Abstract:  T he so -called generalized velocity track display ( GVTD) method was used to retrieve the primary circulation structure of typhoon inner core from single Doppler radar observations. However, this method can not
objectively resolve the mean wind, thus leading to bias in the estimation of the axisymmetric circulation. Although the hurricane volume velocity processing ( HVVP) technique can be used to estimate the mean wind of typhoon, it is
of limitations in the following two areas: 1) the inability due to objectively resolve the exponential decrease of the tangential wind speed with increasing the radius, and 2) the inability due to resolve the contribution to the radial
confluence from the downwind wind shear of the tangential wind. To accurately separate the mean wind and typhoonfrom single Doppler radar observations, this study develops a new method, i. e. , the extended -HVVP ( EHVVP)
method by the hybrid way to combining the advantages of GVT D and HVVP methods. The ideal experiments with the Rankine vortex plus the mean wind have been conducted to verify this method. The results show EHVVP
method can resolve the mean -wind accurately with the mean error less than 1 ms - 1 in wind speed and 6 - in the wind direction. The retrieval errors increase with the ratio of the radius of maximum tangential wind ( RMW) to the
distance from the radar to the vortex center, and the deviations of the typhoon center location. In addition, the retrieval errors vary with the phase angle of asymmetric peak wind component.