A framework for regional GNSS situational awareness

Reliance on GPS for Position, Navigation, and Timing (PNT) to support mission or safety critical functions requires robust monitoring and verification to assure that reported PNT solutions are accurate and reliable. We are developing a GNSS situational awareness tool to gather, analyze, and display real-time reports of the positions and satellites tracked by a cooperative group of participants. Reported paths and satellite tracking are compared to planned routes and expected visibility accounting for GNSS orbits and surrounding terrain. A graphical user interface allows a supervisor to view the motion of the participants and reports from their devices simultaneously in map and time displays, including alerts that highlight discrepancies in their motion and satellite tracking. The system is demonstrated in two experiments with two participants equipped with cell phones, traveling through natural canyons and mountainous terrain near Boulder, Colorado.