Background
Phenology, the sequence and timing of plant developmental stages and their relationship with climate, provides a foundation for many agricultural studies. Conventional phenologic measurement involves periodic physical observation of growth and development.
Crop phenologic information can also be acquired from vegetation indices derived from satellite images which provide regular measurements of crop growth, due to their consistent revisit frequencies
Plotting a series of vegetation index data over time produces a curve that provides an overview of the seasonal crop growth. Parameters or metrics derived from this curve can be used to detect the important phenological events of the crop. Some of the major phenologic metrics are start of season (Onset), time of start of season, maximum vegetation index, time of maximum, End of season (Offset), time of end of season, length of the growing season and time-integrated vegetation index.
MODIS is one of the most widely used imagery for phenologic studies.
