LadyInBed
Well-Known Member
This is mine. Note that the orientation of triangle at the base is the same as the orientation at the top.
Someone commented - How to rig a 'rain catcher' radar reflector :
- Thread starter Refueler
- Start date
Refueler
Well-Known Member
deleted
Yeh takes yer biscuit and eats or not ...
Yeh takes yer biscuit and eats or not ...
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lw395
Well-Known Member
There's a strange lack of vertical planes in all those reflectors. I don't see anything that supports your argument at all TBH.
But there are plenty of reflectors out there with one or even two vertical planes working well enough in the real world.
zoidberg
Well-Known Member
"Lessons will be learned......"
Refueler
Well-Known Member
deleted
Anyway - I've said my piece .. shown examples ....
Anyway - I've said my piece .. shown examples ....
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anoccasionalyachtsman
Well-Known Member
@lw3895's point was that of the reflectors on every single buoy in the links you've provided (including the extensive range in Trinity House's video) not one has a vertical surface. None.
So more of a question as to why you provided links that don't back up the point you're making.
I also think that he knows his way round grown up protractors.
I found some American ones that do support you.
Refueler
Well-Known Member
Deleted ... if forum experts cannot be bothered - why should I
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lw395
Well-Known Member
And how does your simplistic ray tracing work in a regime where the reflecting surfaces are not much bigger than a wavelength?
If you're really interested in this , I suggest Skolnik's bigger book as a suitable starting point. Takes up a bit of shelf space at 1300 pages.
Radar Handbook, Third Edition: Amazon.co.uk: Skolnik, Merrill: 9780071485470: Books
anoccasionalyachtsman
Well-Known Member
Oh dear. Once more. The pictures in the links you provided. None have any vertical surfaces. Your reflector in your opening post of your treatise on how to rig a reflector has vertical surfaces. Yours in not oriented in the same way as theirs. Yours will not hold any water when it rains.
Did you read the link to Qintiq's report? Do you understand that bouncing a beam from a three plane corner will always return it on the reciprocal, while a two plane will only return it on the reciprocal if the incident beam is in a plane normal to those two?
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pvb
Well-Known Member
Sadly, he doesn't understand what the "catch rain" position means. And the irony is that he started this thread supposedly to demonstrate the correct method.
LadyInBed
Well-Known Member
lw395
Well-Known Member
The seal possibly doubles up as a foghorn?@lw3895's point was that of the reflectors on every single buoy in the links you've provided (including the extensive range in Trinity House's video) not one has a vertical surface. None.
So more of a question as to why you provided links that don't back up the point you're making.
I also think that he knows his way round grown up protractors.
I found some American ones that do support you.
I've seen very similar radar reflectors on buoys and posts in UK waters.
I've seen one with a shitehawk sat in the reflector, not sure exactly how that would affect the radar cross section, but it's unlikely to be a good thing.
bedouin
Well-Known Member
In most circumstances the octohedral reflector does pretty well. The difference in orientations is mostly about eliminating or minimising the nulls in the return. The advantage of the catch rain position over the double catch rain is that with the reflector upright there are always at least 2 corner reflectors returning a signal at any orientation whereas in your suggested orientation there are likely to be bigger nulls when one of the corners is pointing (almost) directly towards the signal.
ghostlymoron
Well-Known Member
For many sailors (like me) the octohedral reflector is something that languishes at the bottom of a locker and is only looked at seriously when the fog closes in. You then find that the suspension holes are in completely the wrong places and you haven't got a drill on board so you lash up something as best you can.
That's what we did on a trip up the Bristol channel. On arrival at Milford Haven I bought a proper one.
I'd advise anyone to take it out and assemble it when there's no fog and devise a means of hoisting it that works best
That's what we did on a trip up the Bristol channel. On arrival at Milford Haven I bought a proper one.
I'd advise anyone to take it out and assemble it when there's no fog and devise a means of hoisting it that works best
Refueler
Well-Known Member
Well done girls .....
prv
Well-Known Member
I tend to think so.
I saw your original post and thought “Well, that’s wrong. How silly to start a thread purporting to bestow your expertise upon the world, illustrated with a picture thats obviously incorrect[1]. Oh well, life’s too short, I’m not going to bother arguing with the guy.”
I’ve just looked back in a couple of days later, and found that your misinformation has been comprehensively debunked and you’ve deleted it. As misinformation goes it’s hardly up there with injecting bleach, but still, this strikes me as the forum working as it should.
Yes indeed, well done “girls”.
Pete
[1] It’s not even about which position is most effective. You said “This is the catch-rain position”, which it isn’t, for the rather obvious reason that it won’t catch any rain.
ghostlymoron
Well-Known Member
If you stand it on a flat surface, it's in the rain catching position. How you string it up to remain so is the tricky part.
ghostlymoron
Well-Known Member
Mine is like this. As you can see the stringing hole was in completely the wrong place. I've now drilled some extra ones.
Octahedral Radar Reflector - 340 x 340mm (P10074)
Octahedral Radar Reflector - 340 x 340mm (P10074)
LadyInBed
Well-Known Member
Hang it from three equal length lines tied together at one end and attached to the new holes in the picture. You can do the same on the opposite (bottom) side and run it up to a spreader.
