Next Generation Radio Telescope Calibration

当计划获得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对焦。这可能是一个及时的过程，正如最近詹姆斯韦伯太空望远镜的镜子需要四个月的调整所证明的那样。 现代射电望远镜中数百个天线的对准比詹姆斯韦伯太空望远镜主镜的18个部分的对准更具挑战性。颜色相关的校准过程在射电天文学中被称为校准，该项目将开发并免费共享一种新的精确校准过程。华盛顿大学的团队专门从事这种精确校准工作，并开发了一种新的大大改进的校准算法所需的数学和统计学。在该项目期间，将通过对第一批恒星进行无线电观测来检验这一新方法的有效性。本计画将邀请社区大学转学生参与研究。 21厘米宇宙学观测的要求大大提高了干涉射电数据的精确校准。一种全新的贝叶斯校准方法，称为统一校准，可以量化不确定性，并生成相关的最佳校准。这一进展有可能大大加强标准射电校准和21厘米宇宙学观测。该项目旨在产生两种形式的统一校准。其中一个将用python编写，并利用围绕pyuvdata的社区来产生一个灵活而健壮的实现。这一实施将使社区能够探索最佳的校准参数化，并将这些方法应用于各种各样的干涉测量数据。第二次实施将侧重于再电离时代功率谱分析的精度和速度，并实现深度数据驱动的校准探索，这将为仪器和天空模型及其相关不确定性的最有效参数化提供信息。该项目还将通过更好地参与研究来提高社区学院转学生在大学的留存率。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值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.