Evaluating the Properties of Railway Ballast Using Spectral Analysis of Ground Penetrating Radar Signal Based on Optimized Variational Mode Decomposition

Figure 6

(a) GPR signals of dry ballast vs wet ballast (solid line: dry; dotted line: wet). (b) FFT of GPR signals of dry ballast vs wet ballast (solid line: dry; dotted line: wet).

(a)

(b)