원문정보
초록
영어
Low frequency electromagnetic signals play an important role in the detection of underground electrical structure. After propagation of long distance, signal will be attenuated to a certain extent and probably buried in noise, make it difficult to extract. In this paper, the method of multi-layer autocorrelation will be used to detect and extract the weak low frequency electromagnetic signal, and its performance will be compared with the narrow-band filter and the method of synchronous accumulation. Simulation results show that the correlation coefficient of signal obtained by multi-layer autocorrelation and source signal can achieve more than 0.8 when SNR is -18dB. However, the value of narrow-band filter and synchronous accumulation is lower than that mentioned above when SNR is only -14dB. Experimental verifies that multi-layer autocorrelation method can suppress noise more effectively and detect weak signals more accurately.
목차
1. Introduction
2. The Basic Principle of Weak Signal Extraction
2.1 Multi-Layer Correlation
2.2 Narrowband Filter and Synchronous Accumulation
3. Simulations and Performance Analysis
3.1 The Comparison of Time-Domain Waveform
3.2 The Comparison of Frequency Spectrum
3.3 The Comparison of Correlation Coefficient
4. Conclusions
Acknowledgements
References