Laser Doppler Velocimetry for Two-Dimensional Directional Discrimination by Monitoring Scattered Beams in Different Directions

2-D laser Doppler velocimetry without polarization discrimination, wavelength discrimination or frequency-shift discrimination is proposed. In the proposed velocimetry, scattered beams in different directions are monitored with two detection blocks in order to discriminate the direction of velocity. The principle of the proposed velocimetry is described and the discrimination of velocity direction is theoretically analyzed by simulation. The simulation result indicates that the direction of velocity can be discriminated by using the proposed velocimetry as well as the magnitude of velocity.