please clarify: I read your other threads and seems like you have the reflectors with stripes. One reflects 5 pulses each time and the other 10 pulses, so you can distinguish left from right.

How that system can identify forward and bacward, closer or farther from the mirrors? From your other posts I understood that you are trying to measure the delay from the *speed of light* in a small room to determine the distance. Is that? Speed ok light is c. c=300.000.000 m/s. That kind of delay?

good luck...