ABSTRACT
To achieve high performance with spatial-filtering velocimetry, a narrow band-pass characteristic of the spatial filter and an accurate estimation of the central frequency of the output signal are required. This entry describes the principle and the applications of spatial-filtering velocimetry. A narrow band-pass characteristic of the tripolar parallel-slit reticle, an effective estimation of the output signal's central frequency by maximum entropy method analysis, a utilization of computer-based spatial-filtering method, and a possibility of velocity vector measurement are demonstrated.
