Anisoplanatism effect on the E-ELT SCAO point spread function. A preserved coherent core across the field
Anisoplanatism effect on the E-ELT SCAO point spread function. A preserved coherent core across the field
复制标题
各向异性对 E-ELT SCAO 点扩散函数的影响。
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
F. Vidal
中科院分区：
文献类型：
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作者：
Y. Clénet;E. Gendron;D. Gratadour;G. Rousset;F. Vidal
上下文科学案例研究和未来自适应光学馈入的超大望远镜仪器的优化设计需要精确模拟其自适应光学系统，可能在其整个视场内，无论仪器将配备何种自适应光学风格。目标。模拟了非等晕效应对超大望远镜单共轭自适应光学点扩散函数的影响。我们对相对于o轴距离的校正性能的这种预期降级的兴趣在于点扩展函数Strehl比率和轮廓。方法.考虑到要探索自适应光学尺寸的大参数空间以及给定一组模拟参数的大量自由度，在超大望远镜的规模下进行自适应光学模拟是具有挑战性的。为了解决这个问题，我们已经使用了三个不同的仿真工具，与真实的自适应光学系统相比，具有更高的保真度。第一个是基于解析公式，并允许我们推导出斯特列尔比退化与o轴的距离。第二个是基于傅立叶的代码，并为我们提供了Strehl比和点扩散函数分布在该领域。最后是一个基于图形处理器技术的端到端代码，并提供了Strehl比和点扩散函数的现场剖面图。结果我们使用的三个工具即使在非常大的望远镜规模下也能快速执行。进行了不同代码之间的交叉检查，并证明了结果的一致性。除了自适应光学器件性能随视场角的预期劣化之外，我们还证明了在适用于E-ELT的模拟条件下，即使在大至60弧秒的o轴距离和因此非常低的Strehl比下，单共轭自适应光学器件点扩散函数仍保持具有相干核心的顶部。我们还研究了外尺度对点扩散函数轮廓的影响，证明了即使外尺度大于望远镜直径，上述Airy样图案也是可观察的。结论.这些结果可以推动在一个大的领域的任何公共路径之间的望远镜和仪器的光学质量的保存在单共轭自适应光学模式。这可以使这些在这种自适应光学模式下工作的仪器具有一定的天体测量能力。
Context. The science case studies and the optimized designing of the future adaptive optics-fed extremely large telescope instruments require the precise simulation of their adaptive optics system, potentially over their whole field of view, whatever the adaptive optics flavor the instruments will be equipped with. Aims. We simulate the anisoplanatism e ect on the extremely large telescope single conjugate adaptive optics point spread function. Our interest in this expected degradation of the correction performance with respect to the o -axis distance is in terms of the point spread function Strehl ratio and profile. Methods. Adaptive optics simulations at the scale of extremely large telescopes are challenging given the large parameter space to explore for the adaptive optics dimensioning and the large number of degrees of freedom at play for a given set of simulation parameters. To address this problem, we have used three di erent simulation tools with increasing degree of fidelity compared to a real adaptive optics system. The first is based on analytical formulae and allowed us to derive the Strehl ratio degradation with the o -axis distance. The second is a Fourier-based code and provided us with both the Strehl ratio and the point spread function profile in the field. The last is an end-to-end code based on the graphical processing unit technology and also provided us with the Strehl ratio and the point spread function profile in the field. Results. The three tools we used demonstrated a fast execution time even at the extremely large telescope scale. Cross-checks between the di erent codes were performed and demonstrated the coherency of the results. In addition to the expected degradation of the adaptive optics performance with the field angle, we demonstrated that in the simulation conditions applicable to the E-ELT, the single conjugate adaptive optics point spread function remains topped with a coherent core even at o -axis distances as large as 60 arcsec and consequently very low Strehl ratios. We also studied the impact of the outer scale on the point spread function profile, demonstrating that the aforementioned Airy-like pattern is observable even when the outer scale is larger than the telescope diameter. Conclusions. These results could push for the preservation over a large field of the optical quality of any common path optics between the telescope and the instruments in single conjugate adaptive optics mode. This could o er some astrometric capabilities to these instruments operating in this adaptive optics mode.