High-efficiency lucky imaging
High-efficiency lucky imaging
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DOI：
10.1093/mnras/stt507
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发表时间：
2013-03
影响因子：
4.8
通讯作者：
C. Mackay
中科院分区：
文献类型：
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作者：
C. Mackay
幸运成像现在是一种成熟的观测程序，可以在直径2.5米的地面望远镜上提供近衍射限制的可见光图像。结合低阶自适应光学，它可以提供比哈勃太空望远镜好几倍的分辨率。许多图像是在高速下拍摄的，因为大气湍流的影响在这些短时间尺度上是静态的。选择最清晰的图像，进行移位和添加，以获得比地面长时间曝光观测通常可能获得的更高分辨率。这种方法的效率相对较低，因为相当一部分帧由于质量相对较差而被丢弃。本文提出了一种基于傅里叶空间选择的幸运图像处理方法，可以显著提高图像的选择率。结果表明，无论是传统的幸运成像方法还是新的幸运傅里叶方法，都可以常规地获得具有大等平面斑块尺寸的高分辨率图像。本文还介绍了提高该方法对暗参星灵敏度的其他方法。
Lucky imaging is now an established observing procedure that delivers near-diffraction-limited images in the visible on ground-based telescopes up to similar to 2.5 m in diameter. Combined with low-order adaptive optics it can deliver a resolution several times better than that of the Hubble Space Telescope. Many images are taken at high speed as atmospheric turbulent effects appear static on these short time-scales. The sharpest images are selected, shifted and added to give a much higher resolution than is normally possible in ground-based long exposure time observations. The method is relatively inefficient as a significant fraction of the frames are discarded because of their relatively poor quality. This paper shows that a new lucky imaging processing method involving selection in Fourier space can substantially improve the selection percentages. The results show that high-resolution images with a large isoplanatic patch size may be obtained routinely both with conventional lucky imaging and with the new lucky Fourier method. Other methods of improving the sensitivity of the method to faint reference stars are also described.