Liu Xuyan 1) ;Huang Shengming 1) ;Liang Quanqiang 2) ;Ji Yingfeng 1,3) ; and Wang Xu 1)
1)Earthquake Administration of Fujian Province,Fuzhou 3500032)Xianmen Research Centre of Earthquake Surveging,Xiamen 3610213)Faculty of Science,Kobe University,Rokkotaimachi 1-1,Nade,Kobe,Japan,Postcode 657-8501
Abstract On the basis of describing the concept of an observation system’s fidelity, it takes a close look on the principle about why the observational system which meets the requirement of fidelity is sure to be an invariable linear system and points out that for an observation system the response function of unit pulse time as well as the transfer function area irrelevant with the quantity and quality of the input. These functions are capable of totally representing the characteristics of the observation system. Besides, by studying the weight coefficient of observation system from the timedomain and frequencydomain along with the characteristics of transfer function, it concludes that a physically realizable observation system for sure will fail to be an ideal linear timeinvariant system. Nevertheless, given an appointed transmissional band and a certain requirement for precision, the transfer function curves will turn similarly into a level line with a phase lag approximately to zero or directly related to the frequency, which can largely meet the demands observation. Finally, it discusses the scale unit and its calibration of observation system, by analyzing a example of horizontal pendulum that derives a theoretical scale unit from the dynamic constantcoefficient linear differential equations, to demonstrate that an excellent observation system should not only has a manual method for scale unit calibration, but also a theoretical formula for the scale unit deriving and it is dependable in any reliability examinations of whatever observation data.
