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  • 16th International Symposium for the Advancement of Boundary-Layer Remote Sensing (ISARS 2012) x
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Laura Bianco, Daniel Gottas, and James M. Wilczak

have characteristics of bird contamination, but it can at times mistakenly flag and eliminate real atmospheric signal. In addition, although the intermittent clutter rejection algorithm (ICRA) technique developed by Merritt (1995) effectively removes interference during periods of light bird contamination, for moderate bird densities it often reduces the magnitude of the SNR and spectral width signal to levels below those associated with birds, but it does not entirely eliminate the velocity

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

coherent and incoherent number of averages for the radar mode. Additionally, BIRCH can enable several algorithms while calculating the spectra: clutter suppression [direct current (dc) bias removal and interpolation across dc spectral value], several window functions (e.g., Hanning, Hamming, Blackman, etc.), removal of RFI from the time series based on signal statistics, and Gabor filtering (Gabor frame decomposition of the data and filtering of signals with intermittent clutter signatures; a detailed

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A. B. White, M. L. Anderson, M. D. Dettinger, F. M. Ralph, A. Hinojosa, D. R. Cayan, R. K. Hartman, D. W. Reynolds, L. E. Johnson, T. L. Schneider, R. Cifelli, Z. Toth, S. I. Gutman, C. W. King, F. Gehrke, P. E. Johnston, C. Walls, D. Mann, D. J. Gottas, and T. Coleman

inside the environmentally controlled cabinet placed between the two antenna enclosures. Table 5. Characteristics of the newly developed snow-level radar for the HMT-Legacy project. Table 6. Locations of the snow-level radars being installed for the HMT-Legacy project. All are installed by ESRL. During precipitation, an automated algorithm based on White et al. (2002) analyzes profiles of radar reflectivity and Doppler vertical velocity measured by the snow-level radar to determine if a radar

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S.-E. Gryning, E. Batchvarova, and R. Floors

Bhattacharya , P. , and R. Bhattacharjee , 2010 : A study on Weibull distribution for estimating the parameters . J. Appl. Quant. Methods , 4 , 234 – 241 . Boilley , A. , and J.-F. Mahfouf , 2012 : Assimilation of low-level wind in a high-resolution mesoscale model using the back and forth nudging algorithm . Tellus , 64A , 18697 , doi:10.3402/tellusa.v64i0.18697 . Chen , F. , and J. Dudhia , 2001 : Coupling an advanced land surface–hydrology model with the Penn State–NCAR MM5

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Mikael Sjöholm, Nikolas Angelou, Per Hansen, Kasper Hjorth Hansen, Torben Mikkelsen, Steinar Haga, Jon Arne Silgjerd, and Neil Starsmore

procedure based on a Gaussian-fit algorithm is used in this study as illustrated in Fig. 2 , where also the influence of the varying sampling volume can be seen. The left spectrum in Fig. 2 is sampled at a line-of-sight distance of 23.4 m with a sampling volume of 0.7 m, whereas the right spectrum is sampled at a distance of 55.4 m with a sampling volume of 3.9 m, which results in a broader spectral distribution due to the rapid spatial variability of the downwash flow. Fig . 2. The spectra from the

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Vasily Lyulyukin, Rostislav Kouznetsov, and Margarita Kallistratova

average space–time distribution of radial velocities, echo signal intensities, and noises for three antennas within a composite billow. The process of constructing a composite shape of the braid pattern is presented in Fig. 2 . Fig . 2. Algorithm of averaging over specific periods of KHB. (a) Echogram from the vertical antenna. The vertical lines show position and amplitude of the billows. (b) Scaled selection of the echogram. (c) Composite shape of selected braids. b. Correlation analysis Composite

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Leslie M. Hartten and Paul E. Johnston

at about 4.5 km during the 0500–1000 UTC rain, which rules out warm-rain processes during that time. Reflectivities above the bright band were too weak for convective precipitation: hence, the choice of the stratiform algorithm. The short-lived rain events between 0000 and 0230 UTC were shallow (below 4.4 km) and produced no bright band, and therefore they might have been warm rain. They made only a small contribution to the accumulated rain during the calibrating period, however. 4 Although it

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Margarita A. Kallistratova, Rostislav D. Kouznetsov, Valerii F. Kramar, and Dmitrii D. Kuznetsov

a tilted beam do not differ much from those measured by the vertical beam. In cases when the corresponding horizontal fluctuations significantly exceed vertical ones, σ x can be used as a proxy of the standard deviation of the corresponding horizontal component. The profile of standard deviation of the radial velocity σ 1 in Fig. 4 practically coincides with the profile of σ w , except for a local peak at 300 m. The peak is an artifact caused by the fixed-echo suppression algorithm that

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C. R. Wood, R. D. Kouznetsov, R. Gierens, A. Nordbo, L. Järvi, M. A. Kallistratova, and J. Kukkonen

for some area around the measurements. Thus, the research question is, “How reproducible is at various scales in the urban environment?” In this paper, we report (i) the first results from many months' data from two scintillometers and compare them with data from two sonic anemometers over Helsinki, Finland, and (ii) the evaluation of an algorithm for obtaining from sonic anemometers. 2. Materials and methods a. Instrumentation and site description Two large-aperture scintillometers (BLS900

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