3 ms·

I really wonder how safe lidar really is for humans. Our retina are sensitive enough to detect single photons (when healthy) and lidar is known to damage digita

• manmal 7y ago
  It really depends on the amount and duration of exposure. Eg lasers that are pulsed won’t warm or irritate tissue as much as continuous radiation. Some energy is also absorbed by the eyeball before it reaches the retina. The wavelength also plays a part, with some wavelengths penetrating water (=tissue) better than others. Laser light is more powerful than eg ordinary LED light because the emitted photons act coherent (possible in both the spatial and temporal dimensions), so they are more efficient heating things up, or reacting with chromophores in cells. But if the energy arriving at the retina is low enough, this will be no issue.
• bdamm 7y ago
  In addition to safety I wonder about interference. Wouldn't lidar become ineffective if there's so much lidar around that all the lidar sources start interfering with each other and effectively blinding all receivers with noise? I really wonder why lidar-based autonomous agents plan to deal with this problem. It seems fundamental.
  • namibj 7y ago
    Usually not. They require resilience against ambient light already, so they are either very dim and use coding gains or they use short pulses which only yield a short time window for valid returns. You basically don't get non-malicious interference issues, except for e.g. the dot projector systems. Real ToF sensors can easily filter any accidental noise. You can often spoof them, however, and there's not much one can do against it considering a blinding DoS is often technically easier (track the LIDAR with a camera to keep the laserpointer on-target)
  • swiley 7y ago
    They probably use PRN codes with low self correlation.
• deepnotderp 7y ago
  Lidar damages CMOS image sensor pixels due to thermal effects. Your eyes have ample cooling capability to deal with that.