Showing posts with label ADF HFCS. Show all posts
Showing posts with label ADF HFCS. Show all posts

Friday, February 08, 2008

US Coast Guard to Continue HF Weather Broadcasts

WASHINGTON - Last April the Coast Guard asked for public comment on the need to continue broadcasting high frequency (HF) high seas weather forecasts for single sideband voice, facsimile charts and text messages over radiotelex (e.g. HF NAVTEX). The Coast Guard required public comment because the infrastructure necessary to provide these services had exceeded its life expectancy and significant costs were involved to continue these services.

After reviewing and analyzing the substantial public response that overwhelmingly urged the continuation of these services, the Coast Guard's "business case study" concluded that it was necessary to continue HF weather broadcasts. The business case study, "An Impact Assessment of Discontinuing USCG High-Frequency Radio Broadcasts of NWS Marine Weather Forecasts" is posted at: http://www.navcen.uscg.gov/marcomms/high_frequency/HF-WX_notice.htm

The study concluded:

"The responding public collectively perceives that the USCG HF broadcasts are essential to their safety. There is no viable alternative to the USCG HF broadcasts because present alternatives are perceived by the public to be out of financial reach. Also, marine weather forecasts available through these alternative sources may not guarantee the same level of accuracy, timeliness, and/or sufficiency as provided by the USCG HF broadcasts."

While the Coast Guard does not have funds necessary to replace all of its HF transmitters, funds are available to replace the 20 transmitters used for
weather broadcasts.

The Coast Guard's HF infrastructure

The Coast Guard's HF infrastructure consisting of 123 10KW transmitters are no longer supportable. Repair parts are increasingly difficult to find, more expensive, and take can months to obtain. Funds should be available to replace many, but not all of these transmitters. Consequently all but the most essential HF services are or will be terminated. However, due to responsive received from the public and the conclusions of the business case report, the Coast Guard has decided to continue HF broadcasts of high seas weather forecasts and warnings without interruption. Transmitters used for this purpose will be included among those recapitalized.

The Coast Guard uses 20 high power transmitters to broadcast HF weather facsimile, voice and text (SITOR) high seas weather forecasts to mariners. Three additional Navy transmitters are used to broadcast weather information from Guam. The cost to replace one of these transmitters is ~$200K with installation ($4M total for those used for weather broadcasts).

Reliable, high power transmitters are needed to ensure mariners can reliably receive weather information anywhere within the National Weather Service’s area of responsibility.



Note: VHF (Channel 22A) broadcasts are not in any way affected by this notice, nor are Coast Guard voice broadcasts on 2670 kHz single sideband..

More information can be found on the USCG Marine Safety Information Broadcast page at http://www.navcen.uscg.gov/marcomms/gmdss/msi.htm

Blog Note: Heads up courtesy of Mark J. Cleary. Thanks Mark.

Sunday, August 26, 2007

Pacific Rim Air Force HF Frequency Update



New information has been uncovered on three of the Pacific rim air force HF communications systems. Additional frequencies are known to be associated with these networks and updates would be appreciated.

Australian Defense Force HF Communications System
The ADF HFCS radio network provides communication services for the operational control of ADF and RNZAF aircraft and HF equipped marine craft. The DCSA HFCS is controlled by Defence Communications Station Australia (DCSA) located in Canberra.
The DCSA HFCS consists of four Nodes located at Exmouth, WA; Darwin, NT; Townsville, QLD; and Riverina, NSW.

Voice Contact Nets (VCN) Operations are continuous on all frequencies and in the USB mode.

Callsign: Australia Control (DCSA)

5696.0 Military Distress (monitoring H24)
5878.0 VCN-2
9340.0 VCN-3
12172.0 VCN-5
15962.0 VCN-4
22868.0 VCN-1

Papua New Guinea Defense Force General Purpose Net

3175.0 LGF
5746.0 LGG
7496.0 LGH

Stations:
P2A2 Port Moresby
P2A3 Lae

RNZAF Air Operations Communications Centre Auckland (AOCCAK)
AOCCAK is a providing HF communications services to RNZAF, RAAF and other allied aircraft. AOCC Auckland is located at RNZAF Whenuapai, Auckland, New Zealand.

AOCCAK General Purpose Net (GPN) frequencies (USB):
3032.0 5687.0 8974.0 11235.0 13206.0

Callsign:
AOCCAK Air Force Auckland