Passive Sensor Imaging Using Cross Correlations of Noisy Signals in a Scattering Medium
Passive Sensor Imaging Using Cross Correlations of Noisy Signals in a Scattering Medium
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DOI：
10.1137/080723454
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发表时间：
2009-04
期刊：
影响因子：
--
通讯作者：
J. Garnier;G. Papanicolaou
中科院分区：
文献类型：
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作者：
J. Garnier;G. Papanicolaou
众所周知，两个无源传感器之间的传播时间甚至完整的绿色函数可以从由环境噪声源产生的记录信号幅度的互相关来估计。还已知的是，来自噪声源的能量通量的方向影响行进时间的估计。使用固定相位法，我们在这里表明，旅行时间可以有效地估计时，射线加入两个传感器继续进入噪声源区域。我们扩展这种分析，以被动传感器成像的反射器与不同的环境噪声源配置适当迁移的互相关。此外，如果在介质中存在多次散射，则可以通过迁移适当的四阶互相关来用无源传感器网络或阵列对反射器成像。四阶互相关也可以与辅助无源传感器一起使用，以便增强散射介质中的传播时间估计。
It is well known that the travel time or even the full Green's function between two passive sensors can be estimated from the cross correlation of recorded signal amplitudes generated by ambient noise sources. It is also known that the direction of the energy flux from the noise sources affects the estimation of the travel time. Using the stationary phase method, we show here that the travel time can be effectively estimated when the ray joining the two sensors continues into the noise source region. We extend this analysis to passive sensor imaging of reflectors with different ambient noise source configurations by suitably migrating the cross correlations. If in addition there is multiple scattering in the medium, then reflectors can be imaged with passive sensor networks or arrays by migrating suitable fourth-order cross correlations. Fourth-order cross correlations can also be used with auxiliary passive sensors in order to enhance travel time estimation in a scattering medium.