Antenna system characteristics and solar radio burst observations

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.