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

Remote Sensing

Hao Yang⁵  Zengyuan Li⁵  Erxue Chen⁵  Chunjiang Zhao³  Guijun Yang³  Raffaele Casa²  Stefano Pignatti⁴  Qi Feng⁵  Nicolas Baghdadi¹ 

[1] Institute of Forest Resource Information Techniques, Chinese Academy of Forestry, Beijing 100091, China;;Department of Agriculture, Forests, Nature and Energy (DAFNE), Universita’ della Tuscia, Viterbo 01100, Italy; E-Mail:;Beijing Research Center for Information Technology in Agriculture, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China; E-Mails:;Institute of Methodologies for Environmental Analysis, Consiglio Nazionale delle Ricerche, Tito Scalo (PZ) 85050, Italy; E-Mail:;Institute of Forest Resource Information Techniques, Chinese Academy of Forestry, Beijing 100091, China; E-Mails:

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

DOI  :  10.3390/rs61110375

来源: mdpi

【 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.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.