Coordinates Determination of Underwater Mobile Sensors Using Cayley-Menger Determinant

Abstract

Underwater wireless sensor Networks(UWSNs) are usually deployed over a large sea area and the nodes are usually floating, due to their special environment. This results in a lower beacon node distribution density, a longer time for localization, and more energy consumption. Currently most of the localization algorithm in this field do not pay enough consideration on the mobility of the nodes. This paper investigates the problem of localizing submerged sensors that are mobile and provides a new mechanism to determine the coordinates of those sensors using only one beacon node. In underwater wireless sensor networks (UWSN), precise coordinate of the sensors that actuate or collect data is vital, as data without the knowledge of its actual origin has limited value. In this study, the method of determining the underwater distances between beacon and sensor nodes has been presented using combined radio and acoustic signals, which has better immunity from multipath fading. The velocity of unknown node is calculated by using the spatial correlation of underwater object’s mobility, and then their locations can be predicted. Moreover, Cayley-Menger determinant is used to determine the coordinates of the nodes where none of nodes have a priori knowledge about its location. Simulation results validate the proposed mathematical models by computing coordinates of sensor nodes with mobility with negligible errors.