Combining the Spatial and Frequency Domain Interferometry techniques, the three dimensional behavior of the E region Field Aligned Irregularity (FAI) patches are studied via Chung-Li VHF radar. The echo patches are found to be localized within the radar bearn. They are of pancake shape with dimensions in the plane containing the field line but transverse to the radar beam at least one order of magnitude greater than the dimension along the radar beam. A zonal westward drift velocity of the patches is found to be about 90 m/s at 107 km altitude in the night time. Mean Doppler (radial) velocity is about 50 m/s with a broad spectral width of 25 to 35 m/s.
