地震观测传递函数的精度问题

Precision problem of transfer function in earthquake observation

数字地震观测的传递函数由反馈地震计和地震数据采集器的传递函数合成。地震数据采集器的传递函数主要用数字算法生成,其精度可以做得很高。反馈地震计是机电一体化的模拟传感部件,其传递函数的精度和稳定性均欠佳。尤其是由反馈地震计生成的主导二阶极点,对应传统地震观测的周期和阻尼两个重要参数,其精度和稳定性往往较低,不利于地震学研究深入发展的需要。以四川地震观测的标定数据为例,说明数字地震观测传递函数的精度和稳定性急待改进。

The transfer function of digital earthquake observation is composed of the transfer function of feedback seismometer and earthquake data aequisition system. The transfer function of earthquake data acquisition system is mainly designed by digital means, so the precision can be made higher. However, the feedback seismorneter is an analogous sensor with mechatronics, both of precision and stability of the transfer function are not good enough. In particular, the dominant seeond-order poles from feedback seismometer, which corresponds to the period and damp in traditional earthquake observation with lower precision and stability, that can not meet the needs of seismology study. The ease of calibration data from Siehuan earth-quake network shows that the preeision and stability of the transfer funetion of digital earth-quake observation are urgent to be improved.