Summary
Aerial imagery and other raster type files are great ways to look at change over time. Many demos include time sliders that allow cycling through imagery to see sprawl, deforestation, changes in a landscape, or other factors.
Procedure
To progress through rasters by collection date, add the rasters to a mosaic dataset. The mosaic dataset has an attribute table, where fields can be added to include metadata in the rasters within the mosaic dataset. The attribute table can then be used with the time slider in the map to flip through the images by date.
The instructions provided describe how to assign date or time information to a mosaic dataset.
- Create a mosaic dataset inside a geodatabase by either right-clicking the geodatabase and selecting New > Mosaic Dataset or by using the Create Mosaic Dataset tool.
- Right-click the mosaic dataset and select Add Rasters to add the relevant rasters.
- Import or add the mosaic dataset to ArcMap.
- Right-click the mosaic dataset in the Table Of Contents, and Open the attribute table.
- Click the Table Options icon in the top left of the Table window, and select Add Field. Give the field a name, and select Date as the field type. Click OK.
- Start an edit session using the Editor toolbar.
- Populate the newly added date field according to the collection dates of the datasets.
- Save the edits and stop editing.
- Right-click the mosaic dataset in the Table Of Contents and click Properties.
- In the Time tab, check the checkbox to Enable time on this layer.
- Ensure that the date field selected (Time Field) is the newly created field from Step 5.
- Click Calculate to calculate the Layer Time Extent.
- At the bottom left corner of the Time window, check the checkbox to Display data cumulatively. This prevents the imagery from disappearing between timestamps. Click Apply > OK.
- In the standard toolbar, click the Time Slider button to open the time slider window:
- Click Play to see the rasters change over time.