It fools the tech into recording false positives.
Frowning takes 68 muscles.
Smiling takes 6.
Pulling this trigger takes 2.
I'm lazy.
Posted on 10/20/2009 3:42:41 PM PDT by devane617
ShotSpotter sensors were slated to be installed on electrical poles in a one-square-mile area in a north Oak Cliff neighborhood. The sensors work by picking up the sonic waves emitted by gunshots, triangulating the location of the gunfire and notifying 911 operators to send police.
(Excerpt) Read more at dallasnews.com ...
That’s racist. To be non-racist they need to put them in Highland Park.
If they put them in Highland Park...
“You only want to protect White People”
Do any Freepers know how easy it is to spoof these things? Gunshots have fairly distinctive sound patterns but I think some common items might mimic them fairly well.
A 2 liter plastic bottle taped to the muzzle.
I suspect the project was pulled for that very reason.
It's been around for a while.
I've also read of a portable system that can be mounted on vehicle. It only determines azimuth, but is useful for a patrol to focus on the threat when they are ambushed by a sniper.
How do you spoof it? whack a pie tin?
Did you even read the article?
The problem is a dispute between the company installing the system and Oncor (the local electric utility). Oncor wants a contract that the installer believes exposes them to too much liability.
I believe this is in your second novel?
A gunshot has a very specific impulse signature. What sounds similar to your ear is completely different to a digital signal processor.
I read the article, and I know Dallas County politics—very well.
Pop a paper bag, perhaps. The same idea - sudden release of gas under pressure. I could see kids having lots of fun with this system if the appropriate noise filters are not used to process the noise data.
The technology isn’t that tough. Gun shots have a pretty identifiable wave pattern, you stick a bunch of microphones around, have some software that looks for the wave pattern, and when it spots one it looks for identical waves in other nearby mikes, then you use the time signatures to figure out where the sound came from. The problem comes in with other gun shot sounds (what happens when somebody in the neighborhood decides to watch a Rambo movie with their TV turned way up). And finally with what are you really going to gain, most of the time once shots get fired the shooter will either be running or calling the cops in short order.
Something like dry ice in a 2 liter bottle might mimic the effect when the bottle explodes.
I wonder if it would have picked up Oswald shooting Officer Tippit.
A sound supressor with subsonic ammo would change the signature but I don’t know that it would fool the system. It would seem easier to fool the system with multiple signatures.
A sound supressor with subsonic ammo would change the signature but I don’t know that it would fool the system. It would seem easier to fool the system with multiple signatures.
crap
So there’s a big problem with gunshots happening, yet nobody calls the police?
Seems a little odd. Maybe saves a minute or two I suppose.
But on another level: If a shot is fired and nobody cares enough to call the police, is it really a problem?
Nah, the boom boxes used by the homies are confusing the sensors. Have you ever driven through Oak Cliff?
It fools the tech into recording false positives.
Why would you want to do that?
From their FAQ:
What about silencers?
The ShotSpotter GLS uses acoustics to detect and locate the sound of explosions and gunfire produced by all types of firearms (including those used in homicides, errant and celebratory gunfire). If the silencer (also known as "muzzle blast suppressors") is sufficiently effective, our sensors simply won't hear the shots. According to the FBI, firearms equipped with silencers are used in less than 1% of all gun crime. Despite 15 years of deployment history there is no evidence in any city in which ShotSpotter is deployed that the use of silencers in the commission of crimes increases subsequent to system installation. In fact, quite the opposite is true: illegal gunfire generally decreases after ShotSpotter systems are installed.
Wow, thanks for the info.
It might sound the same to you, but it's an entirely different sound when analyzed.
It's not just the frequency or the volume. It's the rise and fall of the amplitude that distinguishes a gunshot from everything else.
Then, it's followed by the sound made by the bullet as it travels through the air. If it's supersonic, the bullet literally creates a "sonic boom". Of course, subsonic rounds will be more difficult to identify.
However, not all gunshots are the same, either. Handguns, rifles, and shotguns have different signatures. But, they can be distinguished from sounds that seem similar, like a car backfiring. There's an extensive article about the technology here:
http://en.wikipedia.org/wiki/Gunshot_Location_Detection_System.
Once installed where gunshots are common several things will happen right off.
The Gang Bangers will create a rite of passage for 12-13 year olds based upon firing a shot and running off. How many times can you get the police to respond and not get caught.
Then the police will get tired of the false alarms their response will slow, or they will only respond to multiple shots.. something stupid and unforeseeable.
They may want Cameras to observe the area, so they can see who is firing the shots. Another big debate.
Now million dollars later they will need all new cameras and sensors because by that time the gang bangers will have gotten bored with shooting at random into the air and taking off and will fire up the sensors.. All of which will at some point no doubt cost people 10 blocks away their lives as those random shots return to earth.
Now do you see any upside to all this?
Neither do I.
Public Officials driven by businesses eager to sell their technology as often as not just do stuff because they can. To apply technology and not think of the consequences as they will occur in the real world..
Deploying these devices will not stop drive by shootings. They will not stop hits or violent encouters of any kind.. They will not even slow them down.. They will only cost more innocent lives...all while being touted as a great success so that the responsible politician is not subject to ridicule and the business selling the products can get more sales.
The law of unintended consequences is very much alive and well.
W
A system like this was how the shooting of Lt Quarles Harris was discovered in DC (of passport intrusion case of Obama’s files).
Well that suggests it did not deter anyone?
The question really has to be.. Does the evidence suggest it deters crime.. Is it worth it?
As far as I am concerned .. no..
W
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