Open main menu
A HSS Engineering TWS 295 electronic sirens warning Civil Defense siren.
There are 8,200 alarm sirens for civil protection throughout Switzerland. They are tested once a year, on the first Wednesday in February.[1] About this soundSound sample 
Warning light indicating danger of laser exposure

Warning system is any system of biological or technical nature deployed by an individual or group to inform of a future danger. Its purpose is to enable the deployer of the warning system to prepare for the danger and act accordingly to mitigate or avoid it.

Warnings cannot be effective unless people react to them. People are more likely to ignore a system that regularly produces false warnings (the cry-wolf effect), but reducing the number of false warnings generally also increases the risk of not giving a warning when it is needed.[2] Some warnings are non-specific: for instance, the probability of an earthquake of a certain magnitude in a certain area over the next decade. Such warnings cannot be used to guide short-term precautions such as evacuation. Opportunities to take long-term precautions, such as better building codes and disaster preparedness, may be ignored.[3][better source needed]


Biological warning systemsEdit

Man-made warning systemsEdit

Civilian warning systemsEdit

A fire alarm that warns people if a building is on fire

Military warning systemsEdit

Historical beacon-based systems:

Space based missile early warning systems:

Airborne early warning systems:

Ground-based early warning radar systems:

Optical sensors:

Emergency broadcasting:

See alsoEdit

Notes and referencesEdit

  1. ^ Testing sirens, Swiss Federal Office for Civil Protection (page visited on 7 September 2013).
  2. ^ Sättele, Martina; Bründl, Michael; Straub, Daniel (October 2015). "Reliability and effectiveness of early warning systems for natural hazards: Concept and application to debris flow warning" (PDF). Reliability Engineering & System Safety. 142: 192–202. doi:10.1016/j.ress.2015.05.003. ISSN 0951-8320. Retrieved 2018-02-07.
  3. ^
  4. ^ [1] Archived December 12, 2006, at the Wayback Machine