"WISSDOM uses radial winds observed by multiple Doppler weather radars to synthesize the 3D wind fields in the atmosphere. Using variational approach to make the retrieved winds satisfy the following mathematicalphysical laws : (1)The geometric relationship between the retrieved windsthe radial winds observed by each individual radar (2)anelastic continuity equation (3)vertical vorticity equation (4) background wind field (5) Laplacian smoothing term. Special treatment is made allowing direct wind retrieval over complex terrain, which is necessary for weather analysis in Taiwan."