Relatrion between sea clutter and wind speed?

Question

Relatrion between sea clutter and wind speed?

radarmike (Electrical)

(OP)

3 Jul 12 08:14

Hello,

I am new to this forum so please forgive me if my question is posted in the wrong forum.

I am currently trying to update my knowledge on sea clutter and in one of the books I am reading the author implies there can be a relation between sea clutter and wind speed. Is this really true? Isn't he really meaning there is a relationship between clutter and the state of the sea, characterized by for instance wave height? There is in some sense a relation between wind speed and waves but that is not an unambiguous one. Please help me with this question.

RadarMike

VEBill (Military) · Answer 1 · 2012-07-03 20:00:59

Wind speed, reach, and duration leads to waves. But, for example, if the wind reversed then it would start knocking down the existing waves before building them up in the opposite direction.

The height of the waves will affect the radar clutter in a non-trivial relationship to the radar wavelength and the geometry.

Disclaimer: I'm not really a subject matter expert in the details. The above is mostly informed common sense.

radarmike (Electrical) · Answer 2 · 2012-07-04 03:45:15

In response to VE1BLL,

Ok, thanks.

It would be nice if someone else in this forum with knowledge within this field could give their opinion as well.

VEBill (Military) · Answer 3 · 2012-07-04 05:58:04

This is a relatively quiet forum. But perhaps someone else will chime in.

I Googled the search terms: radar sea clutter wind speed

...and there seems to be quite a bit of info. Some of summaries hint at counter examples to refute the claim of a simple relationship.

Higgler (Electrical) · Answer 4 · 2012-07-15 16:19:22

you may get a formula for sea clutter for use on a radar who's beam contacts water at a great distance, and if you consider smooth water vs. wind whipped water, you'd easily surmise reflections are higher in windy conditions. You likely won't find anything for close in wave reflection. Years ago we had to change antennas on a Navy ship from wide beam to narrow beam to reduce sea clutter as nobody attempted to calculate splash back from waves at 200 meters, which swamped the receiver. So in searching for info, if reflections are from close in waves, you will have more trouble getting an answer.

GregLocock (Automotive) · Answer 5 · 2012-07-15 18:45:50

Sea state is roughly proportional to wind state, and more or less corresponds in a typical wave height in metres.

So Beaufort wind 6 produces sea state 6 produces 6 metre (trough to peak) waves eventually.

That is a horrible simplification.

Cheers

Greg Locock

New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?

radarmike (Electrical) · Answer 6 · 2012-07-18 03:48:01

In response to Higgler,

My primary interest is when energy (radar beam) hits the waves at great distance. Your experience from the naval vessel was an interesting one and something to take in to consideration when placing the radar antenna. I suppose the antenna was not placed very high up on that ship.

RadarMike

radarmike (Electrical) · Answer 7 · 2012-07-18 03:51:38

In response to GregLocock,

You are right it is a horrible simplification and only works on great oceans in combination with fully developed seas

RadarMike

Higgler (Electrical) · Answer 8 · 2012-07-23 11:44:25

The ship was an FFG, and it was close to the deck. So fairly low. The splash back effect problem from the ocean depends on the systems tx power and the sensitivity of the rx system.
We needed full duplex. If you're pulsed, no problem. If you need to look thru 100% of the time, could be an issue.

Come Join Us!

Posting Guidelines

Relatrion between sea clutter and wind speed?