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A new form of the probabilistically strongest neighbor filter (PSNF) algorithm taking into account the number of validated measurements is proposed. The probabilistic nature of the strongest neighbor (SN) measurement in a cluttered environment is shown to be varied with respect to the number of validated measurements. Incorporating the number of validated measurements into design of the PSNF produces a consistent and cost effective data association method. Simulation studies show that the new filter is less sensitive to the unknown spatial clutter density and is more reliable for practical target tracking in nonhomogeneous clutter than the existing PSNF. It has similar performances to the probabilistic data association filter amplitude information (PDAF-AI) with much less computational complexities.

As a part of trajectory modulation to increase terminal effectiveness, impact angle control is required in the terminal phase of tactical missile systems. Moreover, the missile systems are allowed to have only low altitude and minimum flight time to reduce the probability of detection by sensors of missile defense systems and thus to increase survivability. In this paper, a simple numerical solution for a time-optimal control law is suggested in the case of constrained missile maneuverability and impact angle for a first-order-lag autopilot. The numerical solution utilizes an analytic solution of a simplified problem with a zero-lag autopilot assumption to determine optimal switching instants. Performance of the proposed control law is tested by a simulation study.

Observability requirements are obtained for three-dimensional maneuvering target tracking with bearings-only measurements. The approach taken here using pseudomeasurements is completely different from the previous work in this area such that it does not involve solutions of nonlinear differential equations resulting from complicated time differentiations and it can treat a more general class of target motions not restricted to Nth-order target dynamics.

Observability is analyzed for the target tracking with bearings-only measurements (BOM) applied to a passive homing missile system using augmented proportional navigation guidance (APNG). Based on the analysis, a practical homing guidance law is proposed to enhance observability for tactical missile applications. The new guidance law is tailored to provide oscillation of line-of-sight (LOS) angle induced by initial missile heading errors without sacrificing terminal effectiveness. Simulation studies indicate that the proposed guidance law provides convergence of the state estimates essential to homing guidance applications as well as terminal effectiveness.