Performance Specification for Public Alert Receivers (ANSI/CTA-2009-B)
The National Weather Service operates a network of radio transmitters throughout the United States that broadcasts local weather information. Meteorological Services of Canada operates a similar network in Canada. When important events (thunderstorm warnings, tornado watches, etc.) happen these networks transmit digital codes that can cause radios equipped to receive them to turn on. To the user, these radios work essentially like alarm clocks – except that instead of turning on at specific user-programmed times, they turn on for specific user-programmed events. ANSI/CTA-2009-B describes the events these radios should recognize, how users should be able to program them, what sort of indications the radios should give when an alert is received, the quality of the audio they should produce, and other things.