Low-frequency near-field rapid calculation method based on vertical magnetic dipole in half space

Abstract

The invention discloses a low-frequency near-field rapid calculation method based on a vertical magnetic dipole in a half space. The method comprises steps of S100, expanding an integrand function in a Somerfeld integral formula of the magnetic dipole in the half space in the vicinity of a singular point into a form of a sum of multiple terms according to a low-frequency condition approximation relation, and solving to obtain a corresponding analytical expression; s200, comparing the theoretical value with an empirical formula and experimental data, and verifying the accuracy of the analytical expression obtained in the step S100; and S300, based on the analytical expression in the step S100 and the verification result in the step S200, extracting low-frequency near-field and energy flow distribution conditions in the underwater half space, and applying the low-frequency near-field and energy flow distribution conditions in an air and underwater communication environment for calculation. According to the method, the original complex Somerfeld integral expression can be effectively simplified, calculation complexity is reduced, and the algorithm is accelerated.

Description

technical field [0001] The invention relates to the technical field of low-frequency electromagnetic wave calculation methods, in particular to a low-frequency near-field fast calculation method based on a vertical magnetic dipole in a half space. Background technique [0002] Low frequency (30kHz~300kHz, also known as long wave), very low frequency (3kHz~30kHz, also known as ultra long wave), extremely low frequency (3Hz~30Hz, also known as very long wave) radio waves are very characteristic frequency bands in the radio spectrum. In this frequency band, the radio wave wavelength is relatively long, the signal propagation loss is small, the signal amplitude and phase are stable, and can penetrate into soil and seawater at a certain depth, and can be received by underwater or underground receiving equipment, so it is widely used in time service, Navigation and military communication, especially for submarine communication and navigation, have an irreplaceable role in the mili...

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Problems solved by technology

[0006] The purpose of the present invention is to address the above defects, to provide an improved low-frequency near-field fast calculation method based on vertical magnetic dipoles in half space, to solve the difficulty of grid division and long calculation time faced by traditional numerical methods in the past, There are even problems such as "low frequency crash"

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