True Color imagery shows natural red, green and blue band colors, similar to how the human eye would see the field. Color imagery provides an opportunity to identify areas potentially in need of greater water management and the effects of management systems; e.g., turnarounds in the headlands and planter skips. Additionally, it can be used to perform an initial quantification of lost production acres.
NDVI (Normalized Difference Vegetation Index) calculated index is used to monitor crop health and vegetation density. The higher the index value, the greater the crop health and density. A color gradient is applied to make the image easier to interpret. A commonly used gradient is red to green, with red representing the low values and green the high. Typically, four colors are used, with each accounting for approximately 25% of the field. This is similar to how a yield map represents data.
Thermal imagery can be used to look at differences in plant or soil temperature and water transpiration, thus can potentially provide early detections of irrigation malfunctions, even before it results in variation in the vegetation.