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addaontoday at 1:18 AM1 replyview on HN

> No, LIDAR is relatively trivial to render immune to interference from other LIDARs.

For rotating pulsed lidar, this really isn't the case. It's possible, but certainly not trivial. The challenge is that eye safety is determined by the energy in a pulse, but detection range is determined by the power of a pulse, driving towards minimum pulse width for a given lens size. This width is under 10 ns, and leaning closer to 2-4 ns for more modern systems. With laser diode currents in the tens of amps range, producing a gaussian pulse this width is already a challenging inductance-minimization problem -- think GaN, thin PCBs, wire-bonded LDs etc to get loop area down. And an inductance-limited pulse is inherently gaussian. To play any anti-interference games means being able to modulate the pulse more finely than that, without increasing the effective pulse width enough to make you uncompetitive on range. This is hard.


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CamperBob2today at 1:26 AM

I think we may have had this discussion before, but from an engineering perspective, I don't buy it. For coding, the number of pulses per second is what matters, not power.

Large numbers of bits per unit of time are what it takes to make two sequences correlate (or not), and large numbers of bits per unit of time are not a problem in this business. Signal power limits imposed by eye safety requirements will kick in long after noise limits imposed by Shannon-Hartley.

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