passive radar theory refrence needed

Hi,

I heard there are some types of radar which operate passively, this
means, they dont send any signal and dont wait for the echo, but they
get some random electromagnetic waves from the air which are reflected
on objects as well and it is possible get some image in exchange of
some computation.
I also heard of a swiss company who are using the same principle but in
geology, seismology, oil exploration. They dont produce any signal
(like explosion under the surface) but instead use very sensitive
detectors and catch the random seismic noise from the earth which
reflects as well and get the image based on this.

So. I am interested in the mathematical and algorithmical part of the
topic. Does anyone know any good references? Like keywords or book
titles.

Many thanks
Peter

.

Relevant Pages

  • Re: passive radar theory refrence needed
    ... means, they dont send any signal and dont wait for the echo, but they ... get some random electromagnetic waves from the air which are reflected ... reflections, or just listen to what is coming along, acoustically or ... In fact the eyes are a nice passive radar, ...
    (sci.physics)
  • passive radar theory refrence needed
    ... I heard there are some types of radar which operate passively, ... means, they dont send any signal and dont wait for the echo, but they ... get some random electromagnetic waves from the air which are reflected ...
    (sci.math)
  • passive radar theory refrence needed
    ... I heard there are some types of radar which operate passively, ... means, they dont send any signal and dont wait for the echo, but they ... get some random electromagnetic waves from the air which are reflected ...
    (comp.theory)
  • Made a video show script, it works, can anyone find visible bugs in it that might crash later
    ... The script below is a drop in that reads a folder full of .wmv or .asf files ... and lets you play them like the slideshow scripts for images ... dont know how to code for other file types ... echo 'width=379'; ...
    (php.general)
  • Re: Going back to Motorola
    ... Few things besides the echo was the flip ... was week in the open mode. ... Just a slight move and it wanted to close. ... Signal was a slight bit better on the 815 but dont have any problems with ...
    (alt.cellular.verizon)