Slitherine

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Purely as a matter of interest, have you read anything about how well FCRs are supposed to work in employing CIWS and missile defenses? It's hard to imagine how you can keep tracking a tiny supersonic missile without rolling the radar past its gimbal limits in heavy seas.

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ORIGINAL: ExNusquam

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Purely as a matter of interest, have you read anything about how well FCRs are supposed to work in employing CIWS and missile defenses? It's hard to imagine how you can keep tracking a tiny supersonic missile without rolling the radar past its gimbal limits in heavy seas.

Don't forget the opposite is also true: How well does the missile seeker find it's target on extremely rough seas?

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ORIGINAL: ppitm
Much more easily, I would assume. A ship heaving in large waves only changes the shape of its signature. From the perspective of a radar on that ship, an air contact is changing position by thirty or forty degrees.

I'm sure pk would be lower, but it's not as hard to imagine a weapon maintaining lock until the terminal phase.

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As far as possible radars are designed to minimize noise and reject clutters, but their natures are too signal-like for total elimination. Modern radars go far to removal of distracting clutter paints from the display. Nevertheless, if precipitation is falling around the target, or it is in a rough sea, the resulting clutter always impairs performance, even when hidden from display by a clever data extraction system. Inquiring the prevailing sea state in the approaches to a major Mediterranean port, the author was shaken to be assured by the naval officer conducting a VTS procurement: 'Quite immaterial, modern radars are completely immune to clutter'. Beware of salesmen bearing glossy literature!
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Many military radars defeat clutter by the moving target indication (MTI) technique. MTI relies on target movement being much faster than that of the surrounding waves or hydrometeors. It is not currently available to marine radars, where target and clutter speeds may be similar. Wave crests travel at about one-third the wind speed; so do some ships.

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No single theory of sea clutter seems fully to agree with all observations.

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Large individual gravity and swell waves may persist for many seconds, requiring several scans to achieve decorrelation. Particularly with short pulses (~.1 µs), the radar may resolve and display waves as discrete targets.