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How laser rangefinder or laser distance meter work and what chip can measure Time of Flight ?

Started by a a August 12, 2022
what chip, clocked at what frequency, is used to measure Time of Flight of laser light at sucjh short time intervals ?

notjhing found on the internet

https://en.wikipedia.org/wiki/Time_of_flight

https://www.fullyinstrumented.com/how-a-laser-measure-works/

https://sciencing.com/ultrasonic-sensors-work-4947693.html
On Friday, 12 August 2022 at 12:18:44 UTC+2, a a wrote:
> what chip, clocked at what frequency, is used to measure Time of Flight of laser light at sucjh short time intervals ? > > notjhing found on the internet > > https://en.wikipedia.org/wiki/Time_of_flight > > https://www.fullyinstrumented.com/how-a-laser-measure-works/ > > https://sciencing.com/ultrasonic-sensors-work-4947693.html
"The computer chip in the LRF uses a high-speed digital clock to calculate the time taken to hit the target. what is an operating frequency of the clock in LRF ?
On Friday, August 12, 2022 at 3:23:57 AM UTC-7, a a wrote:
> On Friday, 12 August 2022 at 12:18:44 UTC+2, a a wrote: > > what chip, clocked at what frequency, is used to measure Time of Flight of laser light at sucjh short time intervals ?
GHz ASIC 3E-9 second per meter
On 12/08/2022 14:46, Ed Lee wrote:
> On Friday, August 12, 2022 at 3:23:57 AM UTC-7, a a wrote: >> On Friday, 12 August 2022 at 12:18:44 UTC+2, a a wrote: >>> what chip, clocked at what frequency, is used to measure Time of Flight of laser light at sucjh short time intervals ? > > GHz ASIC > 3E-9 second per meter > >
FPGA...I worked on one... -- This email has been checked for viruses by Avast antivirus software. www.avast.com
On Friday, August 12, 2022 at 12:06:42 PM UTC-4, TTman wrote:
> On 12/08/2022 14:46, Ed Lee wrote: > > On Friday, August 12, 2022 at 3:23:57 AM UTC-7, a a wrote: > >> On Friday, 12 August 2022 at 12:18:44 UTC+2, a a wrote: > >>> what chip, clocked at what frequency, is used to measure Time of Flight of laser light at sucjh short time intervals ? > > > > GHz ASIC > > 3E-9 second per meter > > > > > FPGA...I worked on one...
I have one of the laser devices. It measures to a fraction of an inch. That would be an equivalent frequency of maybe 100 GHz which is a bit difficult, even inside an FPGA. Does this require multiple inputs with varying delays to define timing to a finer resolution than the clock period? -- Rick C. - Get 1,000 miles of free Supercharging - Tesla referral code - https://ts.la/richard11209
On Friday, 12 August 2022 at 15:46:11 UTC+2, Ed Lee wrote:
> On Friday, August 12, 2022 at 3:23:57 AM UTC-7, a a wrote: > > On Friday, 12 August 2022 at 12:18:44 UTC+2, a a wrote: > > > what chip, clocked at what frequency, is used to measure Time of Flight of laser light at such short time intervals ? > GHz ASIC > 3E-9 second per meter
c = 299 792 458 m/s > >>> c = 300 000 000 m/s 3E-9 s/m x 300 000 000 m/s = 0.9 ok but for 1 cm resolution we need 100 x faster clock and for parallel analysis of point cloud 100 x 100 we need 100 x 100 faster clock could you explain ?
On Friday, 12 August 2022 at 18:48:21 UTC+2, Ricky wrote:
> On Friday, August 12, 2022 at 12:06:42 PM UTC-4, TTman wrote: > > On 12/08/2022 14:46, Ed Lee wrote: > > > On Friday, August 12, 2022 at 3:23:57 AM UTC-7, a a wrote: > > >> On Friday, 12 August 2022 at 12:18:44 UTC+2, a a wrote: > > >>> what chip, clocked at what frequency, is used to measure Time of Flight of laser light at sucjh short time intervals ? > > > > > > GHz ASIC > > > 3E-9 second per meter > > > > > > > > FPGA...I worked on one... > I have one of the laser devices. It measures to a fraction of an inch. That would be an equivalent frequency of maybe 100 GHz which is a bit difficult, even inside an FPGA. Does this require multiple inputs with varying delays to define timing to a finer resolution than the clock period? > > -- > > Rick C. > > - Get 1,000 miles of free Supercharging > - Tesla referral code - https://ts.la/richard11209
thank you Ricky since iPhone claims Lidar in smartphone and parallel distance array calculation on-the-fly For 1cm resolution 10 GHz single point turns into 100 x 100 x 10 GHz clock frequency for 100 points x 100 points array
On Friday, August 12, 2022 at 9:06:42 AM UTC-7, TTman wrote:
> On 12/08/2022 14:46, Ed Lee wrote: > > On Friday, August 12, 2022 at 3:23:57 AM UTC-7, a a wrote: > >> On Friday, 12 August 2022 at 12:18:44 UTC+2, a a wrote: > >>> what chip, clocked at what frequency, is used to measure Time of Flight of laser light at sucjh short time intervals ? > > > > GHz ASIC > > 3E-9 second per meter > > > > > FPGA...I worked on one...
Too slow. I have only seen a few hundred MHz FPGA.
On Friday, August 12, 2022 at 11:45:18 AM UTC-7, a a wrote:
> On Friday, 12 August 2022 at 15:46:11 UTC+2, Ed Lee wrote: > > On Friday, August 12, 2022 at 3:23:57 AM UTC-7, a a wrote: > > > On Friday, 12 August 2022 at 12:18:44 UTC+2, a a wrote: > > > > what chip, clocked at what frequency, is used to measure Time of Flight of laser light at such short time intervals ? > > GHz ASIC > > 3E-9 second per meter > c = 299 792 458 m/s > >>> c = 300 000 000 m/s > > 3E-9 s/m x 300 000 000 m/s = 0.9 > > ok > but for 1 cm resolution > we need 100 x faster clock > > and for parallel analysis of point cloud 100 x 100 > we need 100 x 100 faster clock > > could you explain ?
There is no point in measuring all 10,000 points all at once.
On Friday, 12 August 2022 at 21:55:26 UTC+2, Ed Lee wrote:
> On Friday, August 12, 2022 at 11:45:18 AM UTC-7, a a wrote: > > On Friday, 12 August 2022 at 15:46:11 UTC+2, Ed Lee wrote: > > > On Friday, August 12, 2022 at 3:23:57 AM UTC-7, a a wrote: > > > > On Friday, 12 August 2022 at 12:18:44 UTC+2, a a wrote: > > > > > what chip, clocked at what frequency, is used to measure Time of Flight of laser light at such short time intervals ? > > > GHz ASIC > > > 3E-9 second per meter > > c = 299 792 458 m/s > >>> c = 300 000 000 m/s > > > > 3E-9 s/m x 300 000 000 m/s = 0.9 > > > > ok > > but for 1 cm resolution > > we need 100 x faster clock > > > > and for parallel analysis of point cloud 100 x 100 > > we need 100 x 100 faster clock > > > > could you explain ? > There is no point in measuring all 10,000 points all at once.
so do you suggest, what is marketed by iPhone and called Lidar in smartphone, is a single point Laser Range Meter functionality ? If you are correct, so why do they present 2D laser scanner functionality on images ? Single point laser Lidar requires rotating head to work \so some kind od mechanics is involved