用冷空作为定标基准测天线增益

本文介绍用天线指向冷空时的天线噪声温度TAN作为定标基准,并以射电源为信标,测量天线剩余噪声温度Tas的基本原理和方法。与用冷、热负载为定标基准测量Tas相比,两者测量结果基本吻合;但该方法具有测量方法简便和测量设备简单等优点。Tas的测量误差约为3％。天线增益测量精度可保持在0.3dB左右。

MEASUREMENT OF ANTENNA GAIN USING BACKGROUND TEMPERATURE OF SKY AS STANDARD OF CALIBRATION

The basic principle and method of measuring the antenna excess noise temperature Tas by using the radio stars as calibration are presented in this paper. In this method, the antenna noise temperature TAN is used as a standard of calibration when the antenna points at sky. It was found that the results of measurement using this method agree with that obtained by using liquid nitrogen at low and normal ambient temperature as standard of calibration. The method has advantage of more simplicity of the measurement and equipment. The total error of antenna excess noise temperature obtained by this method could be estimated to be ±3%. The error of antenna gain measured is about ±0.3%. ±