Planetary Exporation Program

Gazetteer Layer

PEP contains NASA's gazetteer for the solar system. Thanks to this information, the map can display feature names over top of the planetary imagery.

This screen shot contains several labels. The names of impact craters are in red and the names all other geologic features are in yellow. The size of the label is a function of the size of the geologic feature.

If you move the mouse over top of a label, the title bar of the PEP frame changes to give more information about the feature. This is demonstrated with the above screen shot where the frame title shows the name, geologic type and diameter of a feature. If that isn't enough information, you can hold down the shift key and click on a label. Then, the entire gazetteer entry is displayed in a separate window.

This panel also displays how common this feature is and if it is atypically large or small so you know if you're looking at something unusual.

As you zoom the map in and out, you'll also notice that individual labels sometime appear and disappear. By default, the gazetteer layer uses "smart labels". With smart labels, a feature size threshold is calculated based on the map scale. Features smaller than the threshold are not displayed so the map doesn't become completely cluttered with labels of little features. The smart labels can be turned off via the configuration panel

Configuration Panel

Each layer may have a custom configuration panel. It has controls that allow you to tweak various parameters. To access the Gazetteer Layer configuration panel, go to the main menu bar and click Layers->Edit Layer. Then, the Layers Editor Panel will pop up. On this panel, click on the bulleted list icon immediately next to the word "Gazetteer". This will display the Gazetteer Layer Configuration Panel:

The gazetteer layer allows you to set three values. The color to use for crater labels, the color to use for non-crater labels and whether to use small labels or always display all labels.