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HURRICANE WIND RETRIEVAL ALGORITHM DEVELOPMENT FOR AN AIRBORNE CONICAL SCANNING SCATTEROMETER
Title
HURRICANE WIND RETRIEVAL ALGORITHM DEVELOPMENT FOR AN AIRBORNE CONICAL SCANNING SCATTEROMETER.
Creator
Vasudevan, Santhosh, Jones, Linwood, University of Central Florida
Abstract / Description
Reliable ocean wind vector measurements can be obtained using active microwave remote sensing (scatterometry) techniques. With the increase in the number of severe hurricanes making landfall in the United States, there is increased emphasis on operational monitoring of hurricane winds from aircraft. This thesis presents a data processing algorithm to provide real-time hurricane wind vector retrievals (wind speed and direction) from conically scanning airborne microwave scatterometer...
Show moreReliable ocean wind vector measurements can be obtained using active microwave remote sensing (scatterometry) techniques. With the increase in the number of severe hurricanes making landfall in the United States, there is increased emphasis on operational monitoring of hurricane winds from aircraft. This thesis presents a data processing algorithm to provide real-time hurricane wind vector retrievals (wind speed and direction) from conically scanning airborne microwave scatterometer measurements of ocean surface backscatter. The algorithm is developed to best suit the specifications for the National Oceanic and Atmospheric Administration (NOAA) Hurricane Research Division's airborne scatterometer – Integrated Wind and Rain Airborne Profiler (IWRAP). Based on previous scatterometer wind retrieval methodologies, the main focus of the work is to achieve rapid data processing to provide real-time measurements to the NOAA Hurricane Center. A detailed description is presented of special techniques used. Because IWRAP flight data were not available at the time of this development, the wind retrieval performance was evaluated using a Monte Carlo simulation, whereby radar backscatter measurements were simulated with instrument and geophysical noise and then used to infer the surface wind conditions in a simulated (numerical weather model) hurricane wind field
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Date Issued
2006
Identifier
CFE0001477, ucf:47093
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0001477
AN OCEAN SURFACE WIND VECTOR MODEL FUNCTION FOR A SPACEBORNE MICROWAVE RADIOMETER AND ITS APPLICATION
Title
AN OCEAN SURFACE WIND VECTOR MODEL FUNCTION FOR A SPACEBORNE MICROWAVE RADIOMETER AND ITS APPLICATION.
Creator
Soisuvarn, Seubson, Jones, W. Linwood, University of Central Florida
Abstract / Description
Ocean surface wind vectors over the ocean present vital information for scientists and forecasters in their attempt to understand the Earth's global weather and climate. As the demand for global wind velocity information has increased, the number of satellite missions that carry wind-measuring sensors has also increased; however, there are still not sufficient numbers of instruments in orbit today to fulfill the need for operational meteorological and scientific wind vector data. Over the...
Show moreOcean surface wind vectors over the ocean present vital information for scientists and forecasters in their attempt to understand the Earth's global weather and climate. As the demand for global wind velocity information has increased, the number of satellite missions that carry wind-measuring sensors has also increased; however, there are still not sufficient numbers of instruments in orbit today to fulfill the need for operational meteorological and scientific wind vector data. Over the last three decades operational measurements of global ocean wind speeds have been obtained from passive microwave radiometers. Also, vector ocean surface wind data were primarily obtained from several scatterometry missions that have flown since the early 1990's. However, other than SeaSat-A in 1978, there has not been combined active and passive wind measurements on the same satellite until the launch of the second Advanced Earth Observing Satellite (ADEOS-II) in 2002. This mission has provided a unique data set of coincident measurements between the SeaWinds scatterometer and the Advanced Microwave Scanning Radiometer (AMSR). AMSR observes the vertical and horizontal brightness temperature (TB) at six frequency bands between 6.9 GHz and 89.0 GHz. Although these measurements contain some wind direction information, the overlying atmospheric influence can easily obscure this signal and make wind direction retrieval from passive microwave measurements very difficult. However, at radiometer frequencies between 10 and 37 GHz, a certain linear combination of vertical and horizontal brightness temperatures causes the atmospheric dependence to be nearly cancelled and surface parameters such as wind speed, wind direction and sea surface temperature to dominate the resulting signal. This brightness temperature combination may be expressed as ATBV-TBH, where A is a constant to be determined and the TBV and TBH are the brightness temperatures for the vertical and horizontal polarization respectively. In this dissertation, an empirical relationship between the AMSR's ATBV-TBH and SeaWinds' surface wind vector retrievals was established for three microwave frequencies: 10, 18 and 37 GHz. This newly developed model function for a passive microwave radiometer could provide the basis for wind vector retrievals either separately or in combination with scatterometer measurements.
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Date Issued
2006
Identifier
CFE0001493, ucf:47088
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0001493
SEAWINDS RADIOMETER BRIGHTNESS TEMPERATURE CALIBRATION AND VALIDATION
Title
SEAWINDS RADIOMETER BRIGHTNESS TEMPERATURE CALIBRATION AND VALIDATION.
Creator
Rastogi, Mayank, Jones, Linwood, University of Central Florida
Abstract / Description
The NASA SeaWinds scatterometer is a radar remote sensor which operates on two satellites; NASA's QuikSCAT launched in June 1999 and on Japan's ADEOS-II satellite launched in December 2002. The purpose of SeaWinds is to provide global measurements of the ocean surface wind vector. On QuikSCAT, a ground data processing algorithm was developed, which allowed the instrument to function as a QuikSCAT Radiometer (QRad) and measure the ocean microwave emissions (brightness temperature, Tb)...
Show moreThe NASA SeaWinds scatterometer is a radar remote sensor which operates on two satellites; NASA's QuikSCAT launched in June 1999 and on Japan's ADEOS-II satellite launched in December 2002. The purpose of SeaWinds is to provide global measurements of the ocean surface wind vector. On QuikSCAT, a ground data processing algorithm was developed, which allowed the instrument to function as a QuikSCAT Radiometer (QRad) and measure the ocean microwave emissions (brightness temperature, Tb) simultaneously with the backscattered power. When SeaWinds on ADEOS was launched, this same algorithm was applied, but the results were anomalous. The initial SRad brightness temperatures exhibited significant, unexpected, ascending/descending orbit Tb biases. This thesis presents an empirical correction algorithm to correct the anomalous SeaWinds Radiometer (SRad) ocean brightness temperature measurements. I use the Advanced Microwave Scanning Radiometer (AMSR) as a brightness temperature standard to calibrate and then, with independent measurements, validate the corrected SRad Tb measurements. AMSR is a well-calibrated multi-frequency, dual-polarized microwave radiometer that also operates on ADEOS-II. These results demonstrate that, after tuning the Tb algorithm, good quality SRad brightness temperature measurements are obtained over the oceans.
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Date Issued
2005
Identifier
CFE0000689, ucf:46490
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0000689