Management Zones maps are generated based on the combination of Vegetation Index maps, through a process called 'cluster analysis'. It's also possible to include information from previous yield monitor maps if available.
This is a procedure relatively simple, automated and objective, that allows to compare the field production and variability in different times, in a single map. Remote sensing imagery is selected in key dates, when crops are vigorous, and Vegetation Index (NDVI) maps are generated on those dates. These layers are then normalized, and integrated in the management zone map.
Methodology - Cluster analysis
A cluster is a predefined area, for statistical analysis purposes. For instance a cluster could be the pixel of a satellite image, such as 30x30 mts for Landsat images, 15 x 15 mts for Aster images, or 10 x 10 mts for Spot images. Once the Cluster area is defined, a normalized NDVI map is generated, with a grid with the cluster size.
the following sample images and corresponding NDVI illustrate the process:
//insert images in the table
Image:IMAGEN_1.jpg Imagen Landsat 25-01-2006
279x200px Imagen Landsat 06-01-2005
300x200px Imagen Landsat 08-03-2004
These images are integrated by analyzing each cluster, defining homogeneous production areas, and obtaining the management zones map.