C-Nav 2050, User Manual

Page: 70 / 75

2050 User Guide
civilian code see Coarse Acquisition code .
Coarse Acquisition code (C/A or Civilian code )
the pseudo-random code generated by GPS satellites. It is intended for civilian use and the
accuracy of readings using this code can be degraded if selective availability ( S/A ) is introduced by
the US Department of Defense.
COM# shortened form of the word Communications. Indicated a data communications port to/from
the GPS sensor to a controller or data collection device.
controller a device consisting of hardware and software used to communicate and manipulate the
I/O functions of the GPS sensor.
Compact Measurement Record (CMR) a standard format for DGPS corrections used to transmit
corrections from a reference station to rover sensors.
data files files that contain Proprietary, GPS , NMEA, RTCM or any type of data logged from a GPS
receiver.
DB9P a type of electrical connector containing 9 contacts. The P indicates a plug pin (male).
DB9S a type of electrical connector containing 9 contacts. The S indicates a slot pin (female).
DGPS see Differential GPS .
Differential GPS ( DGPS ) a positioning procedure that uses two receivers, a rover at an unknown
location and a reference station at a known, fixed location. The reference station computes
corrections based on the actual and observed ranges to the satellites being tracked. The
coordinates of the unknown location can be computed with sub-meter level precision by applying
these corrections to the satellite data received by the
rover .
Dilution of Precision ( DOP ) a class of measures of the magnitude of error in GPS position fixes
due to the orientation of the GPS satellites with respect to the GPS receiver. There are several
DOP s to measure different components of the error. Note: this is a unit less value. see also PDOP .
DOP see Dilution of Precision .
dual-frequency a type of GPS receiver that uses both L1 and L2 signals from GPS satellites. A
dual-frequency receiver can compute more precise position fixes over longer distances and under
more adverse conditions because it compensates for ionospheric delays. The 2050 is a dual
frequency receiver.
dynamic mode when a GPS receiver operates in dynamic mode , it assumes that it is in motion and
certain algorithms for GPS position fixing are enabled in order to calculate a tighter position fix.
EGNOS (European Geostationary Navigation Overlay Service) a European satellite system used
to augment the two military satellite navigation systems now operating, the US GPS and Russian
GLONASS systems.
elevation distance above or below Local Vertical Datum.
elevation mask the lowest elevation , in degrees, at which a receiver can track a satellite. Measured
from the horizon to zenith, 0º to 90º.
Glossary-62