Efficient implementation of pseudo open-loop control for adaptive optics on Extremely Large Telescopes
Efficient implementation of pseudo open-loop control for adaptive optics on Extremely Large Telescopes
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DOI：
10.1093/mnras/stz918
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发表时间：
2019-03
影响因子：
4.8
通讯作者：
A. Basden;D. Jenkins;T. J. Morris;J. Osborn;M. Townson
中科院分区：
文献类型：
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作者：
A. Basden;D. Jenkins;T. J. Morris;J. Osborn;M. Townson
采用最小均方误差波前重构的闭环自适应光学系统需要计算伪开环波前斜率。这些技术结合了大气统计知识，因此必须在波前斜率测量中表示。这些伪开环斜率是由测量的残余斜率和变形镜为平面时给出的重建斜率的总和计算得来的，通常涉及到前一个时间步长的相互作用矩阵与执行器需求的乘法。当使用密集代数时，这种乘法对于超大望远镜来说计算成本很高，需要很大的内存带宽。在这里，我们展示了这种需求可以显著减少，保持数学正确性并显著降低系统复杂性。因此，这降低了这些系统的成本，并提高了鲁棒性和可靠性。
Closed-loop adaptive optics systems which use minimum mean square error wavefront reconstruction require the computation of pseudo open loop wavefront slopes. These techniques incorporate a knowledge of atmospheric statistics which must therefore be represented within the wavefront slope measurements. These pseudo open loop slopes are computed from the sum of the measured residual slopes and the reconstructed slopes that would be given if the deformable mirror was flat, generally involving the multiplication of an interaction matrix with actuator demands from the previous time-step. When using dense algebra, this multiplication is computationally expensive for Extremely Large Telescopes, requiring a large memory bandwidth. Here we show that this requirement can be significantly reduced, maintaining mathematical correctness and significantly reducing system complexity. This therefore reduces the cost of these systems and increases robustness and reliability.