G438 - Introduction to GIS

Question: How do I convert a vector dataset to a raster dataset in ArcGIS?

Answer: This can be done in a few different ways in ArcGIS, the method depends on what type of vector dataset you have:

1) Converting a vector coverage (ArcInfo) to a raster grid

Open ArcToolbox, select Conversion Tools - Import to Raster - <cov-type> Coverage to Grid

Where <cov-type> is Point, Line or Polygon

A dialog box will appear, enter the name of the coverage, the attribute in the coverage to be used for the cell assignment, the cell size for the output raster grid and the name for the output raster grid.

2) Converting a shapefile or geodatabse dataset to a raster grid

In ArcMap, go to Tools and select Extensions. Check the box for Spatial Analyst (note, this requires the machine you are working on to be licensed for Spatial Analyst. All the machines in SB 221 do have a license for Spatial Analyst). Then in the main ArcMap session, select View - Toolbars - Spatial Analyst. This will open the Spatial Analyst Toolbar. In the Spatial Analyst Toolbar select Convert - Features to Raster. This will open a dialog box where you can select the vector dataset, the attribute for the cell assignment in the output raster dataset, the cell size for the output raster dataset and the name of the output raster dataset.

Special usage notes:

1) As with all data conversions, pay careful attention to the parameters used. The cell size in particular is critical for the data representation in the output raster dataset.

2) Be careful which features are selected when using the ArcMap method of converting vector data to raster data. If you have 10 of 20 polygons selected when you perform the Features to Raster conversion, then only those polygons will be converted.