Application of Regional Arrays in Seismic Verification Research

The paper gives an account of the work related to the development of the NORESS concept of a regional array. The array design considerations and objectives are reviewed, and a description is given of the NORESS and ARCESS array facilities in Norway with their field installations, data transmission lines and data receiving center functions. The automatic signal detection processing of NORESS data applies multiple narrow-band frequency filters in parallel and forms array beams from selected subgeometries. The detection algorithm is based on computing the STA/LTA ratio for each beam individually, and a detection is declared whenever this ratio exceeds and given threshold. It is explained how the beam deployment and the individual threshold values can be tuned to ensure that the interesting phase arrivals are not missed, but at the same time avoiding coda detections.