应用于稀疏孔径的滤波切趾相位差异法的研究

Study of Filter-Apodization Phase Diversity Applied in Sparse Aperture

采用相位差异法应用于稀疏孔径系统的波前相位传感,对图像噪声引起的波前相位估计的准确性下降以及迭代时间较长等进行研究。采用二阶巴特沃斯低通滤波器对退化图像进行降噪处理,同时对滤波后的图像频谱和光学传递函数应用切趾法截取高信噪比的低频区域和与之相应的光学传递函数作为约束条件,推导了滤波切趾处理后的相位差异法目标函数的表达式。仿真结果表明,所提出的方法在不同强度噪声情况下,都能有效地降低噪声影响提高相位估计精度,同时缩减算法迭代时间。

Phase diversity is applied in the sensing of sparse-aperture systems. The accuracy of the wavefront phase estimation and the iteration time are researched by the image noise. The noise reduction is processing for the noise degradation images by the second order butterworth low-pass filter. Meanwhile the image spectrum by filtering and the optical transfer function are being as constraint with apodization to obtain the low frequency area of high signal- to-noise ratio, and take the corresponding optical transfer function. The improvement of the object function for the phase diversity is derived after filtering by apodization. Digital simulation indicates that under the condition of different noise intensities, the proposed method can reduce the noise effectively and improve the phase estimation precision, the algorithm iteration time can be reduced simultaneously.