Research on Feasibility of Low-Observable Acoustic Communication in AUV Group Navigation

Abstract

Under the water, the data are transmitted for ranges above dozens of meters using the acoustic modems. The acoustic modems are employed, in particular, for data transmission in positioning and navigation of both single and grouped underwater vehicles. Network communication methods are widely used for exchanging the navigation data between grouped autonomous underwater vehicles (AUVs). They are applied, for example, to keep the AUV formation geometry and/or to exchange the navigation data with the lead vessels. These methods can be combined, i.e., provide not only the exchange of mutual/relative positions between the AUVs for formation keeping, but also underwater georeferenced positioning for the group navigation in the geographical frame. A number of factors should be taken into account in the coordinated or cooperated AUV group navigation. As the number of interacting AUVs increases, their frequent addressing the acoustic medium is undesirable, because low capacity of the acoustic channel severely limits the underwater data traffic. Moreover, it is important to minimize the effect produced by the AUV acoustic system on the acoustic medium, particularly, to make the AUV less visible when its acoustic communication and positioning system is operating.