Improvements to spectrum width measurements

Spectrum width is one of base data products of a Doppler weather radar. The spectrum width (SW) field is the least used of the spectral moment fields, even though there is significant meteorological information contained in its field. Usually the SW is calculated via the pulse pair processing (PPP) which is based on computations of the correlation function of weather signal. A new method of estimating SW is proposed. The method utilizes the one-lag estimation of a type of structure function of the weather signal power. The new method outperforms the PPP for SW < 3 m/s; the estimates have smaller biases and standard deviations. The problem of ‘imaginary spectrum width’ anomalies associated with the PPP estimates is discussed. It is shown that the proposed method has no such anomalies. Radar measurements confirm the theoretical conclusions.