Opto-electro Passive Target Tracking Based on UKF and Its Observability Analysis

During the tracking of the theodolite,targets often lost in the FOV(filed of view)because of the shielding of cloud.An effective method to ensure continuously and smoothly tracking is utilizing the data fusion technology.Due to the status of target need to be estimated in the data fusion,two difficulties which are nonlinear estimation and observability should be solved.The solution of traditional Extended Kalman Filter(EKF)often results in large estimation error and easily diverges.The Unscented Kalman Filter(UKF)is introduced to finish the nonlinear estimation.Meanwhile the observability of opto-electro theodolite is discussed during the actual target tracking,and a kind of method is brought out to maintain filter stability in unobservable situation.The results of Monte-Carlo simulation test that the algorithm is effective and feasible.