Research on Interference Signal Recognition in P Wave Pickup and Magnitude Estimation

In order to analyze the ability of STA/LTA, AIC, STA/LTA + AIC, and W-AIC methods to recognize interference signals during P wave pickup, we selected a large number of KiK-Net records for P wave arrival time recognition. The results indicate that a single method has limited recognition ability for interference signals. The STA/LTA combined with AIC method adds limiting conditions at the trigger point, achieving recognition accuracy of 93.0% and 91.7% for spike signals and drift signals. This method has good stability and accuracy for picking up P wave arrival. For regular interference signals, the accuracy of picking up after wavelet decomposition and reconstruction reaches 87.8%. In order to more accurately identify interference signals and improve pickup accuracy, different methods can be combined. On the other hand, there is a linear relationship between the amplitude and magnitude of the P band Fourier spectrum. The variances for P waves in the first 5 s in calculating earthquake magnitudes are 0.602, 0.462, and 0.423 for acceleration, velocity, and displacement, respectively. The results can provide reference for earthquake early warning algorithms based on artificial intelligence technology.