Evaluation of the First Deployment of Operational SFMR Instruments on the Hurricane Hunter Fleet

During the 2007 hurricane season, the Air Force Reserves Hurricane Hunter squadron at Keesler AFB, Mississippi operated newly-installed Stepped Frequency Microwave Radiometers (SMFRs) on six C-130J aircraft. These six instruments are the first of thirteen units to be delivered to the Air Force, which will install SFMRs on all ten C-130J Hurricane Hunter aircraft by mid-2008. Installation of the first six SFMRs allowed near-continuous coverage of ocean surface winds throughout the 2007 hurricane season, which included hurricanes, Felix, Dean and Humberto.

The continuous reporting of surface level winds, and the availability of SFMR on multiple aircraft is a significant milestone in hurricane reconnaissance. One example is the recording of continuous surface winds that resulted in new record high maximum surface wind reports from the SFMR, 78 m/s in Dean from a SFMR on WC-130J and 85 m/s in Felix from a SFMR on WP-3D SFMR. These SFMR measurements exceeded eyewall wind speeds measured with dropsondes, which by necessity, provide infrequent data points. The accuracy and precision of SFMR wind speed measurements throughout the hurricane season was consistent with data from SFMRs flown in previous years on NOAA WP-3D hurricane research aircraft.

Our presentation will also cover developments to improve the accuracy of the rain rate estimates provided by the SFMR wind retrieval algorithm. With funding from the NOAA SBIR program, ProSensing Inc., manufacturer of the SFMR, is developing a miniaturized Multi-Channel C-Band Radiometer, which could be integrated with the SFMR in an upward looking configuration, which has the potential to significantly improve rain rate estimates.