PSN-L Message - Subject: Re: Intrusion Sensors

writes: John, agreed a lot of pipe would be needed. But also a lot of seismic sensors if they would be used. I think it depends on what kind of protection Mr King is looking for. A standard 4.5Hz geophones can detect motion of a human body walking normally at about 5-10 meters but not more and not at all if he is walking softly. The cost of a 50 meters of rubber pipe is small if compared to the cost of a single geophones that cannot pick that range. You have to consider that spacing geophones at 50 meters (to be large) you will need anyway 50 meters or more of twisted cable to lead the signal to a sort of peamplifier or digitizer for analysis. If I don't remember bad there should also some sort of piezo wires that could be useful for the same pourposes but obviously several km of piezo wire would be very expensive. Regards Mauro ----- Original Message ----- From: John Hernlund To: psn-l@.............. Sent: Wednesday, April 09, 2003 9:35 AM Subject: Re: Intrusion Sensors On Tuesday, April 8, 2003, at 11:56 PM, Mauro Mariotti wrote: Hi Mr. King, I think that the major problem is what sensor to use instead of what amplifier use. Geophones have a limited detection range and not detect a person that eventually walk softly. It could detect a running animal instead or an animal trying to bury something near the sensor. Probably a better sensor is a pressurized rubber pipe buried along the border that could be long 10 - 20 meters or more. Then you can measure the pressure variation at one extremity when someone walk over it. That would take a lot of pipe...but maybe a better idea for sensors. I talked to an army guy who once did seismic sensors in the first Iraq war. They have (of course!) an acronym for this job, though I don't remember it...I don't think he even remembered what it stood for. He told me they are mostly designed to detect artillery sources, and combined with radar methods (he called it fire-finding radar, or something like that) pin point the location of an enemy's artillery and then be able to fire back at the correct position. He also said that it could pick up large vehicle convoys or even people on foot when they were very numerous and fairly close. What works in the Army tends not to be the case along the AZ border, which is run by coyotes hauling mostly smaller groups of people on foot...some times abandoning large numbers of them in the middle of the desert leading to hundreds of deaths from heat exhaustion, etc.. On a number of occasions I've run across a taxi looking for fares in the middle of the desert! In a few border towns there have been incidents of thousands of people lining up along the border, and then crossing all at once...thus overwhelming the border patrol...but not much is able to stop this from happening. The worst is the drug runners who are almost always armed and quite willing to shoot first and see who it is later...this may account for the low morale in the border patrol in some areas, since quite a few of them have been killed. No doubt about it, the lax border enforcement in the past decade in Arizona has caused this to be the main conduit for illegal cross-border activity in the US. It has brought the Mexican mafia into Phoenix, where they took control of much of the illegal activity there. They are a bold and brutal organization, and even wear clothing, drive trucks, etc. in a uniform way that announces who they are; i.e. their presence and lack of fear. A friend of mine, a Phoenix cop, lost his partner when a group of them telephoned the police and laid a trap...apparently just for "fun." So no doubt about it, this is a serious problem. Dealing with it is not trivial, and the complexities involved are mind-boggling. Arizona is the sixth largest state in the US, and contains 193 separate (and unsettled) mountain ranges that really makes it possible for much to happen off the beaten track. But there is always room for innovations. Some cities have set up microphones to detect gun shot locations before the inevitable 911 call. People need to just keep thinking and being creative, and a solution could present itself. Cheers!

I would concentrate on prevention, not detection. An electrified

fence with, say a half million volts would probably work. Also,

we could take a lesson from Saddam and have trenches full of

burning oil...

Seriously, though, I think you have a big challenge. Seismic

detection of people walking at any significant distance would

be next to impossible because, even though you might achieve

some kind of amazing sensitivity, you would never be able to

decode the data and the false positive rate would be excessive.

Hell, just the 6 second noise and background would cover

over everything but King Kong.

I think some kind of visual system would be able to monitor

huge areas at little expense, especially compared to seismic

sensors. A digital camera with an expansive and essentially

static field of view could definitely be used along with a

program to analyze the images for changes. A random change

of pixels, for instance would not be indicative, however a

chain of adjacent pixels that have changed would be. And,

of course IR detection at night is a no-brainer.

How about using R/C model planes as drones with little

video cameras? I like that approach because they are noisy,

which lends a preventive element. You can always fly the

plane right into there head if they don't turn around.

You might even get some of them to surrender!

On Wed, 9 Apr 2003 10:35:55 +0200 "Mauro Mariotti" <mariotti@.........> writes:

John,

agreed a lot of pipe would be=20 needed.

But also a lot of seismic sensors if = they would=20 be used.

I think it depends on what kind of = protection Mr=20 King is looking for.

A standard 4.5Hz geophones can detect = motion of a=20 human body

walking normally at about 5-10 = meters but=20 not more and not at all if

he is walking softly.

The cost of a 50 meters of rubber pipe = is small=20 if compared to the

cost of a single geophones that cannot = pick that=20 range.

You have to consider that spacing = geophones at 50=20 meters

(to be large) you will need anyway 50 = meters or=20 more of twisted

cable to lead the signal to a sort of = peamplifier=20 or digitizer for

analysis.

If I don't remember bad there should = also some=20 sort of piezo wires

that could be useful for the same = pourposes but=20 obviously

several km of piezo wire would be very=20 expensive.

Regards

Mauro

----- Original Message -----
= From:=20 = John=20 Hernlund
To: psn-l@..............

Sent: Wednesday, April 09, 2003 = 9:35=20 AM

Subject: Re: Intrusion Sensors

On Tuesday, April 8, 2003, at 11:56 PM, Mauro Mariotti=20 wrote:

Hi Mr. King,
I=20 think that the major problem is what sensor to use instead of
what=20 amplifier use.
Geophones=20 have a limited detection range and not detect a person
that=20 eventually walk softly.
It=20 could detect a running animal instead or an animal trying to bury
something=20 near the sensor.
Probably=20 a better sensor is a pressurized rubber pipe buried along the border<= ?/smaller>
that=20 could be long 10 - 20 meters or more.
Then=20 you can measure the pressure variation at one extremity when
someone=20 walk over it.

That would= take a=20 lot of pipe...but maybe a better idea for sensors. I talked to an army = guy=20 who once did seismic sensors in the first Iraq war. They have (of = course!)=20 an acronym for this job, though I don't remember it...I don't think he = even=20 remembered what it stood for. He told me they are mostly designed to = detect=20 artillery sources, and combined with radar methods (he called it=20 fire-finding radar, or something like that) pin point the location of = an=20 enemy's artillery and then be able to fire back at the correct position= .. He=20 also said that it could pick up large vehicle convoys or even people on= foot=20 when they were very numerous and fairly close.

What works in = the=20 Army tends not to be the case along the AZ border, which is run by = coyotes=20 hauling mostly smaller groups of people on foot...some times abandoning= =20 large numbers of them in the middle of the desert leading to hundreds = of=20 deaths from heat exhaustion, etc.. On a number of occasions I've run = across=20 a taxi looking for fares in the middle of the desert! In a few border = towns=20 there have been incidents of thousands of people lining up along the = border,=20 and then crossing all at once...thus overwhelming the border patrol...= but=20 not much is able to stop this from happening. The worst is the drug = runners=20 who are almost always armed and quite willing to shoot first and see = who it=20 is later...this may account for the low morale in the border patrol in = some=20 areas, since quite a few of them have been killed. No doubt about it, = the=20 lax border enforcement in the past decade in Arizona has caused this to= be=20 the main conduit for illegal cross-border activity in the US. It has = brought=20 the Mexican mafia into Phoenix, where they took control of much of the= =20 illegal activity there. They are a bold and brutal organization, and = even=20 wear clothing, drive trucks, etc. in a uniform way that announces who = they=20 are; i.e. their presence and lack of fear. A friend of mine, a Phoenix = cop,=20 lost his partner when a group of them telephoned the police and laid a= =20 trap...apparently just for "fun."

So no doubt about it, this is = a=20 serious problem. Dealing with it is not trivial, and the complexities=20 involved are mind-boggling. Arizona is the sixth largest state in the = US,=20 and contains 193 separate (and unsettled) mountain ranges that really = makes=20 it possible for much to happen off the beaten track. But there is = always=20 room for innovations. Some cities have set up microphones to detect gun= shot=20 locations before the inevitable 911 call. People need to just keep = thinking=20 and being creative, and a solution could present=20 itself.

Cheers!
John

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