A Method to Suppress the Precipitation Interference on Horizontal Wind of Wind Profile Radar

Wind profile radar (WPR) is a kind of clear air radar, which takes atmospheric turbulence as the main detecting object. In the past few decades, WPR spectral data processing mainly focus on the wind spectrum estimation. In recent years, with the use of WPR data expansion, there are increasingly high demands for WPR data accuracy. However, ground clutter, external noise, flying objects, presence of disturbances such as precipitation and limitations of Fourier Transform often lead multiple peaks overlapping phenomenon, which makes it difficult to judge spectral moments, resulting in large error detection products. Especially in the case of precipitation, wind speed measurement may be even completely wrong. Therefore, the radar power spectrum data need further processing under different weather conditions especially for turbulence and precipitation to establish an effective spectral extraction programs and enhance the wind profile accuracy of radar detection.WPR has a large dynamic reception range, so it can receive the echo of scattering of atmosphere turbulence and scattering of precipitation particles simultaneously during precipitation. In this case, spectrum of atmosphere turbulence and spectrum of precipitation are superimposed. It requires uniform wind-field on horizon when calculating the horizontal wind, but the spatial variability of precipitation will bring distorted horizontal wind-field if the superimposed spectrum data. To avoid this problem, the radar power spectrum data are processed with three steps. First, the original radar power spectrum is processed by interpolation and moving average, judging whether it is affected by precipitation according to the number of maximum points. Second, in the case that the radar power spectrum is affected by precipitation, spectrums of atmosphere turbulence and precipitation are separated by two methods in accordance with spectrum of atmosphere turbulence and spectrum of precipitation's tending to symmetry. And then the horizontal wind-field is derived utilizing the separated spectrum of atmosphere turbulence. Case analysis shows that the consistency of derived wind-field has significant improvement using the spectrum of atmosphere turbulence instead of the original spectrum.