基于Σ-Δ的地震采集系统前置放大器探讨
|
摘要
作为石油勘探中使用的地震数据采集系统,目前主要采用Σ-Δ技术完成A/D转换。而其在整个电压范围内,依线性要求,地震数据采集中的时域起始段大信号与时域后段反射层的小信号,共用同一增益的前置信号放大器,因前置放大器对大信号不能过载,限制了小信号在前端采集时的放大处理。为了更好地在小信号放大上发挥Σ-ΔA/D转换器的强噪声抑制能力、良好的24位处理能力,通过信号分析,提出采用非线性前置放大器的方法,对大、小信号的增益分别处理,并完成了相应的仿真设计。
Σ-Δ technology is normally adopted for A/D conversion who as the seismic data acquisition systems used in oil exploration.For the entire working voltage coverage of the A/D conversion,a common pre-amplifier with the same gain is shared with time-domain large-signals in the initial segment of seismic data acquisition,and small-signals from the rear section of time-domain reflecting layer depending on its linearity requirements.The amplification of small signals during the front-end data acquisition could be limited accordingly due to the consideration that the pre-amplifier should avoid being over-loaded by the large-signals.An approach to the non-linear pre-amplifier for seismic data acquisition systems by means of signal analysis is proposed,in order to improve the performance for small-signal amplification,taking better advantage of the strong noise suppression and excellent 24 b processing capability of the Σ-Δ technology-based A/D converters.Methods to handle gains for both large and small-signals are discussed respectively,the corresponding simulation results are provided as well.
Σ-Δ technology is normally adopted for A/D conversion who as the seismic data acquisition systems used in oil exploration.For the entire working voltage coverage of the A/D conversion,a common pre-amplifier with the same gain is shared with time-domain large-signals in the initial segment of seismic data acquisition,and small-signals from the rear section of time-domain reflecting layer depending on its linearity requirements.The amplification of small signals during the front-end data acquisition could be limited accordingly due to the consideration that the pre-amplifier should avoid being over-loaded by the large-signals.An approach to the non-linear pre-amplifier for seismic data acquisition systems by means of signal analysis is proposed,in order to improve the performance for small-signal amplification,taking better advantage of the strong noise suppression and excellent 24 b processing capability of the Σ-Δ technology-based A/D converters.Methods to handle gains for both large and small-signals are discussed respectively,the corresponding simulation results are provided as well.
引文
[1]李庆忠.走向精确勘探的道路[M].北京:石油工业出版社,1993.
[2]韩世勤,喻成.利用小波变换识别油、气、水分界面[J].工程数学学报,2001,18(Z1):93-98.
[3]袁子龙,韦丹宁,李婷婷.高分辨率地震勘探智能程控型前置放大器的设计[J].地球物理学进展,2006,21(1):61-63.
[4]CAST.工业应用Sigma-Delta ADC常见问题解答[M].An-alog Devices Inc.,2007.
[5][美]韦特J V.运算放大器原理与应用导论[M].沈承杭,译.北京:人民邮电出版社,1980.
[6]National Semiconductor.DAC0808 8 B D/Aconverter[M].[S.l.]:National Semiconductor,1999.
[7]张靖武,周灵彬.单片机系统的Proteus设计与仿真[M].北京:电子工业出版社,2007.
[8]Atmel Corporation.AT89 series hardware description[M].[S.l.]:Atmel Corporation,1997.
[9][德]梯策U,胜克CH.高级电子电路[M].王祥贵,周旋,译.北京:人民邮电出版社,1984.
[10]CHUI C K.Anintroduction to wavelets[M].New York:Academic Press,1992.
[2]韩世勤,喻成.利用小波变换识别油、气、水分界面[J].工程数学学报,2001,18(Z1):93-98.
[3]袁子龙,韦丹宁,李婷婷.高分辨率地震勘探智能程控型前置放大器的设计[J].地球物理学进展,2006,21(1):61-63.
[4]CAST.工业应用Sigma-Delta ADC常见问题解答[M].An-alog Devices Inc.,2007.
[5][美]韦特J V.运算放大器原理与应用导论[M].沈承杭,译.北京:人民邮电出版社,1980.
[6]National Semiconductor.DAC0808 8 B D/Aconverter[M].[S.l.]:National Semiconductor,1999.
[7]张靖武,周灵彬.单片机系统的Proteus设计与仿真[M].北京:电子工业出版社,2007.
[8]Atmel Corporation.AT89 series hardware description[M].[S.l.]:Atmel Corporation,1997.
[9][德]梯策U,胜克CH.高级电子电路[M].王祥贵,周旋,译.北京:人民邮电出版社,1984.
[10]CHUI C K.Anintroduction to wavelets[M].New York:Academic Press,1992.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心