WordNet
n. an internationally recognized signal sent out by a ship or plane indicating that help is needed [syn: distress call]
Wikipedia
A distress signal or distress call is an internationally recognized means for obtaining help. Distress signals take the form of or are commonly made by using radio signals, displaying a visually detected item or illumination, or making an audible sound, from a distance.
A distress signal indicates that a person or group of people, ship, aircraft, or other vehicle is threatened by grave and imminent danger and requests immediate assistance. Use of distress signals in other circumstances may be against local or international law.
In order for distress signalling to be the most effective, two parameters must be communicated:
- Alert or notification of a distress in progress
- Position or location (or localization or pinpointing) of the party in distress.
For example, a single aerial flare alerts observers to the existence of a vessel in distress somewhere in the general direction of the flare sighting on the horizon but extinguishes within one minute or less. A hand-held flare burns for three minutes and can be used to localize or pinpoint more precisely the exact location or position of the party in trouble. An EPIRB both notifies or alerts authorities and at the same time provides position indication information.
Usage examples of "distress signal".
I bent right forward, as if that would help to bring me into closer contact with the distant sender, and sent out the distress signal again.
They also waited until they could be reasonably certain our distress signal was unheard and then too weak.
He hadn't switched off the comm and in the background he could hear the distress signal.
Kyp and the Dozen-and-Two pick up a distress signal from Danni's wrecked ship and divert to investigate.
We received a distress signal, we moved to assist, and now I’.
Mechanisms have also been devised by the hospital which distort the audible distress signal so that it becomes unrecognizable.