Spatial resolution offers great value in monitoring crop appearance, but it is spectral data that reveals the most information about plant stress and health. An important point to keep in mind is that hyperspectral, multispectral, panchromatic, and even radar images are each individual tools that provide a complete picture of crop condition when they are used together. This is why Research Systems, for example, has integrated the ability to process all these remote sensing data types into one software package. The objective of satellite and airborne remote sensing in precision farming is to provide farmers with detailed crop condition information that can be used to program variable-rate technology equipment. Application of water, pesticides or fertilizer can be tailored to the needs of the crop, based on conditions seen in the imagery.
Plant health is a major factor that dictates the amount of energy reflected.
The difference between multispectral and hyperspectral imagery is the detail of the spectral signature. Most multispectral sensors take one measurement in a wide portion of each major wavelength band, such as visible blue, near infrared, etc. Hyperspectral, on the other hand, measures energy in numerous narrow units of each band. As a result of this higher number of measurements, the hyperspectral signature is more detailed and contains more specific information about crop health. But, the many narrow bands in hyperspectral imagery can potentially indicate whether stress in caused by water depletion, insect infestation, or poor fertilization.