1. Raster Analysis Raster math Topography: Slope, aspect, contours Reclassify Raster / Vector Conversions Statistics: min, max, mean, std. dev. –Local, Neighborhood, Zonal Histograms No Data / Null Value Issues Future: –Distance (cost)

2. Jim’s Secrets for Rasters Keep the overall size of the rasters below 200 Meg Use “Resample” to convert to relatively small “IMG” files (or GRIDS) –Data Management Tools -> Raster -> Raster Processing -> Resample Watch “Results” for errors –Geoprocessing -> “Results” Use “Task Manager” when Arc crashes

3. Task Manager Right Click on Menu Bar, “Start Task Manager” “End Process” on all “Arc” processes

4. Raster Statistics Local –Operate on one pixel in each raster Neighborhood (or Focal) –Operate on a few pixels around each pixel Zonal –Collection of regions –Region is a contiguous area of the same pixel values Global –Operate on the “whole” raster

5. Local Stats “Cell Statistics” computes stats on all the values for a pixel in a multi-band raster. Example for “Sum”: Esri ArcGIS 10 Help

6. Neighborhood (or Focal) Result=Operation on pixels nearby 1220233440 1523303139 1522293040 1420282938 1319253237 Columns Rows

7. Focal Statistics Computes stats on pixels around an existing pixel Example for Sum: Esri ArcGIS 10 Help

8. Zonal Statistics Computes statistics for defined regions (features) Tools: –Zonal Statistics: Outputs a raster (not sure of the value) –Zonal Statistics as Table: Outputs a table Used to compute all kinds of valuable things: –Percent land cover –Percent impervious cover –Percent water below a certain depth –Etc.

9. Zonal Statistics Esri ArcGIS 10 Help Zone Layer Value layer Output layer (or table)

10. Con(,, ) Given a raster “condition”: –Puts the true value where true and false value where false Conditional Operator Con!

11. Elevations over 3000 meters Con("W100N40.DEM“>3000,0,1)

12. Elevations over 3000 meters

13. Issues with No Data

14. Issues with Signed Data

15. Convert Values to “No Data” SetNull("W100N40.DEM"==55537,"W100N40.DEM")

16. Rasters Draw as “Solid” Color Click on “Type:” and select “Minimum- Maximum” ArcGIS will compute statistics

17. Histograms

18. Exporting Histograms

19. Titles and Axis Labels!