A new motion model with a tracking algorithm is introduced in this paper to track a maneuvering target such as a sea-skimming anti-ship cruise missile (ASCM) in spherical coordinates.The algorithm is based on a more accurate analysis of the motion of maneuver targets.Unlike previous models that treat uncertainties introduced by maneuvering as general random process

this model takes emphasis on nonlinear relationships between maneuver accelerations.A modified adaptive two-stage Kalman filter

named Two-Stage Adaptive Filter Group (TSAFG)

is implemented with this model to track simulated incoming ASCM and other maneuvering targets.It is manifested that the proposed method is simple and effective under many situations

and can be extended to track various types of maneuvers.