Imagine that you are looking for something -- such as your lost keys -- in a dark room.
Suppose
your eyes can't sort out the photons coming back from all different angles
averaged over time (in other words, the flashlight is out).
But -- as long as we're imagining
-- say you have your unique panoramic camera that takes photos four feet
wide and only six inches tall. Now you can shoot off a flash and take a
black and white photo of a strip of the floor. Orient the strip perpendicular
to the way you are traveling and make successive flash pictures of the ground.
Pop your flash and photograph
the carpet six inches ahead and four feet to the sides. Walk ahead (pop,
pop, pop), and you'll see things drift by underneath you. There goes the
dog off to starboard (pop, pop, pop). There goes your teddy bear to port.
You hit the wall, but no keys, so you turn around, move over four feet and
start a new strip.
This technique of imaging
the carpet is similar to the way the side-scan sonar works, except the side-scan
sonar uses sound instead of light.
-- Will Sager
http://oceanography.tamu.edu/Quarterdeck/1998/3/sager-imagine.html
Copyright 1998-1999, Department
of Oceanography, Texas A&M University.
Updated November 24, 1998. (abdw)
Send Quarterdeck inquiries to quarterdeck@ocean.tamu.edu.
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