Sea-trials with active EM for sea-mine detection

Sea-trials with an active electromagnetic transmitter/receiver are presented in this report. The receiver was constructed to be orthogonal to the transmitter principal axis. The trials were divided into two parts. Firstly, the field, measured by the receiver due to misalignment between the receiver and transmitter, was minimised. An attenuation of 82 dB was possible to achieve. Secondly, the detection of a mine-like object was performed. After the optimisation of orthogonality, detection of a spherical steel object was performed by dragging it parallel to the transmitter main axis. The distance between the sphere and the transmitter was 2 meters. The response from the sphere was clearly seen in the measured signal. Finally, experimental and theoretical results were compared.