DO-CRIME: Dynamic On-sky Covariance Random Interaction Matrix Evaluation, a novel method for calibrating adaptive optics systems
DO-CRIME: Dynamic On-sky Covariance Random Interaction Matrix Evaluation, a novel method for calibrating adaptive optics systems
复制标题
DO-CRIME：动态空中协方差随机交互矩阵评估，一种校准自适应光学系统的新颖方法
DOI：
10.1093/mnras/staa3874
复制
发表时间：
2020
影响因子：
4.8
通讯作者：
M. Carbillet
中科院分区：
文献类型：
--
作者：
O. Lai;M. Chun;Ryan Dungee;Jessica R. Lu;M. Carbillet
自适应光学系统需要校准程序来操作，无论是在闭环中还是更重要的是在前向控制中。这种校准通常采取相互作用矩阵的形式，并且是波前传感器对波前校正器刺激的响应的量度。如果该矩阵被充分良好地调节，则可以对其求逆以产生控制矩阵，该控制矩阵允许计算最优命令以应用于给定波前传感器测量矢量的波前校正器。相互作用矩阵通常通过自适应光学系统的入口焦点处的人工源来测量;然而，卡塞格伦望远镜上的自适应二次镜不提供这样的焦点，并且它们的相互作用矩阵的测量变得更具挑战性，并且需要使用天然星星在天空中完成。最常见的方法是生成理论或模拟的相互作用矩阵，并使用天空测量值对其进行参数化调整（例如，偏心，放大，旋转）。我们提出了一种新的方法，测量在天空中的相互作用矩阵从头开始从遥测流的AO系统使用随机图案的变形镜与对角命令协方差矩阵。该方法，正在开发的UH2.2米望远镜项目的imaka宽视场AO系统的自适应次镜升级，工作在天空中使用目前的imaka试验台。
Adaptive optics systems require a calibration procedure to operate, whether in closed loop or even more importantly in forward control. This calibration usually takes the form of an interaction matrix and is a measure of the response on the wavefront sensor to wavefront corrector stimulus. If this matrix is sufficiently well conditioned, it can be inverted to produce a control matrix, which allows to compute the optimal commands to apply to the wavefront corrector for a given wavefront sensor measurement vector. Interaction matrices are usually measured by means of an artificial source at the entrance focus of the adaptive optics system; however, adaptive secondary mirrors on Cassegrain telescopes offer no such focus and the measurement of their interaction matrices becomes more challenging and needs to be done on-sky using a natural star. The most common method is to generate a theoretical or simulated interaction matrix and adjust it parametrically (for example, decenter, magnification, rotation) using on-sky measurements. We propose a novel method of measuring on-sky interaction matrices ab initio from the telemetry stream of the AO system using random patterns on the deformable mirror with diagonal commands covariance matrices. The approach, being developed for the adaptive secondary mirror upgrade for the imaka wide-field AO system on the UH2.2m telescope project, is shown to work on-sky using the current imaka testbed.