High-Sensitivity Military GPS Receivers for Ground-Users

This proposal addresses the NGA SBIR program objective to develop and demonstrate GPS receiver improvements for ground users to provide significant “high-sensitivity” signal tracking performance over conventional military GPS receivers. The proposed system consists of (i) the Mayflower “NavAssure” SAASM GPS receiver; and (ii) receiver software signal processing enhancements, in order to mitigate weak signal-to-noise ratio (SNR) conditions by increasing the effective SNR and lowering the tracking SNR threshold. Mayflower is developing the “NavAssure” single chip SAASM GPS receiver (under the Navy GIF SBIR III program) which is expected to be available in 2009 at a production cost of about $500 and typical power consumption of significantly less than 0.5 Watt. In this program, Mayflower plans to develop high-sensitivity algorithms for signal acquisition, tracking, and navigation to obtain about 20 dB SNR improvement compared to conventional military GPS receivers. The specific performance goals for the High-Sensitivity NavAssure SAASM GPS receiver are: (i) direct P(Y) signal acquisition at -160 dBm (10 dBHz C/No) with accurate PVT (i.e. from existing navigation mode or accurate time/data transfer), and (ii) P(Y) signal tracking and navigation at -160 dBm with low dynamics. The Phase I study will quantify the performance benefits of the proposed enhancements and demonstrate the feasibility of signal acquisition and tracking in low-SNR applications. The follow-on Phase II effort will implement these enhancements in software on the NavAssure SAASM GPS receiver platform, and demonstrate their effectiveness in low-SNR applications.