RichD
Guest
Wed Jan 06, 2010 9:13 pm
There's this new surveillance / law enforcement tool,
used in ghetto areas, consists of multiple microphones,
to identify and locate gun shots. Pretty impressive, if it works.
Anybody know - or guess - what algorithms they use?
--
Rich
jonnie
Guest
Wed Jan 06, 2010 9:13 pm
"RichD" <r_delaney2001_at_yahoo.com> wrote in message
news:d2ac4bb0-f841-4448-b90d-132ac9d3e477_at_h9g2000yqa.googlegroups.com...
Quote:
There's this new surveillance / law enforcement tool,
used in ghetto areas, consists of multiple microphones,
to identify and locate gun shots. Pretty impressive, if it works.
Anybody know - or guess - what algorithms they use?
--
Rich
timing.
use first impulse, ignore reflections.
why you want to know ?
Guest
Wed Jan 06, 2010 9:13 pm
In sci.physics RichD <r_delaney2001_at_yahoo.com> wrote:
Quote:
There's this new surveillance / law enforcement tool,
used in ghetto areas, consists of multiple microphones,
to identify and locate gun shots. Pretty impressive, if it works.
It has been around for over a decade at least and doesn't really work all
that well in urban areas.
Wiki has several articles about it; start here:
http://en.wikipedia.org/wiki/Gunshot_Location_Detection_System
--
Jim Pennino
Remove .spam.sux to reply.
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JeffM
Guest
Thu Jan 07, 2010 6:38 am
RichD wrote:
Quote:
There's this new surveillance / law enforcement tool,
used in ghetto areas, consists of multiple microphones,
to identify and locate gun shots. Pretty impressive, if it works.
I remember there was some similar stuff going on
with a Dictabelt recording from November 22, 1963.
http://google.com/search?q=motorcycle+microphone+%22+Dealey.Plaza%22+%22+Gallery.Magazine
John Nagle
Guest
Sat Jan 23, 2010 9:57 am
jimp_at_specsol.spam.sux.com wrote:
Quote:
In sci.physics RichD <r_delaney2001_at_yahoo.com> wrote:
There's this new surveillance / law enforcement tool,
used in ghetto areas, consists of multiple microphones,
to identify and locate gun shots. Pretty impressive, if it works.
It has been around for over a decade at least and doesn't really work all
that well in urban areas.
Wiki has several articles about it; start here:
http://en.wikipedia.org/wiki/Gunshot_Location_Detection_System
The first one was installed in Redwood City, near me. The original
version used analog microphones connected to dedicated analog phone
lines. Each microphone had an interface unit which increased dynamic
range while reducing bandwidth. (A phone line is normally 8-bit audio
at 8KHz. Think of this as going to 16-bit audio at 4KHz, although in
fact they used analog circuits.)
The headend of the system was simply a PC running a LabView application.
It was really very simple.
Newer units are much fancier, with built-in GPS and clock synchronization,
so they don't need a dedicated hard-wired phone line.
John Nagle
(Don't crosspost so much.)
