Radar Observer · Plotting — Relative Motion
In a radar plot, the direction and length of the relative motion line (the line through successive plotted positions of a target) indicates the target's:
- ATrue course and speed
- BDirection of relative movement and relative speed✓ Correct
- CRange scale in use
- DAspect angle only
Explanation
Connecting the target's plotted positions gives the relative motion line; its direction is the way the target moves relative to you and its length over the plotting interval gives relative speed. Extending it shows the CPA.
Authority: Radar Plotting (USCG topic)
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