Cross correlations and cross spectra for spaced antenna wind profilers: 2. Algorithms to estimate wind and turbulence

Abstract

Abstract. In part 1 of this paper we developed analytic relationships linking the cross correlation and cross spectrum of the echoes from a spaced antenna system to the properties of a horizontally isotropic scattering medium (e.g., clear-air refractive index irregularities) and the background flow (e.g., laminar or isotropic turbulent flow). Using these analytic expressions, in the present paper, part 2, we construct algorithms (for both the time domain and frequency domain) for extracting unbiased wind and turbulence estimates. We derive a condition under which one can ignore turbulence when computing winds from the time delay to the peak of the cross-correlation functions. We show profiles of the horizontal wind and turbulence based on these algorithms using data from the unique 33-cm wavelength spaced antenna wind profiler developed by the National Center for Atmospheric Research.

MF and HF radar techniques for investigating the dynamics and structure of the 50 to 110 km height region: a review

“…This has some advantages, but the simple implementation of the technique at MF does not appear to be as robust as the FCA (Holdsworth and Reid 1997). Further development of the technique is described by Holloway et al (1997) and by Venkatesh and Frasier (2013).…”

“…Other analysis approaches to SA data are described by Lataitis et al (1995), Doviak et al (1996), and Holloway et al (1997). Lataitis et al (1995) showed that the slope of the cross-correlation amplitude at zero lag, normalized by the level of the cross-correlation amplitude at zero lag, is directly proportional to the component of the wind velocity along the antenna pair baseline.…”

“…This would correspond to wind profiling in the atmospheric boundary layer. Doviak et al (1996) and Holloway et al (1997) further considered the application of spaced antenna technique in situations of more isotropic turbulence, a condition more likely to hold only as generally true in the troposphere when using upper VHF, UHF, or higher frequencies. For example, in a typical study, Tsuda et al (1997) found significant aspect sensitivity at lower VHF in the troposphere and lower stratosphere when using the MU radar in Japan.…”

MU radar spaced antenna observations with varying apertures: Scatterer and antenna contributions to the ground diffraction pattern

“…The structure of the turbulent medium can therefore not be measured. A different development, such as that by Doviak et al [1996] and Holloway et al [1997aHolloway et al [ , 1997b, is based on a description of the physical process of scattering in the antenna beam volume Liu et al [1990], and relates the spatial spectrum of the scatterers to the cross-correlation of the diffraction pattern of the scattered field, and hence to the crosscorrelation of signals received at spaced antennas. An estimation method based on the latter enables measurement not only the horizontal wind field and the lateral diffraction pattern scales as seen at the receiver antennas, RADIO SCIENCE, VOL.…”

“…In this paper the FCA algorithm and method described by Holloway et al [1997aHolloway et al [ , 1997b are used with six differing spaced antenna configurations to determine the consistency of estimating horizontally anisotropic three-dimensional refractive index perturbation scales.…”