THE VAP METHOD TO RETRIEVE THE WIND VECTOR FIELD BASED ON SINGLE-DOPPLER VELOCITY FIELD

Under the assumption that the wind vectors of two contiguous azimuth are same, the VAP (Velocity Azimuth Processing) method is proposed to retrieve the wind vector field from the distributions of Doppler velocity on the distance.circle. The information of sub-synoptic scale can be maintained in the retrieved wind field. The error analysis indicates that the error of retrieved wind direction is about 20 to 30 degree, and the scale of the wind speed error is 100 m/s (it could reach to 101 m/s in special situation).The pulsation in the original data of Doppler velocity has to be removed before the retrieval. It can be brought into being by one-demension linear smooth. The shear line and convergent line with sub-synoptic scale are revealed in a case of retrieved wind field and confirmed by the synoptic charts and the wind profile observed by UHF radar. The disposition of radar echo in the retrieved wind field suggests that the rainfall is associated with those mesoscale synoptic systems.