Using the ${C_{n}^{2}}$ and wind profiler method with wide-field laser-guide-stars adaptive optics to quantify the frozen-flow decay
Using the ${C_{n}^{2}}$ and wind profiler method with wide-field laser-guide-stars adaptive optics to quantify the frozen-flow decay
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使用 ${C_{n}^{2}}$ 和风剖面仪方法以及宽视场激光导星自适应光学器件来量化冻结流衰减
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
D. Guzmán
中科院分区：
文献类型：
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作者：
A. Guesalaga;B. Neichel;Á. Cortés;C. Béchet;D. Guzmán
利用5个Shack-Hartmann波前传感器的波前斜率的时空互相关，分析了不同高度大气湍流层的时间演变。重点是冻结流假设的验证。这些数据来自Gemini South多共轭自适应光学系统（GeMS）。首先，我们介绍了C-n（2）和风廓线技术。该方法为自适应光学系统的操作提供了有用的信息，例如现有湍流层的数量，其相关的速度，高度和强度，以及估计圆顶看到对总湍流的贡献的机制。接下来，通过识别湍流层，我们表明，它是可能的，以估计湍流测量之间的相关性的时间衰减率。我们减少了2011年、2012年和2013年活动期间获得的天空数据。第一个结果表明，时间去相关率可以表示在一个单一的参数，是独立的层高度和湍流强度。最后，我们表明，冻结流贡献的衰减率随层速度线性增加。观测到的衰减率的演变证实了预测控制的宽视场自适应光学系统的潜在利益。
We use the spatio-temporal cross-correlations of slopes from five Shack-Hartmann wavefront sensors to analyse the temporal evolution of the atmospheric turbulence layers at different altitudes. The focus is on the verification of the frozen-flow assumption. The data come from the Gemini South Multiconjugate Adaptive Optics System (GeMS). First, we present the C-n(2) and wind profiling technique. This method provides useful information for the operation of the adaptive optics system, such as the number of existing turbulence layers, their associated velocities, altitudes and strengths, and also a mechanism to estimate the dome-seeing contribution to the total turbulence. Next, by identifying the turbulence layers, we show that it is possible to estimate the rate of decay in time of the correlation among turbulence measurements. We reduce on-sky data obtained during the 2011, 2012 and 2013 campaigns. The first results suggest that the rate of temporal decorrelation can be expressed in terms of a single parameter that is independent of the layer altitude and turbulence strength. Finally, we show that the decay rate of the frozen-flow contribution increases linearly with the layer speed. The observed evolution of the decay rate confirms the potential interest of the predictive control for wide-field adaptive optics systems.