论文标题
带有太阳引力镜头的图像恢复
Image recovery with the solar gravitational lens
论文作者
论文摘要
我们报告使用图像卷积/反卷积的计算机代码获得的初始结果,并用于研究太阳能透镜(SGL)的图像形成能力。尽管球形太阳的SGL产生了极大的模糊图像,但对SGL的点传播功能(PSF)的知识使得可以重建原始图像并通过反卷积的方式消除模糊。我们讨论了反卷积过程,该过程可以通过直接矩阵反转或傅立叶商方法实现。我们观察到,与收集模糊图像数据的SNR相比,该过程以降低恢复图像的信噪比(SNR)的形式引入了``惩罚''。我们使用分析方法估计了这种惩罚的大小,并通过一系列数值模拟确认结果。我们发现,与望远镜光圈相比,当图像样品之间的间距很大时,罚款大大降低。可以通过合适的噪声过滤进一步减少惩罚,这可以产生$ {\ cal o}(10)$或更好的改进,以改善低质量成像数据。我们的结果证实,可以将SGL用于成像目的。我们提供有关数据收集和图像处理策略的见解,这些策略可以在图像数据收集时间内产生与现实空间任务持续时间一致的图像数据收集时间内的系外行星的详细图像。
We report on the initial results obtained with an image convolution/deconvolution computer code that we developed and used to study the image formation capabilities of the solar gravitational lens (SGL). Although the SGL of a spherical Sun creates a greatly blurred image, knowledge of the SGL's point-spread function (PSF) makes it possible to reconstruct the original image and remove the blur by way of deconvolution. We discuss the deconvolution process, which can be implemented either with direct matrix inversion or with the Fourier quotient method. We observe that the process introduces a ``penalty'' in the form of a reduction in the signal-to-noise ratio (SNR) of a recovered image, compared to the SNR at which the blurred image data is collected. We estimate the magnitude of this penalty using an analytical approach and confirm the results with a series of numerical simulations. We find that the penalty is substantially reduced when the spacing between image samples is large compared to the telescope aperture. The penalty can be further reduced with suitable noise filtering, which can yield ${\cal O}(10)$ or better improvement for low-quality imaging data. Our results confirm that it is possible to use the SGL for imaging purposes. We offer insights on the data collection and image processing strategies that could yield a detailed image of an exoplanet within image data collection times that are consistent with the duration of a realistic space mission.