GMS:Raster Data Workflow

Raster data can be imported and manipulated using the following steps:

1. Import raster data.

1. Import raster data files. Load raster data from local computer files using the File | Open... command. Alternatively, drag and drop the file into the Graphics Window in GMS. 2. Import lidar data files. Load lidar files using the File | Open... command. Alternatively, drag and drop the file into the Graphics Window in GMS. Select import options in the Lidar Load Options dialog. 3. Import raster data from the web. Use the Add Online Maps macro. Select a location in the Virtual Earth Map Locator. If a projection has not been set for the project, set a new project in the Display Projection dialog. Use the Data Service Options dialog to select a web service.

2. Set raster display options.
Open the Display Options dialog. Set the GIS display options.

3. Manipulate raster data.

1. Trim the raster. Select a coverage (or create a new coverage) in the Map module. Select the Create Arc tool and draw a closed set of arcs. While the arcs are selected, go to Feature Objects | Build Polygons. Use the Select Polygon tool to select the polygon just created. Right-click the raster data in the Project Explorer and select Convert To | Trimmed Raster. Save a file with the trimmed data. 2. Resample a raster image. Right-click on the raster object in the Project Explorer and select the Convert To | Resampled Raster command. Use the Resample and Export Raster dialog to specify how to resample the image data values. Save the new resampled raster file. 3. Merge mulitple rasters. Select two or more raster items in the Project Explorer by holding down the Shift key while selecting each item. Right-click on one of the selected objects and select Convert To | Merged Raster. Save a file with the merged data.

4. Convert raster data.

1. Convert raster data to feature contours. Right-click on the raster image and select the Convert To | Feature Contours command to create a new map coverage with elevation contours. 2. Convert raster data to feature contours at a specified elevation. Right-click on the raster image and select the Convert To | Feature Contours at Given Elevation command. In the Create Contour Arc dialog, specify an elevation and click OK to generate a map coverage with contours created along the specified elevation. 3. Convert raster data to 2D scatter set. Right-click on the raster image and select the Convert To | 2D Scatter command. In the Raster → Scatter dialog, give the scatter set a name and click OK to generate the scatter set. 4. Convert image data to 2D grid. Right-click on the raster image and select the Convert To | 2D Grid command. 5. Convert image data to UGrid. Right-click on the raster image and select the Convert To | UGrid command. Select conversion option in the UGrid Points Vs. Cells dialog.

5. Interpolate raster data.