基于Radarsat-2全极化数据的高原牧草覆盖地表土壤水分反演

大面积土壤水分反演对于青海湖流域草场的管理和保护具有重要的意义。利用C波段全极化的Radarsat-2 合成孔径雷达(SAR)影像数据,开展了青海湖流域刚察县附近草场的土壤水分反演研究,在“水-云”模型和Chen模型的基础上,发展了一种新的土壤水分反演算法。该算法消除了植被覆盖以及地表粗糙度对雷达后向散射系数的影响。实验结果表明:预测结果能够与实测数据很好地吻合,R²、RMSE和RPD分别达到0.71\,3.77%和1.64,反演精度较高,能够满足研究区土壤水分的反演精度要求。如果能够更细致地刻画植被层以及地表粗糙度对雷达后向散射系数的影响,土壤水分反演精度有望得到进一步提高。
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Study on Soil Moisture Inversion of Plateau Pasture Using Radarsat-2 Imagery

Accurate soil moisture retrieval of large area is of great significance to the management and protection of the plateau pasture.Using fully polarimetric Radarsat\|2 Synthetic Aperture Radar(SAR) images at C\|band,this paper carried out the study of soil moisture inversion in the country of Gangcha,Qinghai province,which is a part of Qinghai Lake watershed.Based on water\|cloud model and Chen model,an algorithm was developed for soil moisture inversion.Elimination of vegetation cover and soil surface roughness effect for backscattering was achieved by the algorithm.Through field measurement validation,the developed algorithm gained reliable results.The results of R²,RMSE and RPD value(0.71,3.77%,1.64) show that the developed algorithm can meet the requirement of soil moisture inversion in study region.In the future,if the vegetation cover and soil surface roughness effect for backscattering could be described in more detail,the accuracy of soil moisture inversion is expected to be further improved.