Being Seen - I wonder

[philfin]

I have read the MAIB report and subsequent thoughts of you guys with interest. As an old Master once told me, "it takes a court of "experts" sometimes years to decide who is responsible for a collision and what action should have been taken, but as a skipper you may only have a minuit or two to decide what action to take"

Its certainly not always easy or straightforward and obviously focusing on never getting into a close quaters situation in the first place has to be priortity.

Now, what I was wondering was... What diffence do you think it would make by fitting 2(or more) reflectors? would it double you chances of showing up on the others radar screen that hopefully they are watching. Or does this rather simple logic fall apart under some scientific principle or other?

 

[StugeronSteve]

If the two reflectors are out of phase they can cancel each other out. This has been demonstrated in tests conducted by several of the magazines.

 

[fluffc]

... so provided they are mounted the correct distance apart, related to the wavelength of x- and s-band radar, all will be fine...

No what distance would that be...(feel some sums coming up...)

 

[fluffc]

Afterthought:

If one is mounted directly above the other, then they would both be 'in phase'.

-----

X-Band radar @ 9.41 GHz

Velocity = Frequency x Wavelength
V=f l
l = V/f
l = 3.0 x 10e8 / 9.41 x 10e9
l = 3.2cm


Mmm... high risk of being in/out of phase as boat leans.

I have seen what looks like two octaheadral reflectors merged into one, on the top of some navigation bouys. I wonder if these are any better?

 

[philfin]

There you go...Youv'e lost me! What does out of phase mean? I di have in mind joining them together one above t'other. Afterall they do say the bigger the better!

Well, some girls do!

 

[Becky]

Still think that the only way to guarentee being seen at sea is to use an active radar reflector which fires back a response to anything that sends it a radar signal.

We have a Seame on the masthead that does just that. Ships certainly pick Cornish Maid up on their screens. Seemingly we look as big as a supertanker!!

Met the designer last year down in Biscay. Interesting chap, And very pleased to see the equipment on our boat.