Geodesy and Geodynamics (Feb 2011)
Baseline correction for digital strong-motion records by using the pre-event portion
Abstract
Baseline offset in digital strong-motion acceleration record and initial velocity can produce unrealistic results for ground velocity and displacement derived from the acceleration by integration. A new method is proposed for the baseline correction and initial velocity calculation. It is based on linear least-squares fitting of the pre-event portion of velocity derived from the uncorrected acceleration data. Compared with the conventional method, which is based on removing the mean values of the pre-event portions of the acceleration and velocity traces, this method has clearer physical meaning and better stability.
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