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A comment on FingerIO: Using Active Sonar for Fine-Grained Finger Tracking. Parent comment

Re:FingerIO: Using Active Sonar for Fine-Grained Finger Trac... by foobarqux on Friday March 18, 2016 @10:44AM (#11312098)
They need to buffer to get a Fourier transform and to do the autocorrelation.
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Re:FingerIO: Using Active Sonar for Fine-Grained Finger Trac... by tobr on Friday March 18, 2016 @11:20AM (#11312340)
They say they use an "inaudible high frequency soundwave", so that should be > 20kHz. Shouldn't a buffer of a few milliseconds be more than enough then?
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Re:FingerIO: Using Active Sonar for Fine-Grained Finger Trac... by foobarqux on Friday March 18, 2016 @04:23PM (#11314647)
Presumably the buffer is longer to make the system more robust by avoiding spurious detections, not because of some fundamental limit like the Nyquist rate. You would need to set the buffer size experimentally.
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