Inertial navigator error models for large heading uncertainty

This paper is concerned with the development of a modified /spl psi/-angle error model for a strapdown inertial navigator whose platform azimuth is completely unknown, as would be the case during initial coarse heading alignment. The paper is a review of the author's (1994) previous paper, and provides a framework for developing large azimuth uncertainty error models. It then presents the development of a /spl psi/-angle error model as a generalization of the /spl psi/-angle small error model described by Benson (1975), and a modified /spl psi/-angle error model as a generalization of the modified /spl psi/-angle small error model presented by Wauer (1976) and Scherzinger-Reid (1994).