Study of Spectral Reflectance Time Series and Vegetative Indices of Sugar Beet Fields Using MODIS Data

Remote sensing technology is widely used in environmental and agricultural research, and nowadays it has become a valuable and reliable source of information for the management of crop production and assessment of global supply and demands for these products. The objective of this study was to investigate the feasibility of using MODIS data and vegetation indices based on sugar beet growth monitoring. For this purpose, MODIS 8-day red and near infrared surface reflectance data at 250 m spatial resolution (MOD09Q1 collection 5) was used. Imagery data was acquired from mid-May to the end of December 2011 from the sugar beet fields located in Eqlid, Fars province, Iran. Results showed that although red and near infrared reflectance differences were relatively small at the beginning of sugar beet growing season, these differences were enhanced with canopy development and ground cover. The most red absorption and near infrared reflectance were in the maximum ground cover, and the most dramatic declines in the near infrared reflectance and relative increase in red reflectance were observed at harvest time. It was found that the RVI is able to show the status of red absorption and reflection during the growth of sugar beet canopy. The SR and NDVI change patterns demonstrated how to grow sugar beet over the growing season. Thus in the existing climate and crop management conditions in Fars province and Iran, MODIS data and vegetation indices can be used to monitor changes in canopy growth of such crops as sugar beet.