Application of array data processing techniques to a network of ordinary seismograph stations

Summary Array data processing techniques, which are based upon signal similarity between the stations, offer important tools in seismic signal analysis.P waves recorded in the Fennoscandian network in general exhibit the signal resemblance required for applying array processing methods. The largest station separation in this network is about 1800 km, and the site structures range from sedimentary rocks in Denmark to the homogeneous crust of the Baltic shield. Inother words, we can consider the Fennoscandian station network as a super-large aperture seismic array (SLASA). An analysis of the background noise shows that application of even very simple processing techniques results in very effective noise suppression.A general adaptation of array processing techniques to ordinary seismograph stations is considered possible. Such methods will greatly improve our ability to extract reliable information from ordinary seismograms. Although theC-D (compression-dilatation) readings are usually correct, they often do not refer to the very first signal onset. Records of nuclear explosions from stations all over the world exhibit a high degree of signal similarity.