Next Generation Radio Telescope Calibration

当计划获取宇宙中第一批恒星和星系的射电图像时，使用的望远镜必须清晰聚焦，这一点至关重要。这可能是一个及时的过程，最近詹姆斯·韦伯太空望远镜的镜面对准所需的四个月就证明了这一点。现代射电望远镜中数百个天线的对准甚至比组成詹姆斯·韦伯空间望远镜主镜的18个部分的对准更具挑战性。颜色相关的对准过程在射电天文学中被称为校准，该项目将开发并自由共享一种新的精密对准过程。华盛顿大学的团队专门从事这种精度校准工作，并开发了一种新的大幅改进的校准算法所需的数学和统计方法。在这个项目中，将通过对第一批恒星的射电观测来测试这种新方法的有效性。该项目将邀请社区大学转学学生参与这项研究。21厘米宇宙学观测的要求大大提高了干涉射电数据的精度定标。一种被称为统一校准的全新的贝叶斯校准方法允许量化不确定性并生成相关的最优校准。这一进展有可能极大地加强标准射电定标和21厘米宇宙学观测。该项目希望产生两种形式的统一校准。其中一个将使用python编写，并利用围绕pyuvdata的社区来生成灵活而健壮的实现。这一实施将使社区能够探索最佳的校准参数，并将这些方法应用于各种干涉数据。第二个实施将侧重于再电离功率谱分析时代的精度和速度，并实现深入的数据驱动的校准探索，这将为仪器和天空模型及其相关的不确定度提供最有效的参数化信息。该项目还将通过社区学院转学学生更好地参与研究来提高他们在大学的留校率。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

When planning to obtain radio images of the first stars and galaxies in the universe it is crucial that telescope being used is in crisp focus. This can be a timely process, as recently demonstrated by the four months needed for alignment of the James Webb Space Telescope’s mirrors. The alignment of the hundreds of antennas in a modern radio telescope is even more challenging than the alignment of the eighteen segments that compose the James Webb Space Telescope primary mirror. The color-dependent alignment process is called calibration in radio astronomy, and this project will develop, and freely share, a new precision alignment process. The team at the University of Washington specializes in such precision calibration work and has developed the mathematics and statistics needed for a new much improved calibration algorithm. During this project the effectiveness of this new approach will be tested by making radio observations of the first stars. This project will engage community-college transfer students to participate in this research. Precision calibration of interferometric radio data has been greatly advanced by the requirements of 21 cm Cosmology observations. A fundamentally new Bayesian calibration approach referred to as unified calibration allows the uncertainties to be quantified and generates associated optimal calibrations. This advance has the potential to greatly enhance both standard radio calibration and 21 cm Cosmology observations. This project looks to produce two forms of unified calibration. One will be written in python and leverage the community around pyuvdata to produce a flexible and robust implementation. This implementation will enable the community to explore the best calibration parametrizations and to apply the approaches to a wide variety of interferometric data. The second implementation will focus on precision and speed for Epoch of Reionization power spectrum analysis and enable deep data-driven explorations of calibration that will inform the most effective parametrizations of instrument and sky models and their associated uncertainties. The project will also improve the retention rate of community college transfer students at universities through their better engagement in research.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.