基于立体方向图和十字跟踪扫描法校准天线指向

针对明安图射电频谱日像仪(Mingantu spectral radioheliograph, MUSER)天线高指向精度动态跟踪要求,同时为降低非理想因素对复杂系统天线指向测量影响,提出校准天线指向的组合方法.先用网格法测量天线的双圆极化多频率通道立体方向图定性评估系统测量链路状态,后对太阳运行轨道进行十字跟踪扫描测量天线指向偏差,再用最小二乘法拟合获得天线指向模型的8个参数.国家天文台明安图观测基地的2台20 m地平式天线将在MUSER系统观测和校准中起重要作用.对20 m天线跟踪指向进行了校准,指向偏差均方根从12'改善到4.4',验证了方法的可行性,为类似复杂系统的相关工作提供了借鉴和参考.

Antenna pointing calibration based on cubic radiation pattern and cross scan

To get good antenna tracking pointing accuracy under imperfect measurement link status of complicated system, methods and measurements of cubic radiation patterns and cross scanning-and-tracking are proposed for the two 20 m Az-El antennas, which will be updated to take part in the observation and calibration of Mingantu spectral radioheliograph(MUSER), a powerful instrument dedicated for solar radio imaging observation. Least square method is also used to obtain the 8 parameters of the 20 m antenna pointing model. After calibration, the pointing accuracy is improved from about 12' (rms) to about 4.4' (rms), testifying the reliability of the proposed methods and providing a good reference for other complicated telescope systems.