I would really like a way to reach this person.  thank you.
  ----- Original Message -----=20
  From: David H. Youden=20
  To: psn-l@.................
  Sent: Thursday, April 10, 2003 3:06 AM
  Subject: Re: Seismic intrusion detectors part 2


  Mr. King

  Are you aware that the National Institute of Science and Technology =
http://www.nist.gov has a mechanical engineering laboratory (MEL) which, =
in turn has a sensor laboratory studying exactly the subject of your =
question? The laboratory chief, E. Clayton Teague is a friend of mine, =
and I suggest that you get in touch with him. They are working with =
intrusion sensors that are smaller than a cigarette pack, have multiple =
sensors, and are networked via, I think 2.4 GHz radio. The idea is to =
spread a bunch of these along a trail and watch for intruders. If you =
need Clayton's e-mail address, and it's not on the website, please ask =
me.

  Dave...



  At 10:02 AM 4/9/03 -0700, you wrote:

    Here is the overall design.
    =20
    The sensor consists of (2) geophones.  They are places aprox. 30-40 =
feet apart on a known trail that illegals use.=20
    =20
    The prototypes we are using have (2) LT1677 opamp circuits that =
amplify the geophone outputs and feed the signal into a basic stamp 1.  =
The level of signal isn't converted to digital, the signal when large =
enough (about 1.67 volts) will drive the input pin high and thus we have =
a logic switch.
    =20
    In order to limit false hits the software in the basic stamp listens =
for a hit on a geophone.  When there is a hit it basically says if the =
second geopghone is hit within the next 2 seconds cancel the entire hit =
becuase it is most likely rain or some other seismic disturbance.  If =
the gephone is hit after that to seconds the it is a real hit and send a =
signal back to us through our repeater.  The data coming to us tells us =
what "port" hit first and what sensor it is.  By knowing what port was =
hit first we can tell what direction the contact is going. =20
    =20
    During initial powerup we callibrate the instrument by "walking the =
line" or walking by both geophones.  By doing this and counting the =
number of footfalls on an average man we can the have a rudimentary =
counting of the number of people walking by.  By dividing the number of =
detected footfall by the number of detected footfalls in the calibration =
we have the number of intruders.  It all works but the noisy circuit is =
killing me.
    =20
    This system works but our circuit is noisy and when I make the =
software just send hits on either geophone as they come in, sometimes, =
at random,  one or both of the "ports" will show hits for minutes on =
end.  If I touch the circuit board with my finger i can kill the noise =
until some kind of seismic activity start the noise again.
    =20
    =20
    =20
    =20
    Michael S. King
    Technical Director
    American Border Patrol







I would really like a way to reach this =

person.  thank you.

  
----- Original Message ----- 
  From:=20
  David =
H. Youden=20
  
  
To: psn-l@.............. 
  
Sent: Thursday, April 10, 2003 =
3:06=20
  AM
  
Subject: Re: Seismic intrusion =
detectors=20
  part 2
  

Mr. King

Are you aware that the National =
Institute of=20
  Science and Technology http://www.nist.gov has a mechanical =
engineering=20
  laboratory (MEL) which, in turn has a sensor laboratory studying =
exactly the=20
  subject of your question? The laboratory chief, E. Clayton Teague is a =
friend=20
  of mine, and I suggest that you get in touch with him. They are =
working with=20
  intrusion sensors that are smaller than a cigarette pack, have =
multiple=20
  sensors, and are networked via, I think 2.4 GHz radio. The idea is to =
spread a=20
  bunch of these along a trail and watch for intruders. If you need =
Clayton's=20
  e-mail address, and it's not on the website, please ask=20
  me.

Dave...



At 10:02 AM 4/9/03 -0700, you =
wrote:

  
Here is=20
    the overall design.
 
The sensor=20
    consists of (2) geophones.  They are places aprox. 30-40 feet =
apart on=20
    a known trail that illegals use. 
 
The prototypes we are using have (2) LT1677 opamp circuits =
that=20
    amplify the geophone outputs and feed the signal into a basic stamp =
1. =20
    The level of signal isn't converted to digital, the signal when =
large enough=20
    (about 1.67 volts) will drive the input pin high and thus we have a =
logic=20
    switch.
 
In order to =
limit false=20
    hits the software in the basic stamp listens for a hit on a =
geophone. =20
    When there is a hit it basically says if the second geopghone is hit =
within=20
    the next 2 seconds cancel the entire hit becuase it is most likely =
rain or=20
    some other seismic disturbance.  If the gephone is hit after =
that to=20
    seconds the it is a real hit and send a signal back to us through =
our=20
    repeater.  The data coming to us tells us what "port" hit first =
and=20
    what sensor it is.  By knowing what port was hit first we can =
tell what=20
    direction the contact is going.  
 
During initial powerup we callibrate the instrument by =
"walking the=20
    line" or walking by both geophones.  By doing this and counting =
the=20
    number of footfalls on an average man we can the have a rudimentary =
counting=20
    of the number of people walking by.  By dividing the number of =
detected=20
    footfall by the number of detected footfalls in the calibration we =
have the=20
    number of intruders.  It all works but the noisy circuit is =
killing=20
    me.
 
This system =
works but our=20
    circuit is noisy and when I make the software just send hits on =
either=20
    geophone as they come in, sometimes, at random,  one or both of =
the=20
    "ports" will show hits for minutes on end.  If I touch the =
circuit=20
    board with my finger i can kill the noise until some kind of seismic =

    activity start the noise=20
    again.
 
 
 
 
Michael S. King
Technical Director
American Border=20
  Patrol