基于RSP的植被多角度偏振特性研究

偏振探测能够获取新的反应目标属性的信息。相对于传统遥感观测，多角度偏振信息具有更稳定的相关性和规律性。植被是地表最典型的地物之一，利用光与植被相互作用后表现出的偏振特性可以进行植被相关性质研究。RSP（research scanning polarimeter）是美国研制的星载偏振遥感探测器APS(aerosol polarimetery sensor)的原型样机，提供有九个光谱偏振通道，通过对航空飞行试验获取的扫描偏振数据预处理得到的稳定的多角度、多波段偏振探测信息分析，可以得到植被的光学特性和微物理特性。以植被密集区、植被稀疏区（接近裸地）为研究对象，根据仪器飞行时姿态信息进行配准，对比分析了可见光波段和近红外波段在-30°和65°观测天顶角下的强度反射特性和偏振反射特性。结果表明，植被密集区和植被稀疏区在不同的观测角度均表现出规律的偏振度特性，偏振反射在接近热点区域能量小，相比于常规强度反射在接近热点区域反射能量大，可有效防止因反射能量过强影响探测器的稳定性，根据在可见光波段植被密集区偏振度高于植被稀疏区，在近红外波段植被密集区偏振度低于植被稀疏区的反射特性，说明探测器在研究区域的植被密集区接收的可见光波段信号以单次散射为主而在近红外波段以多次散射为主。

Investigation of Multi-Angle Polarization Properties of Vegetation Based on RSP

Polarization detection provides us with novel information to reflect the target attribute .Compared with traditional re-mote sensing methods ,multi-angle polarization has relatively stable correlation and regularity .RSP(research scanning polarime-ter)is an airborne prototype for the APS(aerosol polarimetery sensor) developed by the USA ,which can provide with us the po-larization detection information of 9 channels .We can get optical properties and physical characteristics of vegetation by analyzing stable multi-angle and multi-band polarization detection information from preprocessing scanning polarization data of flight test . In this paper ,after making registration based on flight attitude information ,a comparative analysis is made between characteris-tics of reflectance and polarization reflectance with visible light and near infrared band of the view zenith angles between -30 de-gree and 65 degree ,based on dense area and sparse area(close to bare field) of vegetation .The results show that both dense area and sparse area demonstrate regular characteristics of polarization degree .The area close to hot spot area has highest reflectance energy .In contrast ,it has relatively least energy of polarization degree ,which can prevent strong reflectance energy from influ-encing the stability of detector .Because the degree of polarization in dense area of vegetation is higher than that in sparse area at visible light band while that in concentration area of vegetation is lower than sparse area at near infrared light band ,it shows that the visible light band information of dense area of vegetation that the sensor received is dominated by single scattering while the near infrared light band information of dense area of vegetation is dominated by multiple scattering .