On Sun, 27 Apr 2008 12:34:55 -0700 (PDT), WingFlaps
wrote in
:

A radar reflector like they use on weather balloon ought be
sufficient. It is just a piece of foil with a large cross section.

That's a constructive suggestion. *

How large must such a radar reflector be? *

It's a retroreflector, I have one in the form of a tube about 3 inches
in diameter and 2 feet long. The corner cubes are inside that. I have
no idea how effective it is compared to a classic reflector which
occupies a cube about 1 foot across and retroreflects the radar
equally in all directions.
...

Interesting. Thanks for the information.

How do you think it might affect a sailplane's L/D?

More information:

Marine passive radar reflectors:
http://www.sailgb.com/c/radar_reflectors/

Modulating retro-reflector as a passive radar transponder
http://ieeexplore.ieee.org/xpl/freea...isnumber=15618


Will it activate TCAS? *

Don't see how it could, TCAS uses the information in the active
return from the transponder.


Yep.

Does ATC normally enable the display of primary targets?

As fas as I know ATC radar picks up as many moving targets as it cam
"see". Not sure what you mean by primary tho'.


By 'primary' I mean the radio energy passively reflected by the
target, as opposed to a target generated as a result of a transponder
interrogation. I know ATC can 'see' primary targets, but I am under
the impression that controllers normally configure their 'scopes to
see only transponder targets to reduce screen clutter.

In any event, a passive radar reflector (or two) might be made part of
a system to address this issue, but I'm guessing the FAA would prefer
something capable of alerting TCAS systems.