A New Method for Band-limited Imaging with Undersampled Detectors
A New Method for Band-limited Imaging with Undersampled Detectors
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DOI：
10.1086/659313
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发表时间：
2011-02
影响因子：
3.5
通讯作者：
A. Fruchter
中科院分区：
文献类型：
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作者：
A. Fruchter
自从最初在哈勃深空上使用以来，“毛毛雨”已经成为哈勃太空望远镜拍摄的图像组合的事实标准。然而，Drizzle算法是针对小的、微弱的、部分分辨的源开发的，对于高信噪比的未分辨物体来说，它不是最好的算法。在这里，提出了一种新的方法，用于从欠采样数据创建带限图像。该方法使用毛毛雨图像作为一阶近似，然后迅速收敛到适合数据的带限图像，给出毛毛雨图像提供的统计加权。该方法名为iDrizzle，用于迭代Drizzle，有效地消除了小的高频伪影和卷积与插值核，可以引入毛毛雨。该方法在存在几何失真的情况下工作良好，并且可以轻松地处理宇宙射线，坏像素或其他丢失的数据。它可以联合收割机结合随机抖动拍摄的图像，尽管获得良好的最终图像所需的抖动数量部分取决于抖动位置的质量。iDrizzle可能被证明最有利于从欠采样图像中产生高保真点扩散函数，并且可能对未来的暗能量任务特别有价值，例如宽视场红外巡天望远镜和欧几里得，它们可能会尝试使用欠采样探测器进行高精度超新星测光和透镜实验。
Since its original use on the Hubble Deep Field, “Drizzle” has become a de facto standard for the combination of images taken by the Hubble Space Telescope. However, the Drizzle algorithm was developed with small, faint, partially resolved sources in mind and is not the best possible algorithm for unresolved objects with high signal-to-noise ratios. Here, a new method for creating band-limited images from undersampled data is presented. The method uses a drizzled image as a first-order approximation and then rapidly converges toward a band-limited image that fits the data, given the statistical weighting provided by the drizzled image. The method, named iDrizzle, for iterative Drizzle, effectively eliminates both the small high-frequency artifacts and convolution with an interpolant kernel that can be introduced by drizzling. The method works well in the presence of geometric distortion and can easily handle cosmic rays, bad pixels, or other missing data. It can combine images taken with random dithers, though the number of dithers required to obtain a good final image depends, in part, on the quality of the dither placements. iDrizzle may prove most beneficial for producing high-fidelity point-spread functions from undersampled images and could be particularly valuable for future dark energy missions such as Wide-Field Infrared Survey Telescope and Euclid, which will likely attempt to do high-precision supernova photometry and lensing experiments with undersampled detectors.