Precision missile guidance with angle only measurements

Introduces an application of the robust extended Kalman filter (REKF) in the precision missile guidance problem where only the relative line of sight angle is used as measurements in the design of a successful intercept criterion. The robust extended Kalman filter emerges as a practical approximation to the solution of robust filtering for a class of nonlinear systems with solutions involving set valued state estimates obtained by solving a Hamilton-Jacobi-Bellman equation. The underlying system in this problem is a time-varying uncertain nonlinear system in which the uncertainty satisfies a certain integral quadratic constraint. In this REKF application of state estimation, an H/sup /spl infin// type controller was used as a precision guidance controller. The performance of this REKF application was compared with linear output feedback H/sup /spl infin// controllers.