Radar Reflector, Orientation?

[Guest]

Just picked up an aluminium radar reflector from the Southampton boat jumble. It's the standard aluminium type (but doesn't fold). A real bargain at £2. Trouble is I'm not sure which way round it should be hoisted. I'd read somewhere that it should be in the 'catch rain position'. I've had a look at other boats in the marina and those that had a similar reflector all seemed to be hung in different ways.
Any one care to educate me. If its got to be the 'catch rain' position then does this mean that the top corner-quadrant is positioned such that it catches water?
The hanging/halyard holes in this reflector don't seem to be positioned to allow a true catch rain orientation.

Cheers in anticipation.

 

[johndf]

Yes, the catchrain position is what you need, with the reflector oriented to 'catch as much rain' as possible. The edges of three faces should then form a horizontal triangle. In this position an incoming radar beam will reflect off three faces so as to be returned parallel to itself.

 

[snowbrushy]

Here is a link which has some information about reflectors which were tested:
http://www.ussailing.org/safety/Studies/radar_reflector_test.htm

 

[johnsomerhausen]

I'd add to the previous post that you need three bits of line, about 30 centtimeters long and coming together at a ring to be able to hang it properly and three more bits of line doing the same at the bottom to stabilize it.
john

 

[brian_neale]

Double catchwater position

Interestingly, the review suggests a variation on the usual orientation (see http://www.ussailing.org/safety/Studies/radar_reflector_test.htm#Octahedral Reflectors). This involves one panel of the reflector being vertical (and presumably oriented fore-and-aft) while the other two planes are at 45deg to the vertical. They reckon that this gives better results when heeled, although I did not see specific test data to back this up.

Has anyone personal experience of the effectiveness of the active radar devices, or a pointer to independent test results?