射电频率干扰的消减

发布时间：2018-06-03 14:12

  本文选题：望远镜 + 射频干扰　； 参考：《天文学报》2017年05期

【摘要】：一直以来,射电天文装备不断得到升级和发展,以使其具有更好的观测性能,包括提高数据记录的时间和频率分辨率以及获得更高的接收和记录带宽等.然而与之形成矛盾的是:国际电信联盟(International Telecommunication Union,ITU)仅为射电天文分配了非常有限的频谱资源,导致的后果是射电观测设备不可避免地受到日益增强的非天文信号的影响,后者的来源主要是人类的通信活动和日常生活,这就构成了通常射电天文中所说的射频干扰(Radio Frequency Interference,RFI).射频干扰会降低数据质量甚至导致数据无效,对科学结果的影响越来越严重.对RFI消减的需求进行分析,总结了RFI的特性、抑制和消减的技术和方案,并介绍了一些有代表性的射电望远镜(或阵列)中采用的RFI消减方法;还分析比较了4种常用方案,即预防、预检测、预相关和后相关的优势和不足.对RFI进行准确的识别和标记是减少数据损失从而有效提高数据质量的关键,也是发展RFI消减技术的最终目的.通过研究不难发现,上述4种方案的组合运用将具有更高的实用价值.近几年来,随着高速数字信号处理和高性能计算的迅速发展,依赖大量计算的实时模式下的预检测以及离线模式下从大型望远镜阵列所产生的大规模干涉相关数据中检测RFI已经成为可能.
[Abstract]:Radio astronomical equipment has been continuously upgraded and developed to provide better observation performance, including improving the time and frequency resolution of data recording and obtaining higher receiving and recording bandwidth. Paradoxically, however, the International Telecommunication Union (ITU) has only allocated very limited spectrum resources for radio astronomy, with the consequence that radio observation equipment is inevitably affected by increasing non-astronomical signals. The source of the latter is mainly human communication activities and daily life, which constitutes the radio frequency interference called radio Frequency interference in radio astronomy. RF interference will reduce the quality of data and even lead to invalid data, which has more and more serious impact on scientific results. This paper analyzes the requirements of RFI subtraction, summarizes the characteristics, suppression and reduction techniques and schemes of RFI, introduces some RFI subtractive methods used in some representative radio telescopes (or arrays), and analyzes and compares four common schemes. The advantages and disadvantages of prevention, pre-detection, pre-correlation and post-correlation. Accurate identification and marking of RFI is the key to reduce data loss and improve data quality effectively. It is also the ultimate goal of developing RFI subtractive technology. It is not difficult to find that the combination of the above four schemes will have higher practical value. In recent years, with the rapid development of high-speed digital signal processing and high-performance computing, It is possible to detect RFI in real-time mode based on a large amount of computing and in off-line mode from large scale interference data generated by large telescope arrays.
【作者单位】： 中国科学院上海天文台;中国科学院射电天文重点实验室;
【基金】：中国科学技术部政府间国际合作专项(2016YFE0100300) 国家自然科学基金项目(11650110438) 中国科学院天文财政专项;中国科学院战略性先导科技专项(B类)(XDB23010300);中国科学院国际博士后项目(2016PM024);中国科学院青年创新促进会资助
【分类号】：P161
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本文编号：1973078