Multichannel distance filtering of seismic electric signals

A novel type of distance weighted multichannel filter is used to filter correlated multichannel 1-D seismic electric signals. These signals are weak, short time variations of the geoelectric field occurring prior to an earthquake. The new filters use intersample distances to compute coefficients. Both vector and componentwise correlation is utilised in the computation. The new composite distance filters preserve better, sharp edges and correlated signal features while at the same time possess very good noise suppression properties.