A novel scheme for determination of vessel heading using airborne magnetic wake scanning

Abstract

Practical remote vessel detection schemes are switching from the active lidar and sonar based methods to modern passive schemes such as analyzing the geomagnetic anomaly initiated from a moving remote vessel. The detection of a remote vessel and its heading direction has been fully studied in our recently published work through analyzing the two-dimensional frequency spectrum image of the magnetic wake captured by an array of magnetic sensors positioned under the sea surface. Instead of employing the fixed-positioned multi-sensor detection scheme, in this work, we study the heading detection of a remote vessel traveling in shallow/deep water through analyzing the measured magnetic anomaly captured by a single airborne magnetic sensor. After representing mathematical expressions of the captured magnetic wake initiated from the remote vessel, we manage to formulate the Fourier transform of the magnetic wake, and show that the detection of a remote vessel as well as its heading direction can be estimated through detecting the frequency corresponding to the peak amplitude of the spectrum. We show through theoretical and numerical results that the lower the cross-angle between the drone and vessel traveling directions, the more accurate the estimation of the heading angle.