Advanced GPS Receiver Technology for Autonomous Space Navigation

JChaffee & Associates proposes the development of advanced methods for using GPS with the goal of automating space operations. This includes navigation, attitude determination, and relative positioning from launch through orbital operations and de-orbit. To accompolish this task, a new generation of computational methods for GPS will be applied in a new generation of GPS receivers. The computational methods build on work already accompolished by Chaffee and Zare [Ch 1] combining a two-stage filter with a closed form state transition matrix applicable to orbits of any eccentricity. The receiver innovation is based on a revolutionary design made by a subsidiary of Tracor Aerospace that does all the signal processing numerically in the frequency domain, thereby avoiding the limitations imposed by conventional tracking loops on high dynamic signal tracking and high velocity signal acquisition. A new set of guidance equations for use with GPS carrier phase for active control of docking will be tested. Also proposed is a high fidelity orbit simulator written in MATLAB for PCs for use with GPS signal simulators.