A Real-time data processing method based on orthogonal phase-locked amplification and its application in frequency domain semi-airborne electromagnetic detection

摘要

In the frequency domain semi-airborne electromagnetic detection method, the receiving signal from the coil sensor contains a quantity of noise. In order to improve signal-to-noise ratio (SNR), a novel data processing method based on orthogonal phase-locked amplification is proposed in this paper. By using GPS second-pulse technology, the proposed method has good real-time performance and high SNR. The amplitude and phase of the receiving signals can be easily resolved by simple arithmetical operation and stored in real time, which avoids the large error in the short-term window signal. The proposed method can provide higher resolution in subsurface anomaly and better noise suppression capability. The measured results show that the proposed method amplitude error is less than 3%, and the phase error is less than 0.6 degrees under the condition of double white noise. Noise suppression capability is 10 times of the existing system and resolution is up to 25 times. The smaller anomaly can be reflected more accurately. (c) 2020 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.