Research On Target Localization And Velocity Measurement Based On Ridge Estimation Under Weak Observation Condition

Under the background of information warfare,it is particularly important to obtain spatial information such as position and speed of important targets.When airborne photoelectric platforms acquire spatial information of targets,the constraints of various observation conditions often make the observation of targets by airborne photoelectric platforms in weak observation conditions,that is observation at large tilt angle of photograph or small rendezvous angle.Aiming at the problem that the traditional least squares estimation method has low accuracy in target location and velocity measurement under weak observation conditions,this paper proposes to apply the ridge estimation method of biased estimation to target localization and velocity measurement in order to obtain more stable and less mean square error results.The main contents of this paper are as follows:1.Weak observation conditions and ill-conditioned problems are studied.The influence of several significant weak observation conditions on positioning accuracy is analyzed;the spatial geometry analysis is introduced to link the weak observation condition with ill-conditioned measurement.The results show that weak observation conditions make the design matrix ill-conditioned,which affects the accuracy of localization and velocity measurement.2.The geometric significance and related properties of ridge estimation are studied.Ridge estimation is an improved least squares estimation method.It reduces the mean square error and improves the stability of the estimator by abandoning the unbiasedness of least squares estimation at the expense of certain accuracy.Several methods for determining ridge parameters are compared.3.The method of target localization for airborne photoelectric platform is studied.Based on the principle of location,the measurement equations of range and angle measurement and the measurement equation considering system error are deduced.The stability and accuracy of target location method and its solution based on ridge estimation are studied.4.The velocity measurement method of airborne photoelectric platform for moving target is studied.Based on extended Kalman filter and trajectory parameter method,the ridge estimation method of trajectory parameter is studied,and the accuracy of velocity measurement is simulated by Monte Carlo method.In this paper,the ridge estimation of bias estimation is applied to localization and velocity measurement.Under weak observation conditions,compared with traditional batch least squares estimation,ridge estimation can effectively weaken the ill-conditioned design matrix and improve the accuracy and stability of target location velocity measurement.