| Ceilometer, device for measuring the height of cloud bases and overall cloud thickness. |
| The rotating-transmitter ceilometer has its separate receiver fixed to direct reflections only from directly overhead while the transmitter sweeps the sky. |
| The ceilometer uses a laser to measure the cloud base height. |
| One important use of the ceilometer is to determine cloud ceilings at airports. |
| The ceilometer is designed to produce accurate imagery in varied weather conditions including fog cover and torrential downpours. |
| Reflections of this light from the base of the clouds are detected by a photocell in the receiver of the ceilometer. |
