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Advanced Imaging Wind and Rain Profiler for Tropical Cyclones. Authors: J. Carswell, RSS; S. Frasier, UMass; & P. Chang, NOAA/NESDIS/STAR. Acknowledgements: Funded by NOAA SBIR Program, NOAA AOC. NOAA SBIR Project. Develop airborne sensor to provide :
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Advanced Imaging Wind and Rain Profiler for Tropical Cyclones Authors: J. Carswell, RSS; S. Frasier, UMass; & P. Chang, NOAA/NESDIS/STAR Acknowledgements: Funded by NOAA SBIR Program, NOAA AOC
NOAA SBIR Project • Develop airborne sensor to provide: • Map 3D ABL winds within precipitation bands. • Aircraft altitude to below 100 m altitude (marine layer). • Map ocean surface wind vector (all weather). • Map precipitation rate throughout tropical cyclone. • High resolution: < 1 km pixels; 30-m vertical sampling. • Mission Accomplished! • Sensor individuates volume and surface backscatter contributions near and at surface & measures atmospheric attenuation: • Enables accurateprofiling of the 3D ABL winds to the surface! • Allows ocean vector wind scatterometry to be used in precipitation. • High resolution mapping: < 500 m pixels, 30-m vertical sampling. • 20 dB sensitivity improvement – transmit peak power not changed. 2009 IHC – St. Petersburg, FL
Measurement Approach • 3-D ABL Wind Mapping • Multi-look VAD • Dual-wavelength provides extended dynamic range and direct de-aliasing. • Conical scan provides true vertical profiles. • Ocean Vector Wind Mapping • Ocean Vector Wind Scatterometry. • Dual l extends sensitivity to 70 m/s. • Volume / attenuation directly measured. • Precipitation Mapping • Differential l attenuation method. • Z-R methods. Simultaneous, Multi-beam Doppler/reflectivity profiles at C and Ku-band Conical Scan (60 rpm) Wide Swath 2009 IHC – St. Petersburg, FL
Lower ABL Winds – The Problem Measurements for Hurricane Rita – 22 Sept. 2005 2009 IHC – St. Petersburg, FL
Lower ABL Winds – The Solution Meas. Meas. Vol Vol Ocean Ocean • Developed algorithm to individuate volume and surface backscatter on a profile basis. Vol Spectra Vol Spectra Ocean Spectra Ocean Spectra Overlapping Spectra Case Non-overlapping Spectra 2009 IHC – St. Petersburg, FL
Lower ABL Winds – The Solution Estimated Volume Backscatter Spectra • Measured spectra and estimated volume and ocean surface spectra for a conical scan (30 m altitude). Measured Spectra Precip Ocean Estimated Ocean Surface Spectra * Estimated spectra per azimuth bin (i.e. profile not scan) 2009 IHC – St. Petersburg, FL
ABL Wind Profiling Using Spectral Estimation 233 m 156 m 78 m 0 m 260 m 181 m 103 m 26 m 207 m 129 m 52 m ABL WIND PROFILE 2009 IHC – St. Petersburg, FL
Next Steps . . . • Integrate RSS network based digital receiver and processor system (iRAP). • Supports reception & processing of the hybrid transmit waveform. • Will implement spectral processing in hardware. • Demonstrate / evaluate real-time retrievals. • Integrate into NOAA AAMPS data system. • Work towards transitioning to operations. 2009 IHC – St. Petersburg, FL
QUESTIONS ? & Answers ….
ABL Wind Profile Using Spectral Estimation 233 m 156 m 78 m 0 m 260 m 181 m 103 m 26 m 207 m 129 m 52 m ABL WIND PROFILE 2009 IHC – St. Petersburg, FL
AWRAP Sensitivity Improvement * All RF cables within internal calibration loop further simplifying & improving calibration. 2009 IHC – St. Petersburg, FL