发表机构
Argentine Institute of Radio astronomy (IAR), UNLP - CONICET - CICPBA; LEICI Institute of Research in Electronics, Control and Signal Processing, UNLP - CONICET（阿根廷射电天文研究所（IAR），拉普拉塔国立大学-国家科学研究委员会-圣克鲁斯省科学和技术研究委员会; 电子、控制和信号处理研究所（LEICI），拉普拉塔国立大学-国家科学研究委员会）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文利用指数映射和李群提出一种快速最大似然估计器用于射电干涉校准，其性能达到克拉美-罗下界，且比期望最大化算法快约40倍，并在AS 209观测中验证。
AI 中文摘要
构成射电干涉仪的天线单元形成一种空间滤波器，对目标射电天文源亮度的傅里叶变换分量进行采样。在信号路径中，存在乘性和加性扰动效应，这些效应会改变信号，应予以校正。减轻这些扰动效应的过程称为校准。在本工作中，我们利用指数映射和李群，开发了一种新的、快速的基于最大似然的扰动效应估计器。为评估其性能，我们将其与克拉美-罗下界进行比较；为测试估计时间，我们将其与期望最大化算法（另一种快速最大似然估计器）进行比较。最后，我们将所提出的估计器应用于亚毫米阵列对原行星盘AS 209的一次真实观测。我们发现，所提出的估计器达到了克拉美-罗下界，并且比期望最大化算法快约40倍。
英文摘要
The antenna-elements that make up a radio interferometer form a spatial filter that samples components of the Fourier transform of a target radio astronomical source brightness. Along the signal path, there are multiplicative and additive perturbation effects that alter the signal and that should be corrected. The process of mitigating these perturbation effects is called calibration. In this work, we develop a new and fast Maximum Likelihood based estimator of these perturbation effects using the Exponential Map and Lie groups. To evaluate its performance, we compare it to the Cramér-Rao Lower Bound and, to test the estimation time, we compare it with the Expectation Maximization algorithm, another fast Maximum Likelihood estimator. Finally, we apply our estimator to a real observation of the protoplanetary disk AS 209 made with the Submillimeter Array. We found that our proposed estimator meets the Cramér-Rao Lower Bound and it was approximately 40 times faster than the Expectation Maximization algorithm.
CommentsSubmitted to IEEE Transactions on Signal Processing
