Huazhong University of Science and Technology

Wuhan Institute of Technology

Qinghui Zhang

Tianxu Zhang

Cheng Yang

Tao Zhang

Jiandong Tan

Jiawei Wang

Yuhai Lv

Disclosed are an underwater ferromagnetic target detection method and system employing multiple power frequency radiation sources, pertaining to the technical field of non-acoustic underwater detection. The method includes: a power transmission network generating a power frequency electromagnetic field in a spatial range, and an underwater ferromagnetic target generating an electromagnetic field under the combined action of the power frequency electromagnetic field and seawater inside and outside the underwater ferromagnetic target; if there are multiple ships on the water serving as secondary radiation sources acting on the underwater ferromagnetic target, obtaining a secondary magnetic field generated by the underwater ferromagnetic target, and adding the secondary magnetic field and the electromagnetic field generated by the underwater ferromagnetic target under the combined action of the power frequency electromagnetic field and the seawater inside and outside the underwater ferromagnetic target to obtain a total electromagnetic field generated by the underwater ferromagnetic target; and acquiring a power frequency electromagnetic field distribution around the underwater ferromagnetic target, and performing underwater ferromagnetic target detection according to the power frequency electromagnetic field distribution. The present invention can enhance power frequency electromagnetic field signals of an underwater ferromagnetic target, and achieves underwater ferromagnetic target detection.

Underwater ferromagnetic target detection method and system employing multiple power frequency radiation sources

A sequence time window amplitude-phase-frequency characteristics analysis method and system for underwater vehicle power frequency electromagnetic field disturbance are provided. The method includes: establishing a power grid dipole group model, emulating and calculating to obtain background field intensity data of a test location, and constructing an emulated background field database; acquiring measured background field data, comparing the emulated data with the measured data, and providing a relative error; calculating a background field intensity and underwater vehicle target disturbance under the action of the above dipole group, and establishing a measured target signal database; and performing actual measurement according to an underwater vehicle motion and detection topology, performing a Fourier transform and Fourier sliding window decomposition after acquiring original data, and acquiring an amplitude spectrum and a spectrogram of an underwater vehicle target disturbance signal.

Sequence time window amplitude-phase-frequency characteristics analysis method for underwater vehicle power frequency electromagnetic field disturbance

The present invention discloses an electromagnetic wave spatial analysis method based on multi-level dipole group modeling. The electromagnetic wave spatial analysis method includes the following steps: S, obtaining a magnetic dipole group according to three-phase loops of power grids of various different voltage levels, and obtaining spatial coordinates of the magnetic dipole group according to the longitudes and latitudes as well as the altitudes of the power grids of various voltage levels; S, calculating the loop length of each three-phase magnetic dipole according to the spatial coordinates of the magnetic dipole group, and obtaining a multi-level magnetic dipole group according to the loop lengths; S, obtaining the current corresponding to the voltage on power transmission loops in the power grids of various voltage levels at different levels according to the installed capacities of the power grids of various voltage levels in different countries; S, building a multi-level dipole model according to the multi-level magnetic dipole group and the current; and S, solving the multi-level dipole model to obtain spatial power frequency electromagnetic wave distribution. The altitude factor of grid distribution is added in the present invention, and the power grids are divided into multiple levels for modeling analysis respectively, thereby increasing the analytical accuracy of power frequency electromagnetic waves.

Electromagnetic wave spatial analysis method based on multi-level magnetic dipole group modeling

Growing community of inventors

Hubei, China

Qinghui Zhang