Transmitters are electronic tags that broadcast a series of “pings” (sound pulses) into the surrounding water. Tags are either surgically implanted or attached externally to a fish of interest so that once released into the wild, a tagged fish can be “heard” by any receiver within range.

Injectable Acoustic Transmitter Once activated, the transmitter emits a uniquely coded 31 bit binary phase-shift keyed signal, which provides more than 65,000 individual tag codes. The signal is emitted at a frequency of 416.7 kHz and at a source level of approximately 156 dB (relative to 1 µPascal and 1 m).