"Those who would give up essential liberty to purchase a little temporary safety deserve neither liberty nor safety." - Benjamin Franklin (1706-90)
"I would rather be exposed to the inconveniences attending to much liberty than those attending too small a degree of it." - Thomas Jefferson (1743-1826)
"Motorcycling is not inherently dangerous. It is, however, EXTREMELY unforgiving of inattention, ignorance, incompetence and stupidity!" - Anonymous
"Live to Ride, Ride to Live"
Winding up drongos, foil hat wearers and over sensitive KBers for over 14,000 posts...........![]()
" Life is not a rehearsal, it's as happy or miserable as you want to make it"
When I ride I'm anonymous, it's not like I have cloak of invinvibilty on so why am I not paranoid or fearful of tickets
My hot-rod and classic cars stand out yet once I leave town I'm 'just another motorist' - and very conspicuous yet I am not paranoid but people claim cops 'target' modified vehicles or those that look like they have 'wealthy' owners .
Why is this??
Winding up drongos, foil hat wearers and over sensitive KBers for over 14,000 posts...........![]()
" Life is not a rehearsal, it's as happy or miserable as you want to make it"
"Those who would give up essential liberty to purchase a little temporary safety deserve neither liberty nor safety." - Benjamin Franklin (1706-90)
"I would rather be exposed to the inconveniences attending to much liberty than those attending too small a degree of it." - Thomas Jefferson (1743-1826)
"Motorcycling is not inherently dangerous. It is, however, EXTREMELY unforgiving of inattention, ignorance, incompetence and stupidity!" - Anonymous
"Live to Ride, Ride to Live"
My 'perceived threat' is others on the road other than Police.
The chance one of the latter wiping you off the face of the earth is considerably less than the risk the other slack jawed cretins on the road cleaning you up.
Not too many people get physically maimed by a speeding ticket.
Winding up drongos, foil hat wearers and over sensitive KBers for over 14,000 posts...........![]()
" Life is not a rehearsal, it's as happy or miserable as you want to make it"
all of u. Stop ur bickering, this thread was started to understand the legalities and not for all this BS. Lets keep it clean for future reference. Thanks.
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"Those who would give up essential liberty to purchase a little temporary safety deserve neither liberty nor safety." - Benjamin Franklin (1706-90)
"I would rather be exposed to the inconveniences attending to much liberty than those attending too small a degree of it." - Thomas Jefferson (1743-1826)
"Motorcycling is not inherently dangerous. It is, however, EXTREMELY unforgiving of inattention, ignorance, incompetence and stupidity!" - Anonymous
"Live to Ride, Ride to Live"
I'm voting for "free enough and reasonably healthy"!
If you sit on the fence long enough your legs go numb and it stops hurting!
I'm selling my new riding gear!! Only worn a few times get a deal Kiwibikers!!
http://www.kiwibiker.co.nz/forums/sh...53#post1414653
Is it? I very much doubt that for a number of reasons:
- Radar generally has to lock on something to record a speed. I don't know whether or not police radar units have the ability to lock and track multiple objects simultaneously, but if they could, it would bring every speeding ticket where there was more than one car in the vicinty into question, as the police would have no way of knowing which vehicle's speed the unit was displaying at the time.
- How does the unit know what objects in the vicinity are stationary in any given environment?
- Considering radar needs to reflect off something (and preferably something solid / metallic) what objects does the unit use as a reference point where there is nothing in the environment big or reflective enough to use as a stationary reference point; for instance, on the Desert Road?
I also know for an absolute fact that similar units in the UK are wired into the speedo (OK, the gearbox output shaft speed sensor, that drives the speedo). That provides the fixed reference point, and for that reason, all cars must undergo a speedo calibration routine at the start of each shift using a calibrated stopwatch against a measured mile. Any deviance is then dialled into the radar unit.
There are really only two ways of measuring speed; time/distance and doppler shift. Police issue radar and laser guns use both of these techniques together - it's how they get speed and distance readings (i.e. car was doing 112kph when it was 184 metres away). Where a measuring unit is mounted on a moving vehicle, the speed of the vehicle must be known in order to calculate the speed of the object being measured. Simple physics.
Now, I'm happy to be proved wrong over the technicalities of how in-car radar units measure their own speed. However, until someone provides me with those details including how they overcome some pretty interesting technical obstacles (rather than just saying you're wrong, it does it this way), I'm going to assume the designers of such systems simply made the obvious technical choice - to hook into the speed measuring system in the vehicle itself.
Thanks for the response, Speedie. I'm not totally ignorant on the workings of radar; the concept of radar was explained to me by my grand-father of all people. He was one of the research team working for the British army in 1940/41 that developed radar's precursor, RDF. They could get speed and bearing quite well, but had trouble with altitude and distance. Only with the development of radar did the distance bit come into it as well.
I do also know radar does not have to reflect of metallic or even particularly solid surfaces (e.g. rain radar) but I was under the impression that the objects needed to be angled as to bounce back the transmissions to the sender; the same principle stealth airplanes use to hide themselves from radar (or at least, reduce their radar footprint). What I didn't consider was that when you're talking mm-band radio (assuming they use Ka-band here, which I think they do) an otherwise smooth road surface isn't actually all that flat.
You give some interesting facts about the operation of the police radar units, especially in relation to the target / fastest speed display. The first ever ticket I got in NZ was for doing 146 down SH1. I queried the device in use and how it locked onto targets, mainly as I knew I was doing more like 170 at the time. It may be that the radar technology has changed since then, but I did have a written response from the relevant office stating that the unit tracks one vehicle and one vehicle only, and cannot show multiple speeds. They could have been lying, of course.
And I knew about rain scatter ... though I think using that to get of a ticket would be quite difficult. It might make getting a locked reading difficult, but once achieved, I guess you're pretty much stuffed.
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