WP-3000 Developing a flexible system to simulate and assimilate small satellite data

In preparation for running Ensemble of Data Assimilations (EDA) experiments for testing the impact of constellations of small satellites carrying microwave (MW) sounders, a flexible system to simulate and assimilate the small satellite data has been implemented. External orbital parameter files are received and re-formatted for use in the ECMWF assimilation system. High resolution model fields produced using the latest operational version of the system are used in combination with a radiative transfer model and the sampling provided through the external files to calculate the simulated brightness temperatures (BTs) for the small satellites. A thinning procedure is applied to the data and perturbations related to the instrument noise are added to the simulated observations. Finally, assimilation tests show that the data can be used to actively influence the assimilation system. While the underpinning technical work is complete, adjustments should be considered in particular to tune the perturbations to achieve realistic simulated BTs.