[Scan-DC] transmitter signature software

[Larry Sampas]

I was just reading about this for grad school...

It is often possible to identify individual equipment by analyzing
unintentional frequency modulation, the shape of the transmitter power-on
curve, the precise center frequency, and final-stage amplifier harmonics. RF
fingerprinting was declassified in the mid-90s for use in identifying cloned
cellphones. Back in WWII, signal analysts identified operators based on
their "fists" -- the way they sent CW. 

Also, it's possible to determine what frequencies a receiver is tuned to by
picking up stray RF from the radio's local oscillator. SFX Entertainment
does this in parking lots at big concerts -- the same equipment has been
sold to mall operators and radio stations.

This is from Ross Anderson's excellent book, "Security Engineering." (Wiley,
2001)

Sources for RF Fingprinting: 
Goldberg, L, "Recycled Cold-War Electronics Battle Cellular Phone Thieves,"
Electronic Design, v 44 no 18, Sept. 3 1996, p 41-42.
Also:
http://www.amazon.com/gp/product/0890065268/qid=1133470935/sr=11-1/ref=sr_11
_1/104-2074970-1433549?s=books&v=glance&n=283155

-----Original Message-----
From: scan-dc-bounces at mailman.qth.net
[mailto:scan-dc-bounces at mailman.qth.net] On Behalf Of ka3jjz at netscape.com
Sent: Wednesday, November 30, 2005 10:05 PM
To: scan-dc at mailman.qth.net
Subject: [Scan-DC] transmitter signature software

  John B. and others...the software I saw in an article on the DXing.info
(not Hard Core DX as I had mentioned earlier) is here...

  http://www.qsl.net/dl4yhf/spectra1.html

  The article has to do with viewing the transmitted signal of a MW station
and measuring it against a known constant. Viewing the waveform then can see
just how clean that signal actually is. But I suspect it would be just as
applicable to a FM signal, if a discriminator tap were used.

  One unique aspect of this software is it's ability to 'create an interface
to any A/D converter', which is (at least in the units I've seen) at the
heart of devices that capture such a signature.
 
  Is it as good as a good spectrum analyzer or calibrated service monitor?
Of course not...but it might be the next best thing. It looks like it's
quite powerful for being free (yep, costs nada).

  It's a fascinating package, for sure.   73s Mike

links editor,Capitol Hill Monitors
Utility Monitoring Central
editor, Strong Signals software page
Wiki Administrator, Radioreference.Com


_____________________________________________________________
Netscape. Just the Net You Need.
_______________________________________________
Scan-DC mailing list
Scan-DC at mailman.qth.net
http://mailman.qth.net/mailman/listinfo/scan-dc