JRC JMA-9172-SA User Manual

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JMA-9172-SA Instruction Manual > 5.OPERATION OF TARGET TRACKING AND AIS > 5.1 PREPARATION
[2] Relative Vector Mode
The relative vector does not represent the true motion of the target, but its relative
relation with own ship. This means that a target with its relative vector directed to
own ship (passing through the CPA Limit ring) will be a dangerous target. In the
Relative Vector mode, it can be seen at a glance where the CPA Limit of the
dangerous target is.
Therefore, the True / Relative mode shall optionally be used for the purpose of
observation: the True vector mode for grasping the true aspect of a target, and the
Relative vector mode for grasping a target’s closest point of approach (CPA).
Fig 5-5: Relative Vector
5.1.3.3 Vector Length (Vector Time)
The vector length of a target is proportional to its speed, and the vector time can
be switched in a range of 1 to 60 minutes.
The diagram below illustrates a vector length of a target for 6 minutes, and the tip
of the vector represents the target's position expected to reach 6 minutes later.
Fig 5-6: Vector Length
Refer to Section 5.1.6 "Setting Vectors (Vector Time)".
The true vector is
not displayed
Relative vector
CPA ring
HL
Current position
Future predicted position
(6 min later in this example)
HL

JRC JMA-9172-SA Specifications

General

Brand	JRC
Model	JMA-9172-SA
Category	Marine Radar
Language	English