Symbolizing data in a time window by color

Conditions préalables :

Before executing this procedure, you must have a tracking layer in your map document.

When a tracking layer is initially added to a map document, all events in the tracking layer are assigned the same default symbology. This procedure shows you how to symbolize tracking events in a time window using different colors to represent the age of the data.

1. Double-click the tracking layer in the Contents window to open the Layer Properties dialog box. Click the Symbology tab.
2. Click Events on the Show panel and make sure the checkbox next to Events is checked.
3. Click the large button on the Symbol panel to change the base symbol for your tracking layer.

   

The base symbol you choose determines all the properties of the symbols in your tracking layer, except for the color. The color changes based on age. Note that the symbol button on the image above looks different depending on whether you are working with a line or polygon tracking layer.
4. Check the checkbox next to Time Window on the Show panel. This selects Time Window, indicating that the time window options now appear on the Symbology tab.
5. Click Color in the Drawn As panel. Notice that new options appear on the Symbology tab.

   

6. Click the Period drop-down arrow and click a value from the list. You can also enter a number directly into the Period text box.
7. Click the Units drop-down arrow and choose an appropriate unit from the list.

   The period and units selected determine the size of your time window. You must understand your tracking data to determine an appropriate size for your time window. It will probably require some experimentation to find the best time window size for your data.

8. Click the Color Ramp arrow and choose an appropriate color ramp from the list that appears.
9. Click the How drop-down arrow on the Classification panel to determine the orientation of your time window relative to the current time. There are three choices: Past, Future, and Future & Past.

   

10. Click the Classes arrow and choose the desired number of classes from the list. You can also type a number directly into the Classes text box.

    The time window is divided into the number of classes that you specify, and the color of the symbol for each class is shown in the Symbol column of the legend table at the bottom of the Symbology tab. For example, if you have specified a time window size of 60 seconds and six classes, each class spans 10 seconds.

11. If you want, you can click inside the Range or Label columns in the legend table to manually change the values. Changing the ranges in this way allows you to create irregular class ranges for your symbology. Changing the labels does not affect the symbology.

    Make sure you have everything set up properly on the Symbology tab before making manual changes. Manual changes you have made are overwritten if you change other settings.

12. Click OK to save your changes and close the Layer Properties dialog box.

    Notice the Contents window shows the time window symbology for your tracking layer.

13. Click the button on the Tracking Analyst toolbar to open the Playback Manager and play back your data.

    Learn how to play back your data using the Playback Manager.

You can see the results of your time window on the map as you are playing back your data.

Astuce :

If you don't see enough data displayed on the map during playback, your time window may be too small. If you see too much data during playback, your time window might be too big. Try updating the values in the Period and Units drop-down lists on the Symbology tab to adjust the size of your time window.