月球表面微波亮温的时变趋势

Diurnal variation trend of microwave brightness temperature on t he moon

为从嫦娥一号微波亮温数据中解译出月表的物理特性参数,须研究亮温随时间的变化趋势(时变趋势).利用嫦娥一号实测亮温数据(部分时段),拟合得到Apollo地区亮温的时变趋势.为了验证拟合函数的合理性,通过改进热传导方程的边界条件,模拟得到Apollo地区亮温的时变趋势,并将模拟亮温时变趋势与实测亮温时变趋势进行对比分析.结果表明:模拟亮温与实测亮温的时变趋势一致,说明亮温模型具有合理性;采用拟合函数对实测亮温数据进行时间归一化,可以明显减小测量时刻不同导致的月表实测亮温的差异.

In order to interpret the regolith properties parameter s from microwave brightness temperature（TB） data observed by Chang′ E-1 lunar orbiter,it is necessary to study the diurnal variation of the TB.Based on CE-1 TB data,a numerical function was applied to fitted TB diurnal variation at Apollo regions,and fitted model was obtained.Diurnal TB variation at Apollo re gions was simulated by improving the boundary condition of heat conduction equat ion,and compared to the fitted TB variation trend.Result shows that diurnal va riation trend of simulated TB is consistent with that of observed TB,and it sug gests that the fitted TB model employed is reasonable.Hence,the numerical func tion proposed can be used to normalize observed TB data to reduce TB difference obviously brought by the different measured time.