Hagfors seismic array performance analysis

The Hagfors seismic array was modernized during the summer of 2001. New subsurface vaults, cables and instruments were installed and the array was operational on April 5, 2002. During the period 5/4-2002 to 21/9-2003 the old and new Hagfors arrays operated in parallel. Here we report on a variety of measurements and parameters related to the operation and performance of the two arrays. Included is array configuration details, instrument and array noise studies and array gain and response calculations. Using NORSAR´s single array processing we have compared the performance of the two arrays on a regional scale. We have also studied the results of the two array´s participation in the CTBTO IDC processing on a global scale.