I want to implement the technique for obstacle finding , presented in the attached file.
I don't have experience in signal processing. I need information regarding correlation.
As described in paper ,echo pattern is per-stored for matching the received echoes. How reference patterns are determined?
How reference pattern is correlated with the received signals?
Evidently a lookup table (reference) is stored. The algorithm compares the echo times, together with the lookup table. The result is distance of an obstacle, perhaps height and direction.
That's merely my conjecture. The article tells a lot of information, but it conceals a lot too. The Figure 41 shows typical waveforms going through the device, however it's a cryptic diagram because the waveforms do not appear to align on an identical timescale.