Title: ESTIMATION OF CIRCUMFERENTIAL VELOCITY FROM OBSERVED RADIAL VELOCITY---Velocity Image Velocimetry(VIV)---
Abstract: We propose a new measurement technique, Velocity Image Velocimetry (VIV), to obtain two-dimensional velocity fields in the atmosphere. Observational data was obtained by one Doppler lidar, and a pattern tracking method was applied to the radial velocity fields. The lidar observation was conducted at an urbanized area in Tokyo. We analysed three cases which have different mean wind speeds and flow structures. The non-dimensional radial velocity error is 20 to 40 percent. It is suggested that there are a proper time interval of the lidar scanning depending on the mean wind speed, and the interval should be constant. We also applied a simple velocity correction method using observed radial velocity, and compute two-dimensional divergence fields. By comparing with the distributions of radial divergence, analyzed 2D divergence fields reproduce more realistic values, indicating the validity of VIV.