Hi Roman

I've done a fair amount of work with IR, and the best solution I've used =
is a fresnel type lens and linear CCD array.
The fresnel lens was simply a strip cut from a cheap alarm PIR detector.
The CCD array was placed at an angle to the fresnel.The fresnel focusses =
the IR, filters daylight, and "segments" the source. By checking which =
CCD segments are lit, you can determine distance to source. By using 2 =
detectors 1meter apart you can triangulate quite acurately.
Heat seeking missiles generally use a spinning 'reticule' (which is a =
disk with masked off regions, starting wide at the periphery and getting =
narrower toward the center) and a single detector.
If the disk is spinning at a constant known speed, then the pulse width =
of the detected IR is longer the further off axis it is.
I can's say much more without violating various contracts and =
agreements.

Maybee these ideas will help you, but one problem to watch out for. =
Moisture in the air stops IR dead in it's tracks. The more humid or =
misty the conditions, the shorter the travel (makes sense since IR is =
essentially heat)

Cheers
Mark

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Mark Hull
Engineering/Technical
EMS (Africa) (Pty) Ltd
PO Box 1026, Melville, 2109, South Africa
Ph +27 11 482 4470 Fax +27 11 726 2552

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