Lidar (LIght Detection And Ranging), is often refered to as laser radar. Light transmitted by a laser is scattered by atmospheric consituents and detected by an optical telescope. The properties of the incoming light enable certain properties of the targets to be determined, and timing of the measurement determines the altitude of the targets.
At Mauna Loa, Boulder, and Samoa, the Lidars are part of the Network for the Detection of Atmospheric Composition Change (NDACC). At Trinidad Head the Lidar is part of the NASA Micro-pulse lidar network (MPLNET).
CLidar (Camera Lidar), is an innovative on the standard lidar developed at the ESRL Mauna Loa Observatory to measure boundary layer aerosols. Clidar uses a charge-coupled device (CCD) camera to image the entire laser beam from a few hundered meters away.