Passive Reflective Devices

In article , henkelize
writes
Hi everybody

I would like to gather some information about a passive reflective device
which could be used to increase the visibility of a glider. It was
described to me as follows, during one of those typical launch point chats:

It takes the shape of small sphere, mounted just behind the canopy on
the turtle deck
The surface is covered with faceted mirrors, like a disco mirror ball

Apparently this little ball will sparkle as light from the sun is reflected
to the observer, thus making the glider more visible. Now my questions are
as follows:

Has anybody ever seen or heard of such a device?
If yes, how can one obtain these little do-hickeys, i.e. price and point
of sale.
Do they actually work?

Any other suggestions for passive reflective devices will also be
appreciated. Suggestions and thoughts on active devices, i.e. strobes will
also be handy.

Regards

Henk Stander



Many years ago I had the same thought. I made up a reflector from 3
polystyrene ceiling tiles arranged at right angles to each other, and
covered with kitchen foil. (If you arrange mirrors like this a light ray
striking it will be sent back from where it came, it works with radar
too.)

Then I found there wasn't room in the glider for it.

Maritime radar reflectors are available, they are also too big...
--
Mike Lindsay

Mike Lindsay wrote:
Many years ago I had the same thought. I made up a reflector from 3
polystyrene ceiling tiles arranged at right angles to each other,
and
covered with kitchen foil. (If you arrange mirrors like this a light
ray striking it will be sent back from where it came, it works with
radar too.)

Then I found there wasn't room in the glider for it.

Maritime radar reflectors are available, they are also too big...

Mike,
I think Henk was talking about a reflector for sunlight, not radar
transmissions.
This means he needs to have the reflector on the outside of the glider
so it can be seen by others.
The main problem seems to be the drag issue, and then whether it is
any use anyway.
IMO unless very large, it won't be visible at any useful distance.
Even strobe lights aren't that good in bright sunshine after about
half a kilometer.
Cheers, John G.