Equipment specifications for launcher guidance using multivariable frequency methods

A multivariate frequency quantification method for analyzing stability margin losses due to perturbations in a closed loop system is presented. The method is based on the use of singularity values of transfer matrices to establish guidance equipment specifications. The case of a launcher in-flight, using reorientation jets is used as a test case for the method. The method is shown to be applicable to other guidance and control problems. Its use in qualification tests of launcher motors is described.