文献类型：期刊文献

英文题名：Rape (Brassica napus L.) growth monitoring and mapping based on Radarsat-2 time-series data

作者：Zhang, Wangfei[1,2] Chen, Erxue[2] Li, Zengyuan[2] Zhao, Lei[2] Ji, Yongjie[1] Zhang, Yahong[1] Liu, Zhiqin[3]

第一作者：Zhang, Wangfei

通信作者：Li, Zengyuan

机构：[1] College of Forestry, Southwest Forestry University, Kunming, 650224, China; [2] Institute of Forest Resource Information Techniques, Chinese Academy of Forestry, Beijing, 100091, China; [3] College of Ecology and Soil and Water Conservation, Southwest Forestry University, Kunming, 650224, China

年份：2018

卷号：10

期号：2

外文期刊名：Remote Sensing

收录：EI(收录号：20180904849564)

语种：英文

外文关键词：Plants (botany) - Polarimeters - Sensitivity analysis - Regression analysis - Mapping - Synthetic aperture radar - Mean square error

摘要：In this study, 27 polarimetric parameters were extracted from Radarsat-2 polarimetric synthetic aperture radar (SAR) at each growth stage of the rape crop. The sensitivity to growth parameters such as stem height, leaf area index (LAI), and biomass were investigated as a function of days after sowing. Based on the sensitivity analysis, five empirical regression models were compared to determine the best model for stem height, LAI, and biomass inversion. Of these five models, quadratic models had higher R2 values than other models in most cases of growth parameter inversions, but when these results were related to physical scattering mechanisms, the inversion results produced overestimation in the performance of some parameters. By contrast, linear and logarithmic models, which had lower R2 values than the quadratic models, had stable performance for growth parameter inversions, particularly in terms of their performance at each growth stage. The best biomass inversion performance was acquired by the volume component of a quadratic model, with an R2 value of 0.854 and root mean square error (RMSE) of 109.93 g m-2. The best LAI inversion was also acquired by a quadratic model, but used the radar vegetation index (Cloude), with an R2 value of 0.8706 and RMSE of 0.56 m2 m-2. Stem height was acquired by scattering angle alpha (α) using a logarithmic model, with an R2 of 0.926 value and RMSE of 11.09 cm. The performances of these models were also analysed for biomass estimation at the second growth stage (P2), third growth stage (P3), and fourth growth stage (P4). The results showed that the models built at the P3 stage had better substitutability with the models built during all of the growth stages. From the mapping results, we conclude that a model built at the P3 stage can be used for rape biomass inversion, with 90% of estimation errors being less than 100 g m-2. ? 2018 by the authors.