Comment Re:Yeah, but it is reliable. (Score 1) 245
At the risk of being pedantic and not really contributing to an older thread (hey, it's slashdot, right?), radar originally/typically measures range - that's what the last 'R' stands for (RAdio Detection And Ranging). True, that's evolved to where some modern radars use Doppler for things, but ranging is it's bread and butter.
That being said, I think I agree here - vehicle speed measurements seem like an odd application of LIDAR, given the wavelengths. I haven't worked out the math, but I given the distances/velocities we're talking about here I'd be interested to see how speed error is impacted by pointing "jitter" (that is, the beam moving around b/c a human is pointing the beam at a moving target that has many features that are large compared to the laser's wavelength). It would be even more interesting to compare that against that radar errors, especially when on considers that the radar might have problems localizing the speed when vehicles are close (as others have pointed out). One would think someone did tests like these once upon a time, but.....
Perhaps I should rush to patent a combo device that uses both technologies, claiming that the two pieces of evidence together overcome their individual weaknesses. Apparently you don't even need proof that it works!
That being said, I think I agree here - vehicle speed measurements seem like an odd application of LIDAR, given the wavelengths. I haven't worked out the math, but I given the distances/velocities we're talking about here I'd be interested to see how speed error is impacted by pointing "jitter" (that is, the beam moving around b/c a human is pointing the beam at a moving target that has many features that are large compared to the laser's wavelength). It would be even more interesting to compare that against that radar errors, especially when on considers that the radar might have problems localizing the speed when vehicles are close (as others have pointed out). One would think someone did tests like these once upon a time, but.....
Perhaps I should rush to patent a combo device that uses both technologies, claiming that the two pieces of evidence together overcome their individual weaknesses. Apparently you don't even need proof that it works!