solution of the target location value.Finally,the influence of various noise factors on the algorithm is analyzed.The experimental results show that WNLS algorithm has higher positioning accuracy.When the detection distance is 200 km,the ranging error is 0.155 km,and the relative error is 0.1%.