Tips for Using SurferŽ

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Surfer rocks! Golden Software, Inc. designed Surfer 8 for serious analytical work, but you don't need to be an engineer to enjoy the maps produced by the program.

The free trial version is remarkably functional. It renders beautiful 3D images from digital elevation matrices that you can easily download from the Internet. You have complete control over the orientation of the view, color gradients, line density and other factors. Wire frame views can be made to look like engravings.

Following are a few ideas to help you begin exploring Surfer's potential.

  • After starting the program, disregard the File/Open command that you might normally begin with. Have an empty plot document ready and then note the tool icons along the right side of the screen. Click on the shaded cone on the bottom of the tool bar to create a 3D surface like the Mississippi River bluffs above.
  • An "Open Grid" dialog box (below) appears. Use the file manager to locate a Digital Elevation Model (DEM) grid to examine. Surfer will open a variety of grids:
  • STDS Digital Elevation Models from the US Geological Survey are one of the most readily available North American grid types. The Digital Grove Links page has a number of data sources that offer free STDS format DEM data. All of the other types of elevation grids read by Surfer are also available on the Internet. If you have a registered copy of Global Mapper, many additional grid types can be converted to the Surfer Grid (*.grd) format for viewing with the Surfer trial.

 

If you download a SDTS DEM file, it will be named with a format like "1693459.DEM.SDTS.TAR". The "TAR" extension means that it's an archived zip file. If you've been using Global Mapper to view data, that program does not require the TAR file to be unzipped. Surfer (and 3DEM for that matter) requires that you unpack the "tar ball" with a program like Ultimate Zip. When you extract the data, you'll get a series of files like those on the left, all ending in "DDF". Keep the files associated with the archive together in one folder and do not mix unzipped TAR files.  
  • Double click any of the DDF files, and Surfer will create a surface something like this image:

  • In situations like this one, you will need to reduce the vertical "Z-scale" exaggeration. To make the adjustment, either double-click or right-click the image and choose "Properties". The following box opens:

  • Under the "Scale" tab, change the "Length" of the Z factor to a smaller value to bring the peaks down to a more realistic size. You may need to enter a value as small as .10 to get a realistic view, although some vertical exaggeration can be useful. The 3D surface will be redrawn:

  • You can then zoom into the 3D surface map or use the Trackball Tool to change the position of the view. Double-click the image again to go back to the Properties menu. Try the other property tabs to change elevation colors, add a mesh or make other adjustments to create a view you like:

  • Use other tools on the right side of the Surfer project screen to create a wireframe model, a shaded relief map, contour map or other surface maps.

  • Note that when you start a wireframe, Surfer will initially squeeze the entire grid into a very small area, creating a dense black view (below left). You'll need to adjust the z-scale as above and then zoom into an area of interest for a workable image. The magnified image on the right shows a small section displaying the x and y lines. In this example, colors were inverted and adjusted through post processing in an image editor.

  • You control which wireframe lines to draw (x, y or z) through the "General" tab in Wireframe Properties dialog. To add line color that changes with elevation, click on "Line" under the Color Zones tab. That will open another box where you can set the minimum and maximum elevation colors. Surfer will automatically create a color line gradient from bottom to top:

The rich set of options make the program a cartographer's playground.

Surfer has many other functions ...experiment with the program and check the online help system. Visit Golden Software to learn more or to download the program.

 

 

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