Originally posted by titian
Secondly, how would you control the orientation of the metallic particles such that they direct the radar reflections back to a monitoring station on
and not into each other?

See chaff:
4: material (as strips of foil or clusters of fine wires) ejected into the air for reflecting radar waves (as for confusing an enemy's radar
detection or for tracking a descending spacecraft)
www.m-w.com...
www.reviewjournal.com...

RENO -- Some Nevada officials criticized a federal report on military chaff and said the document raised more questions than it answered
about whether the radar-evasion material was harming people or the environment.
The military has insisted the material is not harmful, but the report by the General Accounting Office concluded that its health effects were unknown
and that more studies were needed.
....
Chaff, made of tiny fibers of aluminum-covered fiberglass, is dropped by military aircraft to confuse enemy radar systems. Tons of the stuff have
been dropped over Nevada, mostly by jets from the Fallon Naval Air Station.
Once it reaches the ground, chaff breaks down into particles small enough to inhale. Rural Nevadans complain it is frequently dropped over their
homes, but they have no idea if it is safe.

[Edited on 5/28/2004 by Bangin]