C-Nav IALA Hardware Reference Manual page 91

C-Nav Hardware Reference Guide
Circular Error Probable (CEP) is a measurement of precision using standard deviation that is
applicable in horizontal stations. Probability for CEP is 50%, meaning that if 100 observations
are made, half of them will be within the circular error probable with
Radius = 0.5887 (ơx + ơy)
Civilian code see Coarse Acquisition code.
Clock Bias is the difference between GPS Time and UTC.
Coarse Acquisition code (C/A or Civilian code) is 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.
Collimate is to physically align a survey target or antenna over a mark.
COM is the 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/CMR+) is a standard format for DGPS corrections used
to transmit corrections from a reference station to rover sensors. See Related Standards in
Notices.
Controller is a device consisting of hardware and software used to communicate and
manipulate the I/O functions of the GPS sensor.
Control Point is a point to which coordinates have been assigned. These coordinates can then
be held fixed and are used in other dependant surveys.
Control Segment is a worldwide network of GPS monitoring and control stations that ensure
the accuracy of the GPS satellite orbits and operation of their atomic clocks. The original control
segment consists of control facilities in Diego Garcia, Ascension Island, Kwajalein, and Hawaii,
with a master control station at the Consolidated Space Operations Center (CSPOC) at
Colorado Springs, Colorado.
Convergence Period (C-Nav) is the time necessary for the received C-Nav 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.
Cycle Ambiguity see Ambiguity.
Cycle Slip is a discontinuity in measured carrier beat phase resulting from a temporary loss of
lock in the carrier-tracking loop of 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 Figure 6-1:
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