Quoting from http://alomax.free.fr/FilterPicker/
FilterPicker (Lomax et al., 2011) is a general purpose, broad-band, phase detector and picker which is applicable to real-time seismic monitoring and earthquake early-warning. FP uses an efficient algorithm which operates stably on continuous, real-time, broadband signals, avoids excessive picking during large events, and produces onset timing, realistic timing uncertainty, onset polarity and amplitude information. In practice, it operates on a pre-defined number of frequency bands by generating a set of band-passed time-series with different center frequencies. Characteristic functions are determined for each frequency band and a pick is declared if and when, within a window of predefined time width, the integral of the maximum of the characteristic functions exceeds a pre-defined threshold.
Lomax, A., C. Satriano and M. Vassallo (2012), Automatic picker developments and optimization: FilterPicker - a robust, broadband picker for real-time seismic monitoring and earthquake early-warning, Seism. Res. Lett. , 83, 531-540, doi: 10.1785/gssrl.83.3.531.
Vassallo, M., C. Satriano and A. Lomax, (2012), Automatic picker developments and optimization: A strategy for improving the performances of automatic phase pickers, Seism. Res. Lett. , 83, 541-554, doi: 10.1785/gssrl.83.3.541.
Yavor Kamer (2020). FilterPicker: a robust, broadband phase detector and picker (https://www.mathworks.com/matlabcentral/fileexchange/69211-filterpicker-a-robust-broadband-phase-detector-and-picker), MATLAB Central File Exchange. Retrieved .