The red portion of the electromagnetic spectrum is one of the areas where chlorophyll strongly absorbs light and the NIR is where the leaf cell structure reflects strongly. To illustrate this, the three segments in the above figure show the reflectance values as recorded by the satellite’s Red Edge band for each of the three plant spectra shown. These spectra come from plants with varying levels of vitality, which is reflected by the values at the Red Edge band, together with the other two bands. The different reflectance values show how the Red Edge band provides additional information to characterize plant spectra at different vitality levels. Red Edge band sensitivity to differences in leaf structure and Chlorophyll content can have useful applications on precision agriculture and resource monitoring and management.

Agriculture

Crop yield strongly depends on an adequate supply of nitrogen (N). Therefore, knowledge about N-status represents an important factor for agricultural management. Additionally, N-fertilizer is one of the largest input cost factors of many crops such as corn, wheat and rice, which makes the assessment of the N-status of a crop critical for optimal fertilizer management. N-status cannot be directly measured through the imagery, but it can be estimated through indirect indicators. The N-status of crops can be assessed through Chlorophyll measurements.