warning system
system of biological or technical nature deployed by an individual or group to inform of a future danger
fire alarm system
a system, that works using multiple devices to warn of an emergency.
panic button
electronic device designed to assist in alerting somebody
emergency call
way of contacting an emergency call center usually by a phone to an emergency telephone number
ground proximity warning system
aircraft system which detects when there is a danger of flying into terrain features and warns crew
missile approach warning system
aircraft equipment to detect an approaching anti-aircraft missile
Four-minute warning
1953–1992 British nuclear public alert system
acoustic mirror
technology for detecting incoming enemy aircraft, used before radar was developed
Mid-Canada Line
Canadian radar defence line
Deep-ocean Assessment and Reporting of Tsunamis
component of an enhanced tsunami warning system
early warning system
system providing early detection of problematic outcomes, typically using sensors, event detection and decision subsystems
Head on a spike
severed head on a pole
Short-term conflict alert
collision alert system for air traffic controllers
security alarm
system that detects unauthorised entry to a physical location
Sentry
JPL program to monitor the Minor Planet Center's catalog for potential Earth impacts
Broadmoor Sirens
warning siren system in England
Emergency Alert System
U.S. radio/TV system for public alerts of threats to public safety since 1997
AMBER Alert
child abduction alert system
Silver Alert
public notification about missing persons, especially those with Alzheimer's disease, dementia, or other mental disabilities
warrant canary
method of indirect notification of a subpoena, informing users that there has not been a secret subpoena as of a particular date; if the canary is not updated/removed, users are to assume that the host has been served with such a subpoena
Emergency Warning Functionality
digital radio feature
emergency population warning
warning issued by authorities to the public en masse
S!REN
Emergency warning system
collision avoidance system
vehicle safety system designed to avoid collisions or reduce the severity of a collision
NINA
mobile app
stick shaker
mechanical device to rapidly and noisily vibrate the control yoke of an aircraft to warn the pilot of an imminent stall.
National Severe Weather Warning Service
weather warning system in the United Kingdom
threat level
system to indicate likeliness of terrorist attack