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If we are to have streets full of Lidar-equipped vehicles all constantly blasting out laser light, I can imagine this will become a real problem. Will digital

If we are to have streets full of Lidar-equipped vehicles all constantly blasting out laser light, I can imagine this will become a real problem. Will digital cameras improve so that they are less sensitive to lasers? Or will Lidar improve to use less-powerful lasers?

BuildTheRobots 8y ago
If it can do that to a camera, what's it doing to eyes? edit: > "Cameras are up to 1000x more sensitive to lasers than eyeballs," Dussan wrote. "Occasionally, this can cause thermal damage to a camera's focal plane array." - I'm still not entirely sold.
- jpalomaki 8y ago
  From the article "Cameras are up to 1000x more sensitive to lasers than eyeballs," Dussan wrote. "Occasionally, this can cause thermal damage to a camera's focal plane array." Another site claims "However, there are no MPEs for sensors such as CMOS or CCD chips. This means a show may be perfectly safe for eyes, but could possibly damage a camera sensor. One reason is that camera lenses may gather more laser light, and concentrate it to a finer point. Another reason is that CMOS or CCD sensors are more easily damaged than the eye."[1] [1] http://www.laserpointersafety.com/ilda-camera-info.html http://www.laserpointersafety.com/ilda-camera-info.html
  - BuildTheRobots 8y ago
    I'd love to see some independent results from someone who doesn't have skin in the game. Whilst damage might be more obvious in a camera CCD, even small amounts of cumulative damage over time could be doing serious harm without it being immediately obvious. I've seen f/1.6 lenses, where as the eyes are apparently f/8.3 - f/2.2, so yes the eyes take in less light, but it's substantially harder than an EF-S mount to swapout. edit: also, what about animals with good night vision? they are more sensitive and take in more light - are they at danger?
- ddebernardy 8y ago
  The article actually has the answer: > Other lidar makers use lasers with a wavelength of 1550nm. This tends to be more expensive because sensors have to be made out of exotic materials like indium-gallium arsenide rather than silicon. But it also has a big advantage: the fluid in the human eye is opaque to 1550nm light, so the light can't reach the retina at the back of the eye. This means lasers can operate at much higher power levels without posing an eye safety risk.
  - BuildTheRobots 8y ago
    > the fluid in the human eye is opaque to 1550nm light sure, but does this hold true for most land-based animals and birds? How much range does this give us? reflections can shift by half a wavelength - is that still opaque too? I'm not saying this isn't safe, but suddenly having a tonne of high power laser sources pointing everywhere at all times might actually have some consequences still...
    - csours 8y ago
      Mammals, lizards, amphibians, and birds all have water-based eyes, but I wonder what this would do to insects.
    - jerf 8y ago
      If I am reading the chart labelled "The visible and UV spectra of liquid water" at http://www1.lsbu.ac.uk/water/water_vibrational_spectrum.html http://www1.lsbu.ac.uk/water/water_vibrational_spectrum.html (about 2/3rds down the page) correctly, water is fairly opaque at 1550nm. If my hurried wikipedia education on the topic is correct, that chart is saying it's quite opaque at that frequency, even at bat eyeball scales. Corrections welcomed from people with more training in this field. (I'm not sure I'm not getting some crossed units when I tried to resolve that into numbers normals like me would understand; is that really 1/e^1000 transmitted per centimeter travelled? e^1000 is a big number. There's even bigger ones on that chart. Then again, if a two-atom-thick layer of gold is enough to make something look like gold and completely obscure what's underneath, I guess that might make sense and my intuition is just off, because when I convert that into this sort of scheme I get big numbers there, too.)
- apendleton 8y ago
  They address in the article that the frequency they're using can't damage the retina because the fluid in the eye is opaque to light at this frequency.
- icelancer 8y ago
  A camera is not the human eye. Just because they are both technically optical sensors does not mean they are equivalent really at all.
dllu 8y ago
Most current self driving car lidars operate close to the 900 nm range, and they are required to output 1000 times less power than the 1550 nm lidar in this article. [1] So far these seem totally harmless to cameras. 1550 nm lidars for self driving cars are a relatively recent thing with only a handful of companies (AEye, Luminar, Blackmore) making them. The benefit is that, thanks to the extra power, they have longer range. Unfortunately they fry cameras and are very expensive. It's also worth pointing out that the 1550 nm pulsed lidars like AEye and Luminar with fiber lasers may have much shorter pulses than the 5 ns pulses of, say, a 905 nm Velodyne lidar. So, not only is the average power 1000 times higher, but the peak power may be even higher. [1] https://en.wikipedia.org/wiki/File:IEC60825_MPE_J_nm.png https://en.wikipedia.org/wiki/File:IEC60825_MPE_J_nm.png
- robocat 8y ago
  The relevant part of the article: "But it also has a big advantage: the fluid in the human eye is opaque to 1550nm light, so the light can't reach the retina at the back of the eye. This means lasers can operate at much higher power levels without posing an eye safety risk. AEye uses 1550nm lasers. And unfortunately for Chowdhury, cameras are not filled with fluid like human eyes are. That means that high-power 1550nm lasers can easily cause damage to camera sensors even if they don't pose a threat to human eyes."
  - m3kw9 8y ago
    I imagine it is doing something to the fluid in the eye with that kind of energy it absorbs. Maybe cataracts for example.
    - iClaudiusX 8y ago
      Exactly, it's the same with unshielded microwaves, and it's astonishing that someone would think it's safe to crank the power on these lasers with that justification. > When injury from exposure to microwaves occurs, it usually results from dielectric heating induced in the body. Exposure to microwave radiation can produce cataracts by this mechanism,[28] because the microwave heating denatures proteins in the crystalline lens of the eye (in the same way that heat turns egg whites white and opaque). The lens and cornea of the eye are especially vulnerable because they contain no blood vessels that can carry away heat. https://en.wikipedia.org/wiki/Microwave#Effects_on_health https://en.wikipedia.org/wiki/Microwave#Effects_on_health
gene-h 8y ago
Fortunately, the military industrial complex has the solution to this. For some time now, there have been worries over lasers being used to blind sensors and people so a number of approaches have been developed to defend against this. Lasers only emit at a set of limited wavelengths so one can block out just these wavelengths. Another more exotic approach is to block the light coming in as soon as the laser has been detected. LCDs are an obvious solution to this, though I have seen microshutter arrays proposed for this in a Popular Science/Mechanics magazine a while back. Although, it's probably better to prevent LIDAR from destroying cameras in the first place.
- dogma1138 8y ago
  I’m pretty sure you mean the defense industry, the military industrial complex isn’t the defense industry, it doesn’t make anything ;) And the solution is far more simpler than you think the domes for the sensor packages are simply better rated, as they are rated for true 99.999% absorption for both UV and IR (beyond FLIR ranges) some of them also have an inner layer that would darken if the light penetrates that deep creating a dark spot that would block the light completely since replacing a dome is cheaper than replacing a cryogenic IR sensor array. But beyond that you can blind the sensors with most pen lasers as well as damage it with visible light, the reason why it’s not much of an issue is that due to simple physics you won’t be able to focus a beam narrow enough to hit the sensor even atmospheric refraction alone would prevent that from happening and any laser capable of damaging the sensor at the point would likely be able to damage the drone. The IR dome protection was mostly implemented to protect the sensor if the drone is painted with an illuminated.
SEJeff 8y ago
Another option is that machine vision will improve to the point where Lidars are less of a necessity. This is in fact the thing Tesla is attempting to do, although they are far from pulling it off!
- computerex 8y ago
  > Another option is that machine vision will improve to the point where Lidars are less of a necessity. Highly doubt this will happen anytime soon. Machine vision has come a long way past decade but nonetheless it is far from being reliable for driving. I think lidar is pretty much a necessity for safety's sakes.
  - SEJeff 8y ago
    It is all relative (safety that is). If you’re driving on a new road that hasn’t been mapped with the super high res Lidar, it presents a problem. Machine vision absolutely is the holy grail here. Not you or anyone else can say either machine vision OR lidar are necessary as neither of them currently power a self driving car. There isn’t currently such a thing that can do say a cross country road trip on any highways. Not even Waymo.
    - computerex 8y ago
      >If you’re driving on a new road that hasn’t been mapped with the super high res Lidar, it presents a problem. Not even remotely true. LIDAR is used to SLAM in real-time. Think of it as a radar on steroid. For successful reliable autonomous driving you need both machine vision and lidar. If you only use machine vision, you end up like Teslas and slam into stationary fire trucks. So you use machine vision for reading signs, lane localization, etc and lidar to prevent accidents. > a cross country road trip on any highways. That's not the agreed upon definition of self driving. Also, you should probably take a look at this: https://en.wikipedia.org/wiki/Self-driving_car#Testing https://en.wikipedia.org/wiki/Self-driving_car#Testing Waymo on average travels for 5,127.9 miles before a human disengagement is necessary measured over 635,868 miles. Cruise, 5,224 miles. Tesla, 2.9 miles. > Not you or anyone else can say either machine vision OR lidar are necessary Well since pretty much every single company that exists right now in the autonomous car space with the exception of Tesla uses LIDAR, I am inclined to think that's the way to do it. All in all, machine vision is way too unreliable for anything above SAE level 2. Due to the nature of machine learning algorithms used (CNN) you can't be sure that a firetruck will always be recognized as a firetruck. The only way to reliably "see" a firetruck is via lidar/radar.
pducks32 8y ago
Certainly birds might not adapt to be less sensitive. I certainly would hope that research will be done to check how the type of EM pollution will affect nature. It might not but it also might over time.
segfaultbuserr 8y ago
> Crucially, self-driving cars also rely on conventional cameras. So if those lidars are not camera-safe, it won't just create a headache for people snapping pictures with handheld cameras. Lidar sensors could also damage the cameras on other self-driving cars.
pishpash 8y ago
Seems like something the FCC should regulate. It's the radio spectrum.
- gorkish 8y ago
  FCC regulates only to 3THz (~100µm wavelength). The IR laser emission is near 200THz. Regulatory jurisdiction here is the FDA under 21 CFR 1040. Unfortunately MPE for the regulation is all based on the biology of the eye, so that is where you'd have to find your argument. Probably the best avenue to argue would be that the peak power of the short pulse is above MPE although in a practical sense the total energy may not be a problem. My guess is that in this case there would be allowable measurement methodology that both passes and fails the standard, and the legal argument would center around that.

BuildTheRobots 8y ago

If it can do that to a camera, what's it doing to eyes? edit: > "Cameras are up to 1000x more sensitive to lasers than eyeballs," Dussan wrote. "Occasionally, this can cause thermal damage to a camera's focal plane array." - I'm still not entirely sold.

jpalomaki 8y ago
From the article "Cameras are up to 1000x more sensitive to lasers than eyeballs," Dussan wrote. "Occasionally, this can cause thermal damage to a camera's focal plane array." Another site claims "However, there are no MPEs for sensors such as CMOS or CCD chips. This means a show may be perfectly safe for eyes, but could possibly damage a camera sensor. One reason is that camera lenses may gather more laser light, and concentrate it to a finer point. Another reason is that CMOS or CCD sensors are more easily damaged than the eye."[1] [1] http://www.laserpointersafety.com/ilda-camera-info.html http://www.laserpointersafety.com/ilda-camera-info.html
- BuildTheRobots 8y ago
  I'd love to see some independent results from someone who doesn't have skin in the game. Whilst damage might be more obvious in a camera CCD, even small amounts of cumulative damage over time could be doing serious harm without it being immediately obvious. I've seen f/1.6 lenses, where as the eyes are apparently f/8.3 - f/2.2, so yes the eyes take in less light, but it's substantially harder than an EF-S mount to swapout. edit: also, what about animals with good night vision? they are more sensitive and take in more light - are they at danger?
ddebernardy 8y ago
The article actually has the answer: > Other lidar makers use lasers with a wavelength of 1550nm. This tends to be more expensive because sensors have to be made out of exotic materials like indium-gallium arsenide rather than silicon. But it also has a big advantage: the fluid in the human eye is opaque to 1550nm light, so the light can't reach the retina at the back of the eye. This means lasers can operate at much higher power levels without posing an eye safety risk.
- BuildTheRobots 8y ago
  > the fluid in the human eye is opaque to 1550nm light sure, but does this hold true for most land-based animals and birds? How much range does this give us? reflections can shift by half a wavelength - is that still opaque too? I'm not saying this isn't safe, but suddenly having a tonne of high power laser sources pointing everywhere at all times might actually have some consequences still...
  - csours 8y ago
    Mammals, lizards, amphibians, and birds all have water-based eyes, but I wonder what this would do to insects.
  - jerf 8y ago
    If I am reading the chart labelled "The visible and UV spectra of liquid water" at http://www1.lsbu.ac.uk/water/water_vibrational_spectrum.html http://www1.lsbu.ac.uk/water/water_vibrational_spectrum.html (about 2/3rds down the page) correctly, water is fairly opaque at 1550nm. If my hurried wikipedia education on the topic is correct, that chart is saying it's quite opaque at that frequency, even at bat eyeball scales. Corrections welcomed from people with more training in this field. (I'm not sure I'm not getting some crossed units when I tried to resolve that into numbers normals like me would understand; is that really 1/e^1000 transmitted per centimeter travelled? e^1000 is a big number. There's even bigger ones on that chart. Then again, if a two-atom-thick layer of gold is enough to make something look like gold and completely obscure what's underneath, I guess that might make sense and my intuition is just off, because when I convert that into this sort of scheme I get big numbers there, too.)
apendleton 8y ago
They address in the article that the frequency they're using can't damage the retina because the fluid in the eye is opaque to light at this frequency.
icelancer 8y ago
A camera is not the human eye. Just because they are both technically optical sensors does not mean they are equivalent really at all.

dllu 8y ago

Most current self driving car lidars operate close to the 900 nm range, and they are required to output 1000 times less power than the 1550 nm lidar in this article. [1] So far these seem totally harmless to cameras. 1550 nm lidars for self driving cars are a relatively recent thing with only a handful of companies (AEye, Luminar, Blackmore) making them. The benefit is that, thanks to the extra power, they have longer range. Unfortunately they fry cameras and are very expensive. It's also worth pointing out that the 1550 nm pulsed lidars like AEye and Luminar with fiber lasers may have much shorter pulses than the 5 ns pulses of, say, a 905 nm Velodyne lidar. So, not only is the average power 1000 times higher, but the peak power may be even higher. [1] https://en.wikipedia.org/wiki/File:IEC60825_MPE_J_nm.png https://en.wikipedia.org/wiki/File:IEC60825_MPE_J_nm.png

robocat 8y ago
The relevant part of the article: "But it also has a big advantage: the fluid in the human eye is opaque to 1550nm light, so the light can't reach the retina at the back of the eye. This means lasers can operate at much higher power levels without posing an eye safety risk. AEye uses 1550nm lasers. And unfortunately for Chowdhury, cameras are not filled with fluid like human eyes are. That means that high-power 1550nm lasers can easily cause damage to camera sensors even if they don't pose a threat to human eyes."
- m3kw9 8y ago
  I imagine it is doing something to the fluid in the eye with that kind of energy it absorbs. Maybe cataracts for example.
  - iClaudiusX 8y ago
    Exactly, it's the same with unshielded microwaves, and it's astonishing that someone would think it's safe to crank the power on these lasers with that justification. > When injury from exposure to microwaves occurs, it usually results from dielectric heating induced in the body. Exposure to microwave radiation can produce cataracts by this mechanism,[28] because the microwave heating denatures proteins in the crystalline lens of the eye (in the same way that heat turns egg whites white and opaque). The lens and cornea of the eye are especially vulnerable because they contain no blood vessels that can carry away heat. https://en.wikipedia.org/wiki/Microwave#Effects_on_health https://en.wikipedia.org/wiki/Microwave#Effects_on_health

gene-h 8y ago

Fortunately, the military industrial complex has the solution to this. For some time now, there have been worries over lasers being used to blind sensors and people so a number of approaches have been developed to defend against this. Lasers only emit at a set of limited wavelengths so one can block out just these wavelengths. Another more exotic approach is to block the light coming in as soon as the laser has been detected. LCDs are an obvious solution to this, though I have seen microshutter arrays proposed for this in a Popular Science/Mechanics magazine a while back. Although, it's probably better to prevent LIDAR from destroying cameras in the first place.

dogma1138 8y ago
I’m pretty sure you mean the defense industry, the military industrial complex isn’t the defense industry, it doesn’t make anything ;) And the solution is far more simpler than you think the domes for the sensor packages are simply better rated, as they are rated for true 99.999% absorption for both UV and IR (beyond FLIR ranges) some of them also have an inner layer that would darken if the light penetrates that deep creating a dark spot that would block the light completely since replacing a dome is cheaper than replacing a cryogenic IR sensor array. But beyond that you can blind the sensors with most pen lasers as well as damage it with visible light, the reason why it’s not much of an issue is that due to simple physics you won’t be able to focus a beam narrow enough to hit the sensor even atmospheric refraction alone would prevent that from happening and any laser capable of damaging the sensor at the point would likely be able to damage the drone. The IR dome protection was mostly implemented to protect the sensor if the drone is painted with an illuminated.

SEJeff 8y ago

Another option is that machine vision will improve to the point where Lidars are less of a necessity. This is in fact the thing Tesla is attempting to do, although they are far from pulling it off!

computerex 8y ago
> Another option is that machine vision will improve to the point where Lidars are less of a necessity. Highly doubt this will happen anytime soon. Machine vision has come a long way past decade but nonetheless it is far from being reliable for driving. I think lidar is pretty much a necessity for safety's sakes.
- SEJeff 8y ago
  It is all relative (safety that is). If you’re driving on a new road that hasn’t been mapped with the super high res Lidar, it presents a problem. Machine vision absolutely is the holy grail here. Not you or anyone else can say either machine vision OR lidar are necessary as neither of them currently power a self driving car. There isn’t currently such a thing that can do say a cross country road trip on any highways. Not even Waymo.
  - computerex 8y ago
    >If you’re driving on a new road that hasn’t been mapped with the super high res Lidar, it presents a problem. Not even remotely true. LIDAR is used to SLAM in real-time. Think of it as a radar on steroid. For successful reliable autonomous driving you need both machine vision and lidar. If you only use machine vision, you end up like Teslas and slam into stationary fire trucks. So you use machine vision for reading signs, lane localization, etc and lidar to prevent accidents. > a cross country road trip on any highways. That's not the agreed upon definition of self driving. Also, you should probably take a look at this: https://en.wikipedia.org/wiki/Self-driving_car#Testing https://en.wikipedia.org/wiki/Self-driving_car#Testing Waymo on average travels for 5,127.9 miles before a human disengagement is necessary measured over 635,868 miles. Cruise, 5,224 miles. Tesla, 2.9 miles. > Not you or anyone else can say either machine vision OR lidar are necessary Well since pretty much every single company that exists right now in the autonomous car space with the exception of Tesla uses LIDAR, I am inclined to think that's the way to do it. All in all, machine vision is way too unreliable for anything above SAE level 2. Due to the nature of machine learning algorithms used (CNN) you can't be sure that a firetruck will always be recognized as a firetruck. The only way to reliably "see" a firetruck is via lidar/radar.

pducks32 8y ago

Certainly birds might not adapt to be less sensitive. I certainly would hope that research will be done to check how the type of EM pollution will affect nature. It might not but it also might over time.

segfaultbuserr 8y ago

> Crucially, self-driving cars also rely on conventional cameras. So if those lidars are not camera-safe, it won't just create a headache for people snapping pictures with handheld cameras. Lidar sensors could also damage the cameras on other self-driving cars.

pishpash 8y ago

Seems like something the FCC should regulate. It's the radio spectrum.

gorkish 8y ago
FCC regulates only to 3THz (~100µm wavelength). The IR laser emission is near 200THz. Regulatory jurisdiction here is the FDA under 21 CFR 1040. Unfortunately MPE for the regulation is all based on the biology of the eye, so that is where you'd have to find your argument. Probably the best avenue to argue would be that the peak power of the short pulse is above MPE although in a practical sense the total energy may not be a problem. My guess is that in this case there would be allowable measurement methodology that both passes and fails the standard, and the legal argument would center around that.