Ultrasonic localization systems (UMS) are most commonly used in short-range measurements. UMS determine the position of an object by means of Time-of-Flight of an ultrasound wave travelling through the air. These systems are also called acoustic measurement systems, because the system functions by means of sound waves. The difference between sound and ultrasound is that ultrasound is stealthy for the human ear, which is beneficial in research. A drawback of ultrasound is that the range is limited compared to sound. Also, the directionality of ultrasound can be a disadvantage when working with dynamic measurements. In the chart (Figure 2), one system is included, which is based on ultrasonic localization in sports, with an accuracy of 0.05 m in an area of 9 m2 (Bischoff, Heidmann, Rust, & Paul, 2012). Note, however, that this result was obtained via a fusion with a radio frequency transceiver.
Accuracy of human motion capture systems for sport applications 