High dynamic range imaging with a single-mode pupil remapping system: a self-calibration algorithm for redundant interferometric arrays
High dynamic range imaging with a single-mode pupil remapping system: a self-calibration algorithm for redundant interferometric arrays
复制标题
使用单模光瞳重映射系统的高动态范围成像：冗余干涉阵列的自校准算法
DOI：
10.1111/j.1365-2966.2006.11198.x
复制
发表时间：
2006
影响因子：
4.8
通讯作者：
Guy Perrin
中科院分区：
文献类型：
--
作者：
Sylvestre Lacour;Éric Thiébaut;Guy Perrin
光瞳面位相波纹的校正是实现大动态范围成像的一个基本问题。在本文中，我们研究了一种仪器装置，它包括在单个望远镜上应用干涉技术，通过用一组单模光纤对光瞳进行滤波和分割。我们开发了一种新的算法，利用我们拥有冗余干涉阵列的事实，完全将天文对象从大气扰动(相位和闪烁)中分离出来。这种自校准算法也可以应用于任何稀释或无冗余的干涉装置。在波长为630 nm的8米望远镜上，我们的模拟表明，单模光瞳重新映射系统可以在中央恒星的几个分辨率元素上获得高达106的原始动态范围，这取决于光源的亮度。自校准算法被证明是非常有效的，即使各个空间频率的信噪比为0.1量级，也可以重建微弱的源(震级=15)的图像。最后，我们注意到，通过将这种设置与自适应光学系统相结合，该仪器可以更灵敏。然而，动态范围将受到可变形反射镜的小的高频位移的噪声的限制。
The correction of the influence of phase corrugation in the pupil plane is a fundamental issue in achieving high dynamic range imaging. In this paper, we investigate an instrumental set-up which consists of applying interferometric techniques on a single telescope, by filtering and dividing the pupil with an array of single-mode fibres. We developed a new algorithm, which makes use of the fact that we have a redundant interferometric array, to completely disentangle the astronomical object from the atmospheric perturbations (phase and scintillation). This self-calibrating algorithm can also be applied to any - diluted or not - redundant interferometric set-up. On an 8-m telescope observing at a wavelength of 630 nm, our simulations show that a single-mode pupil remapping system could achieve, at a few resolution elements from the central star, a raw dynamic range up to 10 6 , depending on the brightness of the source. The self-calibration algorithm proved to be very efficient, allowing image reconstruction of faint sources (magnitude = 15) even though the signal-to-noise ratios of individual spatial frequencies are of the order of 0.1. We finally note that the instrument could be more sensitive by combining this set-up with an adaptive optics system. The dynamic range would however be limited by the noise of the small, high-frequency displacements of the deformable mirror.