Automatic low power lidar and ceilometer

ALC IN CCRES

Automatic low-power lidars and ceilometers (ALC) are single-wavelength, low-power, automatic lidars typically operating at wavelengths ranging from 850 to 1064 nm. Ceilometers were originally designed to provide the cloud base altitude. Since clouds are very strong scatterers at near-infrared wavelengths, these systems do not require the high power and complexity expected for aerosol lidar systems. However, the sensitivity of current ALC is sufficient to detect aerosol layers and ice clouds.

In the CCRES retrieval system, ALC observations allow for the detection of liquid layers, including supercooled liquid layers. High-power aerosol lidar systems operating at UV and visible wavelengths can also be used for this purpose, as can long-range Doppler lidar.