Issue 62

Converting Post-processed MapViewer 7 Data to Display on Google Earth

Whether you have points, lines, or polygons, converting your post-processed MapViewer 7 vector data to KML format is easy by following the steps presented below. In this example, we will use US Geological Survey sample data depicting high magnitude earthquakes to generate point locations across the globe, export them from MapViewer 7 as a shapefile, convert the shapefile to the Google Earth file format KML, and display the event location from the past 100 years overlaid on a Google Earth surface.

MapViewer 7

Golden Software's MapViewer 7 is a comprehensive thematic mapping and spatial analysis software package for business, science, and education. You can easily visualize data distribution geographically by creating publication-ready maps in 13 different map types with many customizable features.

A Small, Free Download

With the increasing popularity of the Google Earth Community, MapViewer users' have developed a desire to display post-GIS processed features on the Google Earth model. Data aggregated in MapViewer 7 requires conversion to display on a Google Earth model. There are a number of downloadable conversion utilities and web sites available for free online. For example, GPS TrackMaker® is a very simple and easy to use program. This article will discuss using GPS TrackMaker. Some other GPS data to KML conversion programs include Google Earth KML Creator, GPS Visualizer, and Expert GPS.

Background of KML Format

Keyhole Markup Language (KML) is an XML-based language used for managing the display of 2D and 3D geospatial data based on three required data fields: latitude, longitude, and altitude or X, Y, and Z. The KML format supports vector type geometry and connectivity including point, polygon, and linestring features. Conversion of post-processed data generated from Golden Software products is required for display on Google Earth in the KML file format using a small number of easy steps (see below).

In November 2007, the KML file format was submitted to the Open Geospatial Consortium, Inc.® (OGC®) to be classified as an OGC standard for all geobrowsers, namely Google Earth. In April 2008, the OGC officially endorsed the KML format, adding to the interoperability of major international earth browsers’ functionality and implementation. Both Google and the OGC agreed the KML language fit within the broad OGC Standards Baseline and will foster global sharing of geospatial information, deeming KML an OpenGIS® Encoding Standard.

Note: Golden Software only supports applications designed by our engineers, not shareware or any other free downloadable conversion utility.

Steps to Convert Data to KML and Display on Google Earth

1. The first step is the data acquisition process.
   1. Navigate to: USGS Earthquake Research page, which is a good source to view and download high magnitude earthquake events from 1900 through 2002.
   2. Click on the centennial.xls file.
   3. Click the Open button to open the data in Excel.
   4. In Excel, save the data to an XLS file.
   5. Close Excel.
2. Open the MapViewer 7 application.
3. Use the Map | Pin Map to create a Pin Map of the point locations of the high magnitude earth quake events that occurred from 1900 to 2002.
   1. When the Open Data File dialog appears, navigate to the XLS file created in Step 1, click Open.

       

      
      Figure 1: Open the downloaded data from the USGS.

       

   2. The Pin Map dialog will appear. Make sure your dialog looks the same as Figure 2 below.
      1. Set the Locating method to Coordinate.
      2. Set the PID column to Column A: icat.
      3. Check the box in front of Attribute 1. Set Attribute 1 to Column D: yr.
      4. Check the box in front of Attribute 2. Set Attribute 2 to Column O: M1.
      5. Set the X coordinate to Column K: gLon.
      6. Set the Y coordinate to Column J: gLat.
      7. Click OK.

       

      
      Figure 2: Set the Pin Map dialog parameters to generate a Pin Map.

       

4. Create different layers of the earthquake events by querying the earthquake data to select ranges of different magnitude earthquakes by using the Analysis | Query command. The Analysis | Query command builds a query statement or string that retrieves all points, lines, or areas that satisfy the statement. The statement can be designed in the Query dialog.
   1. Use Analysis | Query to access the Query dialog.
   2. Move to the Query section of the dialog.
   3. Select the word Select from the first drop down menu.
   4. Since the earthquake data is point data, highlight Points in the center section.
   5. To perform the query across all of the earthquake data within the map, select Map in the left-hand drop down menu.
   6. Move down to the Where section of the dialog, this is where you specify the criteria the query will perform. In the Where box, enter the query equation which reads Attrib2 >= “9”. These steps create a query statement that reads Select Points in Map Where Attrib2 >= “9”.
   7. Click OK. Executing this query statement will select all of the earthquake events that have a magnitude of 9.0 or higher.

       

      
      Figure 3: Use Analysis | Query to sort the earthquake data.

       

   8. From the Object Manager, click the Attribute 2 column heading and choose to sort by descending and click OK.
   9. You will notice the earthquakes with a magnitude of 9.0 or higher have been selected in the Object Manager, right-click on the selected earthquakes and choose Move to Another Layer.

       

      
      Figure 4: Select the group of high magnitude earthquakes and move them to a new layer.

       

   10. The Move to Layer dialog will appear, choose [New Layer] and click OK.

        

       
       Figure 5: The Move To Layer dialog moves the selected objects to a new layer.

        

   11. Move your mouse to the Layer Manager and double-click Layer #2 to make the layer active.
   12. Right-click on the selected layer and choose Rename; rename the layer Highest Magnitude Earthquakes.

        

       
       Figure 6: Rename the newly created layer from the previous step.

        

   13. Make Layer #1 active again, by double-clicking the word Layer #1 in the Layer Manager.
   14. Repeat the query steps a through g for the earthquakes with a magnitude from 8.0 through 8.9, 7.0 through 7.9, and 6.0 through 6.9. Your map should now have five layers including the original Pin Map layer.
5. Export the layers to Shapefile format.
   1. Select the Highest Magnitude Earthquakes layer in the Layer Manager by double-clicking it; the red arrow next to the layer will indicate which layer is active.
   2. Use the Edit | Select All command to select all of the points in the active layer.
   3. Use the File | Export command to export the layers as Shapefiles.
   4. When the dialog appears, navigate to the directory where you want to save the Shapefile.
   5. Change the File name to an appropriate name, such as Highest Magnitude Earthquakes.
   6. Change the Save as type to SHP – ESRI Shapefile (*.shp).
   7. Put a check next to the Selected objects only option.
   8. Click Save.
   9. The Export Options dialog will appear, accept the default parameters by clicking OK.
   10. The SHP – ESRI Shapefile Export dialog will appear, select the option Write Points to Separate File.
   11. Click OK.
   12. Repeat steps a through k until you export all of the earthquake event layers.
6. Download and install GPS TrackMaker from: http://www.gpstm.com/.
7. After GPS TrackMaker is installed start the application.
8. Convert the Shapefiles exported from MapViewer to KML in GPS TrackMaker with the following steps.
   1. Use File | Convert Files to access the Convert Files dialog.
   2. Once the dialog appears, navigate to the directory where you exported the Shapefiles in Step 5 in the Origin Directory and File Format box.
   3. The Open File dialog will appear; change the Files of type drop-down menu to ArcView Shapefiles (.shp).

       

      
      Figure 7: GPS TrackMaker allows conversion between SHP and KML formats.

       

   4. Select any one of the Shapefiles and click Open.
   5. When the dialog appears again, click the Target Directory and File Format icon.
   6. The Save File dialog will appear, change the Save as type to Google Earth File (*.kml).
   7. Change the File name to appropriate name, such as Highest Magnitude Earthquakes.
   8. Click Save.

       

      
      Figure 8: Save the file as a KML file.

       

   9. Click the Convert button.

       

      
      Figure 9: Use the Convert command in GPS TrackMaker.

       

   10. The Data Import Tool dialog will appear, accept the defaults and click OK.

        

       
       Figure 10: The Data Import Tool designates the projection and datum of the input SHP.

        

   11. The Data Import Tool dialog will appear as many times as you have Shapefiles in the Origin Directory. Accept the defaults from this dialog and click OK as many times as prompted.
   12. Once the conversion process is complete, click Exit to close the dialog.
   13. Close GPS TrackMaker.
9. Steps to display the KML files on Google Earth:
   1. Download and install Google Earth.
   2. Open the Google Earth application.
   3. Use the File | Open command to load the KML files.
   4. The Open dialog will appear; navigate to the directory where GPS TrackMaker saved the KML files.
   5. Select Highest Magnitude EarthquakesPnts.KML, click Open.
   6. You will notice that under Places on the right-hand side of Google Earth, a file was loaded named GPS TrackMaker. Rename the file to the original name by right-clicking and choosing Rename. In this case, rename the file Highest_Magnitude_Earthquakes.
   7. Repeat these steps for each KML file converted by GPS TrackMaker.
   8. Additional customizations can be made to these files after they are loaded into Google Earth by right-clicking the file name and selecting Properties. In the examples below the display was customized to represent earthquakes of the different magnitudes.

       

      
      Figure 11: Earthquake data displayed on Google Earth after customizations.

       

      
      Figure 12: Earthquake events displayed on Google Earth.

       

      
      Figure 13: Another example of point data converted and displayed on Google Earth.

       

Associated Links:

1. Google Earth Download
2. Google [.KML] tutorial
3. Conversion utilities:
   1. GPS TrackMaker
   2. Google Earth KML Creator
   3. GPS Visualizer
   4. Expert GPS
4. USGS Historic Earthquake Data