This short video demonstrates the Liquivision Lynx scuba diving computer, as it attempts to locate the ultrasonic tank (or location) transmitter. The radar map shows varying levels of gray, indicating the probability that the target is in that sector (white being the greatest probability). The device uses its internal digital compass to rotate the radar map, as the wrist unit rotates. As more packets are received from the transmitter, the radar map updates. Older packets are slowly discarded to allow for the fact that the target may be moving and older location information may be less accurate than new location information. You'll notice the device also says the tank pressure of the target (around 2300 PSI), and it estimates the distance to the target, although this distance estimate is calibrated for underwater operation, not operation in air as shown in the video. The lower right corner gives you the best guess compass heading (i.e. 250 deg W), which is the centroid of the brightest sector.

The blue square that floats around the screen is a feedback to the tilt of the unit. The device requires that the wrist unit be within 20 degrees of level, in order to accept directional information. If the blue square is within the inner blue circle, the unit is sufficiently level to accept directional information. As you tilt the unit around the blue square floats around the screen, giving you instant feedback on the tilt of the unit.

The device uses a combination of phase shift and relative amplitude to determine the direction to the target. It is optimized for the properties of sound underwater, not in air.