[883] in Professors_Quote_Board
Re: Postol 17.477J
enolagay@ATHENA.MIT.EDU (enolagay@ATHENA.MIT.EDU)
Fri Apr 29 13:28:31 1994
Sorry for the technical posting, but someone asked.... there are some
quotes near the end anyway. :)
The warhead he was referring to was a standard sized US nuclear warhead.
They are around 6-8 ft tall, weigh ~400 lbs, are cone-shaped (with a
rounded back), and are coated with a radar absorbing material.
Radar cross-sections are a function of how much of the radar signal gets
bounced back to the reciever. Because the radar usually looks at the
warhead point first, very little of the signal gets reflected, and even
less bounces back in the correct direction to be detected. This leads
to a cross-section on the order of tenths or hundreths of meters.
A duck has nice flat surfaces that reflect the radar signal right back
towards the source. That is why it "appears" to be a larger object to a
radar.
As for the speed of the object, effecting its radar signal...
The speed of the object is mostly irrelevant for determining the size of
the radar signal returned from an object. It does matter for
discriminating targets, however...ie you can get range data from a radar
system and so you could therefore tell objects apart by how fast they
were moving.
Some more quotes from the class:
The professor showed us a copy of the paper that conducted the
experiments on the radar signals of ducks and other birds. Part of the
paper referenced a book for dealing with ducks that are uncooperative
and won't sit still for the radar tests (the book was the Joy of
Cooking).
All of this talk about comparing ducks to nuclear warheads led to the
observation in class that maybe we should consider using ducks as decoys
for warheads when trying to defeat missile defense systems.
