Temporal data symbology in ArcGlobe

Layer types

When you add tracking data in ArcGlobe, you have a choice to display the layer as floating or draped. All tracking layers are initially loaded as floating layers, but you can change them to draped on the Elevation tab of the Layer Properties dialog box.

Floating layers allow you to display tracking events floating at an elevation above the earth's surface. The elevation can be an absolute elevation, or you can set the layer's elevation using a field containing elevation values or an elevation expression. Specifying tracking layers as draped allows you to drape the tracking events on the earth's surface or at a specified height above the elevation of the surface. All elevation settings are managed on the Elevation tab of the Layer Properties dialog box.

TipTip:

The use of complicated elevation expressions can have a negative impact on map refreshing performance. Use caution when working with elevation settings for your tracking layer.

Symbolization

When symbolizing tracking layers in ArcGlobe, you have the choice to use either 2D or 3D symbols.

TipTip:

When defining symbols for tracking layers in ArcGlobe, do not mix 2D symbols with 3D symbols in multilayer symbols. If you do, the resulting multilayer symbol will be drawn as a billboarded 2D symbol, and it will not look as good as using only 3D symbols.

Leader lines and elevated lines for point tracking layers

Tracking Analyst includes enhanced features to display leader lines and elevated lines for point tracking layers in ArcGlobe. These features are found on the Symbol Leader Lines tab of the Layer Properties dialog box.

Symbol Leader Lines tab is used to set leader lines and elevated lines

Leader lines connect a feature's ground location to its actual location. When point features are above the surface of the earth, such as aircraft positions, it can be difficult to determine where one feature is relative to other features. Leader lines help solve this problem by indicating the ground location of the feature. The leader line connects the feature to the point on the surface of the earth directly below the feature. Leader lines can be turned on and off freely, and you can customize the color of your leader lines.

Example of leader lines in ArcGlobe
Leader lines help display the relative locations of airborne objects.

Leader lines are not recommended for features that are already on the surface of the globe, because the leader lines will have no length. However, elevated lines could still be used in this situation. Sometimes the symbols for features on the surface of the globe can intersect the globe, causing part of the symbol to be hidden below the surface. Elevated lines can help to alleviate this problem by offsetting the symbols so they are above the globe's surface.

Using elevated lines causes the symbols of features to appear elevated above the actual location of the feature. The elevated lines connect the actual locations of the features to their offset symbols. Elevated lines can be turned on and off freely, and you can customize the color and length of your elevated lines. When you turn on elevated lines, you also have the option to show a point at the actual location of the feature. This can help to alleviate another potential symbology problem: the size and shape of some symbols can make it difficult to tell exactly where a feature is located. If you are concerned with the exact locations of features in your tracking layers, elevated lines (and points) can be used to display a more accurate position than is possible with symbols.

Example of elevated lines in ArcGlobe
Elevated lines can be used to display a more accurate position for airborne objects.
CautionCaution:

Be careful when using elevated lines with features above the surface of the globe. Users can mistake the meaning of the line and assume it points to the ground location of the feature when it actually points to the airborne location of the feature.

Leader lines and elevated lines can be used together to get the benefits of both.

Example of elevated lines and leader lines in ArcGlobe
Leader lines and elevated lines can be used together to get the benefits of both.

Related Topics


Published 6/8/2010