Detection of Submarines through the Processing of the Magnetic Wake Using a Single Sensor Scheme

The processing of the measured passive magnetic signal instigated from remote ships and submarines is one of the most effective and novel methods for the detection of remote traveling vessels. The geomagnetic field of the earth, the electrical conductivity of seawater, and the electromagnetic induction law are the three elements helping us to detect remote vessels in seawater. The traveling of a vessel in the seawater as an electrical conductor induces magnetic anomaly in the geomagnetic field of the earth whose processing and detection leads to the detection of the remote vessel.

In this paper, we present a mathematical structure for modeling the magnetic anomaly and its relation to the environmental parameters as well as the physical parameters of the traveling body such the vessel’s shape and speed. We propose the detection process through a single magnetic sensor located at some specified depth under the sea surface. The proposed structure has many advantages to the currently available airborne sensors.

We will analytically show that there always exists an optimal depth wherein if the magnetic sensor is located, maximum detection probability is achieved. We will show through numerical results that the optimal depth gets higher if the travelling speed of the vessel is increased. We will also show that if the traveling speed is lower than 10m/s, the optimal depth is lower than 6m and is independent of the sea depth

We will show that the amplitude of the magnetic wake above the sea surface and under the seabed suffers from severe attenuation, and there always exists an optimal depth under the sea surface wherein if the sensor is positioned, maximum magnitude of anomaly is captured. The impact of different parameters such as the location of the sensor, the depth of the sea, as well as the speed, length and traveling depth of the submerged traveling body are evaluated on the performance of our proposed scheme.