Next generation low frequency solutions for alternative positioning, navigation, timing, and data (PNT&D) services and associated receiver technology

The use of the Global Positioning System (GPS) in everyday life is pervasive and its use increasing, especially as additional multi-constellation Global Navigation Satellite Systems (GNSS), i.e. Galileo, Compass, and GLONASS, and Regional Navigation Satellite Systems (RNSS) become fully operational and “fill the world's skies.” In many applications, its use is essential even when the user doesn't know that it is being used (e.g., cell phone service).