探地雷达薄层信号的谱反演算法

A SPECTRAL INVERSION ALGORITHM FOR GPR SIGNALS OF THIN LAYERS

为了从多层介质的探地雷达回波数据中提取薄层的位置和厚度信息,推导和验证了在频率域内实现的谱反演算法。该算法给出了各反射面的广义反射系数,并建立了用于联系反射系数序列频谱和薄层参数的代价函数并进行反演。仿真结果表明,对于厚度小于调谐厚度的薄层,该算法也可以进行准确反演,从而提高了对于薄层的分辨能力。

In order to extract information including thin layer＇ s position and thickness, from reflected wave data of Ground Penetrating Radar （GPR） in multi-layered situation, a spectral inversion algorithm realized in frequency domain is presented. Through analysis of electromagnetic wave propagation in multi-layer media, generalized reflection coefficients are derived. After dividing the coefficients into pairs followed by decomposing the pairs into even and odd components, a cost function is established to connect reflection coefficients＇ spectrum and layer＇ s parameters before inversion is carried out. Some simulations show that accurate inversion results can still be expected when thickness of the layer is less than tuning thickness, which therefore improves resolution of thin layers.