Precision agriculture is a farming management concept based on observing, measuring, and responding to inter & intra-field variability in crops. The farmer’s and/or researcher’s ability to locate a precise position in a field lets him create maps of the spatial variability of as many variables as can be measured (e.g. crop yield, terrain features/topography, organic matter content, moisture levels, nitrogen levels, pH, etc.). Precision agriculture has been enabled by technologies like: crop yield monitors mounted on GPS-equipped combines; variable rate technology (VRT) like seeders, sprayers, etc,; an array of real-time vehicle mountable sensors that measure everything from chlorophyll levels to plant water status; and multi- and hyper-spectral aerial and satellite imagery, from which products like Normalized Difference Vegetation Index (NDVI) maps are made.