Active Monitoring Experiment in Chicheng Using Precision Seismic Vibrator

Two experiments are done in Chicheng in which the CASS-40 seismic vibrator is used to trigger seismic waves and temporary stations are set up to receive the waves. In the experiment, the chirp signal at 5-10-5 Hz and 4-10-4 Hz are used and two survey lines are emplaced from Chicheng to Zhangjiakou and from Chicheng to Zhangbei to continuously record the transmitted signal. STFT(Short-time Fourier Transform) is used to analyze the frequency characteristics of the LFM(Linear Frequency Modulation), and two methods of deconvolution and WHT (Wigner-HoughTransform) are both used to get the seismic wave travelling curve. The difference between their results is analyzed. Clear phases are selected to calculate the velocity ratio (V_p/V_s) of the temporary station. The result is approved to be consistent with the existing researches.