A Modified Shape Model Incorporating Continuous Accumulated Growing Degree Days for Phenology Detection of Early Rice

Using a shape model (SM) is typical method to determine the phenological phases of crops with long-time-series satellite remote sensing data. The average AGDD-based (AAGDD-SM) takes temperature into account compared SM, however, commonly used daily not sufficient exact AGDD owing possibly significant changes in temperatures throughout day. In this paper, modified was proposed for better estimation dates and it incorporated continuous (CAGDD) which calculated based on from 24 h within day, different calendar day or indicators. study, CAGDD replaced abscissa NDVI growth curve over 5-year period (2014 2018, excluding 2015) test site early rice Jiangxi province China. Four key phases, including reviving, tillering, heading anthesis were selected determined reference field-observed results show that AAGDD-SM, paper has basically improved prediction each period. For those cases where lower than minimum (K1) but effective accumulated zero, more accurate can be according paper.