Abstract: The source region electromagnetic pulse (SREMP) can penetrate the engineering geotechnical medium, which has a serious impact on the electronic information equipment in the underground engineering. A test scheme of near-field region of SREMP is proposed based on the equivalent test of continuous wave in order to evaluate the environment of underground engineering. An equivalent test system is built, and the near-field characteristics of antenna are studied. The magnetic induction intensity of line antenna near the earth is test, and the feasibility of the test system is verified. On this foundation, the inversion study of equivalent conductivity of the earth is made by the finite-difference time-domain (FDTD) algorithm, and the field environment at typical frequency points in underground engineering at a certain depth is calculated. The proposed method can be used to evaluate the environment of SREMP in underground engineering for different earth media, which provides a reference for studying the SREMP effect and engineering protection design.

Key words: sourceregionelectromagneticpulse, near-fieldoflineantenna, equivalentconductivityoftheearth, FDTDalgorithm