| Paper: | TH-A1.7 |
| Session: | Applications of Radiometry I |
| Time: | Thursday, March 29, 09:00 - 10:20 |
| Presentation: |
Poster
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| Topic: |
Theory, physical principles and electromagnetic models: |
| Title: |
VALIDATION OF RADIATIVE TRANSFER MODEL FOR THE AIRBORNE HURRICANE IMAGING RADIOMETER (HIRAD) UNDER RAINY CONDITIONS |
| Authors: |
Abdusalam Alasgah; University of Central Florida | | |
| | Maria Jacob; Universidad Nacional de Córdoba | | |
| | W. Linwood Jones; University of Central Florida | | |
| Abstract: |
The NASA Hurricane and Severe Storm Sentinel (HS3) mission was an aircraft field measurements program using NASA’s unmanned Global Hawk (AV1) aircraft system for remote sensing and in-situ observations of Atlantic and Caribbean Sea hurricanes. One of the principal microwave instruments was the Hurricane Imaging Radiometer (HIRAD), which measured surface wind speeds and rain rates.
It’s important to note that the spatial distribution of rain varies both vertically and horizontally so each HIRAD measurement pixel will have a different rain profile than the adjacent pixels. Therefore, the Central Florida Remote Sensing Laboratory (CFRSL) has developed a Radiative Transfer Model (RTM) that accounts for the upwelling and downwelling path of rain separately.
Thus, this paper presents validation results for CFRSL’s RTM from an unplanned rain rate measurement opportunity that occurred in 2013, when AV1 flew over an intense tropical squall line, carrying HIRAD and an active microwave High-altitude Imaging Wind and Rain Airborne Profiler (HIWRAP). Moreover, the event was simultaneously observed by the Tampa NEXRAD meteorological radar. During this experiment, AV1 flying at an altitude of 18 km made 3 passes over the rapidly propagating thunderstorm, while the TAMPA NEXRAD perform volume scans on a 5-minute interval.
For this paper, NEXRAD rain rates (RR) were used to convert HIWRAP reflectivity values (dBZ) to RR. Using these HIWRAP rain profiles, it was possible to produce a 3D rain field, which was resampled along the HIRAD line of sight direction and the specular reflection path and was used as an input of the RTM to generate HIRAD modeled Tbs.
This paper will describe in detail the RTM, as well as the conversion between dBZ values and RR. Finally, results of comparisons between HIRAD modeled and measured Tbs will be presented.
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