Maps GPS Glossary - F
fall line - A line connecting the waterfalls of nearly parallel rivers that marks a drop in land level.
fast switching channel - A channel that is capable of rapidly sampling a number of satellite ranges in order to recover data messages.
Federal Geographic Data Committee - See FGDC.
FDGC - Federal Geographic Data Committee - An agency established by the United States Federal Office of Management and Budget responsible for the coordination of development, use, sharing, and dissemination of surveying, mapping, and related spatial data.
fjord - (also fiord) - A long, narrow inlet of the sea between steep slopes.
flume - A narrow gorge, especially one with a stream.
fluxgate compass - An electronic device used to measure magnetic direction.
ford - A shallow place in a body of water, such as a river, where one can cross on foot, by riding an animal, or in a vehicle.
form factor - A term used to describe the way a device is constructed, such as its shape. For example, GPS receivers come in many form factors, such as handheld, PDA, automotive, USB, etc.
frequency band - A particular range of frequencies.
FRS - Family Radio Service - A walkie talkie system authorized in the United States since 1996 that uses UHF frequencies.