High Resolution Tracking of Distributed Targets

The new Phase Array Radars have range and angle resolutions capable of resolving multiple scattering centers of a single target. This capability produces multiple returns from a single target, creating a new problem for the tracking algorithms, viz. tracking a target that has multiple (resolved) scattering centers The solution proposed here is based on a Multiple Target Tracking (MTT) approach, using either a Joint Probabilistic Data Association Filter (JPDAF) or a Multiple Hypothesis Testing (MHT) filter. In the Multiple Target Tracking approach each of the main scattering centers will be tracked individually, and the estimates for the single target will be obtained from the fusion of the individual tracks. The measurements-to-tracks associations will be done using either JPDAF or MHT. Both of these techniques use simultaneous associations, so that no measurement can be assigned to two different scattering centers at the same time. Each individual track filter will be implemented using an Interacting Multiple Model (IMM) Kalman filter to allow for "glint effects" of each scattering center. The IMM in this case will use two models: one corresponding to the Gaussian measurement noise assumptions, and the other for a "heavy-tail" (glint) measurement noise. In the case of a maneuvering target, this approach will be embedded into another IMM designed to take into account the maneuvers (Hierarchical IMM). The MTT approach will be compared with a suboptimal but computationally more efficient approach that combines the multiple returns associated with a particular target into a single measurement. The centroid of the target and the associated variance are coinputed using a nearest neighbor clustering technique. The IMM filter is used for single target tracking after measurement fusion. ARCON Corporation and Professor Y. Bar-Shalom, both of whom have done pioneering work in target tracking, will provide support during all phases of the SBIR project. Besides applications in tracking of satellites, there are a number of situations where the target will present multiple scatterers: tracking ground vehicles, last stage of missile homing, aircrafts in the radar proximity (landing and take-off of big a