It uses doppler, not radar. All parts of the car are moving at the same speed. It only needs to emit one pulse, although it probably makes several measurements and averages them. It does not measure the time between sending and receiving,321 wrote:So how do you know the speed measuring device has taken its readings from the same part of the vehicle?
The avg car length at 2.1metres is + or - 30mph's during the 0.3 second time period used to emit 3 laser pulses in order to calculate a speed reading.
It does not depend on light intensity for any part of the reading. Not even RADAR depends on intensity. If you get a signal back, then you get a reading. If you don't get a signal back, or don't get a sufficiently strong one, then you don't get a reading.I'm sure the detector on the laser speed measuring device is colour blind, in that it can only detect light frequencies in a certain range close to the laser light that is emitted. In other words not detecting light in the human visible light frequency range or UV/Xray part of the spectrum, and whilst it can detect laser light in a certain frequency, its still treated by the algorithm as a binary value.
I'm also sure it can only detect light intensity (lux), and are weaker in strength than what you find in your optical disc player or supermarket checkout, so knowing that light intensity can vary due to the angle of incidence, how can we be sure the speed measuring device is accurate? Even barcode readers interpret the bars reflection within a certain range when normalised against the others it detects in a certain time frame that matches what an operator takes to scan/wave a product over the checkout.
I guarantee that your brain is not capable of seeing the difference in time of electricity moving. It's of the order of ten billionths of a second. What you may be seeing is the time it takes to heat a light bulb. LEDs don't need to heat and lamp filaments change resistance with temperature. That will change the share of the current they each receive,On top of that, how do you know the detector is working in the right time frame considering the variability of power and delay in power reaching all circuits? An example of this which everyone can see, is watching the brake lights come on from the car in front.
If you are quick enough and concentrating enough, you can see the LED central brake light come on first, followed very very quickly by the right or left brake light which ever has the shortest circuit/run inside the car, followed by the opposite side brake light at the furthest part of the circuit/run.
There are electronics in all devices that regulate the power they receive from the mains. Almost everything can work off any voltage 110V to 240V without manually switching anything. Dry cell batteries are theoretically capable of many times the output they actually produce but bubbles form on the electrodes that break the circuit. Heating them up reverses this effect a little.Likewise I know we have mains that is 240volts, but my little battery backup tells me, this can vary as can the current, and although batteries are used to smooth these power fluctuations in these devices, I know ambient air temperate also affects voltage, when I put flat batteries onto of a radiator to squeeze the last bit of chemical reaction out of them.
A CPU freezing is not the same as a CPU slowing down. You think maybe clocks and watches don't work? They all use electronics and most of them probably contain a CPU. A CPU is not a magic form of electronics anyway.We also know that cpu's can operate at different timings depending on their temperatures, one example being, taking the heatsink off an AMD cpu and it will freeze & crash when the cpu get too hot, ARM and Intel clock back the cpu speed to compensate and minimise damage to the CPU, even though loop based OS's when suggesting their CPU's are only x% busy are still switching away at the same rate regardless of workload. The fact CPU's can alter their clock speed just obfuscates that fact.
That's the one thing you've said that makes sense, but unless you're in Texas, I doubt it would make enough difference to the light path three feet above the road.Plus we also only need a 1 degree difference in air temperature and a surface to create a heat haze, best seen on roads, and we know heat hazes affect light, so can even light then be treated as a constant when measuring speed of something on a road?
Speed guns are not rated for use underwater or through solid objects. The cops understand this.We also know light speed is not constant when passing through some objects although to be fair you wont find the most obvious one on the roads or when bolling up to space ship, but you will in a lab.
Exactly which language in the patent are you referring to?Sometimes it pays to read the patent.