Simplified covariance analysis for midcourse simulation

A simplified seven-state covariance analysis program has been developed that will perform linear error propagation analysis about nominal midcourse guidance trajectories. This program calculates the heading error standard deviation which is one of the most important parameters characterizing each flight. Also calculated are the target tracking components of the guidance error and the IRU initialization errors including misalignment and drift. It combines not only the offset and angular errors, but also includes the correlation terms. Therefore, given the nominal Mach number and velocity angle history, it should prove to be a very powerful and efficient tool in generating missile state uncertainties near terminal handover. This capability may be used to expedite Monte Carlo hybrid simulation performance studies by eliminating the need for repetitive simulation of midcourse phase and instead allowing for starting near the handover to terminal phase. This simple error analysis program has been demonstrated to achieve comparable accuracy to the widely adopted full-size covariance program at a substantial saving in computation and storage.