A method for calculating the transfer function of digital seismograph system

3 Conclusions The given method in the present paper can obtain the transfer function of the digital seismograph system more conveniently, which is very simple, accurate and has a clear physical meaning. It can emulate the recordings of ground movement displacement and speed for different seismometers of DD-1 and DK-1, correctly measure the magnitude and perform fast great earthquake report. Meanwhile, the data of ground movement displacement and speed after the instrument effects are removed can be provided for the further studies on earth media and source physics of earthquake. Actually, the transfer function of seismometer system can be directly obtained by the method in the paper from the output of data acquisition system, if we can produce a simple equipment that makes the seismometer generate a fast displacement of ground movement without the calibration by current and coils. This can avoid the influences caused by the variations in the parameters of seismometer. Foundation item: Natural Science Fund of Yunnan Province (2001 D0080M)