Holographic transmission beam director

摘要

The present invention applies to the art of wind sensing using lidar, and in particular to the art of detecting the speed of objects such as air-borne particles and molecules in the atmosphere in order to determine the speed and direction of the wind which is carrying them. The present invention is a beam director for directing a beam transmitted from a lidar at objects to produce backscattered light and for directing the backscattered light into a lidar receiver. The preferred embodiment of the director comprises a rotatable holographic optical element for directing the transmitted beam in various directions, and then through the same rotatable holographic optical element direct backscattered light from various directions into a receiver. In one alternative embodiment of the director, a prism is disposed in the director for directing the transmitted beam. The lidar having the beam director is moved in a vehicle such as a satellite, so that wind characteristics such as wind speed and direction at a number of altitudes and over a large area can be measured.