Calibration of Dual-Polarization Radar in the Presence of Partial Beam BlockageSource: Journal of Atmospheric and Oceanic Technology:;2005:;volume( 022 ):;issue: 008::page 1156DOI: 10.1175/JTECH1766.1Publisher: American Meteorological Society
Abstract: In the presence of partial beam blockage (PBB), weather radar measurements can experience significant bias that directly compromises the accuracy of the hydrologic applications. Techniques for the calibration of the radar reflectivity factor Z and differential reflectivity ZDR, measured with dual-polarization weather radars in the presence of partial beam obstruction, are examined in this paper. The proposed ZDR calibration technique utilizes radar measurements of ZDR in light rain and dry aggregated snow at unblocked and blocked elevations. This calibration technique was tested for the National Severe Storms Laboratory?s (NSSL?s) Cimarron radar that suffers from PBB, and a polarimetric prototype of the Weather Surveillance Radar-1988 Doppler (WSR-88D) that does not experience PBB. Results indicate that the ZDR bias that is associated with PBB can be calibrated with an accuracy of 0.2?0.3 dB, provided that the dataset is sufficiently large. Calibration of Z in the presence of PBB is based on the idea of self-consistency among Z, ZDR, and the specific differential phase KDP in rain. The self-consistency calibration of Z from the Cimarron radar is performed following an area?time integral method. Integration is partitioned into small azimuthal sectors to assess the azimuthal modulation of the Z bias. The suggested technique is validated by direct comparisons of reflectivity factors that are measured by the Cimarron radar and the unobstructed operational WSR-88D radar. It is shown that the azimuthal modulation of Z that is caused by PBB is well captured, and the accuracy of the Z calibration is within 2?3 dB.
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contributor author | Giangrande, Scott E. | |
contributor author | Ryzhkov, Alexander V. | |
date accessioned | 2017-06-09T17:22:51Z | |
date available | 2017-06-09T17:22:51Z | |
date copyright | 2005/08/01 | |
date issued | 2005 | |
identifier issn | 0739-0572 | |
identifier other | ams-84150.pdf | |
identifier uri | http://onlinelibrary.yabesh.ir/handle/yetl/4227454 | |
description abstract | In the presence of partial beam blockage (PBB), weather radar measurements can experience significant bias that directly compromises the accuracy of the hydrologic applications. Techniques for the calibration of the radar reflectivity factor Z and differential reflectivity ZDR, measured with dual-polarization weather radars in the presence of partial beam obstruction, are examined in this paper. The proposed ZDR calibration technique utilizes radar measurements of ZDR in light rain and dry aggregated snow at unblocked and blocked elevations. This calibration technique was tested for the National Severe Storms Laboratory?s (NSSL?s) Cimarron radar that suffers from PBB, and a polarimetric prototype of the Weather Surveillance Radar-1988 Doppler (WSR-88D) that does not experience PBB. Results indicate that the ZDR bias that is associated with PBB can be calibrated with an accuracy of 0.2?0.3 dB, provided that the dataset is sufficiently large. Calibration of Z in the presence of PBB is based on the idea of self-consistency among Z, ZDR, and the specific differential phase KDP in rain. The self-consistency calibration of Z from the Cimarron radar is performed following an area?time integral method. Integration is partitioned into small azimuthal sectors to assess the azimuthal modulation of the Z bias. The suggested technique is validated by direct comparisons of reflectivity factors that are measured by the Cimarron radar and the unobstructed operational WSR-88D radar. It is shown that the azimuthal modulation of Z that is caused by PBB is well captured, and the accuracy of the Z calibration is within 2?3 dB. | |
publisher | American Meteorological Society | |
title | Calibration of Dual-Polarization Radar in the Presence of Partial Beam Blockage | |
type | Journal Paper | |
journal volume | 22 | |
journal issue | 8 | |
journal title | Journal of Atmospheric and Oceanic Technology | |
identifier doi | 10.1175/JTECH1766.1 | |
journal fristpage | 1156 | |
journal lastpage | 1166 | |
tree | Journal of Atmospheric and Oceanic Technology:;2005:;volume( 022 ):;issue: 008 | |
contenttype | Fulltext |