标题： 基于傅里叶光学的方法评估MICADO的天文学性能 显示英文标题

标题： A Fourier optics approach to evaluate the astrometric performance of MICADO

摘要： 我们研究了波前误差对高精度天体测量的影响，使用了傅里叶光学方法。 即将推出的欧洲极大望远镜（ELT）的近红外成像仪MICADO将提供相对天体测量的能力，其精度可达50微角秒（{\mu }as）。 由于点扩散函数（PSF）的大小比天体测量要求大得多，因此必须很好地理解PSF在探测器上的详细形状和位置。 此外，由于MICADO的大气色散校正器是动态部件，而仪器的其他部分基本是静态的，因此简单的预观测校准可能不足以满足需求。 因此，我们构建了一个傅里叶光学框架，可以评估PSF质心位置随波前误差的小变化。 为了进行全面评估，我们使用泽尼克多项式建模低阶表面形式误差，并使用功率谱密度分析建模中高空间频率。 这项工作将能够通过完整的衍射光束传播，评估MICADO预期的天体测量性能。 显示英文摘要

摘要： We present our investigation into the impact of wavefront errors on high accuracy astrometry using Fourier Optics. MICADO, the upcoming near-IR imaging instrument for the Extremely Large Telescope, will offer capabilities for relative astrometry with an accuracy of 50 micro arcseconds ({\mu}as). Due to the large size of the point spread function (PSF) compared to the astrometric requirement, the detailed shape and position of the PSF on the detector must be well understood. Furthermore, because the atmospheric dispersion corrector of MICADO is a moving component within an otherwise mostly static instrument, it might not be sufficient to perform a simple pre-observation calibration. Therefore, we have built a Fourier Optics framework, allowing us to evaluate the small changes in the centroid position of the PSF as a function of wavefront error. For a complete evaluation, we model both the low order surface form errors, using Zernike polynomials, and the mid- and high-spatial frequencies, using Power Spectral Density analysis. The described work will then make it possible, performing full diffractive beam propagation, to assess the expected astrometric performance of MICADO.