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200m for a mechanically scanned LIDAR isn't a big deal. There are older flash LIDARs that can reach 400m with a 9 degree field of view.[1] Flash LIDARs have a field of view vs. range tradeoff, since they illuminate the entire field of view at one time. Range gated imagers, another form of flash LIDAR, have ranges out to kilometers.[2] (Those guys are using a lot of power, but it's spread over a wide area.)

The eye safety problem can be overcome by making the outgoing beam bigger. What matters is how much energy comes through a hole about 1/4" in diameter, the size of the pupil of the human eye. If you enlarge the outgoing beam, by running it through a collimator backwards, the energy per unit area decreases. Expand a beam to a 2" circle and you have reduced the power per unit area by about 50. The risk is to someone coming up to the thing and staring into the beam, not out at range where energy per unit area is much lower.

Cost remains a bigger issue than range. Give it 2-3 years.

[1] http://www.advancedscientificconcepts.com/products/older-pro... [2] https://www.youtube.com/channel/UCLrAizlR4ry9Nu6A7BXBBdg



Are there any cumulative effects regarding eye safety?

As in: if 100's of cars in your field of view, say a traffic jam in the opposing lane are all firing LIDAR would it add up to trouble?


Excellent question. I foresee a booming market in lidar-blocking sunglasses.


I wonder how this affects non-human eyes.




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