Two-color two-spot laser velocimeter

The design of a two-color two-spot laser velocimeter based on an argon laser and using backscattered light is presented. The prism assembly used in splitting the laser's output beam into 514.5- and 488.0-nm beams, also allows for the rotation of the two spots about a common center, allowing two components of a flow to be measured. The system was tested at ranges of 50, 100, and 150 m, and the results of these tests are presented.