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《天文和天体物理学研究(英文版)》2015,(11)
The Chinese Spectral Radio Heliograph(CSRH) is an advanced aperture synthesis solar radio heliograph, independently developed by National Astronomical Observatories, Chinese Academy of Sciences. It consists of 100 reflector antennas,which are grouped into two antenna arrays(CSRH-I and CSRH-II) for low and high frequency bands respectively. The frequency band of CSRH-I is 0.4–2 GHz and that for CSRH-II is 2–15 GHz. In the antenna and feed system, CSRH uses eleven feeds to receive signals coming from the Sun. The radiation pattern has a lower side lobe and the back lobe of the feed is well illuminated. The characteristics of gain G and antenna noise temperature T affect the quality of solar radio imaging. For CSRH, the measured G is larger than 60 d Bi and T is less than 120 K. After CSRH-I was established, we successfully captured a solar radio burst between 1.2–1.6 GHz on 2010 November12 using this instrument and this event was confirmed through observations with the Solar Broadband Radio Spectrometer at 2.84 GHz and the Geostationary Operational Environmental Satellite. In addition, an image obtained from CSRH-I clearly revealed the profile of the solar radio burst. The other observational work involved the imaging the Fengyun-2E geosynchronous satellite which is assumed to be a point source.Results indicate that the data processing method applied in this study for deleting errors in a noisy image could be used for processing images from other sources. 相似文献
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射电望远镜一般要在宽频段内进行连续观测, 但传统相控阵天线设计方法难以兼顾宽频带和大角度扫描特性. 紧耦合天线的设计方法为宽带大角度扫描天线提供了新的设计思路, 基于此设计了一款宽带双极化 Vivaldi相控阵馈源. 首先结合Wheeler提出的连续电流片概念及等效电路对紧耦合原理进行理论分析, 然后针对Vivaldi天线分析了阵元间的强耦合能够有效拓展天线的工作带宽. 在此基础上设计了一款宽带Vivaldi相控阵馈源. 馈源阵列由8×9 Vivaldi天线阵元组成, 该阵列的工作带宽为2-8GHz, 并且能够在E面和H面均实现±$45^\circ$的扫描特性. 最后对该馈源阵列进行了样机加工和测试, 测试结果与仿真结果具有较好的一致性. 相似文献
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天马13 m射电望远镜是专为空间大地测量的新一代甚长基线干涉测量(Very Long Baseline Interferometry, VLBI)天线,即VGOS(VLBI Global Observing System)系统。VGOS观测将从调度、相关、观测策略到分析各方面改变甚长基线干涉测量。与传统测地观测相比,VGOS观测将数据精度提高1～2个数量级。天马13 m射电望远镜安装了3～15 GHz宽频制冷接收机,一般要求天线指向偏差小于最高频率波束宽度的1/10。为满足高精度指向要求,详细介绍了建立指向的方法和天线控制扫描策略,给出了系统误差修正模型的完全表达式,明确了指向修正模型中的参数意义。基于该天线指向扫描的实测数据,实测评估了望远镜的指向精度。采用最小二乘法对覆盖全天区的数据样本进行拟合,得到天马13 m射电望远镜指向模型,并加载到天线伺服控制系统进行验证,得到了优于10″的盲指误差。 相似文献
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