Commercial Space Weather Data Pilot GNSS Data Processing and Product Evaluation

Under the National Oceanic and Atmospheric Administration (NOAA) space weather Commercial Weather Data Pilot (CWDP) program, a team from NOAA, UCAR, and several other partners evaluated Global Navigation Satellite System (GNSS) space weather data products derived from observation data collected by small satellite constellations designed and operated by PlanetIQ and Spire Global. The pilot study included a 6 month data delivery phase with near real-time processing, reprocessing activities, and evaluation of data products.

COSMIC Data Analysis and Archive Center (CDAAC) system was utilized to generate electron density profile (EDPs), total electron content (TEC), and scintillation metrics. EDPs were generated using the approach utilized for other satellite missions (e.g. COSMIC-1 and -2). We derived absolute TEC tracks reaching from negative (minimum height of straight line 90 km) to positive elevations taking into account differential code bias and multipath calibrations. To characterize scintillation events, high rate carrier phase and signal-to-noise ratio observations (e.g. 50 Hz or 100 Hz) were recorded and downlinked under certain conditions. The high rate observations were used to derive scintillation amplitude and phase indices, and to geolocate ionospheric irregularity regions based on a back-propagation algorithm developed for COSMIC-2.

We present several study results. EDPs are evaluated by comparing to collocated COSMIC-2 EDPs and ionosondes. We evaluate slant TEC distributions and compare to collocated COSMIC-2 TEC tracks where the time and observation geometry are similar and taking into account differences in spacecraft altitude. For scintillation we describe differences between high and low orbit inclination observations and compare geolocation estimates with results from operational COSMIC-2 processing.