One important use of the ceilometer is to determine cloud ceilings at airports. ... The device works day or night by shining an intense beam of light (often produced by an infrared or ultraviolet transmitter or a laser), modulated at an audio frequency, at overhead clouds.

What is a ceilometer used to measure?

The Vaisala Laser Ceilometer (CEIL) is a self-contained, ground-based, active, remote-sensing device designed to measure cloud-base height, vertical visibility, and potential backscatter signals by aerosols. It detects up to three cloud layers simultaneously.

What does a laser Ceilometer measure?

A ceilometer is a device that uses a laser or other light source to determine the height of a cloud ceiling or cloud base. Ceilometers can also be used to measure the aerosol concentration within the atmosphere. When based on laser, it is a type of atmospheric lidar.