LASER has a problem in the USA
Laser Speed Detection - EXPOSED!
From a USA Law Paper
Laser speed detection serves the
same purpose as Radar; however, the two systems are totally
different beyond their common goal. Laser uses a light beam
and takes the measurements based on the speed of light. On
the other hand, radar uses a radio beam and measures at the
speed of sound, which is substantially less than the speed
of light. While radar has a wave length of anywhere from inches
to hundreds of feet, laser has a wave length of only 30 millionths
of an inch. A typical radar beam is 18 degrees (X-Band) to
15 degrees (K-Band) wide.
Comparatively, laser has a beam that is one sixth of a degree.
The results are drastic as the beam radiates out from the
laser gun. While radar can expand to over 500-feet wide at
a distance of one mile, the laser beam will only expand to
19 feet wide. At a more realistic distance of 1000 feet, the
radar expands to over 100' wide while the laser system only
expands to 3-feet wide.
Although laser sounds like the insurmountable speed detection
system, it is not infallible. In fact, Lidar is significantly
affected by weather conditions. Fog and clouds will severely
reduce the effective measuring distance of the laser beam.
For example, the laser system can only be used from a stationary
set up rather than moving like some radar systems. Furthermore,
laser can not be used through a windshield in most cases and
the operator must have additional training that is typically
not required for radar systems. Laser also has a problem getting
an accurate reading when used at a severe angle to the target
vehicle such as from an overpass or the far shoulder of the
road. In addition, maintenance and calibration can only be
performed by a factory authorised repair facility. As you
can see, laser may be tougher to beat than radar, but it can
be accomplished.
The primary target for the laser beam is the vehicle's licence
plate. The light beam relies on a reflective surface for the
successful return signal. This is why dark low slung vehicles
with minimal or no chrome are so hard for laser to detect.
The front licence plate should be removed and the rear plate
should be painted with a high gloss clear coat to help defeat
the laser beam.
Prior to each use, the laser gun should be locally calibrated
by using all three of the following methods:
-
The self test button should
be used and the reading should be 8.8.8.8.
-
A measurement of a non-moving
target should result in a reading of 0 MPH.
-
The sight and audio tone should
be tested by panning across a telephone pole. As the sight
aligns with the pole, the audio tone should change indicating
a positive contact between the beam and the pole itself.
Essentially, the LTI 20.20 Marksman is the main laser gun
being used in the UK. The manufacturer claims a beam width
of two feet at a distance of 1300 feet. The speed measurement
time is one third of a second and the unit is equipped with
an audio seek aid for positive target confirmation. The accuracy
is alleged to be precise within 1 mph up to 60 mph and within
3% for speeds over 60 mph. Despite this impressive list of
performance criteria, the Marksman has some notable downfalls.
For example, tests indicate that the Marksman lacks uniformity
and has an unusual distribution of the beam intensity therefore
resulting in a deviation from the aiming point. The especially
high level of intensity along the right edge creates a deviation
in the horizontal direction. What all this technology translates
to, is the Marksman can actually detect a vehicle as close
as five feet away from the actual target vehicle.
On June 13, 1996, New Jersey Superior Court Judge Reginald
Stanton stated that he was not convinced of the accuracy of
the LTI 20.20 Marksman. As such, he ruled that any readings
taken with the LTI 20.20 would not be accepted as evidence
in any pending or future speeding ticket cases.
For a defence strategy you need to be aware of laser's status
in the jurisdiction where your citation was issued. Only a
few US states have given laser "judicial notice" which is
a legal ruling that establishes specific evidence as beyond
dispute. Radar has "judicial notice" in every state.
If no judicial notice has been awarded, then the prosecutor
will need to have an expert witness testify to the accuracy
and reliability of the laser unit. If this expert witness
ends up as a manufacturer's representative, you can make a
motion to disqualify the witness since he (and his company)
clearly has a financial interest in the outcome of the case
and therefore, the witness is not impartial.
If judicial notice has been awarded, you certainly want to
utilise the New Jersey ruling in your case preparation. The
remaining preparation is very similar to a radar case. You
need to focus the court's attention on the officer's training,
the unit calibration and self-test methods, weather conditions
during the time of the citation and the proximity of surrounding
traffic. As with any case, your best strategy is hoping for
the officer not to appear in court followed by careful preparation
in case he does appear.
As yet I have not heard of a case in the
UK using the LTI 20-20 faults, but if you know of a similar
case let me know.
Did he get you with LASER?
Questions to ask:
- Are you trained to use this Laser gun?
- How accurate is the Laser gun, and in
what situations? How about when used incorrectly? Due
to the Laser beam's narrow path of travel, the Laser gun
can be very accurate when it is used correctly. However,
if it were used incorrectly, the results can be useless
and very misforgiving to you as the driver of the vehicle.
- How exactly did you obtain my speed?
- When was the Laser gun last calibrated?
- Has the gun been subject to any knocks,
Laser gun components are delicate and thereby sensitive.
The actual gun would have to be stored and handled carefully
as to not damage the innards.
- How was the gun held, Laser guns cannot
be mounted in a moving vehicle, because just a minor jolt
will cause the reading to be inaccurate. Therefore, Lasers
must be mounted and used from a stationary vehicle or
on a tripod. Holding by hand is not as good
- Make a note of the weather and the officers
position. (See my section on "Things they don't tell you
about Laser Guns")
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