Sonar Demo

Sonic distance measurement using Windows sound card for data acquisition.

In this demo the Windows sound card is used as a data acquisition device. A chirp waveform is played out the speaker and captured by the microphone concurrently. The time delay between pitch and catch indicates separation distance. The time delay is determined using signal processing concepts (cross correlation and Hilbert pre-envelope). A graphical user interface makes operaton simple. This demo illustrates the basic principle; distances are not calibrated for accuracy.