Maps GPS Glossary - Q, R
quad - See quadrangle.
quadrangle - A four-sided area of the surface of the earth used as a unit in mapping.
quadrifilar helix antenna - A type of GPS receiver antenna in which four spiraling elements form the receiving surface of the antenna.
RAIM - Receiver Autonomous Integrity Monitoring - Technology added to aviation GPS used to detect questionable data from one or more satellites. It works by over-determining position using at least five satellites or four satellites and a barometric altitude input.
range - The fix distance that is between two waypoints or between a satellite and a GPS receiver.
raster maps - Raster maps are commonly referred to as "bit mapped" and are in a GIF or JPEG format. Raster images are well-suited for web sites where editing or resizing are not required. They can be made smaller, but are not meant to be enlarged or customized in the ways that vector maps can be manipulated.
reef - A strip or ridge of rocks, sand, or coral that rises to or near the surface of a body of water.
relief - Changes in terrain; elevations or depressions in the land.
relief shading - The use of light and dark tones to depict the form of the land; makes the map appear as if illuminated by the sun, creating highlights and shadows.
RFID - Radio Frequency Identification - A method of identification using radio frequency. For objects, animals, or people and does not require direct contact or line-of-sight scanning.
rhumb line - A line of the surface of the earth that crosses all meridians at a constant angle.
RINEX - Receiver-Independent Exchange - a GPS data format which includes provisions for pseudorange, carrier-phase, and Doppler observations.
RKP - Relative Kinematic Positioning - Improves GPS accuracy by using a combination of differential GPS (DGPS) correction data, transmitting GPS signal phase information and ambiguity resolution techniques via statistical tests—possibly with processing in real-time (real-time kinematic positioning, RTK).
route - A set of waypoints that define the intended path of travel.
RTCM - Radio Technical Commission for Maritime Services - The commission set up to define a differential data link to relay GPS correction messages from a monitor station to a field user. RTCM SC-104 recommendations define the correction message format and 16 different correction message types.
RTK - Real Time Kinematic - Land survey based on a differential use of carrier phase measurements of the GPS, Glonass and/or Galileo signals where a single reference station provides the real-time corrections of even to a centimetre level of accuracy.