Leadtek LR9548S User Manual - page 21
LR9548S GPS Module Technical Manual v1.52
© 2006 Leadtek Research Inc. All rights reserved.
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Preliminary Confidential - Information is subject to change without prior notice.
Differential GPS (DGPS)
An extension of the GPS system that uses land-based radio beacons to transmit position corrections to
GPS receivers. DGPS reduces the effect of selective availability, propagation delay, etc. and can
improve position accuracy to better than 10 meters.
EGNOS (European Geostationary Navigation Overlay System)
A satellite navigation system being developed by the European Space Agency, the European
Commission, and EUROCONTROL. It is intended to supplement the GPS and GLONASS systems by
reporting on the reliability and accuracy of the signals. According to specifications, horizontal position
accuracy should be better than 7 meters. In practice, the horizontal position accuracy is at the meter
level. It will consist of three geostationary satellites and a network of ground stations.
Similar service is provided in America by the WAAS system. See WAAS.
LNA (Low Noise Amplifier)
A special type of electronic amplifier or amplifier used in communication systems to amplify very
weak signals captured by an antenna. It is usually located at the antenna and is a key component, which
is placed at the front-end of a receiver system.
Multi-path mitigation
Anticipating errors caused when a satellite signal reaches the GPS receiver antenna by more than one
path. Usually caused by one or more paths being bounced or reflected off of structures near the
antenna and occurs to some extent everywhere. The signal which traverses a longer path will yield a
larger pseudo range estimate and increase the error.
NMEA (National Marine Electronics Association)
An U.S. standards committee that defines data message structure, contents, and protocols to allow the
GPS receiver to communicate with other pieces of electronic equipment.