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P. Srinivasulu, P. Yasodha, P. Kamaraj, T. N. Rao, A. Jayaraman, S. N. Reddy, and S. Satyanarayana

1. Introduction In recent years, radar wind profilers (RWPs) operating close to the 1-GHz band have been extensively used for atmospheric research and operational meteorology. It is also referred as the lower-atmospheric wind profiler (LAWP) because it is used to probe the lower part of the atmosphere (up to about 5 km). Many LAWPs have been developed in the recent past by research and commercial groups for meteorological applications, in particular to understand the dynamics of the atmospheric

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Robert Schafer, Susan K. Avery, Kenneth S. Gage, and George N. Kiladis

1. Introduction The sparseness of in situ wind observations over the tropical oceans makes wind profiler observations crucial for understanding weather and climatological processes as well as for validating forecast/analysis/assimilation models. The potential value of profiler data in improving reanalysis products over the central equatorial Pacific was demonstrated by Gage et al. (1988) who showed that the bias between operational analysis and profiler observations was reduced from 1–3 to 0

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Hua Wang, Shipeng Su, Haichuan Tang, Lin Jiao, and Yunbo Li

observed continuously; 2) the equipment is complicated to use and inconvenient; 3) some measurement methods are lossy or less economical, such as the use of radiosondes and sounding rockets. Therefore, it is desirable to find a new remote sensing method to monitor atmospheric ducts, which can continuously observe atmospheric ducts without using sounding equipment. Wind profiler radar (WPR) can measure the wind field, spectral width and volume refractivity ( Tatarski 1961 ), atmospheric refractive index

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Elías Lau, Scott McLaughlin, Frank Pratte, Bob Weber, David Merritt, Maikel Wise, Gary Zimmerman, Matthew James, and Megan Sloan

1. Introduction Radar wind profilers (RWPs) with an operating frequency around 1 GHz are widely used to probe the boundary layer (BL). Although they do not offer the height coverage of radars that operate at very high frequency (VHF) and at the lower UHF range, their antennas are relatively smaller and can effectively measure winds in the BL. BL RWPs are routinely used in atmospheric research and operational applications. Examples of atmospheric research include determination of boundary layer

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P. Srinivasulu, P. Yasodha, A. Jayaraman, S. N. Reddy, and S. Satyanarayana

1. Introduction UHF wind profiling radar (WPR) is a potential tool for atmospheric research and operational meteorology. Two classes of radars, operating at 1 GHz and 400 MHz measuring winds in the lower-troposphere and troposphere regions, respectively, have evolved in the last 30 yr and have been deployed around the world extensively. Many UHF wind profilers have been developed in the recent past by research and commercial groups for applications ranging from air quality studies to climate

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I. Srinivasa Rao, V. K. Anandan, and P. Narasimha Reddy

1. Introduction Over the past three decades wind profiling radars have proven to be a powerful tool for atmospheric research. Remote sensing of winds and the turbulence in the middle atmosphere (over a height range of 3–100 km) by the Doppler beam swinging (DBS) technique is widely incorporated by wind profilers ( Balsley and Gage 1980 ; Gage and Balsley 1984 ; Rottger 1984 ). By performing different experiments at different locations with different operating frequencies of radar, it has been

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Laura Bianco, Daniel Gottas, and James M. Wilczak

1. Introduction The implementation of real-time data quality control is of fundamental importance for observations that are assimilated into operational numerical weather prediction models. One of the most vexing quality-control problems affecting radar wind profilers has been signal contamination from nocturnally migrating birds ( Wilczak et al. 1995 ). Although techniques have been developed that helped reduce the level of contamination ( Wilczak et al. 1995 ; Merritt 1995 ), these were

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Stuart Bradley, Sabine von Hünerbein, and Torben Mikkelsen

1. Introduction In the last few years the use of surface-based remote sensing for wind energy has come to be the preferred method of obtaining wind profiles in the vicinity of large turbines. The useful instruments comprise two types: lidars, which use laser light scattered from naturally occurring atmospheric particulates, and sodars, which use audible sound scattered from atmospheric turbulence ( Emeis 2010 ). Wind components are sensed through the Doppler frequency shift of the light or

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Matthew L. Aitken, Michael E. Rhodes, and Julie K. Lundquist

1. Introduction The importance of reliable vertical wind profiles for both resource assessment and evaluation of turbine performance continues to rise with the rapidly escalating use of wind power in both domestic and worldwide energy production. Meteorological towers used to collect wind data, however, are usually constructed no higher than 60 m in the United States for reasons concerning structural stability, cost, and zoning regulations. With hub heights of 80–100 m and rotor diameters of 80

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Frédéric Tridon, Alessandro Battaglia, Pavlos Kollias, Edward Luke, and Christopher R. Williams

profiles are rather constant below the melting layer. However, in the case of vertical variability of hydrometeor profiles and/or of wind-shear-tilting vertical cores of precipitation, the former assumption does not hold, and this represents the most limiting factor of the accuracy of the retrievals. To improve the accuracy of this methodology and to extend its application to most rain cases, the cloud radar reflectivity should be compared with collocated nonattenuated Rayleigh reflectivity measured by

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