Proceedings with Extended Abstracts (single PDF file) - Radio ...

THE STRUCTURE FUNCTION-BASED APPROACHTO DATA ANALYSIS FOR SPACED ANTENNA RADARS:A COMPARISON WITH TRADITIONAL TECHNIQUESAlexander Praskovsky 1 and Eleanor Praskovskaya 21 National Center for Atmospheric Research, 3450 Mitchell Lane, Boulder, CO 80501, USA2 Colorado Research Associates, 3380 Mitchell Lane, Boulder, CO 80501, USAINTRODUCTIONDuring the last four decades, spaced antenna (SA) methods for measuring characteristicsof a scattering medium at altitudes from the low troposphere to the high mesosphere andionosphere have become widely used, and a diversity of the methods has been developed; forreviews see, e.g., Hocking et al. (1989), Fukao and Palmer (1991), Palmer (1994), andDoviak et al. (1996). The methods are based on the analysis of cross and auto correlationfunctions (CF) of signals from multiple receiving antennas, and each CF-based method hasits spectral counterpart. For example, Full Spectral Analysis in the frequency domaincorresponds to Full Correlation Analysis (FCA) in the time domain; Briggs and Vincent(1992), and Briggs (1984), respectively. The most advanced CF-based SA techniques wereoriginated by Liu et al. (1990); the Liu et al. theory was generalized and further expanded byDoviak et al. (1996), below referred to as DLH. The technique based on the Doviak et al.theory is referred to below as the Holloway and Doviak (HAD) method; see Holloway et al.(1997b), below referred to as HDC.As emphasized by many authors, e.g., Briggs and Vincent (1992), Sheppard et al. (1993),Hocking et al. (1989), all SA methods are basically similar in that they utilize the same initialinformation: time series of amplitude and phase of signals from several receivers. Themethods differ by: (1) mathematical functions for analyzing multiple signals; (2) parametersof these functions to be estimated; (3) equations for relating these parameters tocharacteristics of the scattering medium; and (4) assumptions which are adopted for derivingthe operational equations. Although basically similar, all methods produce importantinformation about a scattering medium. Multiple signals from several receivers provide anenormous amount of raw information. Each mathematical function (spectrum, CF, wavelet,etc.) extracts only a small part of useful information from multiple random signals; therefore,different techniques do not compete but rather complement each other.A structure function (SF)-based SA method UCAR-STARS (University Corporation forAtmospheric Research -- STructure function Analysis of Received Signals) has beendeveloped recently by Praskovsky and Praskovskaya (2003a, b), below referred to as PPa andPPb. The goal of this paper is to compare STARS to the HAD method. The latter is basicallysimilar to FCA (Holloway et al., 1997a); therefore, the results of a comparison can be appliedto any CF-based SA technique. As shown in PPa, equations for SF of any order p ≥ 2 can bederived and applied to practical measurements. On the contrary, only the second order CFhave been used in SA methods, and spectra are second-order functions as well. To compareSTARS and HAD techniques, cross and auto SF at only p = 2 are considered in this paper.ESTIMATING WIND AND TURBULENCEIn this section we summarize the basic equations for estimating the mean horizontal windsand turbulence characteristics with STARS and HAD techniques as well as the assumptions461