Global Positioning System (GPS) User Equipment (UE) Time Aiding Using WWV/WWVB

Toyon proposes to design, develop and build a GPS system that uses external RF signals for timing estimation in order to acquire Precise Positioning Service (P/Y/M-code) signals under jamming conditions where the GPS C/A-code cannot be used. The RF signals will be selected to provide sub-second timing accuracy in order to limit the substantial computation involved in acquiring PPS signals in low signal-to-noise ratio environments. Toyon will develop a highly efficient PPS signal acquisition unit and integrate it into our GPS receiver, targeting PPS acquisition of a given satellite in fewer than 10 sec from availability of the timing reference. The RF timing reference developed under this program can also be used as a synchronization signal to allow PPS signal acquisition in other GPS receivers. BENEFIT: The C/A-code is easily jammed due to its known modulation code. PPS (P/Y/M-code) signals for accurate navigation are difficult to acquire without use of the C/A-code signals for a timing reference. The GPS receiver technology developed under this program will allow hand-held GPS receivers, which must be shut down to conserve battery power, to acquire PPS signals in a jamming environment.