scholarly journals The next generation airborne polarimetric Doppler weather radar

2014 ◽  
Vol 3 (2) ◽  
pp. 111-126 ◽  
Author(s):  
J. Vivekanandan ◽  
W.-C. Lee ◽  
E. Loew ◽  
J. L. Salazar ◽  
V. Grubišić ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Phased Array ◽  
Doppler Velocity ◽  
Airborne Radar ◽  
Dual Polarization ◽  
Polarization Measurements ◽  
Phased Array Radar ◽  
X Band ◽  
Temporal And Spatial ◽  
Airborne Phased Array Radar

Abstract. Results from airborne field deployments emphasized the need to obtain concurrently high temporal and spatial resolution measurements of 3-D winds and microphysics. A phased array radar on an airborne platform using dual-polarization antenna has the potential for retrieving high-resolution, collocated 3-D winds and microphysical measurements. Recently, ground-based phased array radar (PAR) has demonstrated the high time-resolution estimation of accurate Doppler velocity and reflectivity of precipitation and clouds when compared to mechanically scanning radar. PAR uses the electronic scanning (e-scan) to rapidly collect radar measurements. Since an airborne radar has a limited amount of time to collect measurements over a specified sample volume, the e-scan will significantly enhance temporal and spatial resolution of airborne radar observations. At present, airborne weather radars use mechanical scans, and they are not designed for collecting dual-polarization measurements to remotely estimate microphysics. This paper presents a possible configuration of a novel airborne phased array radar (APAR) to be installed on an aircraft for retrieving improved dynamical and microphysical scientific products. The proposed APAR would replace the aging, X-band Electra Doppler radar (ELDORA). The ELDORA X-band radar's penetration into precipitation is limited by attenuation. Since attenuation at C-band is lower than at X-band, the design specification of a C-band airborne phased array radar (APAR) and its measurement accuracies are presented. Preliminary design specifications suggest the proposed APAR will meet or exceed ELDORA's current sensitivity, spatial resolution and Doppler measurement accuracies of ELDORA and it will also acquire dual-polarization measurements.

scholarly journals The next generation airborne polarimetric Doppler weather radar

2014 ◽  
Vol 4 (1) ◽  
pp. 1-42 ◽  
Author(s):  
J. Vivekanandan ◽  
W.-C. Lee ◽  
E. Loew ◽  
J. L. Salazar ◽  
V. Grubišić ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Phased Array ◽  
Doppler Velocity ◽  
Airborne Radar ◽  
High Time Resolution ◽  
Dual Polarization ◽  
Phased Array Radar ◽  
X Band ◽  
Temporal And Spatial ◽  
Airborne Phased Array Radar

Abstract. Results from airborne field deployments emphasized the need to obtain concurrently high temporal and spatial resolution measurements of 3-D winds and microphysics. A phased array radar on an airborne platform using dual-polarization antenna has the potential for retrieving high resolution, collocated 3-D winds and microphysical measurements. Recently, ground-based phased array radar (PAR) demonstrated the high time resolution estimation of accurate Doppler velocity and reflectivity of precipitation and clouds when compared to mechanically scanning radar. PAR uses the electronic scanning (e-scan) to rapidly collect radar measurements. Since an airborne radar has a limited amount of time to collect measurements over a specified sample volume, the e-scan will significantly enhance temporal and spatial resolution of airborne radar observations. At present, airborne weather radars use mechanical scan, and they are not designed for collecting dual-polarization measurements to remotely estimate microphysics. This paper presents a possible configuration of a novel Airborne Phased Array Radar (APAR) to be installed on an aircraft for retrieving improved dynamical and microphysical scientific products. The proposed APAR would replace the aging, X-band Electra Doppler radar (ELDORA). The ELDORA X-band radar's penetration into precipitation is limited by attenuation. Since attenuation at C-band is lower than at X-band, the design specification of a C-band airborne phased array radar (APAR) and its measurement accuracies are presented.

scholarly journals Rapid-Scan Radar Observations of an Oklahoma Tornadic Hailstorm Producing Giant Hail

2018 ◽  
Vol 33 (5) ◽  
pp. 1263-1282 ◽  
Author(s):  
Arthur Witt ◽  
Donald W. Burgess ◽  
Anton Seimon ◽  
John T. Allen ◽  
Jeffrey C. Snyder ◽  
...  
Keyword(s):  
Phased Array ◽  
Rotational Velocity ◽  
Weather Radar ◽  
Dual Polarization ◽  
Radar Observations ◽  
Rapid Scan ◽  
Phased Array Radar ◽  
X Band ◽  
Low Altitude ◽  
Rapid Scanning

Abstract Rapid-scan radar observations of a supercell that produced near-record size hail in Oklahoma are examined. Data from the National Weather Radar Testbed Phased Array Radar (PAR) in Norman, Oklahoma, are used to study the overall character and evolution of the storm. Data from the nearby polarimetric KOUN WSR-88D and rapid-scanning X-band polarimetric (RaXPol) mobile radar are used to study the evolution of low- to midaltitude dual-polarization parameters above two locations where giant hailstones up to 16 cm in diameter were observed. The PAR observation of the supercell’s maximum storm-top divergent outflow is similar to the strongest previously documented value. The storm’s mesocyclone rotational velocity at midaltitudes reached a maximum that is more than double the median value for similar observations from other storms producing giant hail. For the two storm-relative areas where giant hail was observed, noteworthy findings include 1) the giant hail occurred outside the main precipitation core, in areas with low-altitude reflectivities of 40–50 dBZ; 2) the giant hail was associated with dual-polarization signatures consistent with past observations of large hail at 10-cm wavelength, namely, low ZDR, low ρHV, and low KDP; 3) the giant hail fell along both the northeast and southwest edges of the primary updraft at ranges of 6–10 km from the updraft center; and 4) with the exception of one isolated report, the giant hail fell to the northeast and northwest of the large tornado and the parent mesocyclone.

Observations of the Boundary Layer near Tornadoes and in Supercells Using a Mobile, Collocated, Pulsed Doppler Lidar and Radar

2014 ◽  
Vol 31 (2) ◽  
pp. 302-325 ◽  
Author(s):  
Howard B. Bluestein ◽  
Jana B. Houser ◽  
Michael M. French ◽  
Jeffrey C. Snyder ◽  
George D. Emmitt ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Spatial Resolution ◽  
Phased Array ◽  
High Spatial Resolution ◽  
Vertical Shear ◽  
Doppler Velocity ◽  
Doppler Lidar ◽  
Pulsed Doppler ◽  
Ground Clutter ◽  
X Band

Abstract During the Second Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX2), in the spring of 2010, a mobile and pulsed Doppler lidar system [the Truck-Mounted Wind Observing Lidar Facility (TWOLF)] mounted on a truck along with a mobile, phased-array, X-band Doppler radar system [Mobile Weather Radar–2005 X-band, phased array (MWR-05XP)] was used to complement Doppler velocity coverage in clear air near the radar–lidar facility and to provide high-spatial-resolution vertical cross sections of the Doppler wind field in the clear-air boundary layer near and in supercells. It is thought that the magnitude and direction of vertical shear and possibly the orientation and spacing of rolls in the boundary layer have significant effects on both supercell and tornado behavior; MWR-05XP and TWOLF can provide data that can be used to measure vertical shear and detect rolls. However, there are very few detailed, time-dependent and spatially varying observations throughout the depth of the boundary layer of supercells and tornadoes. This paper discusses lidar and radar data collected in or near six supercells. Features seen by the lidar included gust fronts, horizontal convective rolls, and small-scale vortices. The lidar proved useful at detecting high-spatial-resolution, clear-air returns at close range, where the radar was incapable of doing so, thus providing a more complete picture of the boundary layer environment ahead of supercells. The lidar was especially useful in areas where there was ground-clutter contamination. When there was precipitation and probably insects, and beyond the range of the lidar, where there was no ground-clutter contamination, the radar was the more useful instrument. Suggestions are made for improving the system and its use in studying the tornado boundary layer.

Integrated X Band Active Phased Array Radar for Maritime Surveillance

2021 ◽  
Author(s):  
Ramkumar Raghu ◽  
Nanditha Unnikrishnan ◽  
B Sree Kalyani ◽  
R Rajesh ◽  
Reena Sharma
Keyword(s):  
Phased Array ◽  
Maritime Surveillance ◽  
Phased Array Radar ◽  
X Band

X-band antenna module for advanced navigational phased array radar

2017 ◽  
Author(s):  
Stefan Radzijewski ◽  
Nils Hansen ◽  
Jan-Philip Mohncke ◽  
Arne F. Jacob
Keyword(s):  
Phased Array ◽  
Phased Array Radar ◽  
X Band ◽  
Antenna Module

scholarly journals Determination of ice water content (IWC) in tropical convective clouds from X-band dual-polarization airborne radar

2019 ◽  
Vol 12 (11) ◽  
pp. 5897-5911 ◽  
Author(s):  
Cuong M. Nguyen ◽  
Mengistu Wolde ◽  
Alexei Korolev
Keyword(s):  
Water Content ◽  
Ice Crystals ◽  
Airborne Radar ◽  
Dual Polarization ◽  
Differential Phase ◽  
Convective Clouds ◽  
X Band ◽  
Ice Water Content ◽  
Differential Reflectivity ◽  
Ice Water

Abstract. This paper presents a methodology for ice water content (IWC) retrieval from a dual-polarization side-looking X-band airborne radar. Measured IWC from aircraft in situ probes is weighted by a function of the radar differential reflectivity (Zdr) to reduce the effects of ice crystal shape and orientation on the variation in IWC – specific differential phase (Kdp) joint distribution. A theoretical study indicates that the proposed method, which does not require a knowledge of the particle size distribution (PSD) and number density of ice crystals, is suitable for high-ice-water-content (HIWC) regions in tropical convective clouds. Using datasets collected during the High Altitude Ice Crystals – High Ice Water Content (HAIC-HIWC) international field campaign in Cayenne, French Guiana (2015), it is shown that the proposed method improves the estimation bias by 35 % and increases the correlation by 4 % on average, compared to the method using specific differential phase (Kdp) alone.

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