Satellite images covering the visible, near infrared and thermal infrared part of the electromagnetic spectrum have now been established as a powerful tool for precision agriculture. Thanks to the very frequent monitoring of Earth’s surface, satellite images provide high temporal-resolution information, which plays a key role both in crop monitoring and the related decision making process.
The spectral response of the vegetation is mainly influenced by the presence of pigments, the cellular structure and the water content of the leaves. Starting from the digital information registered in satellite images, it is possible to produce distinct indexes, such as the Vegetation Index and the Green Index, which provide direct information regarding the phenological state of vegetation. Furthermore, satellite data can provide very useful information regarding soil humidity monitoring and how to control the irrigation process, the detection and control of plagues, the detection of thermal anomalies in areas under water stress, forest fires prevention, and, finally, the monitoring of crops and productivity.
Landsat imagery courtesy of NASA Goddard Space Flight Center and U.S. Geological Survey