Get fGIS here

Getting Started with SurGe Gridding and Mapping Software

SurGe opens with a Project Manager to locate data files and to set the basic parameters of your mapping project. This enhanced interface is new to SurGe version five. It's a pleasure to use with well-organized features.

You'll need to load a basic data file to begin. Input data must be in a tab (or space) delimited text file organized in four columns with the x-y coordinates of each data point, the data value (z) and a label. A technique for creating data files follows, below.

SurGe employs an inventive file naming convention. Data files must end with a three letter extension starting with "dt" (e.g., "project_name.dt_"). The third letter (the "suffix") can be the characters a-z or 0-9. The suffix can be used to distinguish different versions of your data set. Suffix "a" might be the original data, where "b" might be a percentage of the original or some other factor you want to compare to the original.

Type in a data file name prefix or use the "Find" button to browse folders. (If this is the first time you've used SurGe, the program comes with a folder that includes a couple of examples that you can experiment with. Additional sample data used for the maps on this page are available as a zip file, below.)

After locating the data files you want to map, click the "Run SurGe" button.


SurGe Example

I prefer to begin a project by making a map boundary. Without a map boundary, the color gradients will flow to the edge of the screen.

In this case, I've opened a data file that has points around the edge of the State of Wisconsin outline. To create a boundary file, press Enter on the keyboard (which causes SurGe to enter a digitizing mode) then type Ctrl-H (which starts a boundary). Left click each boundary point in sequence (like a dot-to-dot coloring book) to create a boundary polygon with a red line. Type "U" to close the polygon, and then choose Object/Save. Boundary files may contain up to 777 points.

A boundary is saved as "project_name.HR". You can re-use the boundary with other projects by copying the file and renaming the prefix to match your actual project name. SurGe will automatically load the boundary file (n.HR) if it is present with a data file (n.dt_) that has the same prefix name (n).

See the procedure below for creating the points for a data file.

The next step is to open the project's data points. If the project has a pre-existing boundary file (made as explained above), it will also be loaded.

SurGe needs to create a grid file for the data before it can display color contours or other maps. Choose "Interpolation/Calculate Grid" from the menu bar. A DOS window will open that runs a subprogram to calculate the grid. You are given the opportunity to enter a number of parameters. The basic one to change from the default on the first run is the grid size in the X direction. That determines the size of the map that will be produced. You might want to start with X set at about 300 (circled in red). You can increase the value later if you want a larger map.

The program will set a proportional height (Y=320, above), which you should accept by pressing Enter. Press Enter to accept each of the other defaults on the first run. When the subroutine is finished, press Enter to return to the main SurGe screen.

You are almost ready to make data maps.

First, be sure you have completed the step above to calculate the grid. If you want to make an isoline map, you will also need to calculate isolines as shown in the menu selection on the left.


Next, tell Surge to blank out the area outside of the map boundary as shown below:




Now make your maps. From the menu bar, choose "Display" and pick either Isolines (right), Color Map (above), or 3D View (below). Use the keyboard shortcuts if you wish. You can choose whether or not to display point labels and values, the color scale and other options.

3D View is a separate mode with additional menu choices that customize and move or rotate the display. If you make a 3D View, SurGe will ask how many "steps" to read the grid file. The step value will set the cell size. A step of 3 is shown on the left, with a step of 10 on the right.


SurGe offers many options for adjusting the interpolation parameters, defining fault lines, making cross sections and other features. See the user manual for details.


Making Data Files

The challenge in using SurGe is understanding how to create the text files used either for boundary or data points. My technique involves three freeware programs and a spreadsheet program like Microsoft® Excel:

  1. Use fGIS to digitize either boundary points or data point locations into a shapefile. Load a raster image or vector data into fGIS as a reference basemap. Create a new point shapefile layer in fGIS to hold either boundary points or data points that you want to map in SurGe.  Digitize the points in fGIS and save the shapefile. If you don't know how to operate fGIS, see fGIS Help. (Data points can also come from other sources, such as GPS data.)

  2.  Next, you need to convert the shapefile points from step 1 into a tab-delimited data file for use in SurGe.

    1. Open the shapefile with the freeware Massachusetts DXF Author and convert it to a DXF file.

    2. Open the DXF file in the freeware program DXF2XYZ. DXF2XYZ can convert the DXF file to a comma delimited text file with three columns.

    3. Start Excel and import the XYZ text file. If you are making a boundary file, the z values can be set to zero. A fourth column with a dummy value must also be added if you are making a file for boundary points. If you are making a data file, you can enter the actual z values (third column) and labels (fourth column) at this time. Save the file as a tab-delimited text file.

    4. Use Windows Explorer to rename the tab-delimited text file to have a ".dt_" extension as explained above.

That's all there is to it. If you wish, you can set or modify the values of data points within SurGe. There are also other methods to create data text files to use in SurGe (it's easier, for example, if you have the registered version of Global Mapper), but the above technique works at no cost.

If you'd like to experiment with my data files used in the example above, download and unzip the following file: (268 KB)

The data in the zip archive shows the acreage of family-owned (non-industrial, private) forest land in each Wisconsin county. The zip archive includes data (dta), boundary (HR), grid (GRa) and isoline (vra) files, so you can immediately go to the display options.

You can substitute other Wisconsin data for the z values in the "dta" file and re-use the boundary file (if you rename the file prefix to match the data file). Here, for example, is a color contour map of the acreage planted to corn for grain in 2001:

Additional agricultural statistics can be found at:

Download a copy of SurGe here (GeoCities) or here (Czech site).



Return to the ForestPal Toolbox


- Copyright © 2007-2011 -
Web Statistics