基于DiFX的深空数传异地天线组阵技术研究

项目名称： 基于DiFX的深空数传异地天线组阵技术研究

项目编号： No.11303058

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 数理科学和化学

项目作者： 朱新颖

作者单位： 中国科学院国家天文台

项目金额： 28万元

中文摘要： 随着中国深空探测的不断发展，对天线的数据接收能力提出了更高的要求。由于单口径天线存在工程技术极限，通过对现有的大口径天线进行组阵，是提高天线数据接收能力的一个捷径。现有的大口径天线之间地理距离都比较遥远，与本地天线组阵系统相比，异地阵中单元天线的时延及时延率比较大，而且信号穿过的大气及电离层介质到达单元天线路径存在较大差异，如何获取时延和相位差是异地天线组阵的关键。提出利用DiFX(分布式FX型软件相关系统)的开源内核作为获取天线阵时延差和相位差基础，并根据数传天线阵的特点对其进行有针对研究和适应性改造，从而实现利用现有大口径天线进行异地组阵数据接收。建立一套可以完成密云站50米天线和昆明站40米天线进行异地组阵的实验系统，其中利用经过适应性改造后的DiFX完成核心时延和相位差获取功能；利用GNU Radio（开源软件无线电开发套件）完成基带数据的采集功能和合成后数据输出功能。

中文关键词： 深空探测；天线组阵；通用软件无线电；数据接收；

英文摘要： With the continuous development of China's deep space exploration, much higher antenna performance is needed to meet demand of data acquisition. Because of the technical limits of single parabolic antenna and receiver, it is a shortcut to improve data acquisition capacities by devising long baseline antenna array to compensate for the reduction in signal-to-noise ratio (SNR).Compared with the local area antenna array, long baseline antenna array consist of existing large-diameter antennas located in different regions. On the one hand, big delay and delay rate offset are caused by the antenna's geometric location ;on the other hand, great phase error due to the atmosphere and the overlaying ionosphere along the signal path are coming as the distance between individual elements increases.In a word, accurate delay, delay rate and phase offset obtained by correlation are the key of the long baseline antenna arraying. A new long baseline antenna arraying scheme based on a modified version of the DiFX（Distributed FX-style Software Correlator） kernel is proposed according to the unique demand of deep space data acquisition. An experimental system will be established to implement an long baseline antenna array consist of Miyun Station 50 m antenna and Kunming station 40m antenna. During this system , an modified version

英文关键词： Deep Space Exploration；Antenna Array；GNU Radio；Data Receiving；