Speeding fine question

[Benny]

In the business of handing out fines for speeding I don't believe there is any room for error. If the officer can make a simple mistake of copying your licence No. to the ticket then how is going to operate his radar epuipment without error. If this went to court I think it could possibly come down to the magestrates mood at the time. Good luck.

[curious]

  Ford_Power said:

There are a few types of errors associated with LIDAR

Cosine Error: is the angle from the 0° perpendicular to the target vehicle. The greater the cosine angle the greater the error. However, cosine error is always in favor of the motorist, ie: speed readings will be proportionally less than actual speed of the target vehicle.

Sweep Error: is manifested when the laser is aimed at one part of the vehicle, say the license plate, and due to the motion of the operator, the laser also targets a side mirror during the same trigger pull. Sweep error adds to the real speed of the target vehicle.

Reflection Error: On very hot days with low humidity a visible mirage/reflection of the target vehicle is created. In many cases, when the laser is aimed at the target vehicle the infrared beam also receives readings from both the target vehicle and the mirage causing a Sweep Error.

Overexposure Error: When a laser gun receives an extremely powerful reflective signal, such as a sun flare off a vehicle, the computer’s timer can’t see the return of the 904 nanometer signal it sent. It can’t compute a speed reading. In general, the laser gun is looking for the strongest return reflection of its own emitted beam for speed computation.

What you get in the rainy condition is the "Sweep Error". This happens because the light is refracted by the rain droplets randomly. As such, the light is bent and may very well reflect off your side mirror, then back off your bumper in a small amount of time, thus making the gun "think" you are travelling faster then you really are.

These threads always end up like this. Yes these errors are correct, however the CPU of the Laser picks them up and ignores them. The squeeze of the trigger constitites your vehicle being red forward and and back roughly 38 times. Speed out side paramaters are ignored. Same with stationary speed cameras using Gatso 24 camera and radar. Vehcle speed is checked in the hundreds of times and rounded down.

Sweep error is counted by the operator evidence thet it was clear target and the red sight (a pin point in the scope) was focused on the number plate at all times. You try and operate one of these. You must hold still for it to acquire a speed.

Been to court, explained it all, walked out a winner..........next.

As for the real topic here. All that needs to be proven in court for speeding is, if I can remeber the charge off the top of my head (Qld)

That on the 9th day of August 2004 at Brisbane in the Magistrates Courts District of Brisbane in the State of Queensland one (defendant) did drive a motor vehicle namely a motor car on a road namely the Bruce Highway Brisbane and the said (defendant) did exceed the speed limit set for that road namely 100 kilometres per hour.

It is somewhat like that...........but where does it mention car colour, speed of vehicle, etc etc. All I have to prove is you were driving a car on a road over 100 kilometres per hour.

Credibilty is the only thing that can be attacked here and that's covered by the officer giving the evidence.

I mean being issued a ticket isnt even the start of proceedings.........the summons is.

[Ford_Power]

Curious,

I totally agreee with you - however, I am an electronic engineer, and deal with these devices regularly - most commonly the LTI 20/20 Ultralyte. The devices that come to me are primarily used for surveying, but I have also had many a chance to use it as just a a speed detection device without the additional surveying function.

If I was to go to court, I would almost go so far as to say I could irrefutably beat a LIDAR fine if the officer obtained my speed in the rain.

I know what you are talking about with regard to the errors and how they are handled - the least squares method is what is used and although good, I can clearly prove how it can be flawed in the scenario we are discussing.

And just for the record, the Kustom Signals - ProLaser II and LTI - 20/20 UltraLyte do 43 reads/trigger pull - although you very well may have been refering to a different make/model of laser gun.

Ross

[BA_Turbs]

mickq,

You asked for opinions, I gave one. If you didn't like it sorry.