iliasam

Also I have same project for ESP32 - with GUI: https://github.com/iliasam/ESP32_SDR_GPS

This is a demo project - it can't be used in a real life because it is working too slow, but I think that it can be interesting for all who loves experiments with GPS, SDR and DSP.

You could see real results here: https://github.com/iliasam/OpenTOFLidar/wiki/Resolution-of-t...

> "How did you calculate the appropriate laser lens and standoff"

I can't say that there was too much calculations.

The is some information here: http://www.ti.com/lit/ug/tiduc73b/tiduc73b.pdf (part 2.3.5)

and here: http://www.ti.com/lit/ug/tiducm1b/tiducm1b.pdf (part 2.3.2)

Laser's lens should have maximum possible focal length, but it must not crop light beam from the diode.

Photodiode's lens should have maximum Entrance pupil

> "Is the CS mount lens's focal length important, or is there no need for a sharp image at all distances?"

You need to have sharp image at big distances. At short distances it is not important - light signal is high enough.

> "Why use one CS-mount lens and one M12 lens, rather than two M12 lenses?"

I think that it is easier to find lens with big "Entrance pupil" with CS mount that with M12 mount. Bigger mount - bigger lens diameter, bigger "Entrance pupil".

> "Do you need any sort of dynamic gain"

I don't have any kind of electrical gain control. There is an ability to change APD gain, but I don't use it.

> "optical filtering on the received signal"

I don't have filter in my LIDAR, but it is necessary to have it if you are going to run LIDAR at sunlight. I give links to a several interference filters in "LidarTotalBOM.xlsx".

> "Did you need much fancy $$$$ test equipment to get the design working".

All that I have is Tektronix TDS540D oscilloscope (bought at the Ebay for $300) and multimeter.

Measuring through translucent or transparent surfaces is theoretically possible (TDC is supporting multiple measurements), but received pulse width is too high now - it could be > 30ns after amplifier.

Why did you write "they are using"? Thre was no team, it's my own project.