Challenges of Using Small Satellite Data in Numerical Weather Prediction Models

In 2016, NOAA issued its commercial space policy (NAO 217-109) and seeks to leverage the commercial space capabilities for improved weather forecasts. The small satellites proposed by the industry will carry onboard various instruments to observe the earth atmosphere. Since the small satellite instruments (e.g. calibration, antenna and receiver subsystems) are very different from the NOAA legacy instruments, the applications of the small satellite data in weather forecasts can be very challenging. In this study, we address several fundamental issues related to uses of small satellite microwave sounding data in numerical weather prediction models. The platforms and payload configurations from the Earth Observing Nanosatellite (EON) microwave (EON-MW) are first utilized to illustrate the potential benefits of these EON-MW constellation on NWP and monitoring of severe weather events. Then, the simulated brightness temperatures from the GPS RO profiles are established to serve as an on-orbit reference for validating the EON-MW calibration accuracy. Also, a new forward radiative transfer scheme is developed to simulate the brightness temperature using the EON-MW scanning pattern and polarization. Finally, a new algorithm for thinning and synthesizing the measurements from the constellated microwave sounders is proposed and tested for NWP data assimilation and nowcasting applications.