Underground Compactness Inversion Algorithm Based on Hilbert Marginal Spectrum

Underground caves often cause road collapse. In order to prevent the road surface subsidence, the Hilbert marginal spectrum of ground penetrating radar data can be used to find underground caves. First, the intrinsic mode function was got by the empirical mode decomposition of the GPR data. By summing the marginal spectrum of the intrinsic mode function, the marginal spectrum of the GPR data can be found. Then, the relationship between the marginal spectrum and the underground compactness was explored. Finally, the underground compactness can be found by the marginal spectrum, and the caves under the road can be detected. The result indicates that the average error of the underground compactness is less than 10%. The model experiments confirmed the accuracy of the proposed method can meet the compactness analysis.