What is the definition of USBL?

Stands for ultra-short baseline. USBL is a positioning technology that detects acoustic (sound) signals via a hydrophone array to calculate the range and direction to the acoustic source, based on the reception time of the soundwave at each hydrophone.

Read the full article “”Untangling USBL – comparing the benefits of USBL-squared (USBL2) with classic and inverted USBL“.

USBL squared explained: Classic USBL

Image depicting classic USBL operation, where a transducer at the surface vessel emits an acoustic ping.

  • Transponders that detect the ping, emit a ping back.
  • The return ping is processed to provide range and direction information of the transponder.
  • Position is attained at each ping only, so motion data between pings is not logged.

In the example, the green circles are the pings, the red line is the [unknown] actual path of motion, the blue line is the estimated travel path. Heading of the tracked object is relatively unknown.

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