CAJ | 학술논문

在使用被动微波技术反演土壤水分的过程中,为去除植被的影响,通常采用适用于低频的τ-ω模型.为准确评估较高频率下植被的散射和衰减特性,以玉米为例,采用基于光线跟踪原理的双矩阵(Matrix-Doubling)微波辐射模型,研究不同高度的作物在C(6.925 GHz)、X(10.65 GHz)和Ku(18.7 GHz)波段下的单散射反照率和传输率.模型模拟的亮度温度跟车载微波辐射仪的野外实测数据接近.为验证模拟的玉米自身微波辐射,在玉米地上铺设了一层铝箔屏蔽地表的辐射.通过给验证后的模型输入不同的参数,建立一个亮度温度数据库,以模拟自然状态下不同高度玉米的亮度温度.然后把模型模拟的结果,跟相同环境下τ-ω模型得到的结果按最小二乘法进行匹配,从而获得不同高度的玉米在C、X和Ku波段上等效的单散射反照率和传输率.
재사용피동미파기술반연토양수분적과정중,위거제식피적영향,통상채용괄용우저빈적τ-ω모형.위준학평고교고빈솔하식피적산사화쇠감특성,이옥미위례,채용기우광선근종원리적쌍구진(Matrix-Doubling)미파복사모형,연구불동고도적작물재C(6.925 GHz)、X(10.65 GHz)화Ku(18.7 GHz)파단하적단산사반조솔화전수솔.모형모의적량도온도근차재미파복사의적야외실측수거접근.위험증모의적옥미자신미파복사,재옥미지상포설료일층려박병폐지표적복사.통과급험증후적모형수입불동적삼수,건립일개량도온도수거고,이모의자연상태하불동고도옥미적량도온도.연후파모형모의적결과,근상동배경하τ-ω모형득도적결과안최소이승법진행필배,종이획득불동고도적옥미재C、X화Ku파단상등효적단산사반조솔화전수솔.
To remove vegetation effect in soil moisture retrieval by passive microwave technique at lower frequencies,the τ-ω model is often used. In order to evaluate the scattering and attenuation characteristics of vegetation at higher frequencies,a Matrix-Doubling microwave emission model based on ray-tracing technique was used on com,to study its single scattering albedo and transmissivity with different height at C (6.925GHz),X (10.65GHz) and Ku (18.7GHz) bands. The comparison between simulation results and the data collected by a truck-mounted microwave radiometer in a field experiment are good. To verify the simulated emission from corn layer only,the ground surface of corn field was placed with an Aluminum foil,so as to mask the emission from the soil. A Brightness Temperature database was setup by assigning a variety of parameters to the verified model,to simulate Brightness Temperature of natural corn field with different height. The results by the Matrix-Doubling model were then matched with those by τ-ω model at the same condition by least-square deviation,so as to retrieve the effective single scattering albedo and transmissivity of corn at C,X and Ku-band.