Passive tracking of maneuvering target based on bearings-frequency of two sonar sensors

Passive tracking of maneuvering target in water based on bearings-frequency of two sonar sensors is better than the case of two bearings in observability. The essence of this issue is state estimating, in this paper, the algorithm of Extended Kalman Filtering (EKF) is applied to the nonlinear filtering part of tracking system, and then maneuvering target could be tracked effectively based on two sonar sensors´ information combining with the algorithm of Interactive Multiple Models (IMM). The validity of this method is validated through simulation.