NorthStar 2201 Installation Manual page 52

Glossary and acronyms
geometry
Page 44
Guard beacons, FM signals from local broadcast stations (such
as subscription services offered by DCI and Accqpoint), satellite
signals (such as subscription services offered by Racal and
OMNISTAR), and private DGPS Base stations. Differential
corrections now also include those corrections using WAAS
(Wide Area Augmentation System; see definition of WAAS in
this Glossary).
DGPS Differential GPS—the technique of correcting basic GPS
position data via radio signals to increase its accuracy from
20-30 meters to 1–2 meters.
DRMS Distance Root Mean Square.
EEPROM
Electrically Erasable Programmable Read Only Memory.
The number and location of satellites overhead, determining
the GPS accuracy available at any given time.
GPS Global Positioning System: the satellites and receivers that
enable position and speed to be determined anywhere on earth
with great accuracy. GPS is a system of 24 satellites (with 3
spares) operating in three orbital planes at about 11,000 miles
elevation. Position is determined by measuring the time delay
of the 1575-mHz signal from at least three satellites, and
computing position based on known satellite locations.
HDOP Horizontal Dilution of Precision.
Host Customer system receiving position data from the 2201.
ISO International Standards Organization.
L1 The frequency band used by the 2201, 1574.42 MHz.
LSB Least Significant Bit.
MF Medium Frequency band.
MHz MegaHertz, one million cycles per second.
MSB Most Significant Bit.
2201 INSTALLATION MANUAL, Revision B