Amateur Radio Direction Finding
Encyclopedia
Amateur radio
direction finding (ARDF, also known as radio orienteering and radiosport
) is an amateur racing sport that combines radio direction finding with the map and compass skills of orienteering
. It is a timed race in which individual competitors use a topographic map
, a magnetic compass
and radio direction finding apparatus to navigate through diverse wooded terrain while searching for radio transmitters. The rules of the sport and international competitions are organized by the International Amateur Radio Union
. The sport has been most popular in Eastern Europe
, Russia
, and China
, where it was often used in the physical education
programs in schools.
ARDF events use radio frequencies
on either the two-meter
or eighty-meter
amateur radio bands. These two bands were chosen because of their universal availability to amateur radio licensees in all countries. In the UK events with somewhat different rules are also run on 160 meters
. The radio equipment carried by competitors on a course must be capable of receiving the signal being transmitted by the five transmitters and useful for radio direction finding, including a radio receiver, attenuator, and directional antenna
. Most equipment designs integrate all three components into one handheld device.
The sport originated in Northern Europe and Eastern Europe
in the late 1950s. Amateur radio
was widely promoted in the schools of Northern and Eastern Europe as a modern scientific and technical activity. Most medium to large cities hosted one or more amateur radio clubs at which members could congregate and learn about the technology and operation of radio equipment. One of the activities that schools and radio clubs promoted was radio direction finding, an activity that had important civil defense
applications during the Cold War
. As few individuals in Europe had personal automobiles at the time, most of this radio direction finding activity took place on foot, in parks, natural areas, or school campuses. The sport of orienteering
, popular in its native Scandinavia
, had begun to spread to more and more countries throughout Europe
, including the nations of the Eastern Bloc
. As orienteering became more popular and orienteering map
s became more widely available, it was only natural to combine the two activities and hold radio direction finding events on orienteering maps.
Interest in this kind of on-foot radio direction finding activity using detailed topographic maps for navigation spread throughout Scandinavia, Eastern and Central Europe
, the Soviet Union
, and the People's Republic of China
. Formal rules for the sport were first proposed in England
and Denmark
in the 1950s. The first European Championship in the sport was held in 1961 in Stockholm
, Sweden
. Four additional international championships were held in Europe in the 1960s, and three more were held in the 1970s. The first World Championship was held in 1980 in Cetniewo, Poland
, where competitors from eleven European and Asia
n countries participated. World Championships have been generally held in even-numbered years since 1984, although there was no World Championship in 1996, and there was a World Championship in 1997. Asian nations began sending national teams to international events in 1980, and teams from nations in Oceania
and North America
began competing in the 1990s. Athletes from twenty-six nations attended the 2000 World Championship in Nanjing
, China, the first to be held outside of Europe.
As the sport grew in the 1960s and 1970s, each nation devised its own set of rules and regulations. The need for more clearly defined and consistent rules for international competitions led to the formation of an ARDF working group by the International Amateur Radio Union
(IARU) in the late 1970s. The first ARDF event to use the new standardized rules was the 1980 World Championship. These rules have been revised and updated over the years, increasing the number of gender and age categories into which competitors are classified, as well as formalizing the start and finish line procedures. While some variations exist, these standardized rules have since been used worldwide for ARDF competitions, and the IARU has become the principal international organization promoting the sport. The IARU divides the world into three regions for administrative purposes. These regions correspond with the three regions used by the International Telecommunications Union for its regulatory purposes, but the IARU has also used these regions for sports administration. The first IARU Region I (Europe, Africa
, the Middle East
, and ex-USSR) Championship was held in 1993 in Chtelnica, Slovakia, the first IARU Region III (Asia and Oceania) Championship was held in 1993 in Beijing, China, and the first IARU Region II (North and South America
) Championship was held in 1999 in Portland, Oregon, USA. In addition to participation in international events, most nations with active ARDF organizations hold annual national championships using the IARU rules.
ARDF is a sport that spans much of the globe. Over 400 athletes from twenty-nine countries, representing four continents, entered the 2004 World Championship held in the Czech Republic
. Organized ARDF competitions can be found in almost every European country and in all the nations of northern and eastern Asia. ARDF activity is also found in Thailand
, Australia
, New Zealand
, Canada
, and the United States
. Although they represent a broad range of amateur radio interests in their nations today, several member societies of the International Amateur Radio Union were originally formed for the promotion and organization of the sport and continue to use the term radiosport in their society name. These include the Federation of Radiosport of the Republic of Armenia (FRRA), the Belarusian Federation of Radioamateurs and Radiosportsmen (BFRR), the Chinese Radio Sports Association (CRSA), and the Mongolian Radio Sport Federation (MRSF). To promote the sport, the IARU has delegated individuals as ARDF Coordinators for each IARU region to help educate and organize national radio societies and other ARDF groups, especially in nations without prior activity in the sport.
An ARDF competition takes place in diverse wooded terrain, such as in a public park or natural area. Each competitor receives a detailed topographic map of the competition area. The map will indicate the location of the start with a triangle and the location of the finish with two concentric circles. Somewhere within the competition area designated on the map, the meet organizer will have placed five low power radio transmitters. The locations of the transmitters are kept a secret from the competitors and are not marked on the map. Each transmitter emits a signal in Morse code
by which it is easily identifiable to the competitors. The transmitters automatically transmit one after another in a repeating cycle. Depending on entry classification, a competitor will attempt to locate as many as three, four, or all five of the transmitters in the woods, and then travel to the finish line in the shortest possible time. Competitors start at staggered intervals, are individually timed, and are expected to perform all radio direction finding and navigation skills on their own. Standings are determined first by the number of transmitters found, then by shortest time on course. Competitors who take longer than the specified time limit to finish may be disqualified.
ARDF events use radio frequencies
on either the 2-meter or 80-meter amateur radio bands. These two bands were chosen because of their universal availability to amateur radio licensees in all countries. Each band requires different radio equipment for transmission
and reception
, and requires the use of different radio direction finding skills. Radio direction finding equipment for eighty meters, an HF
band, is relatively easy to design and inexpensive to build. Bearings
taken on eighty meters can be very accurate. Competitors on an eighty meter course must use bearings to determine the locations of the transmitters and choose the fastest route through the terrain to visit them. Two meters, a VHF
band, requires equipment that is relatively more complicated to design and more expensive to build. Radio signals on two meters are more affected by features of the terrain. Competitors on a two meter course must learn to differentiate between accurate, direct bearings to the source of the radio signal and false bearings resulting from reflections of the signal off hillsides, ravines, buildings, or fences. Large national or international events will have one day of competition using a 2-meter frequency and one day of competition using an 80-meter frequency.
In addition to the rules of the sport, ARDF competitions must also comply with radio regulations. Because the transmitters operate on frequencies assigned to the Amateur Radio Service, a radio amateur with a license that is valid for the country in which the competition is taking place must be present and responsible for their operation. Individual competitors, however, are generally not required to have amateur radio licences, as the use of simple handheld radio receivers does not typically require a license. Regulatory prohibitions on the use of amateur radio frequencies for commercial use generally preclude the awarding of monetary prizes to competitors. Typical awards for ARDF events are medals, trophies, plaques, or certificates.
Although all competitors at an ARDF event use the same competition area and listen to the same set of five transmitters, they do not all compete in the same category. Current IARU rules divide entrants into different categories based on their age and gender. Only the M21 category must locate all five transmitters, while the other categories may skip only a specified transmitter or transmitters.
instead of amplitude modulation
for the transmission of the Morse code identifications.
Ideally, the topographic maps used in ARDF competitions are created to the standards set by the International Orienteering Federation
and used for orienteering competitions. In fact, many ARDF competitions use existing orienteering map
s, in collaboration with the orienteering clubs that created those maps.
Course design is an important element of a successful competition. The international rules adopted by the IARU include both requirements and recommendations for basic course design. Important requirements are that no transmitter may be within 750 meters of the start, no transmitter may be within 400 meters of the finish or any other transmitter on course, and that there is no more than 200 meters elevation change between the start, finish, and all transmitters. The IARU rules for international competitions recommend that courses be designed for six to ten kilometers of total travel distance through the terrain. A well-designed course will present the competitors with an athletic challenge in addition to the challenges of land navigation and radio direction finding. Depending on the course design and competition, winning times at World Championship events are often less than 90 minutes for two meter courses, and can be under 60 minutes for eighty meter courses.
s, from published designs or kits is also a popular activity. Clothing and other equipment is sold through specialty orienteering equipment suppliers or general outdoor sports retailers.
ARDF transmitters have a low power output and operate in either the two meter or eighty meter amateur radio band. The transmissions are in Morse code
. Each transmitter sends a unique identification that can be easily interpreted even by those unfamiliar with the Morse code by counting the number of dits that follow a series of dashes. The transmitters on course all transmit on the same frequency and each transmit in sequence for one minute at a time in a repeating cycle. Within a few meters of each transmitter, an orienteering control flag and punch device will be present. The punch device is either a paper punch with which competitors will mark a special card they carry with them, or an electronic recording device that competitors will use to record their visit on a small magnetic storage device they carry with them. Competitors need to locate the control flag at the transmitter site and use the punch device to record their visit. Good course design will attempt to preclude, as much as possible, runners interfering with the transmitter equipment as they approach the control. At large international or national events, jurors might be present at transmitter controls to ensure fair play.
The IARU rules include detailed technical specifications for transmitter equipment. Transmitters for two meters are typically 0.25 to 1 watt
s power output, and use keyed amplitude modulation. The transmitter antennas used on two meters must be horizontally polarized and omnidirectional
. Transmitters for eighty meters are typically one to five watts power output keyed CW
modulation. The transmitter antennas used on eighty meters must be vertically polarized and omnidirectional. It is common for the transmitter, a battery
, and any controlling hardware to be placed inside a weatherproof container such as an old ammunition case or large plastic food storage container for protection from the elements and wildlife.
The radio equipment carried on course must be capable of receiving the signal being transmitted by the five transmitters and useful for radio direction finding. This includes a radio receiver that can tune in the specific frequency of transmission being used for the event, an attenuator
or variable gain control, and a directional antenna
. Directional antennas are more sensitive to radio signals arriving from some directions than others. Most equipment designs integrate all three components into one handheld device. On the two meter band, the most common directional antennas used by competitors are two or three element Yagi antenna
s made from flexible steel tape. This kind of antenna
has a cardioid
receiving pattern
, which means that it has one peak direction where the received signal will be the strongest, and a null direction, 180° from the peak, in which the received signal will be the weakest. Flexible steel tape enables the antenna elements to flex and not break when encountering vegetation in the forest. On the eighty meter band, two common receiver design approaches are to use either a small loop antenna or an even smaller loop antenna wound around a ferrite
rod. These antennas have a bidirectional receiving pattern, with two peak directions 180° apart from one another and two null directions 180° apart from one another. The peak directions are 90° offset from the null directions. A small vertical antenna element can be combined with the loop or ferrite rod antenna to change the receiving pattern to a cardioid shape, but the resulting null in the cardioid is not as sensitive as the nulls in the bidirectional receiving pattern. A switch is often used to allow the competitor to select the bidirectional or cardioid patterns at any moment. ARDF receiver equipment is designed to be lightweight and easy to operate while the competitor is in motion as well as rugged enough to withstand use in areas of thick vegetation.
pants, shirts, or suits, gaiters
or padded socks for lower leg protection, and specialty shoes for cross-country running through wooded terrain are popular choices. Some competitors may choose to carry food or water on course, and wear a small waist pack or hydration pack for this purpose. At large international or national events, competitors may be required by the meet director to wear identifying numbers pinned to their clothing, and many wear team uniforms in their national colors.
equipment on course is prohibited. All competitors are encouraged to wear a watch to keep track of their time on course and not finish over the time limit set for the competition.
is a variation of the sport that requires more orienteering skills. In a Fox Oring course, the radio transmitters put out very little power, and can be received over only very short distances, often no more than 100 meters. The location of each transmitter will be indicated on the map with a circle. The transmitter does not need to be exactly at the circle's center or even located inside the circle, but one should be able to receive its transmissions everywhere within the area indicated by the circle. A competitor must use orienteering skills to navigate to the area of the circle on the map and only then use radio direction finding skills to locate the very low power transmitter.
Another variation of the sport, Radio Orienteering in a Compact Area
, requires less athletic skill and more technical radio direction finding skills. In a ROCA course, the transmitters put out very little power, typically 10 to 200 mW, and can be received over only very short distances. The transmitters are physically small, and marked with a control card that is no larger than a typical postcard with a unique number identification. Because of the low power and short distances involved, most ROCA competitors walk the entire course, and focus their attention on the radio direction finding tasks rather than navigation.
Another form of recreational radio direction finding activity in North America that includes the use of automobiles for transportation is most often referred to as foxhunting or transmitter hunting
, but is sometimes confused with the organized international sport of amateur radio direction finding.
ARDF Events
ARDF Information
Amateur radio
Amateur radio is the use of designated radio frequency spectrum for purposes of private recreation, non-commercial exchange of messages, wireless experimentation, self-training, and emergency communication...
direction finding (ARDF, also known as radio orienteering and radiosport
Radiosport
The term radiosport is of modern Eastern European origin and is used to describe any of several competitive amateur radio activities. It is most often written as a single word, as in radiosport, but can be found as two separate words, as in radio sport.The Friendship Radiosport Games is a...
) is an amateur racing sport that combines radio direction finding with the map and compass skills of orienteering
Orienteering
Orienteering is a family of sports that requires navigational skills using a map and compass to navigate from point to point in diverse and usually unfamiliar terrain, and normally moving at speed. Participants are given a topographical map, usually a specially prepared orienteering map, which they...
. It is a timed race in which individual competitors use a topographic map
Topographic map
A topographic map is a type of map characterized by large-scale detail and quantitative representation of relief, usually using contour lines in modern mapping, but historically using a variety of methods. Traditional definitions require a topographic map to show both natural and man-made features...
, a magnetic compass
Compass
A compass is a navigational instrument that shows directions in a frame of reference that is stationary relative to the surface of the earth. The frame of reference defines the four cardinal directions – north, south, east, and west. Intermediate directions are also defined...
and radio direction finding apparatus to navigate through diverse wooded terrain while searching for radio transmitters. The rules of the sport and international competitions are organized by the International Amateur Radio Union
International Amateur Radio Union
The International Amateur Radio Union is an international confederation of national amateur radio organisations that allows a forum for common matters of concern and collectively represents matters to the International Telecommunication Union...
. The sport has been most popular in Eastern Europe
Eastern Europe
Eastern Europe is the eastern part of Europe. The term has widely disparate geopolitical, geographical, cultural and socioeconomic readings, which makes it highly context-dependent and even volatile, and there are "almost as many definitions of Eastern Europe as there are scholars of the region"...
, Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
, and China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
, where it was often used in the physical education
Physical education
Physical education or gymnastics is a course taken during primary and secondary education that encourages psychomotor learning in a play or movement exploration setting....
programs in schools.
ARDF events use radio frequencies
Radio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...
on either the two-meter
2 meters
The 2-meter amateur radio band is a portion of the VHF radio spectrum, comprising frequencies stretching from 144.000 MHz to 148.000 MHz in International Telecommunication Union region Regions 2 and 3 and from 144.000 MHz to 146.000 MHz in ITU Region 1...
or eighty-meter
80 meters
The 80 meter or 3.5 MHz band is a core amateur radio frequency band, allocated frequencies from 3.5 to 4.0 MHz in IARU Region 2, and generally 3.5 to 3.8 or 3.9 MHz in Regions 1 and 3 respectively. The portion of the band used for phone communications is sometimes referred to as 75 meters...
amateur radio bands. These two bands were chosen because of their universal availability to amateur radio licensees in all countries. In the UK events with somewhat different rules are also run on 160 meters
160 meters
Just above the mediumwave broadcast band, 160 meters is the lowest radio frequency band allocation available to amateur radio operators in most countries. Seasoned operators often refer to 160 meters as the Top Band...
. The radio equipment carried by competitors on a course must be capable of receiving the signal being transmitted by the five transmitters and useful for radio direction finding, including a radio receiver, attenuator, and directional antenna
Directional antenna
A directional antenna or beam antenna is an antenna which radiates greater power in one or more directions allowing for increased performance on transmit and receive and reduced interference from unwanted sources....
. Most equipment designs integrate all three components into one handheld device.
History
Eastern Europe
Eastern Europe is the eastern part of Europe. The term has widely disparate geopolitical, geographical, cultural and socioeconomic readings, which makes it highly context-dependent and even volatile, and there are "almost as many definitions of Eastern Europe as there are scholars of the region"...
in the late 1950s. Amateur radio
Amateur radio
Amateur radio is the use of designated radio frequency spectrum for purposes of private recreation, non-commercial exchange of messages, wireless experimentation, self-training, and emergency communication...
was widely promoted in the schools of Northern and Eastern Europe as a modern scientific and technical activity. Most medium to large cities hosted one or more amateur radio clubs at which members could congregate and learn about the technology and operation of radio equipment. One of the activities that schools and radio clubs promoted was radio direction finding, an activity that had important civil defense
Civil defense
Civil defense, civil defence or civil protection is an effort to protect the citizens of a state from military attack. It uses the principles of emergency operations: prevention, mitigation, preparation, response, or emergency evacuation, and recovery...
applications during the Cold War
Cold War
The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...
. As few individuals in Europe had personal automobiles at the time, most of this radio direction finding activity took place on foot, in parks, natural areas, or school campuses. The sport of orienteering
Orienteering
Orienteering is a family of sports that requires navigational skills using a map and compass to navigate from point to point in diverse and usually unfamiliar terrain, and normally moving at speed. Participants are given a topographical map, usually a specially prepared orienteering map, which they...
, popular in its native Scandinavia
Scandinavia
Scandinavia is a cultural, historical and ethno-linguistic region in northern Europe that includes the three kingdoms of Denmark, Norway and Sweden, characterized by their common ethno-cultural heritage and language. Modern Norway and Sweden proper are situated on the Scandinavian Peninsula,...
, had begun to spread to more and more countries throughout Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, including the nations of the Eastern Bloc
Eastern bloc
The term Eastern Bloc or Communist Bloc refers to the former communist states of Eastern and Central Europe, generally the Soviet Union and the countries of the Warsaw Pact...
. As orienteering became more popular and orienteering map
Orienteering map
An orienteering map is a map specially prepared for use in orienteering competitions. It is a topographic map with extra details to help the competitor navigate through the competition area....
s became more widely available, it was only natural to combine the two activities and hold radio direction finding events on orienteering maps.
Interest in this kind of on-foot radio direction finding activity using detailed topographic maps for navigation spread throughout Scandinavia, Eastern and Central Europe
Central Europe
Central Europe or alternatively Middle Europe is a region of the European continent lying between the variously defined areas of Eastern and Western Europe...
, the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
, and the People's Republic of China
People's Republic of China
China , officially the People's Republic of China , is the most populous country in the world, with over 1.3 billion citizens. Located in East Asia, the country covers approximately 9.6 million square kilometres...
. Formal rules for the sport were first proposed in England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
and Denmark
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...
in the 1950s. The first European Championship in the sport was held in 1961 in Stockholm
Stockholm
Stockholm is the capital and the largest city of Sweden and constitutes the most populated urban area in Scandinavia. Stockholm is the most populous city in Sweden, with a population of 851,155 in the municipality , 1.37 million in the urban area , and around 2.1 million in the metropolitan area...
, Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
. Four additional international championships were held in Europe in the 1960s, and three more were held in the 1970s. The first World Championship was held in 1980 in Cetniewo, Poland
Poland
Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...
, where competitors from eleven European and Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
n countries participated. World Championships have been generally held in even-numbered years since 1984, although there was no World Championship in 1996, and there was a World Championship in 1997. Asian nations began sending national teams to international events in 1980, and teams from nations in Oceania
Oceania
Oceania is a region centered on the islands of the tropical Pacific Ocean. Conceptions of what constitutes Oceania range from the coral atolls and volcanic islands of the South Pacific to the entire insular region between Asia and the Americas, including Australasia and the Malay Archipelago...
and North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
began competing in the 1990s. Athletes from twenty-six nations attended the 2000 World Championship in Nanjing
Nanjing
' is the capital of Jiangsu province in China and has a prominent place in Chinese history and culture, having been the capital of China on several occasions...
, China, the first to be held outside of Europe.
International Amateur Radio Union
The International Amateur Radio Union is an international confederation of national amateur radio organisations that allows a forum for common matters of concern and collectively represents matters to the International Telecommunication Union...
(IARU) in the late 1970s. The first ARDF event to use the new standardized rules was the 1980 World Championship. These rules have been revised and updated over the years, increasing the number of gender and age categories into which competitors are classified, as well as formalizing the start and finish line procedures. While some variations exist, these standardized rules have since been used worldwide for ARDF competitions, and the IARU has become the principal international organization promoting the sport. The IARU divides the world into three regions for administrative purposes. These regions correspond with the three regions used by the International Telecommunications Union for its regulatory purposes, but the IARU has also used these regions for sports administration. The first IARU Region I (Europe, Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
, the Middle East
Middle East
The Middle East is a region that encompasses Western Asia and Northern Africa. It is often used as a synonym for Near East, in opposition to Far East...
, and ex-USSR) Championship was held in 1993 in Chtelnica, Slovakia, the first IARU Region III (Asia and Oceania) Championship was held in 1993 in Beijing, China, and the first IARU Region II (North and South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
) Championship was held in 1999 in Portland, Oregon, USA. In addition to participation in international events, most nations with active ARDF organizations hold annual national championships using the IARU rules.
ARDF is a sport that spans much of the globe. Over 400 athletes from twenty-nine countries, representing four continents, entered the 2004 World Championship held in the Czech Republic
Czech Republic
The Czech Republic is a landlocked country in Central Europe. The country is bordered by Poland to the northeast, Slovakia to the east, Austria to the south, and Germany to the west and northwest....
. Organized ARDF competitions can be found in almost every European country and in all the nations of northern and eastern Asia. ARDF activity is also found in Thailand
Thailand
Thailand , officially the Kingdom of Thailand , formerly known as Siam , is a country located at the centre of the Indochina peninsula and Southeast Asia. It is bordered to the north by Burma and Laos, to the east by Laos and Cambodia, to the south by the Gulf of Thailand and Malaysia, and to the...
, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
, Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
, and the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
. Although they represent a broad range of amateur radio interests in their nations today, several member societies of the International Amateur Radio Union were originally formed for the promotion and organization of the sport and continue to use the term radiosport in their society name. These include the Federation of Radiosport of the Republic of Armenia (FRRA), the Belarusian Federation of Radioamateurs and Radiosportsmen (BFRR), the Chinese Radio Sports Association (CRSA), and the Mongolian Radio Sport Federation (MRSF). To promote the sport, the IARU has delegated individuals as ARDF Coordinators for each IARU region to help educate and organize national radio societies and other ARDF groups, especially in nations without prior activity in the sport.
Description of competition and rules
The rules used throughout the world, with minor variations, are maintained by the IARU Region I ARDF Working Group. Although these rules were developed specifically for international competitions, they have become the de facto standard used as the basis for all international competitions worldwide.An ARDF competition takes place in diverse wooded terrain, such as in a public park or natural area. Each competitor receives a detailed topographic map of the competition area. The map will indicate the location of the start with a triangle and the location of the finish with two concentric circles. Somewhere within the competition area designated on the map, the meet organizer will have placed five low power radio transmitters. The locations of the transmitters are kept a secret from the competitors and are not marked on the map. Each transmitter emits a signal in Morse code
Morse code
Morse code is a method of transmitting textual information as a series of on-off tones, lights, or clicks that can be directly understood by a skilled listener or observer without special equipment...
by which it is easily identifiable to the competitors. The transmitters automatically transmit one after another in a repeating cycle. Depending on entry classification, a competitor will attempt to locate as many as three, four, or all five of the transmitters in the woods, and then travel to the finish line in the shortest possible time. Competitors start at staggered intervals, are individually timed, and are expected to perform all radio direction finding and navigation skills on their own. Standings are determined first by the number of transmitters found, then by shortest time on course. Competitors who take longer than the specified time limit to finish may be disqualified.
ARDF events use radio frequencies
Radio frequency
Radio frequency is a rate of oscillation in the range of about 3 kHz to 300 GHz, which corresponds to the frequency of radio waves, and the alternating currents which carry radio signals...
on either the 2-meter or 80-meter amateur radio bands. These two bands were chosen because of their universal availability to amateur radio licensees in all countries. Each band requires different radio equipment for transmission
Transmission (telecommunications)
Transmission, in telecommunications, is the process of sending, propagating and receiving an analogue or digital information signal over a physical point-to-point or point-to-multipoint transmission medium, either wired, optical fiber or wireless...
and reception
Reception
Reception is a noun form of receiving, or to receive something, such as information, art, experience, or people. It is often used in the following contexts:...
, and requires the use of different radio direction finding skills. Radio direction finding equipment for eighty meters, an HF
High frequency
High frequency radio frequencies are between 3 and 30 MHz. Also known as the decameter band or decameter wave as the wavelengths range from one to ten decameters . Frequencies immediately below HF are denoted Medium-frequency , and the next higher frequencies are known as Very high frequency...
band, is relatively easy to design and inexpensive to build. Bearings
Bearing (navigation)
In marine navigation, a bearing is the direction one object is from another object, usually, the direction of an object from one's own vessel. In aircraft navigation, a bearing is the actual compass direction of the forward course of the aircraft...
taken on eighty meters can be very accurate. Competitors on an eighty meter course must use bearings to determine the locations of the transmitters and choose the fastest route through the terrain to visit them. Two meters, a VHF
Very high frequency
Very high frequency is the radio frequency range from 30 MHz to 300 MHz. Frequencies immediately below VHF are denoted High frequency , and the next higher frequencies are known as Ultra high frequency...
band, requires equipment that is relatively more complicated to design and more expensive to build. Radio signals on two meters are more affected by features of the terrain. Competitors on a two meter course must learn to differentiate between accurate, direct bearings to the source of the radio signal and false bearings resulting from reflections of the signal off hillsides, ravines, buildings, or fences. Large national or international events will have one day of competition using a 2-meter frequency and one day of competition using an 80-meter frequency.
In addition to the rules of the sport, ARDF competitions must also comply with radio regulations. Because the transmitters operate on frequencies assigned to the Amateur Radio Service, a radio amateur with a license that is valid for the country in which the competition is taking place must be present and responsible for their operation. Individual competitors, however, are generally not required to have amateur radio licences, as the use of simple handheld radio receivers does not typically require a license. Regulatory prohibitions on the use of amateur radio frequencies for commercial use generally preclude the awarding of monetary prizes to competitors. Typical awards for ARDF events are medals, trophies, plaques, or certificates.
Entry categories
- M19—Men ages 19 and younger, 4 or 5 transmitters
- M21—Men of any age, 5 transmitters
- M40—Men ages 40 and older, 4 or 5 transmitters
- M50—Men ages 50 and older, 4 or 5 transmitters
- M60—Men ages 60 and older, 3 or 4 transmitters
- M70—Men ages 70 and older, 3 or 4 transmitters
- W19—Women ages 19 and younger, 4 or 5 transmitters
- W21—Women of any age, 4 or 5 transmitters
- W35—Women ages 35 and older, 4 or 5 transmitters
- W50—Women ages 50 and older, 3 or 4 transmitters
- W60—Women ages 60 and older, 3 or 4 transmitters
Youth competitions
The International Amateur Radio Union rules for ARDF competitions include provisions for youth competitions. These competitions are restricted to competitors aged fifteen years or younger. The course lengths are shorter (up to six kilometers), the transmitters may be located closer to the start (500 meters), and a course setter may require that fewer transmitters be located.Local variations
The IARU rules go into great detail about certain procedures that are unique to international championships events. Not every ARDF competition follows all of these rules. Common variations to the generally accepted rules exist at local events. Most smaller events do not have large juries or on-course referees. Some events will use simpler start procedures, such as using only one starting corridor instead of two. ARDF events on the two meter band in North America, including the USA Championship, still commonly use frequency modulationFrequency modulation
In telecommunications and signal processing, frequency modulation conveys information over a carrier wave by varying its instantaneous frequency. This contrasts with amplitude modulation, in which the amplitude of the carrier is varied while its frequency remains constant...
instead of amplitude modulation
Amplitude modulation
Amplitude modulation is a technique used in electronic communication, most commonly for transmitting information via a radio carrier wave. AM works by varying the strength of the transmitted signal in relation to the information being sent...
for the transmission of the Morse code identifications.
Map and course details
International Orienteering Federation
The International Orienteering Federation is the international governing body of the sport of orienteering. The IOF head office is located in Helsinki, Finland....
and used for orienteering competitions. In fact, many ARDF competitions use existing orienteering map
Orienteering map
An orienteering map is a map specially prepared for use in orienteering competitions. It is a topographic map with extra details to help the competitor navigate through the competition area....
s, in collaboration with the orienteering clubs that created those maps.
Course design is an important element of a successful competition. The international rules adopted by the IARU include both requirements and recommendations for basic course design. Important requirements are that no transmitter may be within 750 meters of the start, no transmitter may be within 400 meters of the finish or any other transmitter on course, and that there is no more than 200 meters elevation change between the start, finish, and all transmitters. The IARU rules for international competitions recommend that courses be designed for six to ten kilometers of total travel distance through the terrain. A well-designed course will present the competitors with an athletic challenge in addition to the challenges of land navigation and radio direction finding. Depending on the course design and competition, winning times at World Championship events are often less than 90 minutes for two meter courses, and can be under 60 minutes for eighty meter courses.
Equipment and clothing
ARDF equipment is a specialty market, and much of what is available for purchase comes from small commercial vendors or small-batch production by individuals. Building equipment, such as handheld antennaAntenna (radio)
An antenna is an electrical device which converts electric currents into radio waves, and vice versa. It is usually used with a radio transmitter or radio receiver...
s, from published designs or kits is also a popular activity. Clothing and other equipment is sold through specialty orienteering equipment suppliers or general outdoor sports retailers.
Transmitter equipment
Morse code
Morse code is a method of transmitting textual information as a series of on-off tones, lights, or clicks that can be directly understood by a skilled listener or observer without special equipment...
. Each transmitter sends a unique identification that can be easily interpreted even by those unfamiliar with the Morse code by counting the number of dits that follow a series of dashes. The transmitters on course all transmit on the same frequency and each transmit in sequence for one minute at a time in a repeating cycle. Within a few meters of each transmitter, an orienteering control flag and punch device will be present. The punch device is either a paper punch with which competitors will mark a special card they carry with them, or an electronic recording device that competitors will use to record their visit on a small magnetic storage device they carry with them. Competitors need to locate the control flag at the transmitter site and use the punch device to record their visit. Good course design will attempt to preclude, as much as possible, runners interfering with the transmitter equipment as they approach the control. At large international or national events, jurors might be present at transmitter controls to ensure fair play.
The IARU rules include detailed technical specifications for transmitter equipment. Transmitters for two meters are typically 0.25 to 1 watt
Watt
The watt is a derived unit of power in the International System of Units , named after the Scottish engineer James Watt . The unit, defined as one joule per second, measures the rate of energy conversion.-Definition:...
s power output, and use keyed amplitude modulation. The transmitter antennas used on two meters must be horizontally polarized and omnidirectional
Omnidirectional antenna
In radio communication, an omnidirectional antenna is an antenna which radiates radio wave power uniformly in all directions in one plane, with the radiated power decreasing with elevation angle above or below the plane, dropping to zero on the antenna's axis. This radiation pattern is often...
. Transmitters for eighty meters are typically one to five watts power output keyed CW
Continuous wave
A continuous wave or continuous waveform is an electromagnetic wave of constant amplitude and frequency; and in mathematical analysis, of infinite duration. Continuous wave is also the name given to an early method of radio transmission, in which a carrier wave is switched on and off...
modulation. The transmitter antennas used on eighty meters must be vertically polarized and omnidirectional. It is common for the transmitter, a battery
Battery (electricity)
An electrical battery is one or more electrochemical cells that convert stored chemical energy into electrical energy. Since the invention of the first battery in 1800 by Alessandro Volta and especially since the technically improved Daniell cell in 1836, batteries have become a common power...
, and any controlling hardware to be placed inside a weatherproof container such as an old ammunition case or large plastic food storage container for protection from the elements and wildlife.
Receiver equipment
Attenuator (electronics)
An attenuator is an electronic device that reduces the amplitude or power of a signal without appreciably distorting its waveform.An attenuator is effectively the opposite of an amplifier, though the two work by different methods...
or variable gain control, and a directional antenna
Directional antenna
A directional antenna or beam antenna is an antenna which radiates greater power in one or more directions allowing for increased performance on transmit and receive and reduced interference from unwanted sources....
. Directional antennas are more sensitive to radio signals arriving from some directions than others. Most equipment designs integrate all three components into one handheld device. On the two meter band, the most common directional antennas used by competitors are two or three element Yagi antenna
Yagi antenna
A Yagi-Uda array, commonly known simply as a Yagi antenna, is a directional antenna consisting of a driven element and additional parasitic elements...
s made from flexible steel tape. This kind of antenna
has a cardioid
Cardioid
A cardioid is a plane curve traced by a point on the perimeter of a circle that is rolling around a fixed circle of the same radius. It is therefore a type of limaçon and can also be defined as an epicycloid having a single cusp...
receiving pattern
Radiation pattern
In the field of antenna design the term radiation pattern most commonly refers to the directional dependence of the strength of the radio waves from the antenna or other source ....
, which means that it has one peak direction where the received signal will be the strongest, and a null direction, 180° from the peak, in which the received signal will be the weakest. Flexible steel tape enables the antenna elements to flex and not break when encountering vegetation in the forest. On the eighty meter band, two common receiver design approaches are to use either a small loop antenna or an even smaller loop antenna wound around a ferrite
Ferrite (iron)
Ferrite or alpha iron is a materials science term for iron, or a solid solution with iron as the main constituent, with a body centred cubic crystal structure. It is the component which gives steel and cast iron their magnetic properties, and is the classic example of a ferromagnetic material...
rod. These antennas have a bidirectional receiving pattern, with two peak directions 180° apart from one another and two null directions 180° apart from one another. The peak directions are 90° offset from the null directions. A small vertical antenna element can be combined with the loop or ferrite rod antenna to change the receiving pattern to a cardioid shape, but the resulting null in the cardioid is not as sensitive as the nulls in the bidirectional receiving pattern. A switch is often used to allow the competitor to select the bidirectional or cardioid patterns at any moment. ARDF receiver equipment is designed to be lightweight and easy to operate while the competitor is in motion as well as rugged enough to withstand use in areas of thick vegetation.
Clothing
The IARU rules specify that the choice of clothing is an individual decision of the competitor, unless the meet director specifies otherwise. Although comfortable outdoor clothing is all that is required for participation, specialty clothing developed for the sport of orienteering is also worn by ARDF competitors. NylonNylon
Nylon is a generic designation for a family of synthetic polymers known generically as polyamides, first produced on February 28, 1935, by Wallace Carothers at DuPont's research facility at the DuPont Experimental Station...
pants, shirts, or suits, gaiters
Gaiters
Gaiters are garments worn over the shoe and lower pant leg, and used primarily as personal protective equipment; similar garments used primarily for display are spats....
or padded socks for lower leg protection, and specialty shoes for cross-country running through wooded terrain are popular choices. Some competitors may choose to carry food or water on course, and wear a small waist pack or hydration pack for this purpose. At large international or national events, competitors may be required by the meet director to wear identifying numbers pinned to their clothing, and many wear team uniforms in their national colors.
Other equipment
In addition to the radio equipment and topographic map, an ARDF competitor uses a magnetic compass for navigation. The most popular compass types are those that are also popular for use in orienteering. Some events may require or suggest that competitors carry a whistle for emergency use. In at least one World Championship event, competitors were provided with cards written in the native language of the host country, intended to aid in communications with local citizens in the event that a competitor needed emergency aid or directions. In general, the use of cellular phone, or two-way radioTwo-way radio
A two-way radio is a radio that can both transmit and receive , unlike a broadcast receiver which only receives content. The term refers to a personal radio transceiver that allows the operator to have a two-way conversation with other similar radios operating on the same radio frequency...
equipment on course is prohibited. All competitors are encouraged to wear a watch to keep track of their time on course and not finish over the time limit set for the competition.
Variations
Fox OringFox Oring
Fox Oring is a variation of the sport of Amateur Radio Direction Finding. Fox Oring is a timed race in which individual competitors use a topographic map and a magnetic compass to navigate through diverse, wooded terrain while searching for radio transmitters...
is a variation of the sport that requires more orienteering skills. In a Fox Oring course, the radio transmitters put out very little power, and can be received over only very short distances, often no more than 100 meters. The location of each transmitter will be indicated on the map with a circle. The transmitter does not need to be exactly at the circle's center or even located inside the circle, but one should be able to receive its transmissions everywhere within the area indicated by the circle. A competitor must use orienteering skills to navigate to the area of the circle on the map and only then use radio direction finding skills to locate the very low power transmitter.
Another variation of the sport, Radio Orienteering in a Compact Area
Radio Orienteering in a Compact Area
Radio Orienteering in a Compact Area is a variation of Amateur Radio Direction Finding. ROCA is a timed race in which individual competitors use a topographic map and a magnetic compass to navigate through diverse, wooded terrain while searching for radio transmitters.-Description:ROCA is a sport...
, requires less athletic skill and more technical radio direction finding skills. In a ROCA course, the transmitters put out very little power, typically 10 to 200 mW, and can be received over only very short distances. The transmitters are physically small, and marked with a control card that is no larger than a typical postcard with a unique number identification. Because of the low power and short distances involved, most ROCA competitors walk the entire course, and focus their attention on the radio direction finding tasks rather than navigation.
Another form of recreational radio direction finding activity in North America that includes the use of automobiles for transportation is most often referred to as foxhunting or transmitter hunting
Transmitter hunting
Transmitter hunting , is an activity wherein participants use radio direction finding techniques to locate one or more radio transmitters hidden within a designated search area...
, but is sometimes confused with the organized international sport of amateur radio direction finding.
External links
ARDF organizations- International Amateur Radio Union (IARU)
- ARDF in IARU Region I
- ARDF in IARU Region II
- ARDF in IARU Region III
ARDF Events
- 2010 ARDF World Championships
- 2008 ARDF World Championships
- 2006 ARDF World Championships
- 2004 ARDF World Championships
- 2002 ARDF World Championships
ARDF Information