High-Temporal-Resolution Capabilities of the National Weather Radar Testbed Phased-Array Radar
13 Apr 2011-Journal of Applied Meteorology and Climatology (American Meteorological Society)-Vol. 50, Iss: 3, pp 579-593
TL;DR: To achieve the increase in computational power and data archiving needs required for high-temporal-resolution sampling, the signal processor was upgraded to a scalable, Linux-based cluster with a distributed computing architecture.
Abstract: Since 2007 the advancement of the National Weather Radar Testbed Phased-Array Radar (NWRT PAR) hardware and software capabilities has been supporting the implementation of high-temporal-resolution (∼1 min) sampling. To achieve the increase in computational power and data archiving needs required for high-temporal-resolution sampling, the signal processor was upgraded to a scalable, Linux-based cluster with a distributed computing architecture. The development of electronic adaptive scanning, which can reduce update times by focusing data collection on significant weather, became possible through functionality added to the radar control interface and real-time controller. Signal processing techniques were implemented to address data quality issues, such as artifact removal and range-and-velocity ambiguity mitigation, absent from the NWRT PAR at its installation. The hardware and software advancements described above have made possible the development of conventional and electronic scanning capabil...
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TL;DR: In this article, the authors investigated the impact of different intensities of rain, snow and temperature levels on macroscopic travel times in the Greater London area (UK) during the period 1 October-10 December 2009.
119 citations
Cites background from "High-Temporal-Resolution Capabiliti..."
...Similarly, recent meteorological studies that examine weather satellite and radar technologies, have substantially improved the data granularity at the level of some seconds (Heinselman and Torres, 2011; Sutherland-Stacey et al., 2011); yet their utilisation in the transport field remains somewhat limited....
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...…recent meteorological studies that examine weather satellite and radar technologies, have substantially improved the data granularity at the level of some seconds (Heinselman and Torres, 2011; Sutherland-Stacey et al., 2011); yet their utilisation in the transport field remains somewhat limited....
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TL;DR: Analysis of rapid-scan weather radars revealed that teams examining the same data sometimes came to different conclusions about whether and when to...
Abstract: Rapid-scan weather radars, such as the S-band phased array radar at the National Weather Radar Testbed in Norman, Oklahoma, improve precision in the depiction of severe storm processes. To explore potential impacts of such data on forecaster warning decision making, 12 National Weather Service forecasters participated in a preliminary study with two control conditions: 1) when radar scan time was similar to volume coverage pattern 12 (4.5 min) and 2) when radar scan time was faster (43 s). Under these control conditions, forecasters were paired and worked a tropical tornadic supercell case. Their decision processes were observed and audio was recorded, interactions with data displays were video recorded, and the products were archived. A debriefing was conducted with each of the six teams independently and jointly, to ascertain the forecaster decision-making process. Analysis of these data revealed that teams examining the same data sometimes came to different conclusions about whether and when to...
56 citations
Cites methods from "High-Temporal-Resolution Capabiliti..."
...Data were collected using a 608 sector and the same elevation angles as VCP 12 (NOAA 2006), with 0.58 overlapped azimuthal sampling (Heinselman and Torres 2011)....
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...The development of rapid-scan capabilities with S-band phased array radar (PAR) at the National Weather Radar Testbed in Norman, Oklahoma (Yu et al. 2007; Zrnić et al. 2007; Heinselman and Torres 2011; Curtis and Torres 2011), presents new opportunities for the advancement of weather sensing....
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TL;DR: In this article, the current status of weather radar polarimetry, discuss the issues and limitations of PRD usage, and explore potential approaches to more efficiently use PRD for quantitative precipitation estimation and forecasting based on statistical retrieval with physical constraints.
Abstract: After decades of research and development, the WSR-88D (NEXRAD) network in the United States was upgraded with dual-polarization capability, providing polarimetric radar data (PRD) that have the potential to improve weather observations, quantification, forecasting, and warnings. The weather radar networks in China and other countries are also being upgraded with dual-polarization capability. Now, with radar polarimetry technology having matured, and PRD available both nationally and globally, it is important to understand the current status and future challenges and opportunities. The potential impact of PRD has been limited by their oftentimes subjective and empirical use. More importantly, the community has not begun to regularly derive from PRD the state parameters, such as water mixing ratios and number concentrations, used in numerical weather prediction (NWP) models. In this review, we summarize the current status of weather radar polarimetry, discuss the issues and limitations of PRD usage, and explore potential approaches to more efficiently use PRD for quantitative precipitation estimation and forecasting based on statistical retrieval with physical constraints where prior information is used and observation error is included. This approach aligns the observation-based retrievals favored by the radar meteorology community with the model-based analysis of the NWP community. We also examine the challenges and opportunities of polarimetric phased array radar research and development for future weather observation.
53 citations
TL;DR: In this paper, the University of Oklahoma Advanced Radar Research Center's PX-1000 transportable, polarimetric, X-band weather radar was operating in a single-elevation PPI scanning strategy at the OU Westheimer airport throughout the duration of the 2013 Moore tornado, collecting high spatial and temporal resolution PPI data every 20 s at ranges as close as 10 km and heights below 500 m AGL.
Abstract: On 20 May 2013, the cities of Newcastle, Oklahoma City, and Moore, Oklahoma, were impacted by a long-track violent tornado that was rated as an EF5 on the enhanced Fujita scale by the National Weather Service. Despite a relatively sustained long track, damage surveys revealed a number of small-scale damage indicators that hinted at storm-scale processes that occurred over short time periods. The University of Oklahoma (OU) Advanced Radar Research Center’s PX-1000 transportable, polarimetric, X-band weather radar was operating in a single-elevation PPI scanning strategy at the OU Westheimer airport throughout the duration of the tornado, collecting high spatial and temporal resolution polarimetric data every 20 s at ranges as close as 10 km and heights below 500 m AGL. This dataset contains the only known polarimetric radar observations of the Moore tornado at such high temporal resolution, providing the opportunity to analyze and study finescale phenomena occurring on rapid time scales. Analysis ...
47 citations
Cites background from "High-Temporal-Resolution Capabiliti..."
...While this is due in large part to the wide range of possible scenarios in severe local storms and their environments, an added caveat is the lack of extremely rapid update rates combined with high-quality data (Heinselman et al. 2008; Heinselman and Torres 2011)....
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TL;DR: In this paper, the authors examined storm severity in the mid-Atlantic region of the United States using lightning, radar, and model-derived information, and developed automated warning decision support system (WDSS) procedures to create grids of lightning and radar parameters, cluster individual storm features, and data mine the lightning and Radar attributes of 1252 severe and nonsevere storms.
Abstract: Storm severity in the mid-Atlantic region of the United States is examined using lightning, radar, and model-derived information. Automated Warning Decision Support System (WDSS) procedures are developed to create grids of lightning and radar parameters, cluster individual storm features, and data mine the lightning and radar attributes of 1252 severe and nonsevere storms. The study first examines the influence of serial correlation and uses autocorrelation functions to document the persistence of lightning and radar parameters. Decorrelation times are found to vary by parameter, storm severity, and mathematical operator, but the great majority are between three and six lags, suggesting that consecutive 2-min storm samples (following a storm) are effectively independent after only 6–12 min. The study next describes the distribution of lightning jumps in severe and nonsevere storms, differences between various types of severe storms (e.g., severe wind only), and relationships between lightning and ...
46 citations
Cites background from "High-Temporal-Resolution Capabiliti..."
...Much like the rapid sampling provided by phased array radar (Heinselman et al. 2008; Heinselman and Torres 2011; Bluestein et al. 2010), knowledge of rapidly changing lightning patterns might increase warning confidence by augmenting existing and future radar and satellite products....
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References
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Book•
01 Jan 1971
TL;DR: This article reviewed the principles of Doppler radar and emphasized the quantitative measurement of meteorological parameters, and illustrated the relation of radar data and images to atmospheric phenomena such as tornadoes, microbursts, waves, turbulence, density currents, hurricanes, and lightning.
Abstract: This book reviews the principles of Doppler radar and emphasizes the quantitative measurement of meteorological parameters. It illustrates the relation of Doppler radar data and images to atmospheric phenomena such as tornadoes, microbursts, waves, turbulence, density currents, hurricanes, and lightning.
Geared toward upper-level undergraduates and graduate students, this text was written by two scientists at the National Severe Storms Laboratory in Norman, Oklahoma, a division of the National Oceanic and Atmospheric Administration. Topics include electromagnetic waves and propagation, weather signals and their Doppler spectra, weather signal processing, measurements of precipitation and turbulence, and observations of winds and storms as well as fair weather. Radar images and photographs of weather phenomena highlight the text.
2,178 citations
04 May 2009
TL;DR: The NSF Engineering Research Center for Collaborative Adaptive Sensing of the Atmosphere (CASA) is advancing a new approach to radar network design based on dense networks of short-range radars, which has the potential to supplement - or perhaps replace - the large long-range civil infrastructure radars in use today.
Abstract: The NSF Engineering Research Center for Collaborative Adaptive Sensing of the Atmosphere (CASA) is advancing a new approach to radar network design based on dense networks of short-range radars. The center's concept is to deploy small radars atop communication towers, rooftops, and other elements of the infrastructure as a means to comprehensively map winds, rainfall, and other atmospheric and airborne objects throughout the atmosphere with resolution, low-altitude coverage, Doppler wind vector measurement, and other capabilities that are substantially beyond the current state-of-the-art. The technology has the potential to supplement - or perhaps replace - the large long-range civil infrastructure radars in use today.
267 citations
TL;DR: In this paper, the agile-beam multimission phased array radar (MPAR) discussed in this paper is one potential candidate that can provide faster scanning and offers a unique potential for multipurpose use to not only sample weather, but support air traffic needs and track noncooperative airplanes.
Abstract: Weather radars with conventional antenna cannot provide desired volume scan updates at intervals of one minute or less, which is essential for significant improvement in warning lead time of impending storm hazards. The agile-beam multimission phased array radar (MPAR) discussed herein is one potential candidate that can provide faster scanning. It also offers a unique potential for multipurpose use to not only sample weather, but support air traffic needs and track noncooperative airplanes, thus making it an affordable option. After introducing the basic idea behind electronic beam steering, the needs for frequent observations of convective weather are explained. Then, advantages of the phased array radar (PAR) for weather monitoring and improving data quality are examined. To explore and develop weather-related applications of the PAR, a National Weather Radar Testbed (NWRT) has been established in Norman, Oklahoma. The NWRT's main purpose is to address the advanced capabilities anticipated within the n...
263 citations
TL;DR: In this paper, the horizontal and vertical structure of airflow within microbursts has been determined using Doppler weather radar data from the Joint Airport Weather Studies (JAWS) Project.
Abstract: The horizontal and vertical structure of airflow within microbursts has been determined using Doppler weather radar data from the Joint Airport Weather Studies (JAWS) Project. It is shown that the downdraft typically associated with microbursts is about 1 km wide and begins to spread horizontally at a height below 1 km. The median time from initial divergence at the surface to maximum differential wind velocity across the microburst is five minutes. The height of maximum differential velocity is about 75 m, and the median velocity differential is 22 m/s over an average distance of 3.1 km. The outflow of the air is asymmetric, averaging twice as strong along the maximum axis compared to the mininum axis. Some technical requirements for a radar system to detect microbursts and to provide aircraft with early warnings of the onset of windshear are identified.
177 citations
"High-Temporal-Resolution Capabiliti..." refers background in this paper
...…for some time (e.g., Miller and Kropfli 1980; Carbone et al. 1985) and continues to drive radar research and demonstration initiatives (e.g., Wilson et al. 1984; Lin et al. 1986; Qiu and Xu 1996; Wurman 2002; Bluestein and Wakimoto 2003; Zrnić et al. 2007; Heinselman et al. 2008; Bluestein…...
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01 Jan 1983
TL;DR: In this paper, the utility of Doppler radar measurement techniques for detecting low-level wind shear at airports is examined, in order to determine the optimal resolution, sensitivity, and scanning strategy for a standard system.
Abstract: The utility of Doppler radar measurement techniques for detecting low-level wind shear at airports is examined. The Doppler radar data of the Joint Airport Weather Studies (JAWS) for windshear microburst features are analyzed, in order to determine the optimal resolution, sensitivity, and scanning strategy for a standard system. The performance of three separate systems for measuring wind shear at heights of less than 200 meters is compared. The three systems included a dual-Doppler system, a single off-airport Doppler system, and a single on-airport Doppler system. On the basis of the comparison the following recommendations are offered concerning the optimal performance of a Doppler radar system in the airport environment: (1) the system should be able to measure radial velocities over a range of reflectivity of -10-80 dBZ; (2) ground clutter should be reduced; and techniques for identifying and disseminating wind shear information should be automated.
174 citations