Status and new developments with the Keck I near-infrared tip-tilt sensor
Status and new developments with the Keck I near-infrared tip-tilt sensor
复制标题
Keck I 近红外倾斜传感器的现状和新发展
DOI：
--
复制
发表时间：
2016
期刊：
影响因子：
--
通讯作者：
M. V. van Dam
中科院分区：
文献类型：
--
作者：
B. Femenía Castellá;P. Wizinowich;R. Rampy;S. Cetre;S. Lilley;J. Lyke;S. Ragland;P. Stomski;M. V. van Dam
激光导星（LGS）自适应光学（AO）系统的天空覆盖和性能受到用于低阶校正（倾斜和离焦模式）的自然导星（NGS）的限制。这一限制可以通过测量NGS在近红外波段的图像运动来减少，在近红外波段，LGS AO系统对其进行了部分校正，而在近红外波段，恒星通常比可见光波段亮几个等。我们将一个近红外倾斜传感器（NIRTTS）与Keck I望远镜LGS AO系统集成在一起。传感器是一个基于h2rg的近红外相机，像素为0.05角秒。高采样率下的低噪声是通过仅读取一小块感兴趣的区域来实现的，从2x2到16x16像素，以NGS为中心，在直径100弧秒的任何地方。该传感器使用位于OSIRIS积分场光谱仪前面的二向色分束器反射的光在Ks或h波段工作。NIRTTS的实施涉及对AO工作台、实时控制系统、高级控制和操作软件的修改。NIRTTS已基本准备好以分担风险的方式进行科学操作。我们还对NIRTTS系统进行了一些改进，其中包括对操作软件进行重大更改。这项工作介绍了自参考文献1和参考文献2报道NIRTTS系统以来所进行的工作的更新。
The sky coverage and performance of Laser Guide Star (LGS) adaptive optics (AO) systems is limited by the Natural Guide Star (NGS) used for low order correction (tip-tilt and defocus modes). This limitation can be reduced by measuring image motion of the NGS in the near-infrared where it is partially corrected by the LGS AO system and where stars are generally several magnitudes brighter than at visible wavelengths. We have integrated a Near-InfraRed Tip-Tilt Sensor (NIRTTS) with the Keck I telescopes LGS AO system. The sensor is a H2RG-based near-infrared camera with 0.05 arcsecond pixels. Low noise at high sample rates is achieved by only reading a small region of interest, from 2x2 to 16x16 pixels, centered on an NGS anywhere in an 100 arc second diameter field. The sensor operates at either Ks or H-band using light reflected by a choice of dichroic beam-splitters located in front of the OSIRIS integral field spectrograph. The implementation of the NIRTTS involved modifications to the AO bench, real-time control system, higher-level controls and operations software. NIRTTS is nearly ready for science operation in shared-risk mode. We are also implementing a number of enhancements to the NIRTTS system which involve substantial changes to the operations software. This work presents an update of the work performed since the NIRTTS system was reported in Ref. 1 and Ref. 2.