Figure 1. The 39.5 GHz ~ 40 GHz two-element interferometric system. 2 small antennas with a 50 cm diameter (both sides) are installed on a coplanar slide-out module install. The range between the 2 antennas can be slide-adjusted in between 100 and 300 wavelengths.
A two-element interferometer designed for observing millimeter-wave solar radio bursts has been developed and set up at the Chashan Solar Radio Observatory (CSO). The nulling interferometer effectively eliminates radiation from the peaceful sun, resulting in significant decrease of variations in the quiet solar flux density. Comparison of single antenna and interferometric system output when observing 40 GHz solar signal under a cloudy sky and thick cloud cover.
When cloud occlusion takes place, the radiation flux gotten by a single antenna at 40 GHz with fluctuations of ~ 900 SFU, while the output change of the interferometric system is roughly 190 SFU. Throughout the existence of thick cloud, the reduction in radiation flux is substantially bigger for the single antenna compared to the interferometric system. The radiation flux of the interferometric system modifications by roughly 300 SFU, whereas that of the single antenna reduces by roughly 1000 SFU.
Based upon a recently published post:
YongLin Yu (于永林), Shuo Xu (许硕), Lei Zhang (张磊), ZiQian Shang (尚自乾), ChengLong Qiao (乔成龙), ShuQi Li (李舒琪), Zhao Wu (武昭), YanRui Su (苏艳蕊), HongQiang Song (宋红强), Yao Chen (陈耀), and FaBao Yan (严发宝). A Two-element Interferometer for Millimeter-wave Solar Flare Observations, The Astrophysical Journal Supplement Series, 267:14 (2023 ), DOI: https://doi.org/10.3847/1538-4365/acd9af.
Recommendations:.
Luthi, T., Murk, A., & & Magun, A. 2005, IEEE Transactions on Microwave Theory Techniques, 53, 1168.
Nakajima, H., Sekiguchi, H., Sawa, M., Kai, K., & & Kawashima, S. 1985, PASJ, 37, 163.
* Full list of authors: YongLin Yu (于永林), Shuo Xu (许硕), Lei Zhang (张磊), ZiQian Shang (尚自乾), ChengLong Qiao (乔成龙), ShuQi Li (李舒琪), Zhao Wu (武昭), YanRui Su (苏艳蕊), HongQiang Song (宋红强), Yao Chen (陈耀), and FaBao Yan (严发宝).
Solar radio emission can be substantially influenced by Earths environment when sending towards the Earths surface, due to atmospheric turbulence and the absorption of vapor and oxygen molecules and so on. Weak bursts can be normally observed in three methods: (1) Utilizing big antennas with a narrow beam-width at half power, (2) Compensating for absorption of the quiet sun through atmospheric emission, and (3) Employing a nulling interferometer cancelling the quiet sun element by associating signals from 2 separate little antennas. A number of applications of the nulling interferometer for solar radio observations have been reported. A two-element interferometer developed for observing millimeter-wave solar radio bursts has been established and installed at the Chashan Solar Radio Observatory (CSO). Comparison of single antenna and interferometric system output when observing 40 GHz solar signal under a cloudy sky and thick cloud cover.
Solar radio emission can be considerably affected by Earths atmosphere when sending towards the Earths surface area, due to atmospheric turbulence and the absorption of vapor and oxygen particles etc. Subsequently, antennas receive signals with a dither component, indicating a noise signal displaying random variations. As a result, the level of sensitivity of observing systems distorts severely, specifically for weaker radio bursts in the millimeter passband.
Weak bursts can be normally observed in 3 ways: (1) Utilizing large antennas with a narrow beam-width at half power, (2) Compensating for absorption of the peaceful sun through climatic emission, and (3) Employing a nulling interferometer cancelling the quiet sun element by correlating signals from two different little antennas. A number of applications of the nulling interferometer for solar radio observations have been reported.
