Symbolize stream layers

Stream layers display a live feed of streaming data. You display and symbolize stream layers in the same way as other feature layers. When a stream layer is track aware, you can symbolize previous observations independently from current observations, and in the case of track-aware point stream layers, optionally draw track lines to connect observations.

Stream layer symbology

You can symbolize stream layers with single symbol, unique values, graduated symbols, or graduated colors symbology. As with standard feature layers, the choice depends on the type of data you have, how it's attributed, and what you want to show. You can even modify this symbology with additional variation in color, size, rotation, or transparency based on attributes or an expression.

1. Select a stream layer in the Contents pane.
2. On the Stream Layer tab, in the Drawing group, click Symbology .
3. In the Symbology pane, on the Primary Symbology tab , choose a symbology option from the Primary Symbology menu.
   • Single Symbol—Apply the same symbol to all observations in the layer.
   • Unique Values—Apply different symbols to qualitative categories defined by feature attribution.
   • Graduated Symbols—Apply symbols that vary in size to show quantitative differences. This is only available for point and polyline features. Streamed polygons cannot be symbolized with graduated symbols.
   • Graduated Colors—Apply symbols that vary in color to show quantitative differences.

Caution:

Stream layers can only be placed in the 3D Layers category of a scene. They cannot be draped layers in the 2D category. Polygon and polyline stream layers may visually conflict with the ground surface in a scene, making them only partially visible. To alleviate this, consider adding a small cartographic offset to stream layers in this situation. A Cartographic offset can be configured on the Elevation tab of the Layer Properties dialog box for the stream layer.

Symbolize track-aware stream layers

A track-aware stream layer relies on an attribute to group together observations that correspond to a single object. When a stream layer is track aware, you can symbolize the current (most recent) observations one way and the previous (older) observations another way. Track awareness is specified in the source stream service. You cannot make a stream layer track aware in ArcGIS AllSource if its source stream service is not track aware.

You set the symbology for current and previous observations the same way you symbolize features in stream layers that are not track aware. The Symbology pane shows two tabs, Current and Previous, when you work with a track-aware stream layer. Set up symbology options independently on each tab. You can turn on and off the display of the previous observations without resetting the symbology properties.

Note:

In the case of track-aware attribute-only stream layers, there are no previous observation locations to symbolize, so the Previous and Tracks tabs do not appear in the Symbology pane. To work with previous attribute values, manage the observation expiry on the Stream Layer tab set, on the Data tab, in the Streaming Data group. Previous observation values within the expiry window are retained and can be viewed and queried from the layer's attribute table and charts while streaming is stopped.

You can import symbology from other layers—even other stream layers—but the symbology is applied only to the current observations.

Current observations

Follow these steps to symbolize current observations:

1. Select a stream layer in the Contents pane.
2. On the Stream Layer tab, in the Drawing group, click Symbology .
3. In the Symbology pane, under the Current tab, on the Primary Symbology tab , choose a symbology option from the Primary Symbology menu.

Previous observations

Follow these steps to symbolize previous observations:

1. Select a track-aware, spatial stream layer in the Contents pane.
2. On the Stream Layer tab, in the Drawing group, click Symbology .
3. In the Symbology pane, under the Previous tab, on the Primary Symbology tab , choose a symbology option from the Primary Symbology menu. Adjust the symbology options as necessary.
4. Specify the number of previous observations from the Number per track property. The number of previous observations actually shown may be less if previous observations are set to expire before this number. Observation expiry is set on the ribbon, under the Stream Layer tab, on the Data tab, in the Streaming Data group.
5. Optionally, click the Show previous observations toggle button to turn on or off the display of all previous observations without resetting the symbology properties.

Track lines

Follow these steps to connect observations of point stream layers with a line:

1. Select a track-aware, spatial point stream layer in the Contents pane.
2. On the Stream Layer tab, in the Drawing group, click Symbology .
3. In the Symbology pane, under the Tracks tab, on the Primary Symbology tab , click the Show track lines to connect observations toggle button to turn on or off a line connecting the observations of each feature.
4. Specify the number of Previous observations per track line. This number is synchronized with the Number per track setting on the Previous tab.
5. Optionally, click the symbol to modify it. Click the arrow next to the symbol to change the shape of the legend patch shown in the Contents pane or in a layout legend. Track lines can be drawn with Single Symbol symbology only.

Vary stream layer symbology by transparency, rotation, size, or color

Depending on the symbology used to draw the layer, you can symbolize stream layer observations by additional attributes to vary the transparency, rotation, size, and color. Not all of these options are available with each symbology choice.

Follow these steps to set up additional symbology:

1. In the Symbology pane (under the Current or Previous tab if the stream layer is track aware), click the Vary symbology by attribute tab .
2. Expand Transparency, Rotation, Color, or Size.
3. Adjust as desired.

Label observations

Label stream layers to identify the observations by attribute or expression. When a stream layer is track aware, only the current observations are labeled.

Follow these steps to label stream layers:

1. Select a stream layer in the Contents pane.
2. On the Stream Layer tab set, click the Labeling tab.
3. On the Labeling tab, in the Layer group, click Label .
4. Adjust other labeling properties on the Labeling tab as necessary.