Location of Underground Multi-layer Media Based on BP Neural Network and Near-field Electromagnetic Signal

This paper includes a variety of media location data generated in the paper.According to the wideband near-field signal propagation model, sample data were generated based on four layers of media with known media types. The main differences between simulated data and real data are errors due to electromagnetic dispersion, multipath and noise, which are not currently taken into account because of different electromagnetic characteristics in inhomogeneous media. The setting of condition variables in the experiment was shown in Table I. Based on the experimental conditions, the simulation of the wideband near field electromagnetic ranging and positioning experiment is carried out. Because signals of different frequencies in the medium have different relative permittivity, ALRM, a widely used wideband mixing model, is used to calculate the relative permittivity.And the experimental data in this paper are as much as possible to simulate the signal information obtained by receiving and processing the transmitter in reality, and the noise is added to be closer to the real situation.

本论文涵盖了多种由研究过程中生成的媒体位置数据。依据宽带近场信号传播模型，基于已知媒体类型的四层介质，生成了样本数据。模拟数据与实际数据之间的主要差异在于电磁色散、多径效应及噪声等误差，这些误差目前未纳入考虑范围，主要由于非均匀介质中电磁特性的差异。实验条件中的变量设置如表一所示。基于这些实验条件，进行了宽带近场电磁测距与定位实验的模拟。由于介质中不同频率的信号具有不同的相对介电常数，本研究采用了广泛应用的宽带混合模型ALRM来计算相对介电常数。本论文中的实验数据尽可能地模拟了在实际情况下接收和处理发射器所获得的信号信息，并添加了噪声以更贴近真实环境。