Instrument design simulations for synthetic aperture microwave radiometric imaging of wind speed and rain rate in hurricanes

The measurement of peak winds in hurricanes is critical to forecasting intensity and direction prior to landfall. To date, the NOAA Stepped Frequency Microwave Radiometer, SFMR, is the best tool for providing this information. NASA is now developing the Hurricane Imaging Radiometer, HIRad, which is a candidate follow-on instrument to improve on the SFMR. HIRad will use synthetic thinned array technology to provide wide swath images, adding to the nadir profiles of the SFMR New developments in radiative transfer modeling for hurricane force winds and large incidence angles are required for HIRad. This paper describes modeling and simulations for HIRad, some of the applications in HIRad design to date, and end-to-end performance simulations.