Interacting multiple model filter for tracking maneuvering targets in spherical coordinates

An interacting multiple model (IMM) filter with constant velocity and mean-jerk models is proposed for tracking maneuvering targets in spherical coordinates. The IMM filter consists of multiple models that interact through mixing of state estimates to track an arbitrary target trajectory. The mean-jerk model is the standard constant acceleration model with time-correlated acceleration errors instead of the standard `white´ acceleration errors that are usually assumed. An IMM filter is implemented separately in each spherical coordinate to allow for different model probabilities in each coordinate. Simulated tracking results are given for a constant speed target performing an `S´ trajectory maneuver