User Manual
Reference number: 4111A-RADAR4600-GBD-R1.1
Date: 27 February 2018
Page 144 of 149
Annex II – Radar and Ecdis related terms and definition
activated AIS target
a target representing the automatic or manual
activation of a sleeping target for the display of
additional graphically presented information.
The target is displayed by an “activated target”
symbol including a vector; the heading; and the
ROT or direction of turn indication (if available)
to indicate initiated course changes.
acquisition of a radar target
a process of acquiring a target and initiating its
tracking.
activation of an AIS target
the activation of a sleeping AIS target for the
display
of
additional
graphical
and
alphanumerical information.
acquired radar target
a target acquired by automatic or manual
means to initiate radar tracking. Vectors and
past positions (if provided) are displayed when
data has achieved a steady state condition.
AIS
an Automatic Identification System which
complies with the requirements of IMO
resolution MSC74(69) Annex 3 and international
standard IEC 61993-2.
AIS target
a target generated from an AIS message.
associated target
a target simultaneously representing a tracked
target and a reported AIS target having similar
parameters (for example position, course, speed)
which comply with an association algorithm.
acquisition/activation zone
a zone set up by the operator in which the system
should automatically acquire radar targets and
activate reported AIS targets when entering the
zone.
azimuth stabilised
means that a heading reference input, for
example own ship’s gyro, is used to orientate
the heading line on the radar display so that it
points from the CCRP to own ship’s referenced
heading on the bearing scale.
BCR/BCT
bow crossing range and bow crossing time are
measurements presented as from the bow of
the ship as opposed to the CCRP.
benchmark
an absolute or an objective measure of radar
performance using a calibrated test equipment,
using for example a known set of standard
reflectors or a laboratory test specifically
undertaken against a
device measuring absolute radar performance
and using a dedicated simulator.
cardinal points (compass)
the 0, 090 180, 270 compass points.
CCRP
a Consistent Common Reference Point and is a
location on own ship, to which all horizontal
measurements such as target range, bearing,
relative course, relative speed, closest point of
approach (CPA) or time to closest point of
approach (TCPA) are referenced, typically the
conning position of the bridge.
CPA/TCPA
the closest point of approach / time to the
closest point of approach. They are the distance
to the closest point of approach (CPA) and time
to the closest point of approach (TCPA). Limits
are set by the operator and are related to own
ship.
course
the horizontal direction in which the ship is
moving or intended to move, expressed in
degrees from North, usually from 000° at north,
then in a clockwise direction through 360°.
course over ground - COG
the direction of the ship's movement relative to
the earth, measured on board the ship,
expressed in angular units from true north.
course through water
CTW
the direction of the ship's movement through
the water, defined by the angle between the
meridian through its position and the direction
