tuner part of the hardware with the photomultiplier, we can do all the image processing - filtering, integrating - in software, greatly reducing the cost of the equipment.
I doubt it. Although I only scanned the article, in general you won't be able to replace a fourier-plane optical spacial filter with anything in software using only a photomultiplier tube. A CCD matrix, however might be a different story, and CCDs are getting cheaper a la Moore law (or something similar).
-TD
From: Mike Rosing <[EMAIL PROTECTED]> To: cypherpunks <[EMAIL PROTECTED]> Subject: Re: GNUradio and optical TEMPEST Date: Thu, 6 Mar 2003 09:34:57 -0800 (PST)
On Thu, 6 Mar 2003, Thomas Shaddack wrote:
> Musing over > http://www.cl.cam.ac.uk/~mgk25/ieee02-optical.pdf
The moral seems to be don't work in a dark room with windows :-)
> Using the software-DSP approach of GNUradio project and replacing the
> tuner part of the hardware with the photomultiplier, we can do all the
> image processing - filtering, integrating - in software, greatly reducing
> the cost of the equipment.
But visible is limited to line of sight. With reasonable RF you can bounce all over the planet.
> Applies to lots and lots of other non-radio-related problems as well. Can
> be used for processing any kind of signal, if we replace the tuner stage
> with application-specific hardware.
>
> Another advantage could be to put large FPGA chips between the ADC and the
> computer, which could allow preprocessing of the signal in hardware,
> taking some burden off the computer's CPU. The FPGAs can be reprogrammed
> on-fly for each application.
>
> But it's just an idle musing of one awfully tired technician. Maybe it
> will be useful for someone, though...
Fun toys are fun toys any way you use them :-) Thanks for pointing out the article, looks like a fun read.
Patience, persistence, truth, Dr. mike
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