Date: Wed, 21 Feb 2001 12:34:16 -0500 From: freematt@coil.com (Matthew Gaylor) Subject: RE:Thermal Imaging Privacy Case From Oregon Goes Before High Court To: freematt@coil.com (Matthew Gaylor)
From: "Brown, Pete - DSSD" <PWBrown@ips.bfg.com> Subject: RE:Thermal Imaging Privacy Case From Oregon Goes Before High Court Date: Wed, 21 Feb 2001 12:02:05 -0500
As a Level-1 Infrared Thermographer (Certificate #1-639) I can assure you that infrared imagers cannot see "through" walls, unles they are built of paper-thin polyethylene or some other IR-transparent material. Open windows? Yes, certainly. They can see through screens, also. Closed windows? Depends on the spectral range of the imager, short-wave systems (1-5 micron wavelength) can see through some glass, albeit with some attenuation.
Can they see through an open window someone in a darkened room undressing, making love, painting the walls (in the dark)? You bet, and well enough to identify them if they're close by. But seach a house? Well, no. They might see if a house is occupied by seeing someone through a window, and can likely tell what they're doing. Or, as in this case, they can tell if a part of the house is really warm on the outside, though this could also be caused simply by poor insulation (the "search" in question was conducted at night in January, presumably cold outside with heat on inside). But they cannot see what's behind walls, or what the source of the heat is, just the outside temperature of the wall tself.
IMHO, using an infrared image of heat-loss through an attic as justification for a search warrant is pretty shaky. Wet or missing insulation could make any house look like an oven in the winter.
Peter W. Brown BFGoodrich Aerospace 1555 Corporate Woods Pkwy. Uniontown, OH 44685-8799 330-374-2576 voice 330-374-2575 fax pwbrown@ips.bfg.com
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