Collaborative Global Positioning System (GPS) Receivers for Enhanced Navigation Performance

Under this SBIR effort, we propose to develop a system architecture that provides improved accuracy and availability under adverse conditions for networked GPS receivers operating collaboratively using a GPS Distributed Aperture Processing (GDAP) approach. The proposed collaborative approach operates by using a combination of shared GPS observations, augmented by other networked observations including intra-network ranging to allow robust positioning of all network participants. The collaborative algorithms to be used by the GDAP system will be demonstrated using a combination of test data analysis and modeling and simulation. Test data will be collected using our existing POSCOMM software defined radio test-beds that can provide GPS and intra-network range observations using a 900 MHz transceiver. Modeling and simulation will be performed with our in-house urban navigation simulation tools that use Google Earth"s 3D warehouse combined with a ray propagation path tool to simulate GPS, intra-network ranges and jammer signals. A Phase II design will be developed for a Software Defined Radio implementation suitable for transition onto future handheld military tactical radios. A test plan will also be proposed for demonstrating how the networked GDAP units can maintain accurate positioning in an urban canyon, indoors or under signal spoofing or interference. BENEFIT: The NAVSYS GDAP System (GPS Distributed Aperture Positioning) will provide greatly improved accuracy in the very difficult urban environment that will shorten battles and save lives. The civilian public protectors will be able to execute their tasks more efficiently and with less delays that can save lives. The fact that GDAP is a software product that can be installed in JTRS radios has the additional benefit of providing the above improvements for minimum cost.