Difference between revisions of "HF Maritime Communications"

Latest revision as of 20:54, 1 December 2020

HF Maritime communications have undergone a radical change over the last several years. Many stations that used to have voice communications have either gone dark or using digital modes, some of which are not readable except to the intended target. Let's take a look at what is out there.

Voice

US commercial stations have ceased most voice communications. There are some countries that have stations that are still on the air. Ships and stations are allocated in fixed frequency ranges, and you can find those ranges listed here.
The Canadians have the Radio Aids to Navigation
USCG Voice Marine weather broadcasts can be found here. Click the USCG HF Voice link

Digital (below the AM broadcast band)

Navigational aids such as DGPS are slowly dying out. The US discontinued its DGPS support as of the 30th of June 2020.
SITOR-B / NAVTEX broadcasts are quite plentiful, and there is a wide range of software that can decode them. The main issue with receiving these broadcasts lie with the typical receiver; sensitivity is generally reduced in this band because of a perceived lack of interest (due to the lack of broadcasts in North America on this band) as well as reducing the possibility of mixing products from the MW band appearing here (which it does anyway). SDRs may need some front end preselection to prevent overload in areas where there are many MW stations (such as those found in urban areas). Active Loops are commonly used as antennas to hear these broadcasts.

Drift Net Buoys and Navigational Aids

Drift Net Buoy Beacons can be heard from 1600 Khz to 4 Mhz. The Drift Net Buoys Loggings board on the HF Underground site has numerous logs of these buoys.

Like DGPS, the navigational aids found in the 1700-1800 Khz range are also slowly dying out and being replaced with satellite tracking.

Digital (2-30 Mhz)

CODAR is used to make ocean measurements such as wave height and current. They have a distinctive swishing sound when listened to in USB mode. It has been found being used as high as the 20 meter amateur band.
CW (Morse Code) is frequently found in the lower HF ranges being used by Russian military units, among others. See this PDF document from the UDXF website for a description of different CW alphabets
GMDSS / DSC is a digital system on several fixed frequencies. There are numerous packages for decoding
Baudot RTTY is all but dead in the maritime service. The only station known to use it regularly is the German Weather service (Deutsche Wetterdienst). See the links in the article for the schedule.
There are 4 main types of PACTOR. These are PACTOR I, PACTOR II, PACTOR III and PACTOR IV. It is typically used for communicating with ships at sea; you may see the initial calls in Pactor I or II, but then once the connection is made, the messages may be heavily encrypted and compressed, making the signal unreadable. One such system is the Sailmail system, and this document outlines, among other things, the station locations and frequencies. Although it is a bit old, it gives the reader a rare look into what is needed to run a marine PACTOR station and its operations
SITOR-A used to be used by numerous stations but this mode is gradually dying out. Using the UDXF logs and examination over the last year only show Guangzhou, Shanghai, Istanbul Radio (Turkey) and Olympia Radio (SVO) Greece as being active. Note that this mode is not exclusively used in the maritime service; the Egyptian Diplomatic service also uses this, utilizing the ATU-80 alphabet, making this difficult to read with most applications. There are numerous applications that can copy this mode when used in the maritime service. See this PDF article from the UDXF website on reading the MFA Egypt transmissions.
SITOR-B / NAVTEX is, like GMDSS, found on a few fixed HF frequencies . There are numerous applications that can copy this mode, but like SITOR-A, you will occasionally find other services using it.
STANAG 4285 This mode is used by NATO forces. As a result, it is generally heavily encrypted; however it can be seen in the clear if the station is sending a test tape or sending a CARB broadcast in the clear
Weather FAX (WEFAX) was thought to be going dead years ago, but continues to be heavily used. There are even reports of the Japanese news agency (KYODO) sending newspapers (in Japanese) to fishing fleets. It should be noted that FAX use by other press services died out years ago. There are numerous applications that can copy this mode

Websites

NOTE: The links for the various modes comes from the Signal Identification Wiki
When a hurricane (cyclone in the Pacific) is spotted, the Tropical Cyclone Plan of the Day will give you an idea of when the flights to track these storms will take place
UDXF Links page See the Beacons, Long Wave and Maritime / NAVTEX sections
UDXF Files page See the Aero / Maritime section

William Hepburn's DX Information Center

How to Find Activity?

The spectrum for HF maritime communications is very wide. Unlike VHF/UHF scanning, it's challenging to automatically scan a segment of the band because HF noise will always be present. While some maritime stations are on a fixed schedule, others (such as fishing fleets) are much more difficult to detect due to their transient nature; thus, listening for maritime comms can be a game of patience. The more time passes, the harder it is to hear again. Mailing lists are one of the best ways to keep ahead of what is being heard, as traffic can be passed relatively quickly. See the Utility Related Clubs, Mailing lists and Publications of the Utility_Monitoring article for some suggested resources

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-==HF Maritime Communications==
+HF Maritime communications have undergone a radical change over the last several years. Many stations that used to have voice communications have either gone dark or using digital modes, some of which are not readable except to the intended target.  Let's take a look at what is out there.
-[[HF]] maritime communications can be found below 30 MHz.  Here's a sample of what you can hear:
-* [[United States Coast Guard]] Operations
+==Voice==
-* Weather broadcasts, using voice, data or weather charts (FAX)
+* US commercial stations have ceased most voice communications.  There are some countries that have stations that are still on the air. Ships and stations are allocated in fixed frequency ranges, and you can find those ranges listed [https://www.navcen.uscg.gov/?pageName=mtHighFrequency here].
-* Ship to Shore communications (although this has declined drastically in recent years, due to the popularity of satellite and Internet technologies)
+* The Canadians have the [https://www.ccg-gcc.gc.ca/publications/mcts-sctm/ramn-arnm/part1-eng.html Radio Aids to Navigation]
-* Fishing Fleets (some using illegally modified ham HF gear)
+* USCG Voice Marine weather broadcasts can be found [https://www.weather.gov/marine/uscg_broadcasts here]. Click the ''USCG HF Voice'' link
-* [http://www.navcen.uscg.gov/?pageName=GMDSS USCG Global Maritime Distress and Safety System(GMDSS)] alerts. See the highlighted link for an overview on this system
-* [http://www.navcen.uscg.gov/?pageName=mtHighFrequency USCG MF & HF Channel Information]
-==The HF Maritime Communications Receiver==
-A receiver for monitoring HF maritime communications must have the following
-features:
-* Coverage from 100 kHz to 30 MHz
+==Digital (below the AM broadcast band)==
-* Upper sideband (USB) and lower sideband (LSB) modes
+* Navigational aids such as [https://www.sigidwiki.com/wiki/Differential_Global_Positioning_System_(DGPS) DGPS] are slowly dying out. The US discontinued its DGPS support as of the 30th of June 2020.
-* Good stability (doesn't drift off frequency)
+* [https://www.sigidwiki.com/wiki/SITOR-B SITOR-B / NAVTEX] broadcasts are quite plentiful, and there is a wide range of software that can decode them. The main issue with receiving these broadcasts lie with the typical receiver; sensitivity is generally reduced in this band because of a perceived lack of interest (due to the lack of broadcasts in North America on this band) as well as reducing the possibility of mixing products from the MW band appearing here (which it does anyway). SDRs may need some front end preselection to prevent overload in areas where there are many MW stations (such as those found in urban areas). Active [[Loops]] are commonly used as antennas to hear these broadcasts.
-* Good selectivity (able to seperate 2 stations that are close to one another in frequency)
-Many receivers and portables marketed as shortwave or world band radios will satisfy
-these requirements.  The majority of voice communications use USB, but LSB is
-certainly possible (foreign fishing fleets have been known to use LSB); therefore, whatever you
-select '''must''' have USB and LSB capabilities. The lower band limit of
-kHz is typical of many HF radios, but many marine transmissions occur
-at 2 MHz and above. Other features such as memory channels and alpha tagging
-are desirable, but not necessary.  See the [[:Category:Receiver Reviews|Receiver Reviews]] article for several links on this important topic.
-==Propagation and Antennas==
+==Drift Net Buoys and Navigational Aids==
-Your ability to receive HF maritime communications is affected by signal propagation
+* [https://www.sigidwiki.com/wiki/Driftnet_Buoy_Radio_Beacon Drift Net Buoy Beacons] can be heard from 1600 Khz to 4 Mhz. The [https://www.hfunderground.com/board/index.php/board,40.0.html Drift Net Buoys Loggings] board on the HF Underground site has numerous logs of these buoys.
-conditions in the atmosphere.  Many factors affect propagation, including sunspots, solar
-flares, and the time of day. Frequencies above 10 mhz or so are usable during the
-local daytime, while frequencies below 10 mhz will be usable at night.
-If you are a newcomer to this topic, reading a good primer would be a great benefit. Don't
-get discouraged about all the jargon; whole books and very technical scientific papers have
-been written on the subject; but it's unnecessary to have a degree to gain a basic understanding.
-To get you started, please see the [http://www.ae4rv.com/tn/propflash.htm Propagation Primer]
-website by Geoffrey Noles AE4RV (requires Flash player).
-Your station is only as good as the antenna you can use. The best antennas for
+* Like DGPS, the navigational aids found in the 1700-1800 Khz range are also slowly dying out and being replaced with satellite tracking.
-receiving HF maritime comms is going to depend largely on what you can put up
-and what kind of receiver you are using. Generally, something that is relatively broadbanded -
-such as a random wire or inverted L - will be the best one to get you started. Our [[HF Antennas]]
-page has a number of possibilities, including some that are already assembled - all you need to do
-is supply the feedline and proper connectors.
-If you live in an urban area, or are plagued with noise problems, consider utilizing
-a loop antenna. MW DXers have been utilizing loops for their directional capabilities almost since
-the beginning of the broadcast industy; they are useful for HF listening because they are less
-sensitive to certain kinds of electrical noise. If you're interested in this topic, please
-see our [[Loops]] page.
-Another possibility is to use a Magnetic Longwire Balun(MLB) with a good grade of coax to feed an inverted L design. Plans exist on building baluns on the Shortwave SWL Antenna Yahoo group; or you can purchase the popular PAR EF-SWL antenna, which uses a similar principle. The [[HF Antennas]] article has information on these topics as well.
+==Digital (2-30 Mhz)==
+*[https://www.sigidwiki.com/wiki/CODAR CODAR] is used to make ocean measurements such as wave height and current. They have a distinctive swishing sound when listened to in USB mode. It has been found being used as high as the 20 meter amateur band.
+*CW (Morse Code) is frequently found in the lower HF ranges being used by Russian military units, among others.  See this [http://www.udxf.nl/Morse-document.pdf PDF document] from the UDXF website for a description of different CW alphabets
+*[https://www.sigidwiki.com/wiki/GMDSS_Digital_Selective_Calling GMDSS / DSC] is a digital system on several fixed frequencies. There are numerous packages for decoding
+*[https://www.sigidwiki.com/wiki/Radio_Teletype_(RTTY) Baudot RTTY] is all but dead in the maritime service. The only station known to use it regularly is the German Weather service (Deutsche Wetterdienst). See the links in the article for the schedule.
+*There are 4 main types of PACTOR. These are [https://www.sigidwiki.com/wiki/PACTOR_I PACTOR I], [https://www.sigidwiki.com/wiki/PACTOR_II PACTOR II], [https://www.sigidwiki.com/wiki/PACTOR_III PACTOR III] and [https://www.sigidwiki.com/wiki/PACTOR_IV PACTOR IV]. It is typically used for communicating with ships at sea; you may see the initial calls in Pactor I or II, but then once the connection is made, the messages may be heavily encrypted and compressed, making the signal unreadable. One such system is the Sailmail system, and this [https://sailmail.com/wp-content/uploads/2016/02/smprimer.htm document] outlines, among other things, the station locations and frequencies. Although it is a bit old, it gives the reader a rare look into what is needed to run a marine PACTOR station and its operations
+*[https://www.sigidwiki.com/wiki/SITOR-A SITOR-A] used to be used by numerous stations but this mode is gradually dying out. Using the UDXF logs and examination over the last year only show Guangzhou, Shanghai, Istanbul Radio (Turkey) and Olympia Radio (SVO) Greece as being active. Note that this mode is not exclusively used in the maritime service; the Egyptian Diplomatic service also uses this, utilizing the ATU-80 alphabet, making this difficult to read with most applications. There are numerous applications that can copy this mode when used in the maritime service. See this [http://www.udxf.nl/Decoding-MFA-Egypt.pdf PDF article] from the UDXF website on reading the MFA Egypt transmissions.
+*[https://www.sigidwiki.com/wiki/SITOR-B SITOR-B / NAVTEX] is, like GMDSS, found on a few fixed HF frequencies . There are numerous applications that can copy this mode, but like SITOR-A, you will occasionally find other services using it.
+* [https://www.sigidwiki.com/wiki/STANAG_4285 STANAG 4285] This mode is used by NATO forces. As a result, it is generally heavily encrypted; however it can be seen in the clear if the station is sending a test tape or sending a [http://i56578-swl.blogspot.com/2014/08/the-carb-messages.html CARB broadcast] in the clear
+*[https://www.sigidwiki.com/wiki/WEFAX Weather FAX (WEFAX)] was thought to be going dead years ago, but continues to be heavily used. There are even reports of the Japanese news agency (KYODO) sending newspapers (in Japanese) to fishing fleets. It should be noted that FAX use by other press services died out years ago. There are numerous applications that can copy this mode
-==How to Find Activity?==
-The spectrum for HF maritime communications is very wide.  Unlike VHF/UHF scanning, it's challenging to
-automatically scan a segment of the band because HF noise will always be present.  So, here are some places
-to start searching;
-* Numerous ship-shore HF frequencies exist in the 2, 4, 6, 8, 12, 16, 18 and 22 Mhz bands. Some are simplex (ship and shore on the same frequency) while others are duplex (ship on one frequency, shore on another). See this [http://www.ominous-valve.com/itufqs.txt website] for a complete list
+==Websites==
+* '''NOTE:''' The links for the various modes comes from the Signal Identification Wiki
+* When a hurricane (cyclone in the Pacific) is spotted, the [http://www.nhc.noaa.gov/ftp/pub/forecasts/recon/MIAREPRPD Tropical Cyclone Plan of the Day] will give you an idea of when the flights to track these storms will take place
+* [http://www.udxf.nl/links.html UDXF Links page]   See the ''Beacons'', ''Long Wave'' and ''Maritime / NAVTEX'' sections
+* [http://www.udxf.nl/ute-info.html UDXF Files page]  See the ''Aero / Maritime'' section
-* [http://www.hffax.de/ HFFAX.de] Well known website run by Marius Rensen with extensive HF and satellite FAX information
-* [http://www3.sympatico.ca/hehilgen/vax498.htm Southbound 2 Net page by Herb Hilgenberg VE3LML] Famous for communicating with ships in the Caribbean and elsewhere with weather and other information
+; William Hepburn's DX Information Center
+* [http://www.dxinfocentre.com/navtex.htm NAVTEX Broadcasts]
+* [http://www.dxinfocentre.com/navtex.htm HF Radio Telex Broadcasts]
+* [http://www.dxinfocentre.com/mb.htm Worldwide MF Marine Stations]
+* [http://www.dxinfocentre.com/marineinfo.htm HF Marine Voice Broadcasts]
-* [http://www.nws.noaa.gov/om/marine/home.htm NOAA Maritime Products] The place to begin to find schedules for SITOR and FAX stations from the US and elsewhere
-* [http://www.docksideradio.com/ Dockside Radio] Interesting place to find HF frequencies, both ham and marine for various support nets
+==How to Find Activity?==
+The spectrum for HF maritime communications is very wide.  Unlike VHF/UHF scanning, it's challenging to automatically scan a segment of the band because HF noise will always be present. While some maritime stations are on a fixed schedule, others (such as fishing fleets) are much more difficult to detect due to their transient nature; thus, listening for maritime comms can be a game of patience. The more time passes, the harder it is to hear again. Mailing lists are one of the best ways to keep ahead of what is being heard, as traffic can be passed relatively quickly. See the Utility Related Clubs, Mailing lists and Publications of the [[Utility_Monitoring]] article for some suggested resources
-* [http://www.navcen.uscg.gov/?pageName=highFrequency USCG MF/HF Channels]
-; Digital and other modes
-While many ships are now using encrypted digital signals for email and other traffic, there is still a great deal
-of traffic in the clear. This includes SITOR-B weather broadcasts, FAX (Fascimile weather charts), GMDSS alerts
-and more. Fortunately there are numerous software packages - some ham related, others not - that can decode some
-or all of these modes. The list shown below is not expected to be complete, but is representative of what is
-currently available. Where applicable, the link for the Yahoo support group for the software is also supplied;
-* [http://www.coaa.co.uk/dscdecoder.htm DSC Decoder]
-** [http://groups.yahoo.com/group/shipplotter/ ShipPlotter/DSC Decoder Support Group]
-* [http://www.hoka.net/code300-32/code300-32.htm Hoka Code300-32]
-* [http://www.jvcomm.de/index_e.html JVComm32]
-* [http://mixw.net/ MixW]
-** [http://groups.yahoo.com/group/mixw/ MixW Support Group]
-* [http://www.mscan.com/ MScan Meteo products]
-* [http://www.blackcatsystems.com/software/multimode.html Multimode (MAC software)]
-* [http://multipsk.eqth.info/index.html MultiPSK]
-** [http://groups.yahoo.com/group/multipsk/ MultiPSK Support Group]
-* [http://www.computer-int.com/rc.htm RadioCom]
-** [http://groups.yahoo.com/group/RadioCom/ Bonito RadioCom Support Group]
-* [http://www.cam.org/~noelbou/RxPlus/ RXPlus]
-** [http://groups.yahoo.com/group/RxPlus/ RXPlus Support Group]
-* [http://www.dxsoft.com/en/products/seatty/ SeaTTY]
-** [http://groups.yahoo.com/group/dxsoft/ DX Soft Product Support]
-* [http://www.skysweep.com/ SkySweeper] Discontinued by manufacturer
-** [http://groups.yahoo.com/group/skysweeper/ SkySweeper Support Group]
-===Other Sources of Marine Related Activity===
-While some maritime stations are on a fixed schedule, others (such as fishing fleets) are much more
-difficult to detect due to their transient nature; thus, listening for maritime comms can be
-a game of patience. The more time passes, the harder it is to hear again. Mailing lists are one of
-the best ways to keep ahead of what is being heard, as traffic can be passed relatively quickly.
-The [http://groups.yahoo.com/group/udxf/ Utility DXers Forum] is very active and is only one of many such lists; more are available on the [[Utility Monitoring]] page.
-===Magazine Logs===
+---
-A few magazine publications have columns devoted to HF logs (including maritime stations)
+* Return to [[Utility Monitoring]]
-submitted by readers.  This is a great way to discover to what other people are
-listening.  These logs will often include multiple entries for the same
-frequency, which means that frequency has been active. However, keep in mind
-that, due to publishing constraints, there is often a 60 or 90 day lag between
-when the report is received and when it's actually published.
-* [http://www.popularcommunications.com Popular Communications] - Utility Communications Digest
+[[Category:HF in Marine or Maritime]]
-* [http://www.monitoringtimes.com Monitoring Times] - Utility World Column
+[[Category:HF Frequencies in Marine or Maritime]]
-[[Category:Milcom]]
-[[Category:HF Topics]]