To perform terrain analysis in Maptitude using the Terrain Analysis Toolbar, you need to import a DEM (Digital Elevation Model) Grid layer. Unfortunately, the USGS doesn’t provide layers in this format anymore. However, you can convert the format they currently provide into a usable DEM. The following article will explain how to do this.
First, download a contour for your area of interest from the USGS: https://viewer.nationalmap.gov/basic/#/
Next, unzip the contour and add it to your Maptitude map:
1. In Maptitude, choose Map>Layers and click Add Layer
2. Change the file format to Shapefile (.shp) and browse to your unzipped folder and add the contour.
You can use contours like these to create your own grids and in turn use those for the Terrain Analysis toolbar:
1. Zoom to an area of interest in the contour
2. Choose Tools>Editing>New Grid Layer
3. Choose Point then set the grid size to something appropriate. For example, you can choose Cover the map window with cells of a fixed size and set the grid spacing to 0.1 miles for X and Y.
This creates a grid layer over your area of interest. We can now tag all points in this layer with the respective elevation from the nearest contour line:
1. Right click on your Grid layer and choose New Dataview
2. Right click any column header and choose Modify
3. Click Add Field and change the Field Name to Elevation then click OK and Yes to save your changes.
4. Right click your new Elevation field and choose Fill.
5. Select Tag then choose the Contour layer and the ContourEle field to tag it with. This tags each point in the grid with the elevation of the nearest contour.
6. Click OK. The tagging may take some time depending on how large the area is that you’ve selected
Finally, we just need to do one final conversion to a standard geographic file which can be used with the Terrain Analysis Toolbar:
1. Make your tagged grid layer the Working Layer
2. Choose File>Export>Geography
3. Change the To field to Standard Geographic File, change the Layer Name to Grid dbd, check the box for Add Layer to Map and click OK, then choose a location to save the dbd and save it.
4. Finally, right click your original Grid layer and choose Remove to remove it.
You should now be able to use the Grid dbd layer with the Terrain Analysis Toolbar.