极化分解技术在估算植被覆盖地区土壤水分变化中的应用

Applying the Decomposition Technique in Vegetated Surface to Estimate Soil Moisture by Multi-Temporal Measurements

地表植被覆盖是影响雷达遥感估算土壤水分的主要因素之一。本文探讨了将极化分解技术与植被覆盖地区的一阶散射模型结合估算土壤水分变化的方法。雷达数据经极化目标分解技术分解后得到的双次散射项和一阶植被散射模型的植被-地表的双次散射项一一对应,再利用多时相雷达数据消除植被层后向散射的影响,从而估算出地表土壤水分变化量。最后应用全极化机载雷达数据(AirSAR)对该方法进行了检验,结果表明该方法能够较好的估算植被覆盖地表的土壤水分变化。

Vegetation canopy is one of the important reasons affecting the sensitivity of radar backscattering to soil moisture. This article evaluated the usage of decomposition technique in estimation soil moisture with first order vegetation model. By comparison of them, a relationship was founded between the second term of vegetation model and the double scattering term of decomposition technique. With two repeat pass SAR measurements, we successfully eliminated the vegetation effects and estimated change of soil moisture with L band AirSAR data.