WRSAME - Weather Radio Specific Area Message Encoder
By Skip Voros,
Executive Director; Milwaukee Area SKYWARN Association., Inc.
The Weather Radio "Specific Area Message Encoder" (WR-SAME), more currently called "SAME" is a digitally encoded signal transmitted by the local NOAA Weather Radio station's equipment. This digital code is transmitted just before and at the end of selected messages heard on the NOAA Weather Radio (NWR) station.
The SAME's most important application is to improve the timely and automatic dissemination of weather watches, warnings, severe weather updates, as well as local civil emergency messages through other communication channels; radio, TV, Cable, two-way, etc.
A companion decoder circuit now being incorporated in the newly marketed 'SAME' equipped weather radios can then be user programmed to activate (listen to the voice message/display or print the message/operate a warning device, etc.) when the users pre-programmed code matches the code sent out by the NWR station.
Programming is done by a keyboard on the weather radio, and entering the correct "FIPS" (Federal Information Processing System) code. The FIPS code is a five digit number representing your state and county and/or parish. The first two digits for states, the last three digits for county/parish. On units seeking a six digit code, typically a zero is then entered as the first digit. With the high end industrial units programming will respond to both a specific message and specific area, but most consumer grade units activate only by area (county/parish).
With a industrial receiver you could program your SAME weather radio to only activate when warnings are issued for your specific area (county). And only activate when a specific message is sent (I.E. thunderstorm warning). If you live near a lake and do not want to be awakened at 4AM with a special marine warning, program your SAME weather radio to ignore the marine warning, etc. In addition to hazardous weather related announcements, there are also numerous different events that the radio will respond to with local communities and emergency managers establishing other codes for their specific needs (hazardous chemical spill, school closing, shelter sites following a disaster etc).
Industrial receivers (SAME weather radio) vary in cost from about $595.00 to several thousand dollar and can be highly multi-functional, while consumer grade units (Radio Shack and others) with limited performance features are available for under $100.
The Specific Area Message Encoding (SAME) system is now used on most NOAA Weather Radio Stations and was planned to coincide with the federally mandated upgrade of the old Emergency Broadcast System to the new digital Emergency Alert System (EAS) which is now operational. (The new EAS signaling technologies are identical to the SAME system)
If the local NWS office in your area is sending WR-SAME data on its weather radio station, you will hear buzzes, chirps, & clicking sounds just before the warning tone is sent out and at the conclusion of the voice message.
The current nationwide minimum standard weather radio alerting system has two major weaknesses. First, the warning alarm tone used on all weather radio stations is a single 1050 Hertz tone transmitted for 10 seconds. A typical weather radio transmitter is designed to cover a circular area of approximately 40 miles radius from the transmitter. This is roughly an area of 5,000 square miles and usually covers 8 to 12 average sized counties. A majority of the serious weather events (tornadoes, flash floods, severe thunderstorms, etc.) occur or threaten the population of an area much smaller than the total coverage of the NWR station.
For example, when the NWS issues a tornado warning for a county on the extreme western edge of the coverage area, all radio receivers are activated, even those not threatened at this time. If a storm moves through the station's coverage area, the NWS will continue to issue new warnings and activate the alarm tone for each county the storm passes through. It is possible for many people to receive what might be considered as several "false alarms." The second problem with the present warning alarm system is the lack of a signal indicating to the user or a receiver that the broadcast of the initial watch or warning message is complete.
Without this feature, receivers utilized for automated second tier distribution remain active unless they are equipped with a timeout function. However a timeout function is normally impractical because of the varying length of each message. The current encoder system provides the NWS with the capability to transmit a code that can identify up to 80 separate weather related, civil emergency, test or administrative messages by specific event. It can indicate one or up to any combination of 31 counties or other defined geographical areas affected by the event or message. At the conclusion of the initial broadcast message, a End-of-Message (EOM) code is also transmitted.
The EOM code will then cause your SAME weather radio to de-activate and return user owned equipment to its normal mode of operation or perform some other task. (Typically the radio will again become silent, and any warning alarm device that was activated by the radio [option] will then be shut off.) Most industrial grade SAME radios have similar features that might include: high sensitivity &selectivity, 7 channel frequency agility, battery backup, self testing, flashing LED's for alarm activation, LCD display for viewing messages &signal strength, time stamp, built in speaker, remote alarm output for connecting external warning or alarm devices, program data retention for power failures, and a RS-232 output for connecting to a printer or computer, and a small scale processor to make for programming.
Some of the more useful tasks of the high end SAME radio may include: activating a cable-TV all-channel voice override for an event in the resident county and route the audio from the weather radio to all channels, but reject the task when the same event applies to another county (not served by the cable TV system). It could also switch from the program line of a radio or TV station's audio material directly to the SAME radio, and then with the EOM signal, automatically switch back to the normal sources of the stations' audio. The remote alarm output could be connected to a light for the hearing impaired, or connected to a small communities civil defense siren. Applications and potential of the WR-SAME system are only limited by your imagination.
The WR-SAME data format operates at 520 baud, a non-standard data rate, with a non-standard logic zero and one logic condition. The Baud rate was chosen as a optimum speed to pass data through multiple voice grade communications systems (telephone lines, radio, TV, two-way, etc.) and is not available on modems. Thus increasing security from hackers.
This author will have his SAME weather radio ready for the 1998 severe weather season........I live in Milwaukee, next to Lake Michigan, AND DO NOT want to hear any 4 AM special marine warnings, unless I have a SKYWARN net going!
(Editors note: INFORMATION ON NWR-SAME AND NWR SIGNAL COVERAGE AREAS IS NOW AVAILABLE ON THE WORLD WIDE WEB AT THE FOLLOWING URL: http://www.nws.noaa.gov/nwr/ )