Timing alignment method for data acquired by monitoring units of borehole-surface micro-seismic monitoring system

A timing alignment method for data acquired by monitoring units of a borehole-surface micro-seismic monitoring system, comprising the following steps:

• (1) extracting a first rock-burst waveform data segment and a second rock-burst waveform data segment that are respectively acquired by a surface wireless monitoring unit and an underground wired monitoring unit of the borehole-surface micro-seismic monitoring system and each provided with multiple global positioning system (GPS) timestamps, wherein the first rock-burst waveform data segment and the second rock-burst waveform data segment have different lengths;
• (2) calculating a time difference and a number of sampling points between each pair of adjacent GPS timestamps in each of the first rock-burst waveform data segment and the second rock-burst waveform data segment;
• and adding, on an equal-interval basis, a sampling time to a sampling point missing a timestamp between each pair of adjacent GPS timestamps;
• (3) calculating an average sampling frequency of each of the first rock-burst waveform data segment and the second rock-burst waveform data segment;
• and adding, on an equal-interval basis, a sampling time to a sampling point missing a timestamp except first and last GPS timestamps in each of the first rock-burst waveform data segment and the second rock-burst waveform data segment;
• (4) resampling sampling times of all sampling points obtained in steps (2) and (3), according to a uniform sampling frequency;
• and
• (5) calculating, based on the sampling times of all of the sampling points obtained in steps (2) and (3) and rock-burst waveform data segments at the sampling times, a rock-burst waveform data segment at a new sampling time according to step (4) with a linear interpolation formula;
• and aligning the sampling times of the first rock-burst waveform data segment and the second rock-burst waveform data segment.