Measuring distance & motion with Lidar & Sodar

摘要

Radar has been used for more than a century to detect moving or stationary objects at great distances. But sometimes you need to make precise measurements over much smaller distances - mapping a building or a crime scene, for example. Or you may want to measure wind or water currents. For these tasks, light and sound are more useful than radio waves. Hence, the invention of lidar and SODAR.