Recent improvements in Hurricane Imaging Radiometer’s brightness temperature image reconstruction

Abstract

Abstract NASA MSFCs airborne Hurricane Imaging Radiometer (HIRAD) uses interferometric aperture synthesis to produce high resolution wide swath images of scene brightness temperature (Tb) distribution at four discrete C-band microwave frequencies (4.0, 5.0, 6.0 and 6.6 GHz). Images of ocean surface wind speed under heavy precipitation such as in tropical cyclones, is inferred from these measurements. The baseline HIRAD Tb reconstruction algorithm had produced prominent along-track streaks in the Tb images. Particularly the 4.0 GHz channel had been so dominated by the streaks as to be unusable.The loss of a frequency channel had compromised the final wind speed retrievals. During 2016, the HIRAD team made substantial progress in developing a quality controlled signal processing technique for the HIRAD data collected in 2015’s Tropical Cyclone Intensity (TCI) experiment and reduced the effect of streaks in all channels including 4.0 GHz.