Spectrum Widths from Echo Power Differences Reveal Meteorological Features

Abstract

A new Doppler spectrum width estimator using the absolute power differences (APDs) at lag one is presented, and its performance is evaluated using simulated signals as well as those recorded from the National Severe Storms Laboratory's Research and Development WSR-88D. The APD estimate bias, its standard error of estimation, and the frequency of complex widths are compared with that obtained with other single lag estimators [e.g., the pulse-pair logarithm (PPL) estimator]. For narrow spectra and signal-to-noise ratios more than 15 dB, the APD estimator has lower bias, lower standard deviation, and a lesser number of complex width estimates than the PPL estimator. Spectrum width fields, observed when this estimate technique is applied to the logarithms of echo power from an X-band radar, reveal meteorologically significant features that are not often seen in weather radar displays in regions of relatively small spectrum widths.