论文标题
部分可观测时空混沌系统的无模型预测
Properties of EUV Imaging Spectrometer (EIS) Slot Observations
论文作者
论文摘要
储层计算是预测湍流的有力工具，其简单的架构具有处理大型系统的计算效率。然而，其实现通常需要完整的状态向量测量和系统非线性知识。我们使用非线性投影函数将系统测量扩展到高维空间，然后将其输入到储层中以获得预测。我们展示了这种储层计算网络在时空混沌系统上的应用，该系统模拟了湍流的若干特征。我们表明，使用径向基函数作为非线性投影器，即使只有部分观测并且不知道控制方程，也能稳健地捕捉复杂的系统非线性。最后，我们表明，当测量稀疏、不完整且带有噪声，甚至控制方程变得不准确时，我们的网络仍然可以产生相当准确的预测，从而为实际湍流系统的无模型预测铺平了道路。
The Extreme ultraviolet Imaging Spectrometer (EIS) on board the Hinode spacecraft has been operating since 2006, returning high resolution data in the 170-212 and 246-292 A wavelength regions. EIS has four slit options, with the narrow 1" and 2" slits used for spectroscopy and the wide 40" and 266" slits used for monochromatic imaging. In this article several properties of the 40" slit (or slot) are measured using the Fe XII 195.12 A line, which is formed at 1.5 MK. The projected width of the slot on the detector shows a small variation along the slit with an average value of 40.949". The slot image is tilted on the detector and a quadratic formula is provided to describe the tilt. The tilt corresponds to four pixels on the detector and the slot centroid is offset mostly to the right (longer wavelengths) of the 1" slit by up to four pixels. Measurement of the intensity decrease at the edge of the slot leads to an estimate of the spatial resolution of the images in the x-direction. The resolution varies quadratically along the slot, with a minimum value of 2.9" close to the detector center. Intensities measured from the slot images are found to be on average 14% higher than those measured from the 1" slit at the same spatial location. Background subtraction is necessary to derive accurate intensities in quiet Sun and coronal hole regions. Prescriptions for deriving accurate slot intensities for different types of slot datasets are presented.
