Fig. 3. Accuracy of the ultrasonic and optical localization and rendering on the AR display.

a Photo of the acoustic radar with three transducers. b Photo of the acoustic radar with infrared (IR) markers and the mount base. c Photo of the tablet-based AR system. d Tracking accuracy of the FOG tip in water by the acoustic trilateration when it moves on the x, y (lateral directions), and z (axial direction) axes, respectively. e Optical tracking accuracy of the acoustic radar through a stereo IR camera when the radar moves on the x, y (lateral directions), and z (axial direction) axes, respectively. f Projection accuracy of a given target point on the AR display when it has movement on the x, y, and z axes at ~40, ~50, and ~60 cm distances, respectively