面目标微波辐射特性实验模型

Experimental Models of Microwave Radiometric Characteristics for Extended Targets

提出了一种面目标微波辐射特性实验模型 (经验公式 )的建立方法 :由测得目标的天线温度经反演得到目标的视在温度、剔除天空引起的散射辐射温度后得到目标的亮度温度 ,再对亮度温度数据进行最小二乘拟合得到亮度温度的经验公式。用该方法建立的水面亮度温度的实验模型与水面亮度温度的半经验公式(理论模型 )相比较 ,结果显示在测量所覆盖的水面表面温度范围 ( 4— 35℃ )和测量角度 2 0°— 6 5°内 ,两者很接近。并给出了用该方法建立的混凝土路、沥青路和碎石路的微波辐射特性实验模型。

A method of establishing experimental models of mic row ave radiometric characteristics for extended targets is introduced in this paper . Microwave radiometric characteristics are represented by brightness temperatur e. A large amount of antenna temperature data is obtained through the repeated m easurement of the targets under different conditions and at different time. Appa rent temperature is obtained from antenna temperature through the inversion of t he integral equation. The brightness temperature is obtained from apparent tempe rature by eliminating the scattered radiometric temperature. The formula of brig htness temperature for the targets with respect to incident angle and surface ph ysical temperature are established through two_dimensional curve_fitting of brig htness temperature. Comparing the experimental model established by this method with the semi_empirical formula (theoretical model) of water brightness temperat ure, it is found that they are very close in the range of surface temperature (4 \_35℃) covered by the measurement and measuring angle 20°\_65°. The experimen tal models established with this method for concrete road, asphalt road, and cru shed stone road are also presented.