Ř The distance error is compensated by time-shifting the measured
impulse responses
Ř By implementing the time shift in frequency domain, it was
possible to apply fractional delays
Ř After the sinusidal error component has been removed, only a
residual “random noise” error remains, which is less than 2mm:
Residual positioning error
after compensation
Ř The optimal values of these time shifts are computed by
interpolating the sinusoidal component of the error
Optimized time shift (in
samples) for correcting the positioning error
Now the phase coeherence is
good up to 17 kHz
Mechanical problems:
compensation