Evaluating Anti-Jam GPS/INS System Performance

Harold A. Klotz Jr. and Albert H. Reynolds III

Abstract:	The rapid deployment of GPS receivers on sophisticated weapon systems, coupled with the threat of RF jammers, has led to the development of a large number of Anti-Jam GPS (AJGPS) systems that increase the probability that GPS updates will be available for the user. With the large number of candidate systems and tight budgets, it is imperative to identify the most cost effective AJGPS system for each application. The Phantom Works division of The Boeing Company has developed a three-phase approach to compare the performance of candidate AJGPS systems in jamming environments. This approach consists of: (1), modeling the candidate AJGPS system in a high-fidelity signal processing simulation; (2), testing the candidate system to validate the accuracy of the model; and (3), using a navigation performance evaluation simulation to assess the benefits of the candidate system in scenarios appropriate for the application. Another GPS High Anti-Jam Simulation Tool (AGHAST) is a high-fidelity signal processing simulation that includes antenna and receiver hardware models along with the signal processing algorithm incorporated in specific AJGPS systems. Parameters within AGHAST can be tuned using test data obtained through AJGPS testing, and performance predictions are validated through comparisons with test data obtained in both indoor facilities and outdoor ranges. Outputs from AGHAST serve as inputs to the Modular Aided Inertial Navigation Simulation (MAINS), a simulation that includes both covariance analysis and Monte Carlo techniques to evaluate navigator performance in specific scenarios when the navigator is aided by a GPS receiver. Boeing has used this three-phase AJGPS system analysis technique to optimize system parameters, to evaluate navigator performance in tactical scenarios that cannot be easily tested, and to reduce test cost by limiting the number of flight tests to those that are needed to validate the simulations. Recently, this AJGPS evaluation process was used to design and accurately predict performance in the Anti-Jam GPS Technology Flight Test (AGTFT) program.
Published in:	Proceedings of the 2000 National Technical Meeting of The Institute of Navigation January 26 - 28, 2000 Pacific Hotel Disneyland Anaheim, CA
Pages:	785 - 790
Cite this article:	Klotz, Harold A., Jr., Reynolds, Albert H., III, "Evaluating Anti-Jam GPS/INS System Performance," Proceedings of the 2000 National Technical Meeting of The Institute of Navigation, Anaheim, CA, January 2000, pp. 785-790.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In