I believe this is consistent with Shannon's information theory. Given
stereotypical environments, it is intuitive that the communication channel
of RF or IR is much more susceptible to noise than a solid conductive
I believe if you investigate you'll find that the intelligence is mostly in
the sight, that detects the degree to which the missile has diverged from
its course and issues appropriate steering commands.
Sure, but vision requires a huge amount of data transfer and still don't
know for sure which method would allow the faster exchange of data from
point a to point b in both visual and control situations. I see a thin wire
come into my home going to a box under my TV carrying over 900 channels plus
three computers in my home on high speed internet on that same little wire
carrying music and video. Could that be done with RF?
On Mon, 22 May 2006 22:11:32 +0000, Wayne Lundberg wrote:
Free space has infinite bandwidth. The more of it you use, the more you
spend on terminal equipment, but there is no theoretical limit. The main
advantage of a wired connection is freedom from interference, both the RF
kind and government regulations on what you can radiate.
At least some wire-guided missiles have _no_ brains or sensors in the
missile. The controller tracks the missile, computes the divergence
between the projectile's position and the line to the target, and sends
pulses down the wire to fire off-center rockets at the correct moment to
push the spinning missile back toward the correct path. Smarter missiles,
like submarine torpedoes, have bidirectional data links, but the actual
volume of data is probably modest by World Wide Web standards.
But any "vision" is on the sight, not the missile. The sight sees where the
missile is, sees where the spot is, and steers the missile onto the spot.
What does that have to do with missile guidance?
The only data that has to go down the wire is "a little higher", "a little
lower", "a little left", "a little right". Basically you could handle it
with two bits, three if you want to include "don't do anything", or you can
add more bits if you want more control authority. The Germans managed it
successfully (as in operational deployment in sufficient numbers with
sufficient success for the Allies to start working on countermeasures)
using audio frequencies. This isn't magic--any kid with a radio controlled
airplane has the necessary technology in his hand.
Regardless, the Nazis were making experimental television-guided bombs using
1943 technology, with signalling both ways being wireless--they also had
wire-guided variants which they never needed.
In any case, a broadcast TV channel uses 6 MHz of bandwidth--that just isn't
Hint--what goes down the wire is RF, same as what goes over the air. The
main benefit of the wire is that you don't have to get anybody's permission
to use the bandwidth.
This is what I was looking for. Thank you!
Just brainstorming here.... if I had a wire connected from transmitter to
receiver undeployed antenna... it would do the same as a deployed antenna?
Maybe. Depends on the details of the circuit design. You're almost
certainly going to end up overdriving the receiver, possibly far enough to
damage it--remember that it's designed for less signal strength than it's
going to be getting down the cable. Then there's the matter of matching
impedances. Then there are likely other factors that I haven't
considered--I know enough electronics to be dangerous, but not enough to be
good at it.
Thanks John, I think I have found the solution. There was an interesting
article in the San Diego Union Trib about a startup company
with the apparent solution to ultra-high speed and bandwidth for short
distance communications for all venues. Very interesting!
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