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Why Continental? Flash lidar seems to be a fundamentally broken concept to me wrt range.
by deepnotderp 8y ago
Why Continental?
Flash lidar seems to be a fundamentally broken concept to me wrt range.
- Animats 8y agoOne might think that, except that Advanced Scientific Concepts, which Continental bought, has had it working for a decade.[1] Their units work fine, but are expensive. They're mostly sold to DoD and used for space applications. The Space-X Dragon spacecraft uses one for docking. There's a tradeoff between field of view and range. Automotive systems will probably include a long-range narrow field of view unit and a shorter range wide field of view unit. Flash LIDAR has some advantages. No moving parts. Can be fabbed by semiconductor processes. The one big laser is separate from the sensor array, which helps with cooling. Also, you can spread the outgoing beam, which helps with eye safety. (Eye safety involves how much energy is in an eye iris sized, 1/4" or so, cross section of the beam. If the beam is spread out, energy density is lower.) [1] https://ieeexplore.ieee.org/document/7268968/ https://ieeexplore.ieee.org/document/7268968/
- deepnotderp 8y agoWhat's the power output for the unit in the paper?
- lidarworld 8y ago14-16 W Velodyne's 64-channel is 60 W
- deepnotderp 8y agoAlso note that in space there's way less background noise.
- foota 8y agoThis made me curious, how wide is Earth's shadow the the height the space station is at?
- teraflop 8y agoAlmost exactly as wide as the Earth.
- simcop2387 8y agoI doubt it'd be significantly smaller than the diameter of the earth already. Can't think of how to set it up but the the ISS is only ~250mi above the earth so my guess would be only a couple hundred miles shorter than the earth's diameter at most.
- toomuchtodo 8y agoWhat do you see as the key challenges in driving down the cost of flash LIDAR?
- dllu 8y agoThe light from the flash spreads out with the inverse square law, so you get much less signal compared with collimated laser beams. To compensate for that, you need much higher power. To get more power without blinding people, you need to use 1550 nm. This requires large arrays of exotic gallium arsenide semiconductors, which are expensive.
- analognoise 8y agoASC is a textbook example of what not to do as a company. I honestly think their technology will be better implemented by someone else in a few years, which is tragic given how much of a head start they had. Eh.