星载微波辐射计热定标源热设计与应用

Thermal Design and Application of Thermal Calibration Target Source for Space-Borne Microwave Radiometer

设计开发了一种星载微波辐射计热定标源,运用有限元分析(Finite Element Analysis,FEA)软件对其进行热特性仿真分析,并通过热真空环境模拟试验对其进行验证。仿真表明,热定标源温度随着传递距离的增大(从源体底部向尖劈顶部、从中心向四周)而线性减小;尖劈高度方向的温度梯度d T/dh大于半径方向的温度梯度d T/dr,两者随着空间环境温度的增加(2.7 K→293 K)而逐渐减小。通过试验考核,热定标源温度精度在±0.15 K/16 s范围内,温度均匀性≤0.15 K,具有良好的温度稳定性和均匀性,验证了热定标源热设计的合理性与可行性。

A novel thermal calibration target source for space-borne Microwave Radiometer （MWR） is designed, meanwhile, the thermal performance analysis and thermal vacuum environment simulation test of the thermal calibration target source 3-D model is presented. The simulation results show that the temperature of thermal calibration target source or ab- sorber decreases linearly with the heat transfer distance from absorber bottom to wedge top increases, as well as the distance from absorber center to all around increases. It also shows that the dT/dh is always more than dT/dr , and both decrease with the space environment temperature increase（2.7 K→293 K）. Futher study on the basis of thermal vacuum environment simulation test shows that the thermal calibration target source has hig accuracy of source temperature of ±0.15 K/16 s and the best homogeneity of source temperature is smaller than 0.15 K. These works are useful for further optimum design of the thermal calibration target source.