Dog-Assisted Surveillance
U.S. patent #6782847 granted August 31, 2004 to David Shemesh and Dan Forman, both based in Israel, for an “automated surveillance monitor of non-humans in real time.” The patent contains a sequence of three drawings—reproduced here—that, by themselves, pretty much explain the inventors’ thinking.
In this technical drawing, two of the sensor-bearing dogs are alarmed by a passing terrorist. Both dogs say “WOOF WOOF WOOF.” Shemesh and Forman write that “FIG. 1B illustrates a situation wherein the amplitude and perhaps also the frequency of the barking of a dog indicates an alarm situation.”
(That’s an excerpt from the article “Plucked from Obscurity: Technology + Animals,” published in AIR 14:1.)