Focus Suitable Aspect Layer Suitable Slope Layer Suitable Elevation Layer High Radiation Layer Human Mask Desirable Location Layer Aspect mask An aspect raster was generated from the georeferenced image. From this new aspect raster, a binary aspect raster was created by selecting all the cells that had south, southeast, southwest, or flat aspects and assigning them a value of 1. A low-pass filter was used on the georeferenced image to generate a smoother aspect raster and facilitate the analysis of the final output of the GIS. Slope mask The slope mask was generated in a manner similar to the aspect mask. Using the filtered georeferenced image as an input, a binary raster was created by selecting all cells with a slope less than or equal to 35 degrees and assigning those cells a value of 1. Output from Submodel All criteria are met? No Not Suitable/ Remove Radiation mask A minimum radiation threshold was selected based on the desired power output. Once again, a greater-than conditional block was used to generate a binary raster. Cells equaling or exceeding the threshold value were assigned a value of 1. Human mask A human using knowledge of the area, maps, and visual inspections can eliminate undesirable sites (e.g., the area outside the president's office window; athletic stadium seats; roofs with pipes, air conditioning units). Finding Suitable Locations To find feasible locations for the solar panels, all the binary rasters were combined into a final raster that takes a value of 1 for locations that meet all conditions and 0 for those that do not. This algorithm was converted into ModelBuilder to automate the output generation process. The model uses six main inputs: the DEM, the aspect raster, the slope raster, the radiation raster, the bare earth raster, and the analyst mask. Yes Final Output Suitable Sites/Use Flowchart showing the selection process Ground mask A bare-earth file was generated from the LiDAR data and georeferenced to the same coordinates as the input image. A binary ground raster was generated that identified nonground cells by assigning a value of 1 for any cell greater than or equal to the bare earth value plus five feet and assigning 0 to all others, which were ground cells. ModelBuilder model for generating feasible aspect and elevation rasters Continued on page 26 www.esri.com ArcUser Fall 2010 25