Earth ground electromagnetic pulse response identification method and system based on broadband LFM excitation source

Abstract

The invention discloses an earth ground electromagnetic pulse response identification method and system based on a broadband LFM excitation source. By using the broadband LFM excitation source, the current waveform of an emitted broadband chirp signal and the response voltage of an earth in the broadband chirp signal, then by using an established earth ground electromagnetic pulse response identification model, a convolution inverse operator is determined according to the current waveform and earth ground electromagnetic pulse response is calculated according to the response voltage of a corresponding time, and the fine identification of earth ground electromagnetic pulse response is realized. The broadband chirp signal employed by the invention has the characteristics of wide frequency band, large spectrum density, uniform frequency point energy and an excellent inverse operator characteristic, the random noise and rule noise are effectively suppressed in a identification process, thus the identification precision of the earth ground electromagnetic pulse response is substantially improved, and the signal to noise ratio of detection is improved.

Description

technical field [0001] The present invention relates to the field of geophysical exploration, and more specifically relates to a method and system for identifying magnetotelluric impulse responses based on a broadband LFM excitation source. Background technique [0002] Energy is the lifeblood of a country's survival and development. Without energy, no modern civilization can exist. my country is rich in coal resources, but oil and gas resources are seriously insufficient, the detection ability is weak, and it is difficult to stabilize production. On January 26, 2016, the CNPC Economic and Technological Research Institute released the "2015 Domestic and Foreign Oil and Gas Industry Development Report". The report pointed out that in 2015, China's oil and gas consumption continued to grow, and the dependence on foreign countries broke through 60% for the first time, reaching 60.6%. The net import of petroleum was 328 million tons, an increase of 6.4%, and the growth rate was...

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Problems solved by technology

From this point of view, if a bipolar periodic signal is used as the excitation source, it is difficult to suppress the noise components other than the emission frequency point during the identification process; if a pseudo-random sequence is used as the excitation source, it is difficult during the identification process. Suppresses the noise component at the transmission code rate, resulting in limited selection of the transmission code rate, and even unrecognizable situations in some strong interference work areas

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