Next Generation Radio Telescope Calibration

当计划获得宇宙中第一批恒星和星系的无线电图像时，使用的望远镜具有清晰的焦点是至关重要的。这可以是一个及时的过程，正如最近詹姆斯韦伯太空望远镜的镜子需要四个月的时间来校准所证明的那样。在现代射电望远镜中，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。依赖颜色的对准过程在射电天文学中称为校准，该项目将开发并自由共享一种新的精密对准过程。华盛顿大学的研究小组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。在这个项目中，将通过对第一批恒星的无线电观测来检验这种新方法的有效性。本项目将邀请社区学院的转学生参与本研究。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校准。一种全新的贝叶斯校准方法被称为统一校准，允许不确定性被量化并产生相关的最佳校准。这一进展有可能极大地增强标准无线电校准和21厘米宇宙学观测。这个项目希望产生两种形式的统一校准。其中一个将用python编写，并利用pyuvdata社区来生成灵活而健壮的实现。这种实现将使社区能够探索最佳的校准参数化，并将方法应用于各种干涉测量数据。第二个实现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提供最有效的参数化信息。该项目还将通过更好地参与研究，提高社区学院转校生在大学的保留率。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识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.