星载毫米波辐射计地面定标实验

对CE-1(嫦娥一号)卫星有效载荷微波探测仪初样样机8 mm微波辐射计进行了地面定标实验。测量了接收机的线性度和灵敏度;建立了射频前端微波辐射传输模型;应用该模型并结合测试结果,建立了失配条件下辐射计天线温度的定标方程。实验结果表明,接收机线性度为0.9999,灵敏度为0.17 K,定标误差小于0.85 K。为CE-1正样样机的研制以及科学目标的实现提供了定标参考。

Ground Calibration Experiment of Spaceborne Millimeter Wave Radiometer

ChangE|1(CE|1) will be the first satellite of China in lunar orbit. Its radiometer operates at 3.0, 7.8, 19.35 and 37 GHz in a nadir viewing mode. By now, the pre|launch experimental CE|1 Microwave Radiometer is developed. In this paper, an experiment on the ground calibration of 37GHz channel is carried out. First, the linearity and sensitivity of its receiver is obtained to be 0.9999 and 0.17 K, respectively, and satisfy the performance requirements, so CE|1 Microwave Radiometer can be calibrated through high and low temperature points: the high temperature point is from the matching load, the low one is from the liquid nitrogen refrigerated calibration blackbody target. Moreover, to amend the influence by the transmission network, the modified hardware radiative transfer model is built up. The antenna temperature calibration equation, which accounts for losses and mismatch, is derived finally based on the model and the error of calibration is less than 0.85K. The results provide a constructive reference to the further development of CE|1 Microwave Radiometer for launch.