The Cell Statistics function

You can use the Cell Statistics function to find trends or detect change between corresponding cells in multiple raster surfaces. The assessment works exactly like the mathematical operators in the Raster Calculator, such as multiplying or adding raster datatsets together.

In this case, however, the function uses one of the statistical methods mentioned previously to compare the corresponding cells. For example, you can create a raster with cell values indicating change from one land use type to another.

In this example, the middle layer was developed three years before the top layer. In the resulting raster, the gray cells indicate where more than one land use value has occurred. The Cell Statistics function is like sinking an elevator shaft through the matching cells of each raster dataset.

Monitoring change in the landscape is a way of discovering trends in urban development, habitat loss, and crop management, for example. To monitor the change in the landscape, you need snapshots of the data for an area that show the area's conditions at different points in time. Once you have the snapshots you can compare them using the Cell Statistics function to see where changes have occurred.