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Radiofacsimile, radiofax or HF fax is an analogue mode for transmitting
monochrome A monochrome or monochromatic image, object or palette is composed of one color (or values of one color). Images using only shades of grey are called grayscale (typically digital) or black-and-white (typically analog). In physics, monochrom ...
images via high frequency (HF) radio waves. It was the predecessor to
slow-scan television Slow-scan television (SSTV) is a picture transmission method, used mainly by amateur radio operators, to transmit and receive static pictures via radio in monochrome or color. A literal term for SSTV is narrowband television. Analog broadcast tel ...
(SSTV). It was the primary method of sending photographs from remote sites (especially islands) from the 1930s to the early 1970s. It is still in limited use for transmitting weather charts and information to ships at sea.


History

Richard H. Ranger, an electrical engineer working at
Radio Corporation of America The RCA Corporation was a major American electronics company, which was founded as the Radio Corporation of America in 1919. It was initially a patent trust owned by General Electric (GE), Westinghouse, AT&T Corporation and United Fruit Com ...
(RCA), invented a method for sending photographs through radio transmissions. He called his system the wireless photoradiogram, in contrast to the fifty-year-old telefacsimile devices which used first
telegraph Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message. Thus flag semaphore is a method of telegraphy, whereas p ...
ic wires, and then later was adapted to use the newer
telephone A telephone is a telecommunications device that permits two or more users to conduct a conversation when they are too far apart to be easily heard directly. A telephone converts sound, typically and most efficiently the human voice, into e ...
wires. On 29 November 1924, Ranger's system was used to send a photograph from New York City to London. It was an image of President Calvin Coolidge and was the first transoceanic radio transmission of a photograph. Also that year,
AT&T AT&T Inc. is an American multinational telecommunications holding company headquartered at Whitacre Tower in Downtown Dallas, Texas. It is the world's largest telecommunications company by revenue and the third largest provider of mobile te ...
engineer
Herbert E. Ives Herbert Eugene Ives (July 31, 1882 – November 13, 1953) was a scientist and engineer who headed the development of facsimile and television systems at AT&T in the first half of the twentieth century. He is best known for the 1938 Ives–Stilwel ...
transmitted the first color photograph.Sipley, Louis Walton (1951). ''A Half Century of Color''. Macmillan. Charles J. Young, son of the RCA founder Owen D. Young, and Dr
Ernst Alexanderson Ernst Frederick Werner Alexanderson (January 25, 1878 – May 14, 1975) was a Swedish-American electrical engineer, who was a pioneer in radio and television development. He invented the Alexanderson alternator, an early radio transmitter used ...
, developed a radio facsimile system for
General Electric General Electric Company (GE) is an American multinational conglomerate founded in 1892, and incorporated in New York state and headquartered in Boston. The company operated in sectors including healthcare, aviation, power, renewable en ...
. On 12 August 1931 this system successfully transmitted a copy of the ''Union-Star'' newspaper of
Schenectady, New York Schenectady () is a city in Schenectady County, New York, United States, of which it is the county seat. As of the 2020 census, the city's population of 67,047 made it the state's ninth-largest city by population. The city is in eastern New Y ...
to the transatlantic liners and . It took 15 minutes to copy a single page measuring . The Finch Facsimile system was introduced in the late 1930s, and used to transmit a "radio newspaper" to private homes. The system used ordinary, home, radio-receivers equipped with Finch's thermal paper printer. The radiofacsimile of the newspaper was transmitted by commercial AM radio stations.Schneider, John (2011)
"The Newspaper of the Air: Early Experiments with Radio Facsimile"
theradiohistorian.org. Retrieved May 15, 2017
During
World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...
thousands of photographs were transmitted from Europe, and from the Pacific Islands, to the United States. The major
news agencies A news agency is an organization that gathers news reports and sells them to subscribing news organizations, such as newspapers, magazines and radio and television broadcasters. A news agency may also be referred to as a wire service, newswire, ...
( AP,
UPI United Press International (UPI) is an American international news agency whose newswires, photo, news film, and audio services provided news material to thousands of newspapers, magazines, radio and television stations for most of the 20th c ...
,
Reuters Reuters ( ) is a news agency owned by Thomson Reuters Corporation. It employs around 2,500 journalists and 600 photojournalists in about 200 locations worldwide. Reuters is one of the largest news agencies in the world. The agency was esta ...
), maintained their own transoceanic radio facsimile transmitters as close to the action as they could. The iconic flag raising on Iwo Jima was printed in hundreds of American newspapers within a day of being taken, because it was transmitted from
Guam Guam (; ch, Guåhan ) is an organized, unincorporated territory of the United States in the Micronesia subregion of the western Pacific Ocean. It is the westernmost point and territory of the United States (reckoned from the geographic cent ...
to
New York City New York, often called New York City or NYC, is the most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the most densely populated major city in the Un ...
by wireless radiofacsimile, a distance of 12,781 km (7,942 mi). Beginning in the late 1930s, the Finch Facsimile system was used to transmit a "radio newspaper" to private homes via commercial AM radio stations and ordinary radio receivers equipped with Finch's printer, which used thermal paper. Sensing a new and potentially golden opportunity, competitors soon entered the field, but the printer and special paper were expensive luxuries, AM radio transmission was very slow and vulnerable to static, and the newspaper was too small. After more than ten years of repeated attempts by Finch and others to establish such a service as a viable business, the public, apparently quite content with its cheaper and much more substantial home-delivered daily newspapers, and with conventional spoken radio bulletins to provide any "hot" news, still showed only a passing curiosity about the new medium. By the late 1940s, radiofax receivers were sufficiently miniaturized to be fitted beneath the dashboard of
Western Union The Western Union Company is an American multinational financial services company, headquartered in Denver, Colorado. Founded in 1851 as the New York and Mississippi Valley Printing Telegraph Company in Rochester, New York, the company cha ...
's "Telecar"
telegram Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message. Thus flag semaphore is a method of telegraphy, whereas ...
delivery vehicles.G. H. Ridings
A Facsimile transceiver for Pickup and Delivery of Telegrams
(January 1949); page 17-26.
In the 1960s, the
United States Army The United States Army (USA) is the land warfare, land military branch, service branch of the United States Armed Forces. It is one of the eight Uniformed services of the United States, U.S. uniformed services, and is designated as the Army o ...
transmitted the first photograph via satellite facsimile to
Puerto Rico Puerto Rico (; abbreviated PR; tnq, Boriken, ''Borinquen''), officially the Commonwealth of Puerto Rico ( es, link=yes, Estado Libre Asociado de Puerto Rico, lit=Free Associated State of Puerto Rico), is a Caribbean island and unincorporated ...
from the Deal Test Site using the Courier satellite.


Weatherfax

A decade after the introduction of radiofax
National Weather Service The National Weather Service (NWS) is an agency of the United States federal government that is tasked with providing weather forecasts, warnings of hazardous weather, and other weather-related products to organizations and the public for the ...
(NWS) began transmitting weather maps using the radiofax technology. The NWS named this new service weatherfax (
portmanteau A portmanteau word, or portmanteau (, ) is a blend of wordsweather Weather is the state of the atmosphere, describing for example the degree to which it is hot or cold, wet or dry, calm or stormy, clear or cloud cover, cloudy. On Earth, most weather phenomena occur in the lowest layer of the planet's atmos ...
facsimile") The cover of the regular NOAA publication on frequencies and schedules states "Worldwide Marine Radiofacsimile Broadcast Schedules". Facsimile 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 an enormous amount of flexibility to marine and
aviation Aviation includes the activities surrounding mechanical flight and the aircraft industry. ''Aircraft'' includes fixed-wing and rotary-wing types, morphable wings, wing-less lifting bodies, as well as lighter-than-air craft such as hot a ...
users for they now have the latest weather information and
forecasts Forecasting is the process of making predictions based on past and present data. Later these can be compared (resolved) against what happens. For example, a company might estimate their revenue in the next year, then compare it against the actual ...
at their fingertips 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 Bandwidth commonly refers to: * Bandwidth (signal processing) or ''analog bandwidth'', ''frequency bandwidth'', or ''radio bandwidth'', a measure of the width of a frequency range * Bandwidth (computing), the rate of data transfer, bit rate or thr ...
available, then the speed at which a weather chart can be transmitted will vary depending on the quality of the media used for transmission. Today radiofax data is available via
FTP The File Transfer Protocol (FTP) is a standard communication protocol used for the transfer of computer files from a server to a client on a computer network. FTP is built on a client–server model architecture using separate control and data ...
downloads from sites in the
Internet The Internet (or internet) is the global system of interconnected computer networks that uses the Internet protocol suite (TCP/IP) to communicate between networks and devices. It is a '' network of networks'' that consists of private, pub ...
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. The term weatherfax was coined after the technology that allows the transmission and reception of weather charts (
surface analysis A surface, as the term is most generally used, is the outermost or uppermost layer of a physical object or space. It is the portion or region of the object that can first be perceived by an observer using the senses of sight and touch, and is ...
, forecasts, and others) from a transmission site (usually the meteorological office) to a remote site (where the actual users are).


Transmission details

Radiofax is transmitted in
single sideband In radio communications, single-sideband modulation (SSB) or single-sideband suppressed-carrier modulation (SSB-SC) is a type of modulation used to transmit information, such as an audio signal, by radio waves. A refinement of amplitude m ...
which is a refinement of amplitude 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 (1.9 kHz below the assigned frequency for USB, above for LSB), the signal shares some characteristics with SSTV, with black at 1500 Hz and peak white at 2300 Hz. 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). 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. Usually the IOC is 576.


Automatic Picture Transmission format (APT)

APT format permits unattended monitoring of services. It is employed by most terrestrial weather facsimile stations as well as geostationary weather satellites. * The start tone triggers the receiving system. It was originally meant to allow enough time for the drum of mechanical systems to get up to speed. It consists of rapid modulation of the video carrier, resulting in a characteristic rasp-like sound. * The phasing signal, consisting of a periodic pulse, synchronizes the receiver so that the image will be centered on the paper. * The stop tone, optionally followed by black, marks the end of the transmission.


Stations

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. In the United States, fax weather products are prepared by a number of offices, branches, and agencies within the
National Weather Service The National Weather Service (NWS) is an agency of the United States federal government that is tasked with providing weather forecasts, warnings of hazardous weather, and other weather-related products to organizations and the public for the ...
(NWS) of the
National Oceanic and Atmospheric Administration The National Oceanic and Atmospheric Administration (abbreviated as NOAA ) is an United States scientific and regulatory agency within the United States Department of Commerce that forecasts weather, monitors oceanic and atmospheric conditio ...
(NOAA). Tropical and hurricane products come from the Tropical Analysis and Forecast Branch, part of the Tropical Prediction Center/National Hurricane Center. They are broadcast over US Coast Guard communication stations NMG, in
New Orleans New Orleans ( , ,New Orleans
, LA, and NMC, the Pacific master station on Point Reyes, CA. After Hurricane Katrina damaged NMG, the Boston Coast Guard station NMF added a limited schedule of tropical warning charts. NMG is back at full capability, but NMF continues to broadcast these. All other products come from the
Ocean Prediction Center The Ocean Prediction Center (OPC), established in 1995, is one of the National Centers for Environmental Prediction's (NCEP's) original six service centers. Until 2003, the name of the organization was the Marine Prediction Center.Ocean Predictio ...
(OPC) of the NWS, in cooperation with several other offices depending on the region and nature of information. These also use NMG, NMC, and NMF, plus Coast Guard station NOJ in
Kodiak, Alaska Kodiak ( Alutiiq: , russian: Кадьяк), formerly Paul's Harbor, is the main city and one of seven communities on Kodiak Island in Kodiak Island Borough, Alaska. All commercial transportation between the island's communities and the outside ...
, and Department of Defense station KVM70 in
Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state ...
. Ever since the RMS ''Titanic'' dramatized the dangers of icebergs in the North Atlantic, an
International Ice Patrol The International Ice Patrol is an organization with the purpose of monitoring the presence of icebergs in the Atlantic and Arctic Oceans and reporting their movements for safety purposes. It is operated by United States Coast Guard but is fun ...
has also originated weather data, and its charts are broadcast by the Boston station during the prime iceberg season of February through September, using the callsign NIK. A major producer of Canadian radiofax is the Canadian Forces METOC (Meteorology and Oceanography Centre) in Halifax, NS, using the communication station CFH. Charts are sent on the hour, then the station switches to
radioteletype Radioteletype (RTTY) is a telecommunications system consisting originally of two or more electromechanical teleprinters in different locations connected by radio rather than a wired link. Radioteletype evolved from earlier landline teleprinter ...
(RTTY) for the rest of the period. CBV, Playa Ancha Radio in Valparaiso,
Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...
broadcasts a daily schedule of Armada de Chile weather fax for the southeastern Pacific, all the way to the Antarctic. Also in the Pacific, Japan has two stations, as does the Bureau of Meteorology in Australia. Most European countries have stations, as does
Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-eig ...
. 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 Singapore (), officially the Republic of Singapore, is a sovereign island country and city-state in maritime Southeast Asia. It lies about one degree of latitude () north of the equator, off the southern tip of the Malay Peninsula, bor ...
. The German Meteorological Service (Deutscher Wetterdienst, DWD) transmits a regular daily schedule of weather charts on three frequencies 3855.0 kHz, 7880.0 kHz and 13882.5 kHz from their LF and HF transmitting facility in
Pinneberg Pinneberg (; Northern Low Saxon: ''Pinnbarg'') is a town in the federal state of Schleswig-Holstein in northern Germany. It is the capital of the district of Pinneberg and has a population of about 43,500 inhabitants. Pinneberg is located 18&nbs ...
.


History

*1911: The first amplitude modulator for fax machines is patented, permitting transmission via telephone lines. *1913: Edouard Belin's Belinograph *1922: The first transatlantic facsimile services was provided by RCA. *1922–1925: RCA faxes photos across the Atlantic in six minutes; AT&T, RCA and Western Union develop "high-speed" fax systems. Dr Arthur Korn's facsimile system is used to transmit, by radio, a photograph of Pope Pius XI from Rome to Maine, USA. The picture is published the same day in the New York World newspaper—a major feat in an era when news pictures crossed the ocean by ship. * 1925: AT&T wirephoto starts operations * 1926: RCA radiophoto starts operations * 1926:
Rudolf Hell Rudolf Hell (19 December 1901 – 11 March 2002) was a German inventor and engineer. Career Hell was born in Eggmühl. From 1919 to 1923, he studied electrical engineering in Munich. He worked there from 1923 to 1929 as assistant of Prof. ...
introduced the
Hellschreiber The Hellschreiber, Feldhellschreiber or Typenbildfeldfernschreiber (also Hell-Schreiber named after its inventor Rudolf Hell) is a facsimile-based teleprinter invented by Rudolf Hell. Compared to contemporary teleprinters that were based on ty ...
. * 1927: First Siemens-Karolus-Telefunken facsimile between Berlin and other European cities * 1937: First broadcast of a radiofax newspaper, in the Minneapolis/St-Paul area * 1939: W9XZY St. Louis delivers First Daily Newspaper by Radio Facsimile. More than 1,000 U.S. households are experimentally equipped with fax receivers that electronically print morning newspapers overnight. * 1941: Fax is enlisted by the military to transmit maps, orders and weather charts during World War II. * 1947: Alexander Muirhead's fax * 1948:
Western Union The Western Union Company is an American multinational financial services company, headquartered in Denver, Colorado. Founded in 1851 as the New York and Mississippi Valley Printing Telegraph Company in Rochester, New York, the company cha ...
installs fax machines in "Telecar"
telegram Telegraphy is the long-distance transmission of messages where the sender uses symbolic codes, known to the recipient, rather than a physical exchange of an object bearing the message. Thus flag semaphore is a method of telegraphy, whereas ...
delivery vehicles.G. H. Ridings
A Facsimile transceiver for Pickup and Delivery of Telegrams
(January 1949); pages 17-26; see page 20.
* 1960: First SSTV test transmissions in the USA * 1966: First photographs from the surface of the Moon, transmitted by
Luna 9 Luna 9 (Луна-9), internal designation Ye-6 No.13, was an uncrewed space mission of the Soviet Union's Luna programme. On 3 February 1966, the Luna 9 spacecraft became the first spacecraft to achieve a survivable landing on a celestial body ...
using radiofax format * 1972: First SSTV transmissions in Germany


See also

*
Hellschreiber The Hellschreiber, Feldhellschreiber or Typenbildfeldfernschreiber (also Hell-Schreiber named after its inventor Rudolf Hell) is a facsimile-based teleprinter invented by Rudolf Hell. Compared to contemporary teleprinters that were based on ty ...
*
Navtex NAVTEX (NAVigational TEleX), sometimes styled Navtex or NavTex, is an international automated medium frequency direct-printing service for delivery of navigational and meteorological warnings and forecasts, as well as urgent maritime safety inf ...
*
Slow-scan television Slow-scan television (SSTV) is a picture transmission method, used mainly by amateur radio operators, to transmit and receive static pictures via radio in monochrome or color. A literal term for SSTV is narrowband television. Analog broadcast tel ...


References


External links

* DDH47 - article about the German Meteorological Service FAX & RTTY transmissions on de-wiki.
Facsimile & SSTV HistoryMarine Weatherfax NOAA broadcastsNOAA Schedules and frequencies
(2016-11-09)
Marine Weatherfax Chart Viewer for iPad
{{Authority control Radio electronics Fax Navigational aids