Madlazim, Tjipto Prastowo, Supriyanto Rohadi, Thomas Hardy
The purposes of this research is to improve Indonesia Tsunami Early Warning System (InaTews), especially to improve result of automatic computation of P wave dominant period by applying filter-M to ignore noises signal. To reduce the effect of noise and signal defect on the calculation of the P wave dominant period automatically, this study used M-filter. The M-filter used the concept that the dominant period for small and moderate earthquakes is unlikely to exceed twice the maximum dominant period of the great earthquake. The automatic computation of P wave dominant period uses direct method, where the calculation uses time equation (τc) directly applied to seismogram, without inversion so that calculation process becomes faster. Mfilter has been developed and used to filter out defective and high-null seismogram signals, so the seismogram is not used for the average computation of the P wave dominant period. © 2018 - Tsunami Society International.
Physics Department, Universitas Negeri Surabaya (Unesa), Indonesia; Indonesian Agency for Meteorology, Climatology, and Geophysics (BMKG), Indonesia
