A rapid imaging method of the seismic back‐scattered wavefield for urban road near‐surface anomalous structures

Urban road near-surface anomalous structures are buried at shallow depths (<= 20 m) and small scale. Current geophysical methods, such as the transient electromagnetic, ground-penetrating radar and shallow seismic methods with reflection wave, refraction wave and Rayleigh surface wave, do not provide sufficient detection accuracy for near-surface anomalous structures. Although the back-scattered method is promising in this task, it still needs improvement. This paper proposes an efficient near-surface seismic back-scattered method to realize the rapid lateral imaging of urban road anomalous structures. The proposed method uses a principal component analysis algorithm to directly extract the anomalous structure information. It does not require the knowledge of parameters such as velocity or the seismic wavelet so that the solutions are not affected by these parameters. Moreover, the proposed method retains the high transverse resolution of the back-scattered wavefield and does not lose the wavefield information. Simulation and experimental operation show that the proposed method is very efficient. Combined with the hardware equipment provided by the towed seismograph, the proposed method can realize rapid detection and data imaging, which has a high engineering application value.