Effective denoising can ensure fast and accurate target detection. This paper presents an electric field measurement system based on a high-speed motion platform, which was built to analyze the characteristics of low frequency electric field noise. An offshore test has shown that it is possible to detect a low-frequency electric field using a high-speed motion platform. Low frequency electric field noise was then collected to analyze its characteristics in terms of time and frequency domains. Based on the noise characteristics, complete ensemble empirical mode decomposition with adaptive noise (ICEEMDAN) was improved and combined with an adaptive threshold algorithm for denoising and reconstructing target containing noise signals. As revealed in the results, the proposed algorithm achieved highly effective denoising to overcome the line spectrum detection failure resulting from a high-speed motion platform. The detection range had also been improved from the original 853 m to 1306 m, a 53.1% increase.

To address the challenge of detecting low-frequency electric field signals from vessels in complex marine environments, a vessel shaft frequency electric field feature extraction method based on intrinsic mode function energy arrangement entropy values is proposed, building upon a scaled model. This study initially establishes a measurement system for shaft frequency electric fields, utilizing a titanium-based oxide electrode to construct an equivalent dipole source simulating the shaft frequency electric field signals of different types of vessels. Subsequently, a comparative analysis of the time-domain and frequency-domain characteristics of signals after modal decomposition is conducted. A feature extraction method is then proposed that combines the maximum average energy of intrinsic mode functions with arrangement entropy values to achieve discrimination of target signals. Finally, the feasibility of the proposed method is validated through sea trials. The results indicate that the method can successfully screen different types of typical vessels and address the target screening failure caused by slight differences in the characteristic parameters of the shaft frequency electric field signal. The entropy difference has been improved from 0.05 to about 0.2, and the difference rate of the shaft frequency electric field signal has been improved by 75%. This has effectively reduced the false alarm rate of target detection.

How to design an impact platform that can provide a strong electromagnetic environment for all kinds of precision electronic equipment and experimental reference for strong electromagnetic protection is of great significance. In this article, an electromagnetic coil system that generated a strong magnetic field environment was designed and studied. First, the coil parameters and coil structure were designed. Then, the Comsol finite element software was used to simulate and design the three-component coil. The coil distance and turns were adjusted to make the coil center produce a uniform magnetic field area and meet the strong magnetic field index. Finally, the coil system was built to verify the magnetic field generated by the coil through experiments. This system will be used to simulate the strong magnetic field environment that produces different high precision and may occur in the operating environment of the equipment. It will also be used to provide strong magnetic field impact test support conditions for aerospace, naval vessels, and various types of equipment, so as to find and solve the problem of antistrong magnetic reliability of equipment in the design stage.