What Are Target Vectors And History; How Do I Acquire Marpa Targets - Raymarine RayTech RNS 5.0 User Manual

Chapter 7: Using radar

What are target vectors and history?

You can display MARPA targets with a vector line showing where they will be at a
certain time in the future (assuming their present course and speed remains
unchanged). You can select a relative or true vector, and the vector length.
Relative vector
A relative vector indicates the target's motion relative to your own boat's motion. The
target's relative course and sped are calculated to produce a vector that is displayed on
the target only. Relative vector mode is used for collision avoidance and threat
assessment.
True vector
A true vector indicates the targets motion over ground. In this mode, true vectors for
the target and your own boat are displayed. MARPA measures the direction in which
the target and your own boat are moving over the ground. The result is the boat's true
course and speed. Consider this motion as if you were in a helicopter looking down
watching the targets move across the water. This mode is used as an aid to navigation.
Target history
You can also view a target's history, which appears as a trail of dots left by the target as
it travels. You can change the display interval of these dots.
How do I set up target vectors and history?
To set up target vectors and history:
1. Click
2. Click
3. Click the action boxes to set mode and distance as required.
4. Use the BACK button to return to the top level softkeys.

How do I acquire MARPA targets?

You can acquire up to ten targets, which are then automatically tracked by the MARPA
system. The are two ways in which a MARPA target can be acquired.
To acquire a MARPA target:
Method 1
1. Click
2. Click
3. Move the cursor over the target you want to acquire and click.
The target acquired symbol will appear at the cursor's position, and the radar will
search for a target in the location. If a target is present for several scans, the radar
Target Tracking
.
Marpa Options
. The Marpa options dialog box is displayed.
Target Tracking
.
Acquire Target
.
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