but you still don't know which of the 25 cycles is which by the time they reach the receiver.
This is the the crux of the problem, we cannot know for certain.
We get an approximation using Thresholding:
This is the simplest method and I incorporate it in this design. The tof is measured when the
amplitude of the received pulse exceeds a fixed amplitude.
In theory the error of this measurement can approach zero if you average an infinite number of
samples.
I average over 3 seconds.
We then have a tof with an error, we get a closer result using the phase shift.
You cannot use the phase shift alone as it repeats itself every wavelength(25 micro sec).
Hope that this helps.