Path Length Constrained Interception of Higher Speed Targets Using Retro-Proportional Navigation Guidance Law

This paper uses Retro-Proportional Navigation (RPN) guidance law with the objective of achieving path length constrained interception of a non-maneuvering target, moving at a constant speed greater than that of the interceptor. Based on the condition for the highest time-to-go interception for an interceptor using RPN guidance law, a capture region of launch locations is derived analytically for an interceptor to achieve interception within the desired upper-bound on path length along the target trajectory. The range of launch angles that ensures successful interception of the target is discussed and the variation of capture region geometry with the governing parameters is studied. The paper also analyses the conservativeness of the capture region and presents simulations to verify path length constrained interception for launch points selected from within the capture region.