论文标题
全球和局部优化宽带源的界限
Global, and Local Optimization Beamforming for Broadband Sources
论文作者
论文摘要
本文提出了针对声学宽带源量身定制的全球优化（GO）波束形成的替代能量函数。鉴于，诸如源位置，多极旋转或流动条件之类的属性在频率上被参数化，可以一次对所有频率执行CSM拟合。数值分析表明，标准GO问题的非线性能量函数等于源点扩展函数（PSF），并在光栅和侧叶位置包含局部最小值。随着拟议的宽带能量的平均，能量函数通过提出的宽带能量得到改善。此外，它简化了从结果中识别来源并重建光谱的过程。该论文表明，与标准GO和清洁-SC相比，该方法在合成单翼型上是优越的。对于实际数据，所提出的方法和Clean-SC的结果相似，并且超过标准的GO。主要区别在于，来源假设违规会导致清洁SC的嘈杂图，并对所提出的方法引起错误的光谱估计。通过使用合理的初始值，GO问题将减少到具有相似结果的局部优化问题。此外，所提出的方法能够鉴定具有不同极振幅和未知极旋转的合成多物。
This paper presents an alternative energy function for Global Optimization (GO) beamforming, tailored to acoustic broadband sources. Given, that properties such as the source location, multipole rotation, or flow conditions are parameterized over the frequency, a CSM-fitting can be performed for all frequencies at once. A numerical analysis shows that the nonlinear energy function for the standard GO problem is equivalent to the source's Point Spread Function (PSF) and contains local minima at the grating- and side lobes' locations. The energy function is improved with the proposed broadband energy, as it averages the PSF. Further, it simplifies the process of identifying sources and reconstructing their spectra from the results. The paper shows that the method is superior on synthetic monopoles compared to standard GO and CLEAN-SC. For real-world data the results of the proposed method and CLEAN-SC are similar, and outperform standard GO. The main difference is that source assumption violations cause noisy maps for CLEAN-SC and cause wrong spectral estimations of the proposed method. By using reasonable initial values, the GO problem reduces to a Local Optimization problem with similar results. Further, the proposed method is able to identify synthetic multipoles with different pole amplitudes and unknown pole rotations.
