摘要
随着计算机数字技术的高速发展,甚长基线干涉仪测量(Very Long Baseline Interferometry,VLBI)所需的关键观测终端设备基带转换器(Base Band Converter,BBC)已从模拟系统(Analog BBC,ABBC)发展为数字系统(Digital BBC,DBBC)。相对于模拟系统,数字系统具有很高的灵活性,并能成倍提高VLBI观测带宽,进而能满足各种高灵敏度的观测需求。考虑到这些技术优势,以及新疆天文台南山站在国内和国际VLBI网中的重要作用,南山站2016年对VLBI终端系统进行了升级,引进了一套意大利Hat-Lab公司研发的DBBC2终端。介绍了DBBC2系统的主要构成模块和工作原理以及系统的组装、连接、配置、校准和调试方法。在对系统硬件和软件进行全面的检测和测试后,与国内和国际的主要台站开展了联合观测,并多次成功获得相关干涉条纹。这一系列的成功观测表明,南山DBBC2系统已成功安装,并具有很高的可靠性。应用新的DBBC2系统,南山站可参与2/4 Gbps的记录速率的宽带VLBI观测,极其有助于天文学家对宇宙中更暗弱的射电源开展毫角秒分辨率的成图观测。
Base Band Converters （BBC） are the key components of Very Long Baseline Interferometry （VLBI） backend. With the rapid development of computer and digital technology, Anolog BBCs （ABBC） have recently been superseded by Digital BBCs （DBBC） in the field of radio astronomy. Compared with ABBC, DBBC have much higher flexibility and support much wider bandwidth recording in VLBI observations. Considering these advantages and the key role of Nanshan station in international VLBI networks, a VLBI digital backend with DBBC2, developed by Hat-Lab （Italy） , has been installed at Nanshan station, Xinjiang Astronomical Observatory. The DBBC2 is fully compactible with the European VLBI network （EVN）. In the paper, we gave a proper introduction to the new equipment including its structure, key modules, input and output interfaces. We also mentioned how to assemble, connect, configure, calibrate and test the equipment. After all these necessary verifications, we performed some testing observations. Fringes to Nanshan DBBC2 were successfully found in these experiments. These successes indicate that the new digital backend is successfully established and works quite stably at Nanshan station. With the new digital backend, we can achieve a recording rate of 2/4Gbps in the wide-band VLBI observations. This will enable astronomers to image much fainter radio sources with the milliarcsecond resolution.
出处
《天文研究与技术》
CSCD
2018年第1期32-39,共8页
Astronomical Research & Technology
基金
国家自然科学基金(11503072)
中国科学院西部之光项目(YBXM-2014-02)
新疆射电天体物理重点实验室开放课题(2016D03020)资助
