Position Error Maps for GPS/GNSS

TECHNICAL ABSTRACT: As our nation’s dependence on reliable satellite navigation systems for precise Position, Navigation and Timing (PNT) applications increases, any errors/uncertainties or degradation of service will have significant life, safety, and economic impacts. Ionospheric ‘space weather’ is one of the largest sources of error in PNT applications that use the Global Navigation Satellite System (GNSS) satellite constellations, including the US government’s Global Positioning Satellite (GPS) system. NOAA currently has no operational products or services to provide GPS users accurate information on the magnitude of the ionosphere-induced positioning errors, or to help them recognize conditions where degradation due to GPS scintillation may be a problem. Thus, specification and forecast products are needed to support the broad GPS user community. We propose to develop a software solution to process the existing publicly available GPS data at NOAA/SWPC to generate Precise Point Position (PPP) error maps for single- and dual-frequency GNSS receivers. The proposed Phase II research effort will develop a prototype software framework to provide now-casting and 1-3 day forecasting of GPS PPP and timing errors and for estimating ionospheric scintillations via Rate of TEC Index (ROTI) over the Continental United States (CONUS).SUMMARY OF ANTICIPATED RESULTS: At the end of Phase II, we will have demonstrated the performance and capabilities of the software framework system to create maps of PPP uncertainties as well as timing errors in nowcasting and forecasting modes. These new data products will be produced in real-time at NOAA