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° 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. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

中文翻译：

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基于正交锁相放大的实时数据处理方法及其在频域半机载电磁检测中的应用

在频域半机载电磁检测方法中，来自线圈传感器的接收信号包含大量噪声。为了提高信噪比，提出了一种基于正交锁相放大的数据处理方法。通过使用GPS第二脉冲技术，该方法具有良好的实时性和较高的信噪比。接收信号的幅度和相位可以通过简单的算术运算轻松解决并实时存储，从而避免了短期窗口信号中的大误差。所提出的方法可以提供更高的地下异常分辨率和更好的噪声抑制能力。测量结果表明，该方法的幅度误差小于3％，相位误差小于0。在双重白噪声条件下为6°。噪声抑制能力是现有系统的10倍，分辨率高达25倍。较小的异常可以更准确地反映出来。©2020日本电气工程师学会。由Wiley Periodicals LLC发布。