Accurate acquisition of arrival time of microseismic signals is an important prerequisite for focal location

and the accurate acquisition of arrival time of P-wave and S-wave of microseismic signals has important theoretical significance. Based on the principles of time-frequency analysis and the arrival-time picking

the time-frequency analysis-downhill comparison method is proposed. According to the time-frequency analysis principle of this method

the position and rule of background noise

the frequency

amplitude and energy of microseismic signals before and after the initial arrival of P-wave and S-wave and smooth waveforms that facilitate the comparison of iterative averages can be obtained through spectrogram

power density spectrum and two successive FIR band-pass filters. By setting the mathematical expectation of the full wavelet amplitude as the threshold and iteratively comparing wavelet amplitudes of microseismic signals based on three relationships of power

arrival order and waveform overlap of P-wave and S-wave

the precise arrival time of P-wave and the arrival time of S-wave peak value are obtained. The advantages of this method over the improved STA/LTA method are compared by model tests and have been verified in an engineering example. The results show that: compared with the improved STA/LTA method

this proposed method can simultaneously pick up the precise arrival time of P-wave and the arrival time of S-wave peak value

while the latter can only pick up the accurate arrival time of P-wave. The average time difference and standard deviation of the former are 6.18 ‰ and 3.98 ‰ of the latter

respectively. Additionally

the average calculation time and standard deviation of the former are 43.99% and 10.54% of the latter

respectively. The failure ratio of the former is 0 while that of the latter is 15.63%.