Lidar beam direction measurement by opto-electronic method - is by dividing quadrant detector difference voltages by summed voltages

摘要

An opto-electronic measurement arrangement for the direction of transmission of a laser detector of light scattering particles, or lidar enables unambiguous noise immune measurement of the direction to an accuracy better than 10-4 using direct electro-optical techniques. The scatter trace image of the laser source (10) transmitted beam in the earth's atmosphere is formed on a quadrant detector using a receiver telescope and associated optical system. The deviation of the beam from being parallel with the telescope optical axis is derived by dividing the difference voltages between individual quadrants by the sum of the individual quadrant voltages. The stopped collimated beam is split. One partial beam is fed to the receiver detector and the other via an interference filter and focussing lens to the quadrant detector.