Visualizing change over time is an effective way to analyze local or global trends and predict future scenarios.
In GIS, much information of this type—for example, sea-surface temperature, annual births, labour market statistics, vegetation type, land-use data—is commonly stored in raster format, and it’s very useful to see these data animated. So how do you make your rasters time-aware? An easy way to is to take advantage of two new features available in Version 10: time-enabled layers and the mosaic dataset.
Follow these steps to create an animation showing change in sea surface temperature over time, or vegetation change in South-West QLD. There’s a tonne of data to show change over time—and now we have an easy way to visualize it in ArcGIS!
Create the Mosaic dataset
1. Use the “Create Mosaic Dataset” tool to create a new mosaic dataset and load your rasters. Use the “Add Rasters To Moasic Dataset” tool to load your rasters. Make sure you build pyramids and calculate statistics (under advanced options). This increases display performance.
2. Add a time field to the mosaic dataset. Right click the Mosaic dataset and choose “Open Attribute Table”
3. Add a new “date type” field.
4. Start an edit session and add date information for each raster.
Enable time on your data
1. Right-click on the mosaic dataset in ArcMap > Properties > Time tab.
2. Set the time field to match the field in your attribute table which stores the date information.
3. Click “Calculate” to set up the time step interval and the layer time extent (you can adjust these settings if needed).
4. Click OK.
Now your data are time-enabled. To visualize the time series in ArcMap, open the Time Slider window from the Tools toolbar. Click the “Enable Time on Map” icon in the left corner.
Use the time slider option to adjust playback speed or the time-step interval.
Press play on the time slider window to step through the animation.
For more workflow ideas see this help item Creating a mosaic dataset containing raster data from multiple dates.