Determination of noise spectra from strong motion data recorded in Greece

A large number of strong ground motions in Greece have been recorded by analog accelerographs. The processing of analog strong motion recordings and conversion to a digital form introduces noise in the signal, due to the digitization and processing which significantly affects the record. In the present paper a unified processing and determination of digitization and processing noise for the Greek strong motion records is presented. Moreover, appropriate relations are proposed for the lower cut-off frequency with respect to the epicentral distance and earthquake magnitude for record filtering.