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addaonyesterday at 9:24 PM1 replyview on HN

Yep, 200 m is pretty close to standard. Which is why 32 channel and 20 kHz is a pretty common design point. But customers would love 64 channel and 40 kHz, for example. Also, it's worth noting that if your design range is 200 m -- your beam doesn't just magically stop beyond that. While the inverse square law is on your side in preventing a 250 m target from interfering with the next pulse, a retro-reflector at 250 m can absolutely provide a signal that aliases with a ~16 m signal (assuming 234 m time between pulses) on the next channel under the right conditions. This is an edge case -- but it's one that's observable under steady-state conditions, it's not just a single pulse that gets misinterpreted.


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CamperBob2today at 2:20 AM

Don't these things use Gold codes or something similar to eliminate temporal aliasing problems? I guess that wouldn't make multipath issues go away completely, but it could fix the case you're referring to.

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