Radar Observer · Display — Relative vs True Motion
On a relative-motion display, own ship stays at the center and:
- AAll targets are shown at their true speed over ground
- BAll targets move relative to own ship; a stationary object appears to move opposite to own ship's course at own ship's speed✓ Correct
- CLand masses remain fixed on the screen
- DOwn ship moves across the screen
Explanation
In relative motion own ship is fixed at center and everything is plotted relative to it, so even fixed objects (land, buoys) trail across the screen opposite to own ship's motion. True-motion displays move own ship across the screen so fixed objects stay put and targets show their actual tracks.
Authority: Bowditch (Pub. No. 9), Radar Display
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