项目名称: 宽动态地震数据采集方法和技术研究
项目编号: No.41304142
项目类型: 青年科学基金项目
立项/批准年度: 2014
项目学科: 天文学、地球科学
项目作者: 胡星星
作者单位: 中国地震局地球物理研究所
项目金额: 25万元
中文摘要: 地震数据采集系统是地震信号数字化必不可少的环节,其性能优劣直接关系到最终获得地震信号的质量,并最终影响数据处理结果。地震信号的幅度跨度很大,要观测的信号动态范围甚至达到了160dB以上,宽频带地震计的输出也达到了150dB以上。而目前普遍使用的基于ΣΔAD转换的24位采集器动态范围仅为130dB左右,导致数据采集器在记录地震时对微小信号分辨率不够,而在大地震时又容易使数据采集器出现限幅现象。本项目根据在实际应用中要提高小信号的信噪比需要采集器有更高的分辨率、而对大信号要求采集器能够容许大幅度的信号输入而不出现限幅的使用要求,提出一种按输入信号幅度实行分级采集以提高采集器动态范围的方法:小信号用较高级分辨率采集,大信号用较低级分辨率采集。并研制样机,使其动态范围达到150dB以上。
中文关键词: 地震数据采集器;限幅;宽动态范围;多AD转换;高精度
英文摘要: Seismic data acquisition system is an indispensable step for seismic signal digitizing. Its performance is directly related to the final seismic signal, and ultimately affect the results of the data processing. The amplitude of seismic signal is great span, the dynamic range even reached more than 160dB, and the output signal of broadband seismometer is greater than 150dB too. Yet the dynamic range of currently used 24-bits DAS based on Σ-ΔA/D converter is only about 130dB, this result to that small seismic signal can't be recorded as well as the amplitude of a huge seismic event wave would be limited. So this program make the study on give a method of acquisition wide dynamic range seismic signal, and develop a data acquisition system prototype that dynamic range greater than 150dB.
英文关键词: seismic data acquisition;amplitude-limitation;wide dynamic range;multi-ADC;high resolution