Although this invention may be used as an interface between numerous emergency first communication systems, a primary application of this invention is between the United States Government's National Weather Service's (NWS) National Oceanic and Atmospheric Administration's (NOAA) Weather Radio, as the first communication system, and numerous secondary communication systems, including, but not limited to, school, office building or hospital public address systems, public utility and public safety (such as fire and police) radio systems, commercial land mobile communication systems, commercial AM or FM broadcast radios, marine band radio communication systems, amateur radio communication systems or just about any other type of communication system.
NWS forecast offices around the United States continuously broadcast taped weather messages which are repeated every four to six minutes and are routinely revised every one to three hours, or more frequently if needed. Most of the stations operate twenty-four hours a day. Under a January 1975 White House policy statement, NOAA Weather Radio was designated as the sole government operated radio system to provide direct warnings into private homes for both natural disasters and nuclear attack. This capability is to supplement warnings by sirens and by commercial radio and television. Due to the expense, unreliability and ineffectiveness of warning sirens, many siren systems around the country have been deactivated.
The NWS operates about three hundred and eighty (380) NOAA weather radio stations. Approximately ninety (90%) percent of the nation's population is within listening range of NOAA Weather Radio broadcasts. A similar network of about fifteen stations using the same frequencies broadcast continuous weather information across much of southern Canada.
NOAA Weather Radio broadcasts are made on one of seven high band FM frequencies ranging from 162.400 to 162.55 megahertz (MHz). These frequencies are not found on the average home radio now in use. However, a number of radio manufacturers offer special weather radios to operate on these special frequencies, with or without the emergency warning alarm.
During severe weather, NWS forecasters can interrupt the routine weather broadcast and substitute special warning messages. The forecasters will transmit an alert tone of 1050 Hertz (Hz) to activate specially designed NOAA weather radio warning receivers tuned to special NOAA weather radio frequencies. A single alert tone is normally transmitted for up to thirteen (13) seconds for selected watches and warnings.
Special alert receivers, upon detecting the NWS single alert tone, are usually configured to activate an audible siren alarm in the radio and/or open the squelch of the radio to let the listener hear the alert message and/or flash a signaling light, usually a light emitting diode or LED, to alert the listener that an alert has been issued.
The radios can be set in a latching mode meaning that the siren or light will flash or sound continuously until manually reset, or be set in an automatic reset mode, which will reset shortly after the alert tone is detected. Each of these alert modes has disadvantages. If the radio latches in the siren mode, the siren will sound continuously until the radio is manually reset. If the owner of the radio is away, the siren will be sounding unnecessarily for hours or even days. The usefulness of the alert is usually for a short period of a few minutes for a tornado or thunderstorm, up to a few hours for a winter storm. Therefore, since the majority of important alerts are useful for only a short time frame, it is not useful having the alert sound continuously for many hours or days. The siren tends to aggravate pets. The latching light is not audibly aggravating, but since these radios have no time stamp, the listener will not know when the alert was issued, one minute or one day earlier. Finally, the NWS tests the system at least once per week. Therefore, a latching alert system would latch in the alert setting at least once a week until reset.
If the system is not set in a latching mode, the listener will most likely miss the alert if the listener is not near the radio at the time an alert or test signal is issued.
These operational problems tend to drastically decrease the effectiveness of the alerting system. These defects will tend to cause the listener to turn off or ignore a potentially lifesaving time critical warning, which in the case of a tornado may be less than five minutes.
NOAA Weather Radio broadcasts can usually be heard as far as forty miles from the NWS transmitter site. The effective range depends on many factors including the height of the broadcasting antennae, the average surrounding terrain, quality of the receiver and type of receiving antennae. As a general rule, listeners beyond the forty mile range need a good quality receiver system if they expect to get reliable reception. An outside antennae may be required in these fringe areas. To reliably receive NWS alerts, listeners more than 40 miles from the transmitting antenna often need to spend a significant amount of extra money and effort setting up an outside antenna. Many NOAA weather radio listeners do not have the time, patience, money and/or expertise to put up such an antenna and accordingly may miss the warning message. Many dwellings do not permit outside antennas.
Another problem is that the reliability of the radios available to the general public is at best moderate due to a number of economic and engineering factors. The weather radios are required to be moderately priced by the requirement that the price needs to be low enough so that people will consider buying a special radio. If the price were extremely high, fewer people would be able to afford this important communication warning system. Since the receivers are required to be moderately priced in an effort to encourage wide distribution thereof, the engineering sensitivity and selectivity tends to be similarly moderate.
The invention taught herein overcomes many of the above described radio reception problems by placing a weather radio receiver at a central location with good reception, for example at a transmitter site. These sites are usually in high locations such on top of large buildings or mountains. Since only one installation needs to be set up, it becomes cost effective to invest in a special directional or yagi antenna to increase reception, if needed. Additionally, where applicable law permits the retransmission of weather radio on other frequencies, the second communication system effectively acts as a repeater for the NWS weather radio thereby increasing the effective range and coverage of the NWS transmitter without further cost or equipment. Instead of being limited to approximately a forty mile radius coverage from the NWS transmit antenna, the new area of coverage becomes the second communication system's area of coverage!
From experience, it has been found that most people who purchase weather radios locate them in their home or in an unattended office where the listener may not find out about an alert for hours or days after the alert until that person returns to the radio. When the importance of the alert requires a response time often measured in minutes, the fact that the alert was issued an unknown time (possibly hours or days) before being discovered makes the warning close to meaningless.
The time when a weather alert becomes extremely urgent is when people are away from their usual shelters and are out in their cars, boats, airplanes or are simply outside. In these circumstances, a weather alert radio sitting at home or in the office is essentially worthless.
Even if the weather radio is in an attended office, such as the principal's office of a school, it still takes a knowledgeable person to understand the meaning of the weather alert alarm, to find out the details of the alarm and to issue the appropriate warning over the public address or other alerting system. Often the knowledgeable person, for example the principal or secretary, will be away from the radio or will be busy with other matters when the alarm sounds thereby creating a potentially critical delay in relaying the weather alert message to the relevant public.
The invention described herein overcomes the majority of the above described handicaps in the NOAA weather radio alert system in a simple, inexpensive, and reliable manner.
Previously disclosed alerting systems, such as those disclosed in U.S. Pat. No. 4,031,467, entitled Alerting Process and System of Apparatus Therefor, usually require the use of expensive and dedicated special radio receivers and additional trained personnel to activate the special alerting system. For the reasons set out above, these are the very defects in the current alerting system.
Some repeater controllers have the capability of being modified to provide a weather alert feature. The RC-85 Repeater Controller, manufactured by Advanced Computer Controls, Inc. of Santa Clara, Calif., Owner's Manual, page 8-4, describes, in general terms, a weather alert feature. While the described weather alert feature will transmit an alert on the second communication system in response to an NWS tone alert, this system suffers from many defects.
The RC-85 alert message is transmitted once every fifteen (15) seconds. This period is non adjustable. It was found in trials that this was too often and was extremely annoying to the listeners. The invention described herein permits the user to adjust alert message timing cycle. From experience this was found to be optimally approximately once per minute.
The audio mix level between the alert message audio level and the second communication system audio is not independently adjustable on the RC-85. In practice, the RC-85 alert message level effectively blocked communication on the second communication system during each alert message, which occurred each 15 (fifteen) seconds during the alert cycle. For the alert system to be accepted by the users of the second communication system, it must not interfere with potential emergency communication on the second communication system. The feature of setting the audio level of the alert message at a level to not interfere with ongoing communication is not disclosed in the controller manual. Additionally, the feature on the controller to be used for the weather alert is primarily for a latching repeater site alarm which is meant to be loud to catch listener's attention without respect to permitting ongoing communication.
The RC-85 alarm, once activated, can only be deactivated by the use of a usually secure code usually held only by control operators of system. In most cases, the control operators will not be available to reset the system in the event of a malfunction or a test of the system. The proposed invention permits the alert to be instantly reset through the push of a button which can be conveniently (physically or functionally) located near the users to permit the system to readily be reset as needed.
Although not disclosed in the description of the alarm function, it is possible to preset the duration of the site alarm as a controller function, but it is not possible to set the repetition cycle which is fixed at fifteen (15) seconds.
The RC-85 has a limited digital prerecorded vocabulary and does not have the ability to record special alert messages such as those containing subaudible signaling tones or discrete alert messages to alert management of the alert without causing undo concern to the listening public. In practice, these customizing features are extremely important to making the alert system acceptable to listeners by not causing harmful interference to ongoing communication on the second communication system when the alert sounds.
The alert feature on the RC-85 is one subfeature of a repeater controller which usually costs near one thousand dollars. It would not be realistic to purchase a repeater controller only to receive weather alerts. The proposed invention likely has a cost of a small percentage of the cost of a repeater controller thereby making the proposed invention more likely to be adopted and used by the public.
In view of the above disadvantages, the RC-85, and similar controllers are not an acceptable substitute for the proposed invention. The terse description in the controller's owner's manual does not suggest the important features of the instant invention which have been found in practice to be the features that make the invention useful and acceptable to the listening public.