4. Electromagnetic Interactions with the Earth’s Surface

The objectives of this section are to describe and explain how incident electomagnetic radiation (Visible, Near Infrared and far infrared) from the sun is changed when it impacts vegetation, soil and water. The reflectance plotted against wavelength is a major feature of this discussion and general effects are discussed in relation to this.

It should be noted that the concepts explained are an introduction to this topic area, classifying plant/soil/water types in remotely sensed data is much more complex in reality because vegetation shape, shadows and other factors not discussed can have strong effects on measurements. Classifying cover types is often a technique that must be customised on a case by case basis.