Police use ultrasonic device to make sure drivers stay 3 feet from cyclists

On Mon, 15 Jun 2015 08:39:49 +0700, John B.
wrote:

Even better, the bike shops could sell a device consisting of 3 foot
"whiskers" connected to a paint ball gun. Touch the "whisker" and
BANG! you get indelible evidence that they were too close.

I thought of that, but decided that it might give readers too many
strange ideas. It really depends on whether you consider this device
a passive defense, or an aggressive deterrent. When dealing with the
police, methinks a passive defense is better.

(See Officer, just look for the car with the vomit yellow mark on the
door.)

The not so brilliant son of a friend informed his father than his
newly purchased air powered paintball gun was harmless. To prove it,
he fired a shot at his fathers car, putting a neat dent in the car
door. Oops. Also, the theory that the paint washes off with water is
rather marginal as it tends to be absorbed by any porous surface such
as the redwood siding on my house.
https://answers.yahoo.com/question/index?qid=20090326183008AAfd6kw

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Sun, 14 Jun 2015 17:31:08 -0700 (PDT), wrote:

On Sunday, June 14, 2015 at 6:58:32 PM UTC-4, Jeff Liebermann wrote:
On Sun, 14 Jun 2015 15:23:15 -0700 (PDT), wrote:

http://img1.wikia.nocookie.net/__cb2...Meter_some.jpg

Cute. I have the program:
http://www.tonnesoftware.com/meter2.html ($35)

DID YOU UNLOCK ?

No. I'm using the free version. The type of scales that I need are
rather simple. The initial project was for an audiophile test device
that measured "ambience" and "presence". A more complicated version
was planned but not built that added "depth", "range", "room tone",
and similar audiophile buzzwords. I showed it at an AES convention
was rewarded with near universal disdain and revulsion. Those guys
take their audio seriously. I almost succeeded in getting it into
print as a product release, but it was withdrawn at the last momement
when it was identified as a hoax.

I also built an "attractiveness" meter, that measured male/female
attraction measured in milli-Helens. The meter scale was zero
centered and +/- 1000 milli-Helens. I guess I should explain. Helen
of Troy reputedly had a face that launched 1000 ships (according to
Christopher Marlowe). Therefore, 1 milliHelen would launch one ship.
The negative scale also applies, where -1 milliHelen would sink one
ship. The device actually worked by measuring the differential
temperature between two people faces using two PIR sensors. Besides
determining if someone was angry and ready to violently assault me, it
was also good at detecting people who had a cold or fever. In
differential temperature mode, it could resolve down to about 0.1 C or
better.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Sunday, June 14, 2015 at 9:59:35 PM UTC-4, James wrote:
On 15/06/15 09:25, Jeff Liebermann wrote:
On Mon, 15 Jun 2015 08:39:44 +1000, James
wrote:

On 15/06/15 02:45, Jeff Liebermann wrote:
On Sun, 14 Jun 2015 17:55:35 +0700, John B.
wrote:

On Sat, 13 Jun 2015 21:19:05 -0700, Jeff Liebermann
wrote:

http://arstechnica.com/tech-policy/2015/06/police-use-ultrasonic-device-to-make-sure-drivers-stay-3-feet-from-cyclists/
https://www.youtube.com/watch?v=APlCVp6BW60
http://codaxus.com
Nice revenue enhancement. $200 per ticket and $1400 for the hardware.
7 tickets and it's break even. I'll probably need to install an
ultrasonic detector on the right side of my car (much like a radar
detector) so that I don't get caught. Let the arms race begin.

If it is ultra-sonic than why not an ultra-sonic device to send a
signal from the car. If they work like I think that they do they ping
a signal and measure the time it takes to get a return. If that is
correct than a "pinger" in the car should result in a much quicker
return and the device might even indicate negative distances :-)

"But Officer, how could I have been two feet to his right when I
passed him on the left?"

Ahem... Is that like an ultrasonic jammer? That wouldn't be very
sporting. The FCC regulates RF jammers, but has no jurisdiction over
ultrasonic jamming (yet). So much for my guilty conscience.

If it's the common 40 KHz range finder type of ultrasonic transducer,
it should be easy enough to capture the transmitted burst, and return
a delayed echo that makes it look like you're further away. Some
variable delay FM junk before the returned delayed echo should
convince the receiver that it doesn't have a solid reflection so that
it will only use the strong and stable delayed echo.

You're making assumptions about the receiver. It may receive the real
reflection and correctly realise the close pass before the second
delayed echo is received.

The incident waves from my jammer will be much stronger than the
reflected waves from my vehicle. All I need to do is produce a noisy
(random) FM modulated 40 Khz burst, just before I transmit the fake
reflected pulse. The noise will either overload the receiver front
end, or the FM noise will convince the receiver that it hasn't found a
suitably stable reflection. Try it with an ultrasonic tape measure.
As long as it's moving toward or away from the target, you won't get a
reading. Ultrasonic tape measures use Doppler to determine when NOT
to produce a reading. This is especially true of the proposed jammer,
where the car and bicycle are parallel and the Doppler shift is
minimal. If I feed the receiver some FM modulated noise, it won't
display anything. However, as soon as the FM noise stops, and I
transmit my fake reflection (phase locked to the incident pulse), the
receiver will think it's a nice stable and strong reflection, and
produce a valid reading. Actually, I just realized that the jammer
could be spewing the FM noise almost continuously, and only needs to
be interrupted when it's time to lock onto the incident pulse, and
when to provide a fake reflected pulse.



Way to complicated. Just continue to spew out high intensity noise in
the appropriate band.

--
JS

Iron Curtain ?