A Volume-Imaging Radar Wind Profiler for Atmospheric Boundary Layer Turbulence Studies

Abstract

This paper describes the turbulent eddy profiler (TEP), a volume-imaging, UHF radar wind profiler designed for clear-air measurements in the atmospheric boundary layer on scales comparable to grid cell sizes of large eddy simulation models. TEP employs a large array of antennas-each feeding an independent receiver-to simultaneously generate multiple beams within a 28Њ conical volume illuminated by the transmitter. Range gating provides 30-m spatial resolution in the vertical dimension. Each volume image is updated every 2-10 s, and long datasets can be gathered to study the evolution of turbulent structure over several hours. A summary of the principles of operation and the design of TEP is provided, including examples of clear-air reflectivity and velocity images.

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

“…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.…”

“…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.…”

New Observations by Wind Profiling Radars

“…Further, Yu et al (2000) evaluated relation between CRI performance and receiver arrangement. Effects of uncertainty of receiver gain and phase were evaluated for the case of turbulent Eddy Profiler (TEP), which was developed by the University of Massachusetts in order to carry out CRI measurement in the boundary layer (Mead et al 1998). Fig.…”

Observations of the Small-Scale Variability of Precipitation Using an Imaging Radar

“…In its current configuration, the 915-MHz TEP radar consists of a transmit horn antenna and a receive array of up to 64 microstrip patch elements separated by approximately 0.57 m (Mead et al 1998;Lopez-Dekker and Frasier 2004). The exact number of elements is dependent upon the array configuration used.…”

“…As mentioned earlier, radar observations of the ABL are typically conducted using frequencies close to 1 GHz. With the goal of real-time mapping the three-dimensional turbulent field of the ABL, the turbulent eddy profiler (TEP) was developed by researchers at the University of Massachusetts (Mead et al 1998). This 915-MHz BLR has up to 64 independent receivers, allowing the use of sophisticated imaging algorithms with unprecedented flexibility.…”