Three-level distributed analysis for transmission performance of deep-sea electromagnetic inductive coupling temperature-salinity-depth chain

Abstract

Abstract Inductive coupling temperature-salinity-depth chain is an important instrument for measuring the deep-sea environment. Using the electromagnetic induction principle, the bidirectional data transmission from the overwater control equipment to an underwater sensor can be realized. However, due to attenuation in marine environments, it is difficult to realize a long distance and efficient transmission. In order to accurately analyze the channel transmission characteristics of an inductive coupling temperature-salinity-depth chain, a three-level distributed prototype of the transmission channel using COMSOL Multiphysics is constructed. The transmission characteristics of the channel are analyzed at various depths. The analysis of a three-level simulation model demonstrates that the seawater resistivity is relatively stable, independent of detection depth. When the transmission frequency is 10 kHz and the length of the cable is 60 m, the transmission efficiency of the single node transmission channel is 2.9%. Moreover, the transmission efficiency is reduced to 2.6%, when the sensor nodes in the transmission channel are 10, while it may be less than 1% with the decrease of the inductance. The seawater resistivity and the inductance of magnetic ring significantly influence the performance of transmission channel. Optimizing the inductance of the magnetic ring and improving the frequency of the transmission signal are extremely important for the improvement of the transmission performance of an electromagnetic inductive coupling temperature-salinity-depth chain.