ECSIM: the simulator framework for EarthCARE

Abstract

In 2013 an important ESA Core Explorer Mission, EarthCARE is scheduled to be launched. EarthCARE, (the Earth, Clouds, Aerosol and Radiation Explorer) will comprise two active (a cloud-profiling radar (CPR) and an high spectral resolution atmospheric lidar (ATLID)) and two passive (a Multi-spectral imager (MSI) and a Broad-Band Radiometer (BBR)) instruments. With these, EarthCARE will enable cloud and aerosol properties retrievals consistent with a Top-of-Atmospheric (TOA) flux accuracy of 10 Wm-². This will be achieved by simultaneously probing the atmosphere vertically with the active instruments in synergy with the passive instruments. In order to facilitate and optimize algorithm development and to quantify the effect of different instrument configurations on the mission performance a simulator for EarthCARE (ECSIM) has been developed. ECSIM relies strongly upon a previous prototype developed by ESA/KNMI where a combination of forward and retrieval models (full End-to-End capabilities) have been included. In order to make this tool more useful within the scientific and engineering communities, the prototype simulator has been embedded into a completely reorganized architecture intended to improve a number of aspects: *Complex algorithms have been enclosed within logical entities: models. *Models are connected in a logical sequence with well-defined interfaces. *Users can customize almost every mode's parameter values using configuration XML files. *Model outputs are well documented and stored in easy to access NetCDF files. *Complex simulations can be built up with a few mouse clicks. *Users can run lengthy simulations automatically iterating through different parameter values. *ECSIM can intercept and classify information and error messages from the simulations. *A database is maintained with all the information generated by the system. *It is possible to add third-party algorithms or tools to convert, analyze and visualize data extracted from generated products.