NavCom LAND-PAK Rev.N - Manual (Page 188)

Technical Reference Manual Rev. N
- Glossary 186
COM# shortened form of the word Communications. Indicates a data communications port
to/from the GPS sensor to a controller or data collection device.
Compact Measurement Record (CMR) a standard format for DGPS corrections used to
transmit corrections from a reference station to rover sensors. See Related Standards in
Notices.
controller a device consisting of hardware and software used to communicate and manipulate
the I/O functions of the GPS sensor.
convergence period (StarFire™) is the time necessary for the received StarFire™ signal
corrections to be applied and the position filtered to optimal performance. The convergence
period is typically 30 to 45 minutes to achieve <decimeter accuracy. This period may be
overcome using the Quick Start method.
data files files that contain Proprietary, GPS, NMEA, RTCM, or any type of data logged from a
GPS receiver.
datum A reference datum is a known and constant surface which can be used to describe the
location of unknown points. Geodetic datums define the size and shape of the earth and the
origin and orientation of the coordinate systems used to map the earth.
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).
DCE Data Communications Equipment. Defined pin assignments based on the IEEE RS-232
signaling standard. See the Figure G-1:
Figure G1: DTE to DCE RS-232 Pin Assignments
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 DOPs to measure different components of the error. Note: this is a unitless value. see
also PDOP.
DOP see Dilution of Precision.
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8 1
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CTS
RD
TD
DTR
GND
DSR
RTS
DB9
07-00041-A
DB9 DB25 DB25 RJ45
8
3
2
20
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DTE
DCE
Straight-Through Cable
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DCD
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Modem