Guidance algorithm design: A nonlinear inverse approach

The design of a missile guidance algorithm valid for any initial missile and target orientation is described. The limitations of proportional navigation- (PN-) or line-of-sight rate-based guidance for this problem are pointed out. Design heuristics are explained, and general guidelines for the synthesis of guidance algorithms are stated. It is shown that the design of an algorithm valid for any initial missile and target orientation leads to a nonlinear inverse problem. Standard geometric methods for solving nonlinear inverse problems are adapted to derive a new class of algorithms based on the relative heading error angle (RHEA). Examples of RHEA algorithms are then discussed and compared with PN guidance for different engagement scenarios.