NASA's integrated Instrument Simulator Suite for Atmospheric Remote Sensing from spaceborne platform (ISSARS) and its role for the ACE and GPM missions

Forward simulation is an indispensable tool for evaluation of precipitation retrieval algorithms as well as for studying snow/ice microphysics and their radiative properties. The main challenge of the implementation arises due to the size of the problem domain. To overcome this hurdle, assumptions need to be made to simplify complex cloud microphysics. It is important that these assumptions are applied consistently throughout the simulation process. ISSARS addresses this issue by providing a computationally efficient and modular framework that can integrate currently existing models and also capable of expanding for future development. ISSARS is designed to accommodate the simulation need for ACE and GPM's radar and microwave scanners as well as optical instruments such as lidars and polarimeters that will be included in future missions.

ISSARS's computation is performed in three stages: input reconditioning (IRM), electromagnetic properties (scattering/emission/absorption) calculation (SEAM), and instrument simulation (ISM). The computation is implemented as a web service while its configuration can be accessed through a web-based interface.

This presentation will demonstrate configuration procedures and illustrate some sample intermediate outputs of the IRM and SEAM with an emphasis on the role of ISSARS for the ACE and GPM missions.