ceilometer


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ceilometer

(sēlŏm`ĭtər), in aviation and meteorology, automatic instrument used to record ceiling, i.e., the altitude of the lowest cloud layer covering more than half of the sky. The ceilometer consists essentially of a projector, a detector, and a recorder. The projector emits an intense beam of light into the sky. The detector, located at a fixed distance from the projector, uses a photoelectric cell to detect the projected light when it is reflected from clouds. In the fixed-beam ceilometer, the light is beamed vertically into the sky by the projector and the detector is aligned at various angles to intercept the reflected light; in the rotating-beam ceilometer, the detector is positioned vertically and the light projected at various angles. In either case, trigonometry is used to determine the altitude of the clouds reflecting the light from a knowledge of the angle at which the light is detected and the distance between the projector and detector. The recorder is calibrated to indicate cloud height directly. False readings from extraneous light sources are reduced by modulating the projected light beam so that it can be recognized when it is reflected.

ceilometer

[sē′läm·əd·ər]
(engineering)
An automatic-recording cloud-height indicator.

ceilometer

ceilometer
Cloud ceilometer.
An instrument to measure the heights of clouds during the day. The ceilometer beams a light at the cloud base, which it detects by a photoelectric cell. A process of triangulation then determines the height of the cloud.
References in periodicals archive ?
This technology was replaced by the rotating beam M ceilometer, which in turn was phased out around 1990 and replaced with the laser beam ceilometer, which is widely used today.
It protects the ceilometer's inner life against even the harshest weather conditions.
The other ceilometer used is the Vaisala CL51, which uses a 910 [+ or -] 10 nm diode with a pulse frequency of 6.5 kHz as an optical source.
* The remote miniature weather station and companion laser ceilometer, a small, autonomous weather station capable of recording, storing, and reporting meteoric data for SOF aircrews.
The ceilometer is designed to produce accurate imagery in varied weather conditions including fog cover and torrential downpours.
The observational strategy relied on an intensive distributed network of 49 active meteorological towers (masts), 18 scanning and 8 profiling Udars, 1 water vapor differential absorption lidar (DIAL), 1 profiling radar, 1 profiling radar radio acoustic sounding system (RASS), 2 profiling sodar RASS, 2 radiosonde launch sites, 2 microwave radiometers (MWR), 2 tethered lifting systems (TLS), 1 scintillometer, 1 ceilometer, 9 acoustic sensors (microphones), 3 seismometers, 4 high-resolution microbarometers, and an aerosol particle-sizing instrument.
Pilot balloons were used by observers as far back as WWII, but the electronics revolution of the 1950s drove federal agencies to develop the rotating beam ceilometer (RBC).
Attributing to the application of sky imagers and ceilometer, automatic observation has been realized in cloud cover and cloud base height [6].
Fellbach, Germany, May 23, 2015 --(PR.com)-- Lufft left no stone unturned, to fulfill all requirements of the recent ceilometer tender of the Dutch royal weather service KNMI.
- OpenStack - enhancements include agent-free discovery and analysis of OpenStack Image Service (Glance) images; inventory and reporting for OpenStack Block Storage (Cinder) and OpenStack Object Store (Swift); integration with OpenStack Identity (Keystone) for service discovery and multi-tenancy; enhanced event and alert handling with RabbitMQ and QPID support; capture of additional performance metrics from OpenStack Telemetry (Ceilometer); configuration drift; tracking analysis; policy and governance.