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

The Global Positioning System (GPS) has become essential to U.S. national security and a key tool in military operations at home and abroad. As the military dependence GPS technology increases, the success of the mission can be tied to the soldier’s ability to navigate in GPS degraded or denied areas. Direct acquisition of GPS P(Y) code is desirable to military users as it has a higher tolerance to jamming and spoofing when compared to the C/A-code. An augmentation system is needed that can reduce the amount of time it takes for a GPS receiver to acquire the P(Y)-code signal in GPS denied or degraded operating environments. The objective of this Phase I SBIR effort is to design, develop, and demonstrate GPS User Equipment (UE) time aiding using a Differential WWV, (DWWV) system. WWV is the call sign of The National Institute of Standards and Technology (NIST) shortwave radio station located in Fort Collins, Colorado. The NAVSYS DWWV GPS aiding system allows GPS UE direct acquisition of GPS Precision Code. They NAVSYS system also provides alternative timing solutions if C/A code is unavailable due to interference. Under the Phase I base effort we shall develop a design for Phase II prototype where the WWV algorithms could be implemented in a form factor suitable for testing with the Defense Advance GPS Receiver (DAGR) and Force 22E SAASM GPS receivers. The system will provide to the GPS UE an external timing signal to improve the TTFF for direct acquisition of the GPS Precision coded, and a timing solution to GPS UE in a GPS denied or signal degraded environment. BENEFIT: The NAVSYS DWWV module will provide the timing signals necessary to perform time transfer and direct P(Y) code acquisition. Application of the DWWV technology to our ground forces in urban canyons will also save lives by reducing the GPS signal acquisition time in navigation and targeting applications. Time solution aiding with the NAVSYS DWWV module can benefit commercial equipment by providing highly accurate time estimates in GPS degraded or denied environments.