Radio Orienteering in a Compact Area
Encyclopedia
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.
that requires less athletic skill and more technical radio direction finding skills than ARDF
. In a ROCA course, the radio transmitters put out very little power, typically 10 to 200 mW
, and can be received over only very short distances. Transmitters may identify themselves in Morse code
or with voice recordings, and only transmit for ten seconds during every minute of the competition. The transmitters are physically small, and marked with a control card that is no larger than a typical postcard
with a unique number identification. Decoy control cards may be placed in the competition area, as well, to force competitors to locate the actual transmitting devices. 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
.
ROCA is not as popular as ARDF
, and activity is limited to only active clubs in a few countries. ROCA events can be found today primarily in the San Francisco Bay
area of the United States
and in the People's Republic of China
.
Amateur Radio Direction Finding
Amateur radio direction finding is an amateur racing sport that combines radio direction finding with the map and compass skills of orienteering...
. ROCA is a timed race
Racing
A sport race is a competition of speed, against an objective criterion, usually a clock or to a specific point. The competitors in a race try to complete a given task in the shortest amount of time...
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...
and a magnetic compass to navigate through diverse, wooded terrain while searching for radio transmitters.
Description
ROCA is a sportSport
A Sport is all forms of physical activity which, through casual or organised participation, aim to use, maintain or improve physical fitness and provide entertainment to participants. Sport may be competitive, where a winner or winners can be identified by objective means, and may require a degree...
that requires less athletic skill and more technical radio direction finding skills than ARDF
Amateur Radio Direction Finding
Amateur radio direction finding is an amateur racing sport that combines radio direction finding with the map and compass skills of orienteering...
. In a ROCA course, the radio transmitters put out very little power, typically 10 to 200 mW
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:...
, and can be received over only very short distances. Transmitters may identify themselves 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...
or with voice recordings, and only transmit for ten seconds during every minute of the competition. The transmitters are physically small, and marked with a control card that is no larger than a typical postcard
Postcard
A postcard or post card is a rectangular piece of thick paper or thin cardboard intended for writing and mailing without an envelope....
with a unique number identification. Decoy control cards may be placed in the competition area, as well, to force competitors to locate the actual transmitting devices. 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
Navigation
Navigation is the process of monitoring and controlling the movement of a craft or vehicle from one place to another. It is also the term of art used for the specialized knowledge used by navigators to perform navigation tasks...
.
ROCA is not as popular as ARDF
Amateur Radio Direction Finding
Amateur radio direction finding is an amateur racing sport that combines radio direction finding with the map and compass skills of orienteering...
, and activity is limited to only active clubs in a few countries. ROCA events can be found today primarily in the San Francisco Bay
San Francisco Bay
San Francisco Bay is a shallow, productive estuary through which water draining from approximately forty percent of California, flowing in the Sacramento and San Joaquin rivers from the Sierra Nevada mountains, enters the Pacific Ocean...
area of the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and in 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...
.