1. The Measurement and Analysis of System Noise Temperatures of the TM65m Radio Telescope at Low Frequency Bands1,2
- Author
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Lao Bao-qiang, Dong Jian, Wang Jinqing, Jiang Dong-rong, Lou Fang-xun, Jiang Yongbin, Fan Qing-yuan, Li Bing, Zhao Rong-bing, Liu Qing-hui, Qian Zhi-han, and Yu Linfeng
- Subjects
Radio telescope ,Physics ,Noise temperature ,Space and Planetary Science ,Acoustics ,Noise spectral density ,Astronomy and Astrophysics ,Low frequency ,Noise figure ,Atmospheric noise ,Noise floor ,Noise (radio) - Abstract
At first, the receiving system of the Tianma 65m radio telescope (TM65m in brief) and its noise characteristics at the L, S, C, and X four frequency bands are described. Then, a few measuring methods of system noise temperature are discussed, and the major factors affecting the noise temperature measurement are analyzed, including the errors caused by the non-linearity, feed network insertion loss, mismatch, and so on. With the Y-factor method the noise temperature of the noise source calibrated in the laboratory is verified, indicating that its accuracy attains ∼0.2K. Finally, the system noise temperatures actually measured at the four frequency bands and an analysis on the result are given.
- Published
- 2015
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