Air Force High Frequency Regional Broadcasts

Air Force High Frequency Regional Broadcasts In the late 1980s, with the loss of the NWS meteorological alphanumeric and facsimile HF radio broadcasts, the Air Force initiated a High Frequency Regional Broadcast (HFRB) program to transmit alphanumeric information from the AWN and graphic products from AFWA on several regional broadcasts. These broadcasts are available and compatible with Navy shipboard receivers. Either alphanumeric or graphic data may be directed to the TESS or IMOSS systems. Alternatively, alphanumeric data may be directed through a converter to a shipboard teleprinter, and the graphic data directed to a facsimile recorder. These broadcasts carry AFWA regional graphic products on the upper sideband of the listed frequency and AFMEDS alphanumeric regional information on the lower sideband of the frequency. Broadcast frequencies and transmission times are available from the Worldwide Marine Radiofacsimile Broadcast Schedules published by the Department of Commerce/NOAA. This publication lists worldwide transmissions of meteorological and oceanographic products. Few observational data broadcasts are listed since these are not designed for use by the average mariner. Products are listed by the scheduled UTC transmission time of the product. HFRB sites broadcast only one frequency at any given time with routine frequency shifts at sunrise and sunset at the transmitter site. The broadcast is normally unencrypted, but may be encrypted for special Air Force support. When tuning a receiver to copy the sideband transmissions, you must tune your receiver 1.9 kHz higher than the listed frequency for an upper sideband (USB) signal and 1.9 kHz lower for a lower sideband (LSB) signal. There are three active HFRB broadcast sites currently operational: a United States HFRB site at Elkhorn, Nebraska; a European HFRB site at Croughton, England; and a Caribbean and Central American HFRB site at Roosevelt Roads, Puerto Rico. U.S. Navy Fleet Broadcasts NAVMETOC regional centers still have HF facsimile broadcast capability that may be used as a backup source for meteorological data aboard ship. Navy Mobile Environmental Teams and Marine Corps METMF van sites may copy HF broadcasts as their primary data source when routine fleet meteorological communications are not available. However, these HF broadcasts are activated on a contingency-on-request basis only. Special request for activation of a particular HF broadcast must be sent to the appropriate NAVMETOC regional center. The content of the HF broadcast is controlled by each NAVMETOCCOM regional center to provide support for U.S. Navy units operating within their AOR. Most products are computer-generated graphics of surface and upper-air analysis and forecast products. The data signals for the graphic products are sent from the regional centers to naval communications stations via landline. The communications station then transmits the signal on HF radio. Transmission frequencies and the broadcast time of each particular product are available by mail from each regional center, and are also included as part of the broadcast. U.S. Coast Guard Facsimile Broadcast The U.S. Coast Guard transmits a high-frequency facsimile broadcast of National Weather Service charts and satellite imagery. Broadcast stations include San Francisco, New Orleans, Boston, and Kodiak. Schedules and frequencies are available via the Internet. As with other HF meteorological transmissions, a listing of broadcast frequencies is available in the latest edition of Worldwide Marine Radiofacsimile Broadcast Schedules. Foreign HF Broadcasts Many meteorological and oceanographic data broadcasts containing either radio teletype or facsimile information are also available by copying HF radio transmissions from different countries of the world. U.S. Navy ships conducting an exercise or operation in a particular area may require more detailed meteorological information than is available on the Fleet Environmental Broadcast or regular military HF facsimile broadcasts. You may have to tune into a foreign HF radio meteorological broadcast and copy all of the information that country is willing to share with the rest of the world. Two publications are very useful in determining the frequency and content of the various indigenous broadcasts. We have already mentioned the Worldwide Marine Radiofacsimile Broadcast Schedules publication. Another useful publication for meteorological or oceanographic data collection is Air Force Manual 100-1, Global Weather Intercepts. A portion of this publication lists meteorological broadcast frequencies and transmission times grouped according to the type of broadcast-continuous wave (CW), RATT, or facsimile-region, country, and transmitter site. 1-35