文献类型：期刊文献

英文题名：Temporal Polarimetric Behavior of Oilseed Rape (Brassica napus L.) at C-Band for Early Season Sowing Date Monitoring

作者：Yang, Hao[1,2] Li, Zengyuan[1] Chen, Erxue[1] Zhao, Chunjiang[2] Yang, Guijun[2] Casa, Raffaele[3] Pignatti, Stefano[4] Feng, Qi[1]

第一作者：Yang, Hao

通信作者：Chen, EX[1]

机构：[1]Chinese Acad Forestry, Inst Forest Resource Informat Tech, Beijing 100091, Peoples R China;[2]Beijing Acad Agr & Forestry Sci, Beijing Res Ctr Informat Technol Agr, Beijing 100097, Peoples R China;[3]Univ Tuscia, DAFNE, I-01100 Viterbo, Italy;[4]CNR, Inst Methodol Environm Anal, I-85050 Tito, PZ, Italy

年份：2014

卷号：6

期号：11

起止页码：10375-10394

外文期刊名：REMOTE SENSING

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000345530700006)】；

基金：This work was supported in part by the National Basic Research Program of China (Grant No. 2013CB733404), the National Natural Science Foundation of China (Grant No. 41401477), National science and technology support project (Grant No. 2012BAH29B04), and ESA-NRSCC Dragon III Projects (10448). The authors would also like to thank the four anonymous referees who have helped improve the original manuscript.

语种：英文

外文关键词：RADARSAT-2; SAR; sowing dates; polarimetric features; polarimetric decomposition; rapeseed

摘要：Spatial monitoring of the sowing date plays an important role in crop yield estimation at the regional scale. The feasibility of using polarimetric synthetic aperture radar (SAR) data for early season monitoring of the sowing dates of oilseed rape (Brassica napus L.) fields is explored in this paper. Polarimetric SAR responses of six parameters, relying on polarization decomposition methods, were investigated as a function of days after sowing (DAS) during the entire growing season, by means of five consecutive Radarsat-2 images. A near-continuous temporal evolution of these parameters was observed, based on 88 oilseed rape fields. It provided a solid basis for determining the suitable temporal window and the best polarimetric parameters for sowing date monitoring. A high sensitivity of all polarimetric parameters to the DAS at different growing stages was shown. Simple linear models could be calibrated to estimate sowing dates at early growth stages and were validated on an independent data set. Although Volume and Span parameters provided the highest sowing date estimation accuracy at the earlier growth stages, the other four parameters (Volume/Total, Odd/Total, Entropy and Alpha) were more accurate for a wider temporal window. These results demonstrate the capability and high potential of polarimetric SAR data for monitoring the sowing date of crops in the early season.