The Time-Frequency Analysis of Equvilent-Time Sampling GPR Signal Based on HHT

The problem of time-frequency analysis for non-stationary instantaneous impact signal in ground penetrating radar (GPR) is a difficulty. Meanwhile, the signal is sampling by equivalent-time sampling method and its frequency spectrum contains some particularity. In this article, a new time-frequency analysis method based on Hilbert-Huang transform (HHT) especially for sampling radar signal is put forward. Using the Empirical mode decomposition (EMD) to extract intrinsic model function (IMF), and then combines Hilbert transfer to get the instantaneous frequency. Accordingly, the marginal spectrum of the signal is obtained. Through the compare of theoretical analysis and experimental analysis of measured GPR signal, the result shows the technique of HHT is effective for GPR.