地表振动传感器质量对水平耦合谐频的影响*

使用振声法探测埋地物体时，表层土壤松软导致地表振动传感器在耦合环节发生谐振， 造成谐频附近的信号失真，限制了所采信号的可用频段。针对传感器在水平方向的耦合谐振问题，该文研究了传感器质量对谐振频率的影响。仿真对比了传感器质量为2~250 g情况下信号采集系统的频响特征，并在季节性的冻土地表开展了对比实验与横波波速测量实验。仿真与实验结果表明：250 g传感器所对应的耦合谐频不超过800 Hz；2 g传感器的耦合谐频可超过1200 Hz；传感器质量越轻，耦合谐振频率越高，所采信号的可用频段越宽。

The effect of the surface vibration sensor mass on horizontally coupled harmonic frequencies

The use of the vibroacoustic method for detecting buried objects causes resonance during the couple of the surface vibration sensor due to the softness of the surface soil, resulting in distortion of the signal near the harmonic frequency and limiting the available frequency band of the acquired signal. To address the problem of coupled resonance of the sensor in the horizontal direction, this paper investigates the effect of sensor mass on the resonant frequency. Simulations are carried out to compare the frequency response characteristics of the signal acquisition system for sensor masses from 2~250 g. Comparative experiments and shear wave velocity measurements are carried out on seasonal permafrost surfaces. Simulation and experimental results show that the resonant frequency corresponding to the 250 g sensor does not exceed 800 Hz; for a 2 g sensor the coupling resonance frequency can exceed 1200 Hz; the lighter the sensor mass, the higher resonant frequency and the wider the available frequency band for the signal acquired.