Digital Tightly-Integrated Antenna/Receiver Architecture for Robust GN&C

This Phase I study proposes to address the problem of providing robust guidance, navigation and control in the presence of jamming on high dynamic platforms. Specifically, we propose an innovative all-digital system architecture that tightly integrates an adaptive antenna spatial/temporal filter with the GPS/INS receiver to form multiple simultaneous beam/null patterns - one for each satellite being tracked - to provide greater immunity to GPS receiver jamming. This innovative digital architecture also supports the requirement to directly acquire P(Y) code, thereby alleviating the spoofing vulnerability associated with GPS C/A codes. This architecture also supports the processing of carrier phase as a range measurement to provide centimeter-level accuracy in real-time kinematic differential GPS (KDGPS) mode. In addition to analyzing and evaluating this proposed system architecture, this study will also evaluate the accuracy achievable in determining vehicle attitude, independent of the INS, by interferometric processing of the GPS signals received on the individual antenna elements. It will also seek to define an innovative approach to stabilization of pattern nulls on jammers in the presence of rapid attitude motions of the antenna. This study addresses a fundamental need to assure availability of GPS in hostile battlefield environments. It will also identify the technologies that offer the greatest payoffs toward meeting this objective. Progress in these areas will carry over directly to commercial applications of GPS and spread-spectrum communications systems.