Adaptive Beam Scheduling for Cooperative Phased Array Radars With High-Precision Pencil-Beam

Phased array radar (PAR) has attracted considerable attention in civil and military applications due to its capability of performing multiple tasks such as surveillance, tracking and weapon engagement simultaneously. To make better use of limited radar resources and to offer best operating performance, an efficient resource allocation strategy is necessary. Pencil-beams with super narrow beamwidth is prospective to resource-aware design but using them to cover areas of interest especially in cases of maneuvering targets with high motion uncertainty requires more study. Existing works often assume that a beam can cover the entire area of interest and the problem of scheduling small-beamwidth pencilbeam to perform search and track (SAT) efficiently is barely discussed or addressed in literature. In this paper, the problems of tracking with pencil-beam and its beam scheduling optimization are addressed. Three beam scheduling strategies, fixed linear wipe, open-loop linear wipe that uses hierarchical genetic algorithm (HGA), and expected posterior CramrRao lower bound (EPCRLB) based optimal solution, are proposed to solve the mixed integer nonlinear problem (MINP). To handle the partially covered target existence area by pencil-beam, a new concept of predicted expected posterior CramrRao lower bound (P-EPCRLB) is proposed and used as the main optimization criterion for the scheduling strategy. Numerical results demonstrate the superior performance of the proposed EPCRLB based optimal solution strategy and its effectiveness as a proposed solution.