ceilometer

A ceilometer is a device that uses a laser or other light source to determine the height of a cloud base.

The man-portable version, brought in by combat weathermen, has an additional function, as remote miniature ceilometer.

A laser ceilometer consist of a vertically pointing laser and a receiver in the same location.

Automated airport weather stations use an upward-pointing laser beam ceilometer to detect the amount and height of clouds.

An optical drum ceilometer uses triangulation to determine the height of a spot of light projected onto the base of the cloud.

In 2003-2004, a laser ceilometer was installed at Chennai airport for reporting data on height of base of low cloud for aviation.

The ceilometer and visibility sensor do not always correctly interpret the falling diamond dust and report the visibility and ceiling as zero (overcast skies).

Furthermore, the rate at which diffusion happens can be noted by the diminishing part returned to the ceilometer in clear air, giving the coefficient of extinction of the light signal.

In the worst recorded ceilometer lightbeam kill-off during one night in 1954, approximately 50,000 birds from 53 different species died at the Warner Robins Air Force Base in the United States.

Most automated airport weather stations are connected to the commercial power grid due to the higher power needs of the ceilometer and present weather sensors, which are active sensors and emit energy directly into the environment.

The more challenging case involves sensors, primarily satellite-mounted, such as radiometers, optical sensors, radar, lidar and ceilometer as well as sodar since these cannot measure the quantity of interest, such as temperature, pressure, humidity etc., directly.