By Andrew Dudley on Tuesday, 19 April 2016
Category: Surfer

Quickly Interpolate Elevation Data with Raster Tools

A classified raster layer in ArcMap generated from Raster Tools overlaid with a roads shapefile.

Golden Software’s new Raster Tools add-in for ArcMap leverages Surfer’s 12 different gridding methods directly in the ArcMap ecosystem to create accurate and precise raster datasets from your point data with only a few clicks. Raster Tools is a wizard-based add-in that walks you through all of the necessary interpolation parameters that have been elegantly laid out on 3 pages, so you have quick access to select an interpolation method, customize neighborhood search parameters, choose output raster extents and resolution, and more.

For today’s blog post, I would like to walk you through an example of interpolating elevation point data using the Raster Tools add-in, so you can see how user friendly and easy this new tool is to use. To start things off, I am going to add some elevation data from Oahu (near Honolulu) to ArcMap. Now that the elevation data has been added to an ArcMap project, I am going to start the interpolation by clicking the Raster Tools tool bar and choosing Raster Tools | Interpolation Wizard.

The first page of the Interpolation Wizard opens. On the left-hand side, I can choose from any of the 12 interpolation methods, where each have a nice help tip describing the method.  On the right-hand side of the page, I can choose the dataset I want to interpolate, which field I am interpolating, and how to handle duplicate points with the data (if there are any). For this example, I am going to select the ever-popular Kriging as my interpolation method.

The first page of Raster Tools Interpolation Wizard.

After clicking Next, the second page of the Interpolation Wizard opens.  On this page, I get a quick look at the statistics surrounding the data and a preview of the data point dispersion with an overlapping search ellipse. Since I selected Kriging for my interpolation method, I have the option to pick Kriging-specific parameters on this page. I am working in ArcMap, so I will select the Block Kriging type, which estimates the average value of the cells centered on the grid nodes.  I am also going to use a custom search neighborhood because I don’t want all of the data to influence the resultant interpolated points. I think a search radius of 3000 will work well for the data dispersion of this dataset.

The second page of the Interpolation Wizard showing the search neighborhood options among other interpolation parameters.

I don’t have any breaklines for the area that need to be included in the interpolation, so I’m going to click Next to go to the final page of the wizard. On the third and final page, I can set the output raster’s resolution and extents. The data I’m working with is in meters and I’m working on a large scale mapping project, so it makes sense to generalize a little bit and use a cell size of  25. I am also going to leave the extent parameters as-is because I can clip the raster later in ArcMap, if necessary. Finally, Raster Tools writes the output raster in ADF, IMG, and TIF format in personal geodatabases, file geodatabases, or simple file folders.  The default output raster is ADF, which I’m OK with, and I’m going to click next to Filename to name the raster and click Finish to start the interpolation and save the output raster to the project’s default geodatabase.

The third page of the Interpolation Wizard, where the output raster parameters are assigned.

Now that the interpolation has quickly completed, a new raster layer has been added to my ArcMap project. I can now use the tools available in ArcMap for customizations like changing the symbology, adding a hill shade effect, adding vector files, etc. I also now have the ADF file that was added to the default geodatabase for use in other ArcMap projects and 3rd party applications.

The resulting raster layer created from Raster Tools added to the ArcMap project.

As you can see, Raster Tools is a quick and easy way to interpolate data directly inside of ArcMap, using the intuitive controls and powerful options Surfer offers! For more information, visit the Raster Tools product page, or test it our yourself with the free 14-day trial!

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