When the season and year information is entered, a link to the Surface Roughness Slicer tool is shown. On this page, the user can choose view the underlying NLCD data, and choose the number and location of slices (sectors) to be analyzed, based on the NLCD classes. In general, this is a very subjective process, but we provide a single number* as feedback to help the user optimize the slices as they are chosen. Here is an example where the user has chosen 2 slices:

Note the text minimize this value, and the number that follows. This gives some feedback as to the overall quality of the selection. For example, compare that to the case where the user has chosen 2 different slices that do not seperate the urban (red) from non-urban near as well:

The value is higher. Therefore, these slices are not as good.

In both of the above cases, for the chosen angles, a table of surface roughness by season and slice is shown. It takes about 1 second for that table to appear each time the user submits a new set of angles for calculation.