Planetary Exporation Program

Layers

PEP's map displays every different kind of data on a different layer. Each of these layers can be independently manipulated. You can individually turn layers on and off or change the order of layers so the layer you want is on top of all the other layers.
For example, when PEP 3D starts up it automatically loads in elevation, thermal inertia, albedo and as well as imagery. Displaying all this data at once would create such a jumbled mess you couldn't make sense of it. Since each of the data sets (e.g., imagery, elevation, thermal inertia, albedo, etc.) is on a different layer, you can turn each layer on or off. When you want to see if there is a correlation between features on an image and thermal inertia you simply turn off the albedo and any other layers that get in the way.

To turn layers on or off, click on the Layers menu item on the main panel.

Simply select a layer to toggle it from on to off, or off to on. The map display will automatically update.

As you can see, there are quite a few layers. Here is what each layer holds:

Graticule: The latitude and longitude grid lines
Ruler Layer: The 100 pixel scale line in the lower right hand corner
Gazetteer: All the place names that appear over features
Cross Section Layer: The white reference lines you draw and the colored sensor data lines
Elevation Layer: The Mars MOLA data set
Albedo Layer: The Mars TES Albedo data set
Thermal Inertia Layer: The Mars TES Thermal Inertia data set
Imagery Layer: Holds Magellan radar, Lunar Clementine, Mars Viking or Themis images
Map Annotations Layer: Any labels or polygons you draw on the map
Mars Background Layer: A low resolution image covering roughly the entire planet

You can also change the order of the layers, specifying which layers are drawn on top and which are drawn on the bottom. To call up the layers control panel, click on Edit Layers in the Layers menu.

This panel has a list of all the layers and the order they are draw in. To change the order, simply select a layer and use the up and down arrows to move it. The light bulb icon indicates if a layer is on or off. You can also click on this icon to turn any layer on or off. If you want a layer's cross section drawn when you make a reference line but don't what the data displayed, just move the layer beneath the Mars Background Layer.

Each layer may also have a custom configuration panel. With this panel, you can modify various layer specific parameters. For example, with the Gazetteer layer's configuration panel you can change the colors of the labels. To display a configuration parameter, click on bulleted list icon next to the layer's name.