Luke Johnson and Joshua Kranz
University of Minnesota
Methods of Experimental Physics Spring 2012
Two amplitude modulation techniques were studied with the goal of determining the accuracy and precision of acoustic distance measurements as functions of object distance and size, carrier signal, and modulation signal. The first technique was using maximum length sequences to modulate a carrier signal and the second was the sinusoidal modulation of a carrier signal. The sinusoidal method proved to be too inaccurate to use for reliable distance measuring while the maximum length sequences were showing ± 1 to 2mm precision and accurate measurements over the measured range of 0.5 to 5m.