Objectives As unmanned aerial vehicles are equipped with total field magnetic sensors to detect the total field anomaly above ships, it is necessary to establish a corresponding total field anomaly inversion model in order to evaluate the underwater magnetic signature and airborne far-field magnetic signature of ships.

Methods  A ship magnetic field inversion model based on a magnetic monopole array is established on the basis of the total field anomaly data measured on the plane above the ship. Based on this, the intensity of the ship's magnetic monopole array can be obtained, thereby realizing the evaluation and analysis of the ship's three-component magnetic field signatures above and below the ship. A laboratory validation test of a steel ship model is carried out in which the magnetic fields of the ship model are measured from above and below, and inversion modeling is conducted on the basis of the total field anomaly in the measurement plane above the ship model.

Results  The total field anomaly inversion of the three-dimensional magnetic monopole array distributed on a ship's body can be used to achieve high-precision three-component magnetic field measurements on the basis of the magnetic field evaluation lines above and below the ship.

Conclusions The proposed total field anomaly inversion modeling technique provides a certain theoretical and technical basis for the engineering application of unmanned aerial vehicles for measuring ship magnetic fields, and provides a viable alternative for ship magnetic field detection and analysis.