Ultrasonic tracking
Ultrasonic tracking is a kind of 3D tracking that uses sound waves. It uses high-frequency sound emitted from source components and received by microphones.[1]
It can be used to either track the position of an object, or its full position and orientation.
It uses ultrasound. It involves using an ultrasonic positioning system. It is done using an acoustic tracking system.
It can use MEMS ultrasonic transducers.[2]
There are two classes of methods of acoustic tracking. The first is to measure time-of-flight of the sound from the transmitter(s) to the receivers, performing multilateration. The second is to measure the phase coherence of the sound.[3]
It requires line of sight. It can be done in a very small form factor.
It can be used in a pen form factor.
Ultrasonic tracking was used by Ivan Sutherland's head-mounted display.
Construction[edit]
Acoustic tracking systems may use sets of at least three ultrasonic sensors and at least three ultrasonic transmitters on devices in order to calculate the position and orientation of an object such as a handheld controller.[3]