Wednesday, May 21, 2008

Elevation Tagging with GeoMedia

It is actually very simple to do elevation tagging with GeoMedia and you don't have to use GeoMedia Professional. I'm going to show you how to setup GeoMedia to do it.

For instance, you may have contour vector lines that you want to tag with elevations as part of a digital terrain workflow. The contours feature class needs to have an attribute field for storing the elevation; if it doesn't have, you can use the Feature Class Definition command to create one. Next, find out the elevation range and interval of the contours, say from 0 to 4500.

  1. Select Legend > Add Thematic Legend Entry.

    The Add Thematic Legend Entry dialog box appears.

  2. In the Input feature combo box, select the contours feature.
  3. Choose Unique Value Thematic type.
  4. In the Attribute for classification combo box, select the elevation attribute field.
  5. Define the Style, Value, and Label for each contour elevation you have, e.g. 0, 500, 1000, ... 4500.

    Note: Choose colors that you can distinguish easily from the untagged contours, e.g dull earth colors. You could also choose bold black colors for major elevations and gray colors for intermediate elevations so you can see patterns in the map window.

  6. Define the Style for the Other values.

    Note: This style is used for unassigned contours, so choose a contrasting color e.g. red that can be easily distinguished from the tagged contours.

    The Add Thematic Legend Entry dialog box may look like this.


  7. Click OK.

    The Legend and the map window displays the newly created thematic mapping.

    Note: The unassigned contours are displayed in red and are easily distinguished from the tagged contours.

  8. Double click on the unassigned contours.

    The properties dialog box appears.

  9. Type in the elevation value and press OK.

    The newly tagged contours feature no longer displays in the untagged style.

  10. Continue to assign elevation to all untagged contours until finished.
After you have completed the elevation tagging, you can use the Functional Attributes command or the Update Attributes command to update the contours feature class' geometries with the newly assigned elevation attribute.

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