Bangkok Weather Fax Is Not Dead

This grungy chart was copied on 7396.9 kHz (tune 7395.0), around 1730 UTC on December 1. It's from HSW, Bangkok, Thailand, and should put to rest the claims that this station has left the air. It remains quite active on this single frequency.

The DX-Tuner in Hong Kong was used. Signal was good at start, but dropped off into the crud.

Digital Mode Programs That Work #3: SeaTTY

Recently, I read a rather impromptu test done by WZ7I. It seemed to indicate that a popular ham program called TrueTTY actually had better "sensitivity" than a tweaked version of the older MMTTY, which I'd always figured was the hot setup.

This got me interested, since I'd used TrueTTY in the past, and liked it. So I went to the DXSoft site where the clever Russian programmer Sergei Podstrigailo, UA9OSV, has his latest stuff.

What I noticed, though, is that his other NBDP program, called SeaTTY, was starting to look like a better deal for users who wanted to concentrate on receiving, especially in the maritime bands. Needless to say, I grabbed it, in version 2.30.

SeaTTY looks like TrueTTY, with the same sleek user interface showing the FFT amplitude plot at the top and the bit scope at the bottom. Its purpose, though, is not making ham QSOs. It's listed as a "weather messages decoder," and indeed it's set up to facilitate the unattended grabbing and filing of same.

Modes decoded are RTTY, Navtex/ Sitor-B, DSC (HF/VHF), HF FAX, and NWR-SAME. The latter is a VHF signaling mode used by weather broadcasts to target specific areas.

I put SeaTTY to work on the longwave RTTY weather broadcast from Hamburg/Pinneberg Meteo in Germany, as received by the WebSDR in the Netherlands. It started up, spat out a few garbage characters, then happily produced a steady 100% decode. I ran MMTTY and SkySweeper alongside, and MMTTY was also 100%. SkySweeper was good, but produced the inexplicable character errors I've come to expect from its RTTY mode.

This was too easy. I waited for propagation, and gave it the RTTY weather from CFH in Halifax, NS. This is never a good path to SoCal, and the geomagnetic storm had left some extra fading. Interestingly, SeaTTY and MMTTY produced about the same percentage of characters decoded, but messed up in different places. While the decode rate was about the same, SeaTTY actually produced somewhat more readable copy.

SeaTTY was about as good as DSCDecoder on Navtex and HF Sitor-B weather. It files successful Navtex decodes in a slick directory tree structure, with the copy showing in a window alongside. The save is automatic, as long as the Telex start code (ZCZC) and end code (NNNN) are detected.

DSC decode shows as a numeric dump of the raw symbols, but clicking the time stamp produces the message. The only missing feature compared to DSCDecoder is the instant lookup of MMSI numbers in the ITU database.

Where I really had fun, though, was the FAX. It's a very well thought out interface for this mode. Finally, there's a FAX decoder as intuitive and generally slick as the old JVComm, but which doesn't print "Demo" all over your faxes until you pony up. (SeaTTY, like DSCDecoder, waits a set number of days, then sulks until you pay. It's $35 and easy to register.)

I'd long since learned how to play SkySweeper's fax interface like a musical instrument, and turn out awesome copy, but right now I think I'll switch to SeaTTY. Once I get used to it, I suspect it'll be just as good, and with less general fuss to get working. Faxes, like Navtex messages, get time stamped and autosaved, accessible from the directory tree. Good stuff.

To sum up, SeaTTY is a keeper. I gladly paid up. Now I go forth into the Ether with some good tools.

1800 UTC Fishery Fax Confirmed JFX

Every day at 1800 UTC, a fax is sent over the Japanese Fishery frequency of 8658.0 kHz.

Others have been able to identify this transmission as JFX, Kagoshima Prefectural Fishery Radio, in the southern part of Japan. For the first time ever, the morning of February 10 (local time, 2/11 in Japan) had good enough conditions for readable text here.

Luckily, that day's fax was self-identified with the heading JFX-NOAA. NOAA is the US National Atmospheric and Oceanic Administration, umbrella agency for the National Weather Service and several oceanic prediction centers.

Indeed, the content seemed to be columns of figures showing forecast weather conditions for three days. Well, we know that JFW, Fukushima, sends NOAA weather. Obviously Kagoshima does too.

We now have a pretty good handle on the Japanese fishery faxes. What was once known in utility books as "Chuo Gyogyo" (Central Fishery) turns out to be at least three stations at the prefectural level. These are JFC (Misaki), JFW, and JFX. All of these use common fishery frequencies of 6414.5, 8658.0, 16907.5, and 22559.0 kHz.

In addition JSC, also at Kagoshima, still blisters the US West Coast on 16971.0 kHz with a very strong relay of the Kyodo News oceanic edition. This is at 2300 UTC daily. Other transmissions occur throughout the day.

Fax is tuned 1.9 kHz below these assigned frequencies.

JFX Kagoshima QSL'd in SoCal

Martin Foltz has received an e-QSL from JFX, Kagashima Fishing Radio Station, for a fax fishery chart received at 1500 UTC. This transmission has also been received here, though usually too weak to make much out.

This brings the number of confirmed Japanese fishery radio fax stations received on the US Pacific Coast to four:

JFC Misaki, Kanagawa Prefecture
JFW Fukushima Prefecture
JFX Kagoshima Prefecture
JSC Kagoshima Prefecture (Kyodo News).

JSC uses the old JJC Kyodo frequency of 16971 kHz USB. The others use the common Japanese Fishery Radio frequencies of 6414.5, 8658.0, 16907.5, and 22559.6 kHz USB. As always, FAX dial frequencies are around 1.9 kHz lower than these assigned channel centers.

So Who Is GM-11F?

"GM-11F" is the identification on mysterious radiofaxes apparently coming from the Ukraine, perhaps the Russian Navy in Sevastopol, on 5103 and 7090 kHz USB. These have been seen in Germany for at least a year. Content is the usual marine weather information. One transmission occurs daily at 1430 UTC.

7090 kHz is in the 40 meter amateur band, but other Russian military stations also operate there. This includes one of those single-letter beacon clusters (ENIGMA designator MX). "D" (Sevastopol, 7038.7) and "C" (Moscow, 7039.0) are especially loud pretty much 24/7 in central Europe.

"JFC-FAX" Copied in California

This grungy picture faded up and down at just the right time. It doesn't look like much, but it's enough to identify yet another Japanese fishery station transmitting radio faxes on HF. This was on 16907.5 kHz USB at 0030 UTC on December 9:



Thankfully, fax is a "fuzzy" mode, and people can make decisions computers can't. I knew all but the first two letters of the station callsign. Now I know them too.

JFC is a radio station at the Kanagawa Prefectural Fisheries Technology Center, Misaki, Japan. It has been reported before on Japanese fishery frequencies. Back when there were such things as sunspots, the "JFC-FAX" transmission was seen in Australia on 22559.0 kHz, alternating with other prefectural fisheries.

This brings the number of prefectural fishery fax stations identified in the US up to three. The others are JSC, Kagoshima, and JFW, Fukushima. Primary frequencies for all the fishery fax transmissions are 6414.5, 8658.0, 16907.5, 22559.6 kHz USB. Normal dial offset for fax is around 1.9 kHz lower.

The fishery radio has many other frequencies and modes, often encrypted. What's for sure is that whoever is using some of this stuff does not want the public knowing it.

JMH Wave Chart Received 1 December 09

This chart was received from JMH, Tokyo Meteo (via Kagoshima) on December 1:



As many may know, JMH ("Tokyo Meteo") and the Tokyo VOLMET both changed their transmitter locations on March 4, 2009. They moved from the old Nazaki transmitting site (36.10N by 139.51E) to Kagoshima Fishery Radio (31.19N 130.31E). Kagoshima Prefecture is in the extreme south of Japan, well situated to cover the Pacific Ocean.

Alaskan DXer Attu Bosch has made an interesting point on the SWL Nomad blog, that the "fishery radio" might not always be what it seems.

Here's what I know, and it's not much:

These stations receive funding from various government and private sources;

They broadcast a vast amount of sometimes rather secretive information all over HF in all modes, not just radiofax;

Their coverage is much larger than the area of primary interest to the Japanese fishery (though this might just be the nature of HF propagation, or be designed to include fleets working closer to the US west coast);

And some of it is scrambled, or encrypted.

What I don't know is whether this less public content is commercial data meant only for subscribers, communication by and for specific companies or fleets, or something else. As always in utility, the people who know aren't telling.

Stormy West Pacific November28

This interesting surface chart was sent by KVM 70, Hawaii, this morning on 16135.0 kHz USB (dial frequency 16133.1), at 1815 UTC:



Note the path of Super Typhoon Nida, which has taken the predicted curve to the northeast away from Japan. Everything's going up and around those two huge highs to the east.

UPDATE 29 NOV: Nida has stalled out, now moving very slowly northwestward, expected to curve westward and dissipate.

HLL Korean Typhoon Warning Chart

This fuzzy chart was received late last night in SoCal, around 0800 UTC, on 9165 kHz USB (assigned channel center). It shows the plotted and forecast path of Super Typhoon Nida, a monster with a well-developed stadium-effect eye and 145 kt sustained winds around it.



Fortunately, longer term forecasts show Nida curving eastward and missing Japan, while losing strength out at sea.

Happy Thanksgiving, all!

Japanese FAX Warning Map

Part of a Kyodo News transmission received here in SoCal at 0430 UTC on 25 November 09. Frequency was the usual 16971.0 kHz USB (dial reading 1.9 kHz lower).



I suspect from the mention of JAXA (Japan Aerospace Exploration Agency), that these are warning areas for some type of rocket or missile activity.

WGS-84 refers to the datum for the map coordinates (World Geodetic System 1984), and IGS is the International GNSS Service. Yes, a nested acronym. GNSS is for Global Navigational Satellite Systems, referring to the US GPS and the Russian GLONASS.

GPS is, of course, yet another acronym, for Global Positioning System. GLONASS is a translation of the Russian acronym for ГЛОбальная НАвигационная Спутниковая Система. It translates as GLObal NAvigation Satellite System.

Chilean Navy Forecast Chart, Nov. 17

Chart received here in 120/576 FAX from Playa Ancha (Valparaiso) Radio, Chile. Note the large area covered by the Chilean weather office. It goes clear into Antarctic waters.

Latest Honolulu Weather Fax Schedule

This is the 2009 schedule as broadcast by the station. It is more up to date than most of the ones on the Internet:


HONOLULU, HAWAII, U.S.A.

CALL SIGN KVM70

FREQUENCIES
9982.5 0519-1556 F3C 4 KW
11090 ALL BROADCAST TIMES F3C 4 KW
16135 1719-0356 F3C 4 KW
120/576

0519/1719 TEST PATTERN
0524/1724 SIGNIFICANT CLOUD FEATURES 03/15 D
0535/1735 CYCLONE DANGER AREA 03/15 E
0555/1755 STREAMLINE ANALYSIS 00/12 B
0615/1815 SURFACE ANALYSIS 00/12 C
0635/1835 EAST PACIFIC GOES IR SATELLITE IMAGE 06/18 G
0649/1849 SW PACIFIC GOES IR SATELLITE IMAGE 06/18 H
0701/1901 24HR SURFACE FORECAST 00/12 A
0714/1914 48HR SURFACE FORECAST 00/12 A
0727/1927 72HR SURFACE FORECAST 00/12 A
0740/1940 WIND/WAVE ANALYSIS 00/12 B
0753/1953 24HR WIND/WAVE FORECAST 00/12 B
0806/2006 24HR WIND/WAVE FORECAST 00/12 4
0816/2016 48HR SURFACE FORECAST 00/12 1
0826/2026 48HR WIND/WAVE FORECAST 00/12 1
0836/2036 48/96 HR WAVE PERIOD, SWELL DIR 00/12 1
0846/2046 rebroadcast/ 96HR SURFACE FORECAST 12/12 1
0856/2056 rebroadcast/ 96HR WIND/WAVE FORECAST 12/12 1
0906/2106 PACIFIC GOES IR SATELLITE IMAGE 06/18 5
0917/2117 SURFACE ANALYSIS (PART 1 NE PACIFIC) 06/18 2
0930/2130 SURFACE ANALYSIS (PART 2 NW PACIFIC) 06/18 3
0943/2143 TROPICAL GOES IR SATELLITE IMAGE 06/18 Y
0954/2154 TROPICAL SURFACE ANALYSIS 06/18 Z
1008/2208 24HR TROPICAL WIND/WAVE FORECAST 00/12 Z
1042/2242 CYCLONE DANGER AREA 09/21 E
1102/2302 48HR WIND/WAVE FORECAST 00/12 B
1115/2315 72HR WIND/WAVE FORECAST 00/12 B
1128/2328 SEA SURFACE TEMPS LATEST F
1141/2341 rebroadcast 24HR WIND/WAVE FORECASTS 00/12 B
1154/2354 STREAMLINE ANALYSIS 06/18 B
1214/0014 SURFACE ANALYSIS 06/18 C
1234/0034 EAST PACIFIC GOES IR SATELLITE IMAGE 12/00 G
1248/0048 SW PACIFIC GOES IR SATELLITE IMAGE 12/00 H
1300/0100 SCHEDULE PART I
1320/0120 SCHEDULE PART II
1340/0140 SYMBOLS OR PRODUCT NOTICE BULLETIN
1400/0200 24HR TROPICAL SURFACE FORECAST 00/12 Z
1410/0210 48HR TROPICAL SURFACE FORECAST 00/12 Z
1420/0220 72HR TROPICAL SURFACE FORECAST 00/12 Z
1430/0230 48/72 HR TROPICAL WAVE PER,SWELL DIR 00/00 Z
1440/0240 TROPICAL SEA STATE ANALYSIS 12/00 Z
1450/0250 rebroadcast 24HR WIND/WAVE FORECASTS 00/12 Z
1500/0300 48HR TROPICAL WIND/WAVE FORECAST 00/12 Z
1510/0310 72HR TROPICAL WIND/WAVE FORECAST 00/12 Z
1520/0320 rebroadcast/SEA STATE ANALYSIS 00/00 1
1530/0330 SURFACE ANALYSIS(PART 1 NE PAC) 12/00 2
1543/0343 SURFACE ANALYSIS(PART 2 NW PAC) 12/00 3
1556/0356 TROPICAL SURFACE ANALYSIS 12/00 Z

MAP AREAS:
A. 30S - 50N, 110W - 130E
B. 30S - 30N, 110W - 130E
C. EQ - 50N, 110W - 130E
D. 30S - 50N, 110W - 160E
E. EQ - 40N, 80W - 170E
F. EQ - 55N, 110W - 160E
G. 05S - 55N, 110W - 155E
H. 40S - 05N, 130W - 165E
1. 20N - 70N, 115W - 135E
2. 20N - 70N, 115W - 175W
3. 20N - 70N, 175W - 135E
4. 18N - 62N, EAST OF 157W
5. 05N - 55N, EAST OF 180W
Y. 05N - 32N, EAST OF 130W
Z. 20S - 30N, EAST OF 145W


STREAMLINES ARE LINES OF CONSTANT WIND DIRECTION. WIND SPEEDS ARE GIVEN BY WIND BARBS INDEPENDENT OF STREAMLINES.

THE SIGNIFICANT CLOUD FEATURES CHARTS DEPICT CLOUD FEATURES BASED UPON IMAGES FROM THE VARIOUS GEOSTATIONARY AND POLAR ORBITING SATELLITES OVER THE PACIFIC. ABBREVIATIONS ON THESE CHARTS INCLUDE: AC - ALTOCUMULUS; AS - ALTOSTRATUS; BKN - BROKEN; CB - CUMULONIMBUS; CC - CIRROCUMULUS; CI - CIRRUS; CS - CIRROSTRATUS; CU - CUMULUS; FEW - FEW; ISOL - ISOLATED; LYRS - LAYERS; NS - NIMBOSTRATUS; OVC - OVERCAST; SC - STRATO-CUMULUS; SCT - SCATTERED; TCU - TOWERING CUMULUS; TSTM - THUNDERSTORM

RADIOFAX FREQUENCIES ARE ASSIGNED FREQUENCIES. TO CONVERT TO CARRIER FREQUENCIES, SUBTRACT 1.9 KHZ FROM THE ASSIGNED FREQUENCIES.

YOU MAY ADDRESS COMMENTS ABOUT THIS BROADCAST TO:

Meteorologist In Charge
National Weather Service
2525 Correa Rd.
Honolulu, HI 96822
PHONE: (808) 973-5270/FAX: (808) 973-5281
E-Mail norman.hui@noaa.gov

Many of these charts also broadcast via Pt. Reyes, CA and Kodiak, AK

If you have access to the World Wide Web be certain to check out the following webpages. See these pages for further links.

http://www.nws.noaa.gov NWS Homepage
http://www.nws.noaa.gov/om/marine/home.htm NWS Marine Page
cell.weather.gov Cellphone page
mobile.weather.gov Mobile Page

(Schedule Effective Nov 03, 2008 Information dated Apr 06, 2009)

CFH Fax Image of Nor'Ida, 11/12

This fax sent by CFH, Canadian Forces METOC Centre, Halifax, NS is a 24-hour prognostic chart showing Nor'Ida taking shape in the Mid-Atlantic.

Nor'Ida is the name that people have started giving the combination of the remnants of Hurricane Ida and a cold front. This grew into a Perfect Storm type of nor'easter, which went on to cause considerable damage and some loss of life in VA, NC, and other states.

Frequency was 13508.0 USB, at 12/1716 UTC.



US state lines are no longer visible on this reduced image, but the forecast position of the low is just off North Carolina.

8658.0 Japanese Fishery FAX

Someone is sending FAX fishery information from Japan out to fleets operating in the East Pacific. The frequencies are the ones listed in old utility guides as "Chuo Fishery" or "Chuo Gyogyo" (same thing, different languages). This was 8658.0. A parallel exists on 16907.5. It hasn't been audible in California, but it has been confirmed by Eddy Waters in Australia.

Here's one I snagged at 0650 UTC last night:



The information has to do with fish market prices in Japan. Martin Foltz, another DXer in SoCal, ran one of his intercepts past a Japanese speaker. It was identified as a mackerel market table sent by the "Fukushima Business Radio Station" from the Fukushima Prefecture Fishery on the island of Honshu. Efforts continue to track down this transmitter out of the 900 or so fishery radio stations in Japan.

Afternoon US Kyodo News is JSC, Not JJC

Still getting great reception of the Kyodo News FAX on 16971 kHz USB, 60/576. Today I caught a sign-on, identifying the transmitting station as JSC, Kagoshima Radio, not the usual JJC, Tokyo.



Some Googling around turned up the following (badly translated) information:

07.04.12 [April 2007 -hugh] 16971kHz 10kW JSC Fisheries Kagoshima consignment sent to radio stations (for the direction of Hawaii)

I interpret this to mean that this one frequency is broadcast for part of the day over a separate transmitter with a different beam. This certainly explains why only part of Kyodo's 24/7 sked is being sent, and why it's so much louder on the US Pacific Coast than any of the others. It sounds like a special contract to transmit a newspaper to Japanese fishing boats operating in the Eastern Pacific.

You learn something new every day in this hobby.

JJC Tokyo News FAX Received Nov 3

You know the fall DX season has arrived when Southern California has a relatively clear copy on the Kyodo News FAX from Japan. This is the best one I've received in a long time.

Frequency was 16971.0 kHz USB, time was just after zero UTC. Parameters were 60/576.



It's worth repeating that, unlike the weather charts, the news FAX is copyrighted material, reproduced here at a greatly reduced size under fair use for the purposes of amateur radio propagation reporting. Any unauthorized commercial use would probably prompt Kyodo to start scrambling the faxes again. We'd hate to lose the last news FAX on the air for DXing.

NMC FAX Satellite Image Nov. 2

Copied on 8682 kHz at 2113 UTC. Note the multipath and cyclical selective fading, both of which are typical of this path and time of day.



Also note the pronounced "Pineapple Express" moisture feed from the tropics near Hawaii to the northwestern continental United States.

Honolulu FAX Test Chart

Received in Southern California on 3 Oct 09 (UTC)

"Digital" Mode of the Week: HF FAX

FAX stands for facsimile, or in this case radiofacsimile. Unlike the more recently developed office FAX machines used over wire telephone circuits, it is completely analog, using FM emission (F3C). It dates from work done by various inventors in the late 19th and early 20th centuries to send pictures over telegraph and later radio.

HF FAX was very widely used in the 20th century to send news photos and even entire newspapers over HF point to point circuits. Machines used huge drum scanners and similar drums to print at the other end. They were very precise, and very, very expensive. Now it can be done with simple computer sound card software, though at considerable loss of precision in this rather fussy mode.

Today's HF FAX uses a continuous FM carrier with a narrow 800-Hz deviation. Usually, anything around 1500 Hz, the lower limit, is reproduced as black, with the brightness increasing until it reaches a white point up around the high limit of 2300 Hz. By ear, fax can make a number of different sounds, but usually it makes a cyclic pulsing with a high-pitched shreik underneath.

Nowadays, instead of using true FM transmitters, the corresponding baseband audio tone is sent to a normal, single-sideband, suppressed-carrier, HF transmitter. The result sounds the same, only displaced in frequency due to the offset from the missing carrier. FAX is tuned in USB, or else it will reproduce as a negative, and the dial should read 1.9 kHz (the tone center) lower than published frequencies. Most of the time, one centers the waterfall display between two marks, and it's tuned in. Slight mistuning has no effect except to possibly wash out the blacks or whites, depending on which direction it is.

Two other parameters are essential for the reception of FAX. The first is called drum speed, though obviously nowadays transmission speed would be a better name. It's expressed in lines per minute. The receiving software must sync to this speed, or the pictures will not reproduce properly.

Far, far the most common speed is 120 LPM. It is used for nearly all weather FAX. Some more complex pictures are sent at 60 LPM, a speed which can sound like a time signal.

The second parameter is Index of Cooperation (IOC), expressed as an integer. This is a really arcane thing also dating from the use of drum scanners. It measures the resolution of the FAX. Nobody really has to know what the IOC measures, just what the number is, and it is nearly always 576. On very rare occasion, it's 288. This is way less important for computer screens than it is for rotating drums.

Those who are really curious as to just what the Index of Cooperation is will be pleased to know that it's commonly defined as the product of the total line length and the number of lines per unit length, divided by Pi. It's measuring the ratio of how much distance the scan steps for a new line to the diameter of the drum. The length of time any single FAX can last is determined proportional to the IOC. At 120/576, the standard weather format, this is 18.8 minutes, which is plenty. Going to 60/576 doubles this, along with increasing resolution, though of course the fax takes twice as long to send.

Now it's all clear, right? :-)

Most FAX software allows the setting of black and white or continuous tone (grey scale) modes. Except for satellite weather images, just about every FAX sent on HF nowadays is in black and white. I'll get some argument here, but I've always just kept it on continuous anyway. Otherwise lines get kind of jagged, and typical HF ionospheric multipath fuzz can get grungy looking in a hurry. Plus you have to change it whenever a satellite image is sent, and then change it back again.

Radiofax typically uses a standard called APT (Automatic Picture Transmission). This allows the unattended reception of faxes. Different bands and services use different versions of this, but the one we're interested in is as follows:

5 sec Start Tone (alternate black and white at 300 Hz)

Phasing (30 seconds of white with one black pulse per line)

Image (may have a white interval for sync)

5 sec Stop Tone (alternate black and white at 450 Hz)

Optional 10 sec black

Different agencies have slight variations on this, and these are usually just enough to confuse amateur software. Even so, one will notice that all the information needed to set parameters and receive faxes is here, except maybe for IOC and that's almost always 576 anyway.

Why more computer programs don't take advantage of this is beyond me. They don't however, and so your received fax is usually displaced (left edge is somewhere else in the screen) and slanted (computer is not printing lines at the exact speed of transmission). There are nearly always ways to fix these, either during or after reception.

Slant is way the more annoying of the two, because computer sound cards really aren't up to the task. They don't have the tight frequency tolerance that an expensive dedicated device would have. Typically, the proper slant compensation has to be found manually for a given station, and then it will vary for others, or even change during a long FAX.

I like FAX because it's radio with pictures. One learns how to read the weather charts pretty fast. They're not that different than the ones on the Weather Channel. Also, the satellite images are as good as the ones on your local TV, and better if you get into colorized WEFAX downlinking on higher frequencies.

Many coast guards and weather offices still send hours of these a day, and since they are being used by boats for serious navigation and safety of life at sea, they won't go away any time soon. Check the various lists and radio loggings for something audible in your area.

Press Release: US Coast Guard Continues HF Weather Broadcasts

Press Release
DATE: February 07, 2008 14:39:41 EST
FOR IMMEDIATE RELEASE
Office of Public Affairs
U.S. Coast Guard

Contact: (202) 475-3555


US Coast Guard Continues 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 U.S. Coast Guard is a military, maritime, multi-mission service within the
Department of Homeland Security dedicated to protecting the safety and security of America.

------------

The full report is here. It is very comprehensive and informative, and worth the time to get and read it.

------------

Here's more from USCG Navcen:


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.

[Presumably the services to be affected by the phase-out of the other transmitters include those on this list that are not required by GMDSS or other treaties. More when it happens. -Hugh]