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About Janus

JANUS is an open-source robust signaling method for underwater communications, freely distributed under the GNU General Public License version 3(external link).

JANUS has been developed at the Centre for Maritime Research and Experimentation (CMRE)(external link) with the collaboration of academia, industry and government with the intention of creating an inter-operable communications standard.

JANUS performance has so far been evaluated by many collaborating partners at centre frequencies from 900 Hz - 60 kHz and over distances up to 28 kilometers in waters all over the world.

JANUS packet and bit error rates have been computed as functions of the signal to the noise ratio (SNR) and time spread over periods extending from hours to months. Signal correlation times have been computed and long-term experiments by CMRE(external link) in 2008 and 2009 have helped quantify robustness during variable environmental conditions.

A cabled network of oceanographic instrumentation has measured the ambient noise, water temperature, water velocity, internal wave and tidal information during JANUS transmission and reception for correlating message decoding performance with environmental parameters.

JANUS's open and public nature ensures that academia, industry and governments may all benefit from its use. The tools necessary to create a JANUS signal, encode in a desired frequency band and decode a received signal are all freely available on this site. A traditional hardware underwater acoustic modem is not even required.