Patent ID: 6145790
Filing Date: 2000-11-14
Classification: B64G

Abstract:
A method of controlling the attitude of a spacecraft comprising the steps of:generating a first attitude measurement vector s.sub.m from a first attitude sensor;generating a second attitude measurement vector e.sub.m from a second attitude sensor;computing a noise covariance matrix, R, wherein ##EQU7## where .phi. is the separation angle between said first and second attitude measurement vectors and .sigma..sub.e.sup.2 is the first attitude sensor 1 .sigma. noise covariance and .sigma..sub.s.sup.2 is the second attitude sensor I .sigma. noise covariance;decomposing said noise covariance matrix, R, such thatR=UDU.sup.T andU U.sup.T =I.sub.3.times.3 ;defining a timc-varying gain matrix Kc wherein ##EQU8## wherein q.sub.1 represents gyro angle random walk noise and q.sub.2 represents gyro rate random walk noise; andupdating the attitude of said satellite in a manner directly related to the corresponding value of said Kc.