Correlation Analysis of Doppler Radar Data and Retrieval of the Horizontal Wind

Abstract

A technique for tracking patterns of radial velocity and reflectivity data obtained with a single-Doppler radar is described. Application of the technique to two different scans of the same spatial region may lead to the extraction of a field of ?wind? vectors with both radial and azimuthal components. This is accomplished by displacing, in range and azimuth, small volumes or ?boxes? of data from the earlier scan and then correlating them with boxes of equal dimensions from the later scan. The displacements at which correlation coefficients maximize are assumed to be due to the advection of patterns existing at scales up to the ?box? dimensions. Correlation coefficients of radial velocities are shown, for the clear air cases analyzed, to be higher than those of reflectivity [dB(Z)]. ?Winds? retrieved by correlating velocities and reflectivities independently are compared with each other and with winds synthesized from dual-Doppler radar data. Winds from radial velocity correlations agree better with the dual-Doppler winds than do winds from reflectivity correlations. Convective rolls spaced ?5 km apart are revealed in the planetary boundary layer.