Local Structure of the Convective Boundary Layer from a Volume-Imaging Radar

Pollard, B.; Khanna, Samir; Frasier, Stephen J.; Wyngaard, J. C.; Thomson, Dennis W.; McIntosh, R.E.

doi:10.1175/1520-0469(2000)057<2281:lsotcb>2.0.co;2

Cited by 30 publications

(37 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Horizontal slices Fig. 7a-c appear similar to results of Mead et al (1998) and Pollard et al (2000), despite the use of DBS and VHF instead of spaced antenna and UHF. The pattern of converging horizontal wind and upward vertical wind within the thermal shows continuity as it moves through the radar imaging volume, despite being measured by beams at a variety of angles.…”

Section: Shallow Convectionsupporting

confidence: 63%

“…Another method assumes little about the overall form of the nonuniform wind, except for locally uniform wind between neighbouring radar beams, then using trigonometry to extract the three-dimensional vector wind field (Mead et al, 1998;Pollard et al, 2000). Sato and Hirota (1988) show that wind structures of small horizontal scale compared to radar beam separation can give spurious values for U, V , W ; however, they were measuring in the stratosphere, where the horizontal distance between diverging off-zenith beams is larger than in the lower troposphere.…”

Section: Shallow Convectionmentioning

confidence: 99%

See 1 more Smart Citation

All-weather volume imaging of the boundary layer and troposphere using the MU radar

Worthington

2004

Ann. Geophys.

View full text Add to dashboard Cite

Abstract. This paper shows the first volume-imaging radar that can run in any weather, revealing the turbulent threedimensional structure and airflow of convective cells, rain clouds, breaking waves and deep convection as they evolve and move. Precipitation and clear air can be volume-imaged independently. Birds are detected as small high-power echoes moving near horizontal, at different speeds and directions from background wind. The volume-imaging method could be used to create a real-time virtual-reality view of the atmosphere, in effect making the invisible atmosphere visible in any weather.

show abstract

Section: Shallow Convectionsupporting

confidence: 63%

Section: Shallow Convectionmentioning

confidence: 99%

All-weather volume imaging of the boundary layer and troposphere using the MU radar

Worthington

2004

Ann. Geophys.

View full text Add to dashboard Cite

show abstract

“…Using the characteristic that raindrop fall velocity is much greater than vertical wind velocity, Palmer et al (2005) demonstrated that fine-scale angular distributions of backscattered power from clear air and that from raindrops are able to be obtained separately. From a CRI measurement by TEP, Pollard et al (2000) demonstrated that horizontal distribution of refractive index structure function is able to be measured. (Nishimura et al, 2010).…”

Section: Measurement Resultsmentioning

confidence: 99%

New Observations by Wind Profiling Radars

Yamamoto¹

2012

Doppler Radar Observations - Weather Radar, Wind Profiler, Ionospheric Radar, and Other Advanced Applications

View full text Add to dashboard Cite

“…Arguably, one of the most sophisticated of these types of radar systems is the so-called Turbulent Eddy Profiler (TEP), which was developed at the University of Massachusetts (Mead et al 1998;Pollard et al 2000). The TEP system is a volumetric radar designed for clear-air observations with high temporal and spatial resolution comparable to the grid size used in large eddy simulation (LES) models (Lilly 1967;Wyngaard et al 1998).…”

Section: Introductionmentioning

confidence: 99%

Phased-Array Design for Biological Clutter Rejection: Simulation and Experimental Validation

Cheong

Hoffman

Palmer

et al. 2006

Journal of Atmospheric and Oceanic Technology

Self Cite

View full text Add to dashboard Cite

This paper highlights recent results obtained with the Turbulent Eddy Profiler (TEP), which was developed by the University of Massachusetts. This unique 915-MHz radar has up to 64 spatially separated receiving elements, each with an independent receiver. The calibrated raw data provided by this array could be processed using sophisticated imaging algorithms to resolve the horizontal structures within each range gate. After collecting all of the closely spaced horizontal slices, the TEP radar can produce threedimensional images of echo power, radial velocity, and spectral width. From the radial velocity measurements, it is possible to estimate the three-dimensional wind with high horizontal and vertical resolution. Given the flexibility of the TEP system, various array configurations are possible. In the present work exploitation of the flexibility of TEP is attempted to enhance the rejection of clutter from unwanted biological targets. From statistical studies, most biological clutter results from targets outside the main imaging field of view, that is, the sidelobes and grating lobes (if they exist) of the receiving beam. Because the TEP array's minimum receiver separation exceeds the spatial Nyquist sampling requirement, substantial possibilities for grating-lobe clutter exist and are observed in actual array data. When imaging over the transmit beam volume, the receiving array main lobe is scanned over a Ϯ12.5°region. This scanning also sweeps the grating lobes over a wide angular region, virtually guaranteeing that a biological scatterer outside of the main beam will appear somewhere in the imaged volume. This paper focuses on suppressing pointlike targets in the grating-lobe regions. With a subtle change to the standard TEP array hardware configuration, it is shown via simulations and actual experimental observations (collected in June 2003) that adaptive beamforming methods can subsequently be used to significantly suppress the effects of point targets on the wind field estimates. These pointlike targets can be birds or planes with strong reflectivity. By pointlike the authors mean its appearance is a distinct point (up to the imaging resolution) in the images. The pointlike strong reflectivity signature exploits the capability of adaptive beamforming to suppress the interference using the new array configuration. It should be noted that this same array configuration does not exhibit this beneficial effect when standard Fourier beamforming is employed.

show abstract

Local Structure of the Convective Boundary Layer from a Volume-Imaging Radar

Cited by 30 publications

References 27 publications

All-weather volume imaging of the boundary layer and troposphere using the MU radar

All-weather volume imaging of the boundary layer and troposphere using the MU radar

New Observations by Wind Profiling Radars

Phased-Array Design for Biological Clutter Rejection: Simulation and Experimental Validation

Contact Info

Product

Resources

About