Underwater Communication by Electric Current

Autonomous Robotic Systems

“…The results of the experiment show that the return current phenomenon described in the literature [36,46,56] does indeed exist. The field strength was found to be approximately inversely proportional to the square of the distance between transmitter and receiver, and proportional to the voltage across the transmitter electrodes.…”

“…One other possibility is using electric fields and return current density, as presented in [46][56] [36]. Both the transmitter and receiver consist of two electrodes exposed to water.…”

“…Ranges of up to 100 m in 30 m deep water could be achieved. The literature is very sparse on this topic -the only papers reporting on this effect are from the 1970s [46][56] [36], namely the brief theoretical account given by Schultz in 1971, and the little-known paper by Momma and Tsuchiya, who experimentally investigated the phenomenon at the Japan Marine Science and Technology Center in 1976. The paper [56] by Walther merely mentions electric communication and cites the paper by Schultz; it can therefore be omitted from discussion.…”

“…This section quantifies the effect by densely measuring the field strength and direction. The experiments concentrate on freshwater, as no experimental results could be found; the only publication giving experimental results is [36] by H. Momma and T. Tsuchiya and only reports on return current in seawater.…”

A biomimetic quasi-static electric field physical channel for underwater ocean networks

“…For our purposes it is illustrative to consider a sequence of time-invariant fields with each successive field having more (then less, then more, etc) strength than its predecessor. When this approximation is valid, the field is said to be quasi-static [16].…”