Underwater sensors can track ships with location systems off

A Tallinn school student has shown that underwater pressure sensors can estimate the speed and, in some cases, the distance of passing ships from their wake patterns, ERR reports. The findings could help track vessels when their location systems are disrupted or switched off.

Anna Egorova, a student at Tallinn Reaalkool, based her research on classical Kelvin wave theory and spectral analysis of wave patterns. She examined time-series data from pressure sensors placed on the seabed and used spectrograms to identify patterns characteristic of ship waves.

A ship’s wake quickly fills in, but the water remains unsettled and forms a distinctive pattern that can travel long distances. The pattern can reveal information about the vessel that created it, much like tracks in snow can offer clues about their source.

Egorova applied the method to ships passing near Skulte port in Latvia, in the Gulf of Riga. Her research paper was titled “Determining a ship’s speed and distance from a measurement point using ship-wave recordings.”

Ilja Maljutenko, a senior researcher at Tallinn University of Technology’s Institute of Marine Systems, wrote in the magazine Akadeemiake that analysing waves could provide an alternative way to identify ships when tracking systems are unavailable.