Amateur Radio Direction Finding is a combination of both orienteering and radio direction finding. It is a timed race where competitors use a magnetic compass, a topographic map, and radio direction finding instrument to navigate through a tract of land while searching for radio transmitters. This sport is also referred to as radiosport or radio orienteering.

Amateur radio direction finding (ARDF) is the sport of locating transmitters using radio receiver equipment. Five transmitters are hidden throughout a course filled with varied topographic features. Competitors use a map, a compass and receiving equipment to locate the transmitters in the quickest amount of time possible. The competitor that completes the course in the least amount of time is the winner.

Use radio equipment to locate transmitters hidden throughout a wooded course, and complete the course in the least amount of time.

Competitions are held in diverse wooded terrains. Prior to the race beginning, competitors receive a detailed topographic map of the competition area. Maps indicate the start and finish areas of the course. Inside the course are five radio transmitters. Each transmitter emits a Morse code signal. Competitors attempt to locate as many transmitters as possible, then cross the finish line in the quickest amount of time. Competitors are timed individually, and must complete the course without any assistance. Standings are determined first by the number of transmitters found, then by the shortest time through the course.

The use of amateur radio began in Europe in the 1950's as a widely promoted school activity. This led to the creation of clubs in most large cities. As more people became skilled at using radio equipment, the techniques spilled over into the sport of orienteering. The first European championship was held in Sweden in 1961. Rules were became formalized in the late 1970's, under the supervision of the International Amateur Radio Union. The first world championship was held in Poland in 1980, and is now held every four years. ARDF leagues and groups can now be found in dozens of countries around the world.

Attenuator
Compass
Directional Antenna
Radio Receiver
Radio Transmitters
Topographic Map

Most injuries occur due to carelessness while traveling quickly over uneven terrain. Proper footwear can reduce the chances of some injuries.

Good working knowledge of maps and radio equipment is essential. A high level of fitness is also key due to amount of running involved in competition.

Attenuator - electronic device used to reduce the strength of a signal in order to make it easier to measure

Directional Antenna - antenna that radiates power in one or more directions to receive incoming signals

Morse code - type of character encoding that transmits information using rhythm; short and long elements are used in combination to create letters and numbers

Topographic Map - map characterized by large-scale detail and quantitative representation of relief; shows both natural and man-made features

Radio Transmitters - an electronic device that uses an antenna to propagate a radio signal

http://en.wikipedia.org/wiki/Amateur_Radio_Direction_Finding