While driving an 11 year old Mazda GLC filled with 31 balloons and a
passenger, I was stopped for speeding — 88 km/h in a 60 km/h zone.
I had just turned onto the road from a side street, and had only gone
a few hundred metres before being stopped.
The 31 balloons were filled with helium and had "metallic" colours.
Are "metallic" colours on balloons really metallic?
Might speed-detect radar respond to such balloons?
We know that lighter-than-air balloons move forward
inside an accelerating car.
And the balloons are vibrating (back and _forth_) in the car.
Does anyone with expertise in these matters care to comment on this?
–
, @ _{)_ ,
\/( )\/"\/\ /\/ Peter Renzland, Ontario Ministry of Health
/=\ /==\ (416) 964-9141 pe…@ontmoh.UUCP
/___\ |/\| uunet!attcan!ontmoh!peter
_/ \_ \# _# << Je danse, donc je suis. >>
In article <880928.0208.11…@ontmoh.UUCP> pe…@ontmoh.UUCP (Peter Renzland) writes:
>While driving an 11 year old Mazda GLC filled with 31 balloons and a
>passenger, I was stopped for speeding — 88 km/h in a 60 km/h zone.
>The 31 balloons were filled with helium and had "metallic" colours.
>Are "metallic" colours on balloons really metallic?
>Might speed-detect radar respond to such balloons?
I believe such balloons are made of aluminized mylar. I’d guess
that they could, indeed, reflect police radar. However, they’d probably
make a much smaller target than your Mazda, being of much "stealthier"
design (no sharp edges, etc) and generally less area. I wouldn’t think
they caused the high reading; more likely, the radar was at fault.
But I’m not an expert…
You might try to fight the case in court because of the balloon
interference, but that begs the obvious question : Why, for the love of
God, were you driving a compact car stuffed full of opaque balloons ?
Surely it obstructed the view from your rearview mirror, and even out
your side windows ! I’d say you’re lucky the cop only gave you the
speeding ticket; I’d consider that "reckless endangerment" or some
such.
BTW, it would have been much more ironic if the radar had caught you
carrying 99 red balloons…
—————————— valuable coupon ——————————-
Bill Thacker cbosgd!cbema!wbt
"C" combines the power of assembly language with the
flexibility of assembly language.
Disclaimer: Farg ‘em if they can’t take a joke !
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In article <880928.0208.11…@ontmoh.UUCP>, pe…@ontmoh.UUCP (Peter Renzland) writes:
> While driving an 11 year old Mazda GLC filled with 31 balloons and a
> passenger, I was stopped for speeding — 88 km/h in a 60 km/h zone.
> I had just turned onto the road from a side street, and had only gone
> a few hundred metres before being stopped.
> The 31 balloons were filled with helium and had "metallic" colours.
> Are "metallic" colours on balloons really metallic?
My wife works for a balloon shop, I can say a definate Yes!
> Might speed-detect radar respond to such balloons?
Yes, they are also good for shorting out high tesion power lines. I sat in near
pitch black due to one of those balloons shorting out the stadium lights at a
local footgame, besides check out the following:
->2. if item 1 fails to stop the ticket, be ready to show how the cop can
->introduce errors. Remember ANY amplitude modulation of the radar signal
->will be displayed. You want to have the gun and the cop car at the court
->house. One of the most common sources of errors is allowing the gun to
->read the heater fan in the car! The fan makes a nice chopper which will
->modulate the microwave beam. To show this, simply have the gun in the car,
->behind the dashboard and kinda aim it down toward the defrost vents. You may
->have to wave it around a bit to find the fan (which should be on max hi).
->Most fans will generate a speed of between 40 and 70 mph. In addition to
->generating a speed indication of it’s own, the fan can interefere with or
->mix with the reflection of the car.
If this can be happening with the heater fan, why can’t it be happening with
metallic balloons?
Here’s the entire text of a previous message. Hope it proves useful.
Newsgroups: sci.electronics,sci.misc
Subject: Re: Radar
In article <12…@duke.cs.duke.edu> ga…@bein.UUCP (Hillel Gazit) writes:
>I was caught by a police radar which claimed that I was going 65 MPH.
>My speed was 55 MPH. I think that something was wrong with the radar,
>so I want to challenge the policeman in court.
>Can someone please post a list of things that can wrong with a radar?
>(I want to ask the policeman if he is absolutly sure that his radar
>was OK, and then ask him to
>explain to me why cannot all the things on the list happen).
>Hillel ga…@cs.duke.edu
Aha, you lucky soul.. living in North Carolina, where the state Gestapo writes
.
at 56
first comment.. kill the remark to the iranian airline.. you don’t want to
piss off a judge that might take offense to the remark.. besides it’s not
really germane to the discussion.
Last time I had the misfortune to be in NC, the gestapo was using mostly
Kustom Signals MR-7′s or KH-11 units. I happen to have an MR-7 and so
am familiar with it’s operation and problems. (bought it just so i could
know my enemy.) I’ll state flatly – every radar ticket can be beaten –
if you put forth the effort. You have to decide if the effort is worth it.
If you have some points and your insurance is in the 5 figure range, then
maybe it is.
First some theory. The radar works by measuring the doppler shift, eg, the
change in frequency of an RF beam caused by motion. This motion must be
normal to the radar. They cannot measure speed perpendicular to the beam.
The gun contains an rf generator that transmits a microwave beam out the
horn. A portion of this signal is diverted to the receiver. Reflections
from all objects (cars, trees, atmospheric inversions, etc) are collected
by the horn and applied to the receiver. The receiver mixes the 2
signals and outputs the difference. With no motion, the difference is 0,
of course. With increasing speed, an increasing audio beat frequency is
produced. The readout unit counts the frequency of this audio signal,
scales it and displays it as a speed.
The first important thing to note is that the signal is an audio tone.
There are many ways for an audio tone to become superimposed on the
signal other than from speed. ANY tone withing the expected bandwidth
will be displayed as the equivilent speed.
The second thing to note is that the receiver, since it responds to amplitude
signals, will "capture" and display the strongest signal. This may very
well be your car or it could be the semi truck a half mile back or
even the heater blower in the cop car.
Following are some techniques I’ve used.
1. First, process them to death. Supoena (sp) the radar unit, the
ticket book, his calibration log, his radio log, the service record on
the radar unit, the FCC license of the radar gun, his patrol car, and the
tickets he’s issued over the last 6 months or so. Here’s why. The radar
gun must be licensed by the FCC. IT’s call letters must be attached to
the transmitter. A log of operations must be kept. No highway patrol I’ve
ever encountered has ever conformed to these rules. You can attack his ability
to properly operate the unit by showing his non-conformance to the rules.
Radar units are known to be unstable. All units are shipped with tuning
forks that are designed to display a known frequency. Most states require
that a calibration be performed immediately before and after the stop. The
only way to prove that is to show a log. No cop I’ve ever seen maintains
a log. This is easy shooting. You also want to look at the service history
of the unit. If it’s been in the shop often, the it may have been mal-
functioning when he stopped you. If it has NOT been in the shop, then
question the maintenance practices and calibration. (nifty logic, eh?).
You will want to review his ticket book to look at his pattern. If all his
tickets are written for about the same speed, you can raise the possiblility
of a systematic error in his gun or his use of the gun. If he writes them
close together, you can maintain that he did not have time to calibrate adn
log the unit between stops.
you will want to have the car available to demonstrate other sources of
error to be listed.
As a practical matter, many tickets end here. The state does not want to
take a revenue producing car and radar out of service and the cop probably
does not want to use an off-day in court.
2. if item 1 fails to stop the ticket, be ready to show how the cop can
introduce errors. Remember ANY amplitude modulation of the radar signal
will be displayed. You want to have the gun and the cop car at the court
house. One of the most common sources of errors is allowing the gun to
read the heater fan in the car! The fan makes a nice chopper which will
modulate the microwave beam. To show this, simply have the gun in the car,
behind the dashboard and kinda aim it down toward the defrost vents. You may
have to wave it around a bit to find the fan (which should be on max hi).
Most fans will generate a speed of between 40 and 70 mph. In addition to
generating a speed indication of it’s own, the fan can interefere with or
mix with the reflection of the car.
Another source of intereference is the car’s alternator. the ripple of the
alternator can be detected by the gun. In one of my cars, I have to run
the radar from a separate battery because of the intereference.
3. Propose that the signal that the cop read was not from your car and
instead came from a vehicle behind you. Typically a semi truck. I have
a video tape I made of some real life situations where the radar gun picked
up a truck a half mile away while ignoring a compact car fairly close in.
(don’t ask for the tape, lord knows where it is). I’d suggest arranging a
demo or a tape of this phenomena. You should have a real good "memory" of
trucks behind you. I’ll guarantee that the cop will not remember this
detail. He’s so intent on nabbing that "damn speeder" that he gets
tunnel vision while concentrating on the pursuit.
4. If it was raining or inclement or foggy, then attack that as an important
source of error. Most states prohibit use of radar in inclement weather
because of intereference from lightning, rain drops, hail, etc.
5. Ask if the cop operated his radio while clocking traffic. he probably
cannot remember or will say he did not. Be prepared for this. Ask him
about his reporting procedures when beginning pursuit and when stopping a
vehicle. ALL departments require thier officers to make a radio report
when doing either of the above. ANY radio will cause intereference with
the radar. I can generate all manner of speed indications with my
amateur radio handi-talkie. Most police radios run much more power
than my amateur radios.
6. Ask about any emergency equipment such as flashing lights or sirens
in use during clocking. all contain motors or high power electronics
which cause intereference.
7. Have the cop demonstrate the electronic calibration feature of the
readout. This is different from the tuning fork calibration. This function,
normally invoked by a CAL switch on the unit, verifies the readout operation
by making the unit display a speed of 64 mph. This "speed" can be
locked in just like a real reading. It is suspiciously close to 65 mph,
especially considering all digital circuits’ +-1 count inherent uncertanty.
I acutally had a cop try this ploy on me once. It pissed him off that I
had a radar detector so he fabricated a 64 mph speed and pulled me over.
Most all radar guns have a little indicator on the display which shows that
the "reading" came from the CAL function. When I pointed this indicator out
to the cop, he got real hostile real fast … but he let me go, hi. This
defense is very effective but must be approached with caution. You do not
want to piss the cop-sympathetic judge off by calling the cop an out-and-out
liar. you want to kinda skirt the issue and imply the course of action.
The above should give you a good selection of options. the key here is
wear the bastards down and create a reasonable level of doubt in the
judge’s mind
…
read more »
In article <880928.0208.11…@ontmoh.UUCP> pe…@ontmoh.UUCP (Peter Renzland) writes:
>While driving an 11 year old Mazda GLC filled with 31 balloons and a
>passenger, I was stopped for speeding — 88 km/h in a 60 km/h zone.
Er, … How fast *were* you going?
–
Pat Vilbrandt John Fluke Mfg. Co., Inc. Everett, Washington USA
UUCP: p…@tc.fluke.COM or: { uw-beaver, sun, ssc-vax }!fluke!pwv
ARPA: fluke!…@uw-beaver.ARPA
In article <1…@cbnews.ATT.COM> w…@cbnews.ATT.COM (William B. Thacker) writes:
>>While driving an 11 year old Mazda GLC filled with 31 balloons and a
>>passenger, I was stopped for speeding — 88 km/h in a 60 km/h zone.
>>The 31 balloons were filled with helium and had "metallic" colours.
>I believe such balloons are made of aluminized mylar. I’d guess
>that they could, indeed, reflect police radar. However, they’d probably
>make a much smaller target than your Mazda, being of much "stealthier"
>design (no sharp edges, etc) and generally less area. I wouldn’t think
>they caused the high reading; more likely, the radar was at fault.
That many balloons in that car would be bunched together – you’d have your
"sharp" edges there. The balloons would not likely make up the 28km/h
difference by their linear motion, but I have no idea about vibration (I’d
think it unlikely, though). I would suspect the radar.
–
William Swan ..!tikal.teltone.com!sigma!bill
In article <880928.0208.11…@ontmoh.UUCP> pe…@ontmoh.UUCP (Peter Renzland) writes:
>While driving an 11 year old Mazda GLC filled with 31 balloons and a
>passenger, I was stopped for speeding — 88 km/h in a 60 km/h zone.
>I had just turned onto the road from a side street, and had only gone
>a few hundred metres before being stopped.
> \/( )\/"\/\ /\/ Peter Renzland, Ontario Ministry of Health
Don’t overlook the obvious: If you can prove that
(1) You indeed turned on to the road a distance, x, before the
reading was taken, and
(2) That your 11 year old Mazda couldn’t possibly achieve a speed
over 60 km/h in the distance x,
then you should have no trouble contesting the ticket! You should
measure the distance carefully and conduct an accelaration test
with your car (in a legal manner), both with witnesses.
With respect to other people’s replies, let me remind you that
radar guns are by no means infallable, and also that the laws in
Ontario differ drastically from those in many states. In
particular: radar detectors are illegal. I don’t know what
calibration procedure, etc. is mandatory in Ontario. Does anyone
know how to find out? Highway-Traffic Act?
—
Michael.
====================< kmh…@watvlsi.waterloo.edu >=====================
In article <880928.0208.11…@ontmoh.UUCP> pe…@ontmoh.UUCP (Peter Renzland) writes:
>While driving an 11 year old Mazda GLC filled with 31 balloons and a
>passenger, I was stopped for speeding — 88 km/h in a 60 km/h zone.
>I had just turned onto the road from a side street, and had only gone
>a few hundred metres before being stopped.
Peter, typically the speedometer lags behind the true speed of the
vehichle. If you had just turned the corner and finished accelerating
and your speedo read 70, with error, it is not unreasonable to guess
that you were really doing 88.
28kph is starting to sound unreasonable I’ll admit but I know that
when I accelerate *hard* to "80" kph (where I safely cruise in 60 zones)
my engine speed drops off almost 20%. Therefore, I was actually doing
closer to 100 kph when I eased off the throttle. ( I often do this
to give myself lots of room when I leave an intersection.)
Also, I never go below 20kph over the speed limit unless traffic
prohibits. I have gone through numerous speed traps and never
been pulled over. This is on a flashy looking sport bike (BMW K75s)
that typically is not going to be forgiven easily.
One final comment, if your 11 year old Mazda is at all noisy when
it is accelerating, this is likely to attract attention. This is
not to say that the cop is right/fair/justified to pull you over,
it is just a statement of my experience watching.
Fight it though, and make sure you read Matthew Lee Stier’s article
first.
Good luck,
Keith
In article <1…@leibniz.UUCP>, kei…@leibniz.UUCP (Keith Hanlan) writes:
> Peter, typically the speedometer lags behind the true speed of the
> vehichle. If you had just turned the corner and finished accelerating
> and your speedo read 70, with error, it is not unreasonable to guess
> that you were really doing 88.
I don’t agree.
Typically the manufacturers set the speedometers
to read HIGHER than what you are actually going.
So if you think you’re going 70, you’re really going 67mph or so.
They probably do this for safety concerns.
I have calibrated (used LOTS of sample points) my ’86 RX7 with the mile
markers on the highway and have found my speedo to read 2-3% higher
than actual.
My friends’ results are also the same, so I have a two sample points
to back my observations.
Other viewpoints?
–
Those that will burn in hell:
1) homicidal maniacs
2) terrorists
3) people who drive too slow in the fast lane.
THE FAR SIDE cartoon by Gary Larson
George Valentini
att!mtuxo!gv
In article <3…@mtuxo.att.com>, g…@mtuxo.att.com (52341-G.VALENTINI) writes:
> Typically the manufacturers set the speedometers
> to read HIGHER than what you are actually going.
> So if you think you’re going 70, you’re really going 67mph or so.
> They probably do this for safety concerns.
I don’t drive a car (unless I make arrangements with my wife, since
it’s her car…), so this may not apply, but it is illegal in CA to
sell a motorcycle whose speedometer reads less than the actual speed
being ridden. Manufacturers therefore set the meters to read up to
10% high, just to be safe. (What you do in the way of adjusting them
after sale is not their concern.) I assume that this is also the case
with cars.
In article <3…@mtuxo.att.com> g…@mtuxo.att.com (52341-G.VALENTINI) writes:
>In article <1…@leibniz.UUCP>, kei…@leibniz.UUCP (Keith Hanlan) writes:
>> Peter, typically the speedometer lags behind the true speed of the
>> vehicle. If you had just turned the corner and finished accelerating
>> and your speedo read 70, with error, it is not unreasonable to guess
>> that you were really doing 88.
>I don’t agree.
>Typically the manufacturers set the speedometers
>to read HIGHER than what you are actually going.
>…
> George Valentini
Sorry, I guess I didn’t make myself clear. By "lag behind", I meant
the speedometer’s reading, *UNDER ACCELERATION*, is inaccurate. Once
the car’s speed stabalizes (0 delta-v), the speedometer "catches up"
and becomes accurate. Note that "catches up" and "becomes" are not
instantanious. Thus for "finished accelerating" read "*just*
stopped accelerating".
I hope that this clarifies the issue.
On the subject of speedmeter inaccuracies, I agree that most read
high (most notoriously Ferraris). My posting did not mean to imply
anything on this topic. Both my car’s and my bike’s speedometers have
been calibrated dead-on though so I wouldn’t get in the habit of
correcting your speedometer as you drive. ("But officer, I assumed that
my speedo was 5% fast and that you wouldn’t mind +15% so I tried to keep
it at 120 in the 100 zone…")
Keith