Maritime Fax Transmissions - Revision history

R4002 at 13:43, 23 October 2022

2022-10-23T13:43:54Z

← Older revision		Revision as of 13:43, 23 October 2022
Line 10:		Line 10:

	== Transmission details ==		== Transmission details ==
-	Radiofax is transmitted in [[SSB\|single sideband]] and uses [[FM\|frequency modulation]]. The signal shifts up or down a given amount to designate white or black pixels. A [[deviation]] less than that for a white or black pixel is taken to be a shade of grey. With correct tuning (1.9kHz below the carrier frequency for USB, above for LSB), the signal shares some characteristics with [[SSTV]], with black at 1500Hz and peak white at 2300Hz. The official [[ITU]] radio [[~~Emission_designator~~\|emission designation]] is '''F1C'''. Note that some sources list this a "J1C". Some sources list the center frequency. In USB mode, the frequency is 1.9 kHz lower (dial frequency).	+	Radiofax is transmitted in [[SSB\|single sideband]] and uses [[FM\|frequency modulation]]. The signal shifts up or down a given amount to designate white or black pixels. A [[deviation]] less than that for a white or black pixel is taken to be a shade of grey. With correct tuning (1.9kHz below the carrier frequency for USB, above for LSB), the signal shares some characteristics with [[SSTV]], with black at 1500Hz and peak white at 2300Hz. The official [[ITU]] radio [[Emission_Designator\|emission designation]] is '''F1C'''. Note that some sources list this a "J1C". Some sources list the center frequency. In USB mode, the frequency is 1.9 kHz lower (dial frequency).

	Usually, 120 lines per minute (LPM) are sent (For monochrome fax, possible values are: 60, 90, 100, 120, 180, 240. For colour fax, LPM can be: 120, 240).<sup>[1]</sup> A value known as the ''index of cooperation'' (IOC) must also be known to decode a radio fax transmission - this governs the image resolution, and derives from early radio fax machines which used drum readers, and is the product of the total line length and the number of lines per unit length (known sometimes as the ''factor of cooperation''), divided by π (3.1416). Usually the IOC is 576.		Usually, 120 lines per minute (LPM) are sent (For monochrome fax, possible values are: 60, 90, 100, 120, 180, 240. For colour fax, LPM can be: 120, 240).<sup>[1]</sup> A value known as the ''index of cooperation'' (IOC) must also be known to decode a radio fax transmission - this governs the image resolution, and derives from early radio fax machines which used drum readers, and is the product of the total line length and the number of lines per unit length (known sometimes as the ''factor of cooperation''), divided by π (3.1416). Usually the IOC is 576.

R4002: /* Transmission details */

2022-10-23T13:43:07Z

Transmission details

← Older revision		Revision as of 13:43, 23 October 2022
Line 10:		Line 10:

	== Transmission details ==		== Transmission details ==
-	Radiofax is transmitted in [[SSB\|single sideband]] and uses [[FM\|frequency modulation]]. The signal shifts up or down a given amount to designate white or black pixels. A [[deviation]] less than that for a white or black pixel is taken to be a shade of grey. With correct tuning (1.9kHz below the carrier frequency for USB, above for LSB), the signal shares some characteristics with [[SSTV]], with black at 1500Hz and peak white at 2300Hz. The official [[ITU]] radio emission designation is '''F1C'''.	+	Radiofax is transmitted in [[SSB\|single sideband]] and uses [[FM\|frequency modulation]]. The signal shifts up or down a given amount to designate white or black pixels. A [[deviation]] less than that for a white or black pixel is taken to be a shade of grey. With correct tuning (1.9kHz below the carrier frequency for USB, above for LSB), the signal shares some characteristics with [[SSTV]], with black at 1500Hz and peak white at 2300Hz. The official [[ITU]] radio [[Emission_designator\|emission designation]] is '''F1C'''. Note that some sources list this a "J1C". Some sources list the center frequency. In USB mode, the frequency is 1.9 kHz lower (dial frequency).

	Usually, 120 lines per minute (LPM) are sent (For monochrome fax, possible values are: 60, 90, 100, 120, 180, 240. For colour fax, LPM can be: 120, 240).<sup>[1]</sup> A value known as the ''index of cooperation'' (IOC) must also be known to decode a radio fax transmission - this governs the image resolution, and derives from early radio fax machines which used drum readers, and is the product of the total line length and the number of lines per unit length (known sometimes as the ''factor of cooperation''), divided by π (3.1416). Usually the IOC is 576.		Usually, 120 lines per minute (LPM) are sent (For monochrome fax, possible values are: 60, 90, 100, 120, 180, 240. For colour fax, LPM can be: 120, 240).<sup>[1]</sup> A value known as the ''index of cooperation'' (IOC) must also be known to decode a radio fax transmission - this governs the image resolution, and derives from early radio fax machines which used drum readers, and is the product of the total line length and the number of lines per unit length (known sometimes as the ''factor of cooperation''), divided by π (3.1416). Usually the IOC is 576.

Ka3jjz: updated links

2020-11-14T01:38:24Z

updated links

← Older revision		Revision as of 01:38, 14 November 2020
Line 348:		Line 348:

	==External links==		==External links==
-	* [http://~~www~~.~~hffax~~.de/ ~~HF-FAX~~] ~~by Marius Rensen~~.	+	* Typically around 3 to 16 MHz. See [http://info.yachtcom.co.uk/Weather/ here] for Yachtcom UK Weatherfax frequencies.
-	* [~~http~~://weather~~.noaa~~.gov/~~fax~~/marine.~~shtml Marine Weatherfax~~ NOAA ~~broadcasts~~]	+	* [https://www.weather.gov/media/marine/rfax.pdf NOAA Worldwide Radiofax Guide]
-	* [~~http~~://www.~~nws.noaa~~.gov~~/om~~/marine/~~rfax.pdf Schedules and frequencies~~]	+	* [https://www.weather.gov/marine/uscg_broadcasts USCG Marine Weather Broadcasts] '''Note:''' Click on the ''USCG Radiofax'' link
		+

	{{CC-BY-SA-WP}}		{{CC-BY-SA-WP}}

	[[Category:Utility radio stations]]		[[Category:Utility radio stations]]

R4002 at 16:22, 23 January 2019

2019-01-23T16:22:25Z

← Older revision		Revision as of 16:22, 23 January 2019
Line 1:		Line 1:
-	'''Radiofax''', also known as '''weatherfax''' and '''HF fax''' ([[HF marine\|due to its common use in the short waves]]), is an analogue mode for transmitting images in grayscale. It is also related to slow-scan television ([[SSTV]]). The term weatherfax was coined after the technology that allows the transmission and reception of weather charts (surface analysis, forecasts, and others) from a transmission site (usually the meteorological office) to a remote site (where the actual users are).	+	'''Radiofax''', also known as '''weatherfax''' and '''HF fax''' ([[HF marine\|due to its common use in the short waves]]), is an analogue mode for transmitting images in grayscale. It is also related to slow-scan television ([[SSTV]]). The term weatherfax was coined after the technology that allows the transmission and reception of weather charts (surface analysis, forecasts, and others) from a transmission site (usually the meteorological office) to a remote site (where the actual users are).
		+
		+	Many of these products are used in conjunction with [[Maritime_Weather_Transmissions\|maritime weather transmissions]] in [[SSB]] voice (almost always USB mode) and [[RTTY]].

	Facsmile machines were used in the 1950s to transmit weather charts across the United States via land-lines first and then internationally via HF radio. Radio transmission of weather charts provides great flexibility to marine and aviation users, for they now have the latest weather information and forecasts at their disposal to use in the planning of voyages.		Facsmile machines were used in the 1950s to transmit weather charts across the United States via land-lines first and then internationally via HF radio. Radio transmission of weather charts provides great flexibility to marine and aviation users, for they now have the latest weather information and forecasts at their disposal to use in the planning of voyages.

R4002 at 16:19, 23 January 2019

2019-01-23T16:19:23Z

← Older revision		Revision as of 16:19, 23 January 2019
Line 1:		Line 1:
	'''Radiofax''', also known as '''weatherfax''' and '''HF fax''' ([[HF marine\|due to its common use in the short waves]]), is an analogue mode for transmitting images in grayscale. It is also related to slow-scan television ([[SSTV]]). The term weatherfax was coined after the technology that allows the transmission and reception of weather charts (surface analysis, forecasts, and others) from a transmission site (usually the meteorological office) to a remote site (where the actual users are).		'''Radiofax''', also known as '''weatherfax''' and '''HF fax''' ([[HF marine\|due to its common use in the short waves]]), is an analogue mode for transmitting images in grayscale. It is also related to slow-scan television ([[SSTV]]). The term weatherfax was coined after the technology that allows the transmission and reception of weather charts (surface analysis, forecasts, and others) from a transmission site (usually the meteorological office) to a remote site (where the actual users are).

-	Facsmile machines were used in the ~~1950's~~ to transmit weather charts across the United States via land-lines first and then internationally via HF radio. Radio transmission of weather charts provides great flexibility to marine and aviation users, for they now have the latest weather information and forecasts at their disposal to use in the planning of voyages.	+	Facsmile machines were used in the 1950s to transmit weather charts across the United States via land-lines first and then internationally via HF radio. Radio transmission of weather charts provides great flexibility to marine and aviation users, for they now have the latest weather information and forecasts at their disposal to use in the planning of voyages.

	Radiofax relies on facsimile technology, where printed information is scanned line by line and encoded into an electrical signal which can then be transmitted over land-line or via radio waves to great distances. Since the amount of information transmitted per unit time is directly proportional to the bandwidth available, the speed at which a weather chart can be transmitted varies depending on the quality of the media used for transmission.		Radiofax relies on facsimile technology, where printed information is scanned line by line and encoded into an electrical signal which can then be transmitted over land-line or via radio waves to great distances. Since the amount of information transmitted per unit time is directly proportional to the bandwidth available, the speed at which a weather chart can be transmitted varies depending on the quality of the media used for transmission.
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	[[Kyodo News]] is the only remaining news agency to transmit news via radiofax. It broadcasts complete newspapers in Japanese and English, often at 60 lines per minute instead of the more normal 120 because of the greater complexity of written Japanese. A full day's news takes hours to transmit. Kyodo has a dedicated transmission to Pacific fishing fleets from Kagoshima Prefectural Fishery Radio, and a relay from 9VF, possibly still in Singapore. The frequencies formerly used by JJC radio outside Tokyo are now sent from an unknown location, using the same identification in Japanese as 9VF. They are still active and heard daily in 2010.		[[Kyodo News]] is the only remaining news agency to transmit news via radiofax. It broadcasts complete newspapers in Japanese and English, often at 60 lines per minute instead of the more normal 120 because of the greater complexity of written Japanese. A full day's news takes hours to transmit. Kyodo has a dedicated transmission to Pacific fishing fleets from Kagoshima Prefectural Fishery Radio, and a relay from 9VF, possibly still in Singapore. The frequencies formerly used by JJC radio outside Tokyo are now sent from an unknown location, using the same identification in Japanese as 9VF. They are still active and heard daily in 2010.

-	The ''Joint Operational Meteorology & Oceanography Centre'', Nortwood, UK (callsign GYA) transmits various weather charts for the the Royal Navy on 2618.5, 4610.0, 6834.0, 8040.0, 11086.5, 12390.0 and 18261.0~~ ~~kHz. The charts cover North Atlantic, Europe and the Persian Gulf areas.	+	The ''Joint Operational Meteorology & Oceanography Centre'', Nortwood, UK (callsign GYA) transmits various weather charts for the the Royal Navy on 2618.5 kHz, 4610.0 kHz, 6834.0 kHz, 8040.0 kHz, 11086.5 kHz, 12390.0 kHz and 18261.0 kHz. The charts cover North Atlantic, Europe and the Persian Gulf areas.

	{\| border="1" cellspacing="0" cellpadding="5" align="center"		{\| border="1" cellspacing="0" cellpadding="5" align="center"

R4002: /* Transmission details */

2018-10-26T14:08:00Z

Transmission details

← Older revision		Revision as of 14:08, 26 October 2018
Line 8:		Line 8:

	== Transmission details ==		== Transmission details ==
-	Radiofax is transmitted in [[single sideband]] and uses [[frequency modulation]]. The signal shifts up or down a given amount to designate white or black pixels. A [[deviation]] less than that for a white or black pixel is taken to be a shade of grey. With correct tuning (1.9kHz below the carrier frequency for USB, above for LSB), the signal shares some characteristics with [[SSTV]], with black at 1500Hz and peak white at 2300Hz. The official [[ITU]] radio emission designation is '''F1C'''.	+	Radiofax is transmitted in [[SSB\|single sideband]] and uses [[FM\|frequency modulation]]. The signal shifts up or down a given amount to designate white or black pixels. A [[deviation]] less than that for a white or black pixel is taken to be a shade of grey. With correct tuning (1.9kHz below the carrier frequency for USB, above for LSB), the signal shares some characteristics with [[SSTV]], with black at 1500Hz and peak white at 2300Hz. The official [[ITU]] radio emission designation is '''F1C'''.

	Usually, 120 lines per minute (LPM) are sent (For monochrome fax, possible values are: 60, 90, 100, 120, 180, 240. For colour fax, LPM can be: 120, 240).<sup>[1]</sup> A value known as the ''index of cooperation'' (IOC) must also be known to decode a radio fax transmission - this governs the image resolution, and derives from early radio fax machines which used drum readers, and is the product of the total line length and the number of lines per unit length (known sometimes as the ''factor of cooperation''), divided by π (3.1416). Usually the IOC is 576.		Usually, 120 lines per minute (LPM) are sent (For monochrome fax, possible values are: 60, 90, 100, 120, 180, 240. For colour fax, LPM can be: 120, 240).<sup>[1]</sup> A value known as the ''index of cooperation'' (IOC) must also be known to decode a radio fax transmission - this governs the image resolution, and derives from early radio fax machines which used drum readers, and is the product of the total line length and the number of lines per unit length (known sometimes as the ''factor of cooperation''), divided by π (3.1416). Usually the IOC is 576.

R4002 at 14:03, 26 October 2018

2018-10-26T14:03:26Z

← Older revision		Revision as of 14:03, 26 October 2018
Line 1:		Line 1:
-	'''Radiofax''', also known as '''weatherfax''' and '''HF fax''' (due to its common use in the ~~[[HF marine\|~~short waves]]), is an analogue mode for transmitting images in grayscale. It is also related to slow-scan television ([[SSTV]]). The term weatherfax was coined after the technology that allows the transmission and reception of weather charts (surface analysis, forecasts, and others) from a transmission site (usually the meteorological office) to a remote site (where the actual users are).	+	'''Radiofax''', also known as '''weatherfax''' and '''HF fax''' ([[HF marine\|due to its common use in the short waves]]), is an analogue mode for transmitting images in grayscale. It is also related to slow-scan television ([[SSTV]]). The term weatherfax was coined after the technology that allows the transmission and reception of weather charts (surface analysis, forecasts, and others) from a transmission site (usually the meteorological office) to a remote site (where the actual users are).

	Facsmile machines were used in the 1950's to transmit weather charts across the United States via land-lines first and then internationally via HF radio. Radio transmission of weather charts provides great flexibility to marine and aviation users, for they now have the latest weather information and forecasts at their disposal to use in the planning of voyages.		Facsmile machines were used in the 1950's to transmit weather charts across the United States via land-lines first and then internationally via HF radio. Radio transmission of weather charts provides great flexibility to marine and aviation users, for they now have the latest weather information and forecasts at their disposal to use in the planning of voyages.

R4002 at 17:52, 12 October 2018

2018-10-12T17:52:58Z

← Older revision		Revision as of 17:52, 12 October 2018
Line 1:		Line 1:
-	'''Radiofax''', also known as '''weatherfax''' and '''HF fax''' (due to its common use in the short waves), is an analogue mode for transmitting images in grayscale. It is also related to slow-scan television ([[SSTV]]). The term weatherfax was coined after the technology that allows the transmission and reception of weather charts (surface analysis, forecasts, and others) from a transmission site (usually the meteorological office) to a remote site (where the actual users are).	+	'''Radiofax''', also known as '''weatherfax''' and '''HF fax''' (due to its common use in the [[HF marine\|short waves]]), is an analogue mode for transmitting images in grayscale. It is also related to slow-scan television ([[SSTV]]). The term weatherfax was coined after the technology that allows the transmission and reception of weather charts (surface analysis, forecasts, and others) from a transmission site (usually the meteorological office) to a remote site (where the actual users are).

	Facsmile machines were used in the 1950's to transmit weather charts across the United States via land-lines first and then internationally via HF radio. Radio transmission of weather charts provides great flexibility to marine and aviation users, for they now have the latest weather information and forecasts at their disposal to use in the planning of voyages.		Facsmile machines were used in the 1950's to transmit weather charts across the United States via land-lines first and then internationally via HF radio. Radio transmission of weather charts provides great flexibility to marine and aviation users, for they now have the latest weather information and forecasts at their disposal to use in the planning of voyages.

Strange Attractor at 19:49, 17 November 2013

2013-11-17T19:49:54Z

← Older revision		Revision as of 19:49, 17 November 2013
Line 1:		Line 1:
-	'''Radiofax''', also known as '''weatherfax''' and '''HF fax''' (due to its common use in the short waves), is an analogue mode for transmitting images in grayscale. It ~~was the predecessor~~ to slow-scan television ([[SSTV]]).	+	'''Radiofax''', also known as '''weatherfax''' and '''HF fax''' (due to its common use in the short waves), is an analogue mode for transmitting images in grayscale. It is also related to slow-scan television ([[SSTV]]). The term weatherfax was coined after the technology that allows the transmission and reception of weather charts (surface analysis, forecasts, and others) from a transmission site (usually the meteorological office) to a remote site (where the actual users are).

-	Facsmile machines were used in the 1950's to transmit weather charts across the United States via land-lines first and then internationally via HF radio. Radio transmission of weather charts provides ~~an enormous amount of~~ flexibility to marine and aviation users for they now have the latest weather information and forecasts at their ~~fingertips~~ to use in the planning of voyages.	+	Facsmile machines were used in the 1950's to transmit weather charts across the United States via land-lines first and then internationally via HF radio. Radio transmission of weather charts provides great flexibility to marine and aviation users, for they now have the latest weather information and forecasts at their disposal to use in the planning of voyages.

-	Radiofax relies on facsimile technology where printed information is scanned line by line and encoded into an electrical signal which can then be transmitted ~~via physical~~ line or radio waves to ~~remote locations~~. Since the amount of information transmitted per unit time is directly proportional to the bandwidth available, ~~then~~ the speed at which a weather chart can be transmitted ~~will vary~~ depending on the quality of the media used for transmission.	+	Radiofax relies on facsimile technology, where printed information is scanned line by line and encoded into an electrical signal which can then be transmitted over land-line or via radio waves to great distances. Since the amount of information transmitted per unit time is directly proportional to the bandwidth available, the speed at which a weather chart can be transmitted varies depending on the quality of the media used for transmission.

-	Today radiofax ~~data is~~ available via FTP downloads from sites in the Internet such as the ones hosted by the National Oceanic and Atmospheric Administration (NOAA). Radiofax transmissions are also broadcast by [[NOAA]] from multiple sites in the ~~country~~ at regular daily schedules. Radio weatherfax transmissions are particularly useful to shipping, where there are limited facilities for accessing the Internet.	+	Today radiofax charts and images are available via FTP or HTTP downloads from sites in the Internet, such as the ones hosted by the National Oceanic and Atmospheric Administration (NOAA). Radiofax transmissions are also broadcast by [[NOAA]] from multiple sites in the USA at regular daily schedules. Radio weatherfax transmissions are particularly useful to shipping, where there are limited facilities for accessing the Internet. The German Meteorological Service (DWD) is another major producer of FAX charts, which are also transmitted on HF frequecies from a location near Kiel.
-		+
-	The ~~term weatherfax was coined after the technology that allows the transmission and reception~~ of ~~weather~~ charts ~~(surface analysis~~, ~~forecasts, and others)~~ from a ~~transmission site (usually the meteorological office) to a remote site (where the actual users are)~~.	+

	== Transmission details ==		== Transmission details ==

Strange Attractor: /* Stations */

2010-07-23T05:30:41Z

Stations

← Older revision		Revision as of 05:30, 23 July 2010
Line 63:		Line 63:

	==Stations==		==Stations==
-	~~[[Image:HF-Fax 20100721 0525.png\|center\|640px]]~~	+
	Today, radiofax is primarily used worldwide for the dissemination of weather charts, satellite weather images, and forecasts to ships at sea. The oceans are covered by coastal stations in various countries.		Today, radiofax is primarily used worldwide for the dissemination of weather charts, satellite weather images, and forecasts to ships at sea. The oceans are covered by coastal stations in various countries.

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	The ''Joint Operational Meteorology & Oceanography Centre'', Nortwood, UK (callsign GYA) transmits various weather charts for the the Royal Navy on 2618.5, 4610.0, 6834.0, 8040.0, 11086.5, 12390.0 and 18261.0 kHz. The charts cover North Atlantic, Europe and the Persian Gulf areas.		The ''Joint Operational Meteorology & Oceanography Centre'', Nortwood, UK (callsign GYA) transmits various weather charts for the the Royal Navy on 2618.5, 4610.0, 6834.0, 8040.0, 11086.5, 12390.0 and 18261.0 kHz. The charts cover North Atlantic, Europe and the Persian Gulf areas.

-		+	{\| border="1" cellspacing="0" cellpadding="5" align="center"
		+	\|- style="background: #E7E7FF"
		+	! Callsign !! Frequency !! Power !! Program
		+	\|-
		+	\| GYA \|\| 2618.5 kHz \|\| 10 kW \|\| Europe (2000-0600 UTC)
		+	\|-
		+	\| GYA \|\| 4610.0 kHz\|\| 10 kW \|\| Europe (24h)
		+	\|-
		+	\| GYA \|\| 6834.0 kHz \|\| 10 kW \|\| Persian Gulf (1800-0800 UTC)
		+	\|-
		+	\| GYA \|\| 8040.0 kHz \|\| 10 kW \|\| Europe (24h)
		+	\|-
		+	\| GYA \|\| 11886.5 kHz\|\| 10 kW \|\| Europe (0600-2000 UTC)
		+	\|-
		+	\| GYA \|\| 12390.0 kHz \|\| 10 kW \|\| Persian Gulf (24h)
		+	\|-
		+	\| GYA \|\| 18261.0 kHz \|\| 10 kW \|\| Persian Gulf (0800-1800 UTC)
		+	\|-
		+	\|}

	==List of FAX transmissions==		==List of FAX transmissions==