Technical Note on Quality Assessment for SPIRE GNSS-RO

In this study the quality assessment of SPIRE GNSS-RO atmopsheric data (pressure and temperature profiles) are presented. Measurements are acquired by STRATOS paylod that makes use of GPS occultation measurements to determine temperature,pressure and humidity profiles of Earth's atmosphere for application in operationalmeteorology.The instrument consists of GPS receivers to track the signals of several MEO satellitesand measure the time delay and bend angle of signals that travel through the atmospherelocated in the line of sight of the two spacecraft. The Level 2 Products provided are representing the "dry" temperature, pressure (~ 6 - 70 km,although climatology dominates above ~50 km), "wet" temperature, pressure, and watervapor pressure (< 6 km), with the following characteristics:- Vertical sounding resolution: ~100 m- Along-track resolution: ~200 km- Across-track resolution: ~1 km- Accuracy: ~0.5 K- Vertical resolution: ~5 Pa