93-162
Observability During Planetary Approach Navigation
Robert H. Bishop*, P. Daniel Burkhart**and Sam W. Thurman***
Abstract
The objective of the research is to develop an analytic technique to predict the relative navigation capability of different Earth-based radio navigation measurements. In particular, the problem is to determine the relative ability of geocentric range and Doppler measurements to detect the effects of the target planet gravitational attraction on the spacecraft during the planetary aprproach and near-encounter mission phases. A complete solution to the two-dimensional problem has been developed. Relatively simple analytic formulas are obtained for range and Doppler measurements which describe the observability content of thc measurement data along the approach trajectories. An observability measure is defined which is based on the observability matrix for nonlinear systems. The results show good agreement between analytic observability analysis and the computational batch processing method.
* Assistant Professor, Department of Aerospace Engineering and Engineering Mechanics, The University of Texas Austin, Texas 78712-1085. Senior Member AIAA; Member AAS.
** Research Assistant, Department of Aerospace Engineering and Engineering Mechanics, The University of Texas Austin, Texas 78712-1085. Member AIAA
*** Member of the Technical Staff, Radio Metric Systems Analysis Group, Navigation Systems Section, Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, California 91109. Member AAS.