Viewing one or more rasters within the mosaic dataset

The mosaic dataset is ideal for managing a collection of raster data. You can view the mosaic dataset as a single mosaicked image; however, you can also view and access individual rasters within the mosaic dataset if necessary. There are multiple ways to do this:

• Use the Lock Raster mosaic method.
• Open the table and view the image and its properties.
• Download rasters.

Using the Lock Raster mosaic method

There are many mosaic methods to use with the mosaic dataset. By default, the Closest To Center method is used. This displays the best image at the scale and location you're viewing. However, if you pan or zoom, the parameters used to select the mosaicked image may result in another raster within the mosaic dataset being displayed. There are times when this is not ideal because you are looking at a specific feature or view angle and don't want anything to change within the mosaicked image. If there is an attribute, such as a date, you can use the By Attribute mosaic method to view only the images from a specific date, but if you want to be more specific, you can identify or select specific rasters within the mosaic dataset and only display them. You do this using the Lock Raster mosaic method. There are several ways to utilize this mosaic method; each is discussed below.

Lock to selected rasters

There are many ways to make a selection within a mosaic dataset. You can query using the options on the Selection menu, open the attribute table and use the table's tools to make a selection, or use the feature selection tools within the interface. These steps will use this last method, but you can use whatever method is best for you.

Note:

This selection only impacts your display and does not alter the source mosaic dataset.

To undo these display changes to the mosaic dataset, you can change the mosaic method back to Closest To Center.

Steps:

1. Click the Select Features By Rectangle button and draw a rectangle, or click a location within the mosaic dataset to select the footprints of the rasters you want to view.

   This selects any rasters within the area you defined. This may include the primary rasters and any overviews.

2. Optionally, right-click the Footprint layer, click Selection, then click Reselect Only Primary Rasters.

   This removes any overview footprints that may have been selected.

3. Right-click the Footprint layer, click Selection, then click Lock To Selected Rasters.

   You may have to zoom in to see the selected rasters.

   Only those rasters whose footprints you selected are displayed.

Lock to specified rasters

This method allows you to enter the specific raster ObjectID value rather than use the selection tools.

Steps:

1. Use the Identify tool to find one or more rasters to display by recording the ObjectID for the footprint feature.
2. Right-click the Image layer and click Properties.
3. Click the Mosaic tab.
4. Click the Mosaic Method arrow and click Lock Raster.
5. Type the ObjectID in the Lock Raster ID text box.

   You can enter more than one value by using a comma to separate the values.

6. Click Apply to preview the change.
7. Click OK to close the dialog box.

   You may have to zoom in to see the selected rasters.

Display selected rasters as layers in ArcMap

You can display the selected rasters as individual layers within the ArcMap table of contents. When you use this method, it makes a new connection to the mosaic dataset and adds a new layer to the table of contents, locked to each image you've selected. Each layer is represented as a single raster layer and does not appear as a mosaic dataset layer. Each layer is added within a group layer and ordered according to an attribute you specify.

Steps:

1. Click the Select Features By Rectangle button and draw a rectangle, or click a location within the mosaic dataset to select the footprints of the rasters you want to view.

   This selects any rasters within the area you defined. This may include the primary rasters and any overviews.

2. Right-click the Footprint layer, click Selection, then click Reselect Only Primary Rasters.

   This removes any overview footprints that may have been selected.

3. Right-click the Footprint layer, click Selection, then click Add Selected Rasters to Map.

   This opens the Add Selected Rasters to Map dialog box.

4. Type a name in the Group layer name text box.
5. Click the Layer name based on drop-down arrow and choose an attribute field name.
6. Click OK.

   Each selected raster is added to the table of contents as a single raster layer within a group layer.

Viewing rasters from within the table

When you open the Footprint attribute table, you can preview the raster from within the table. This can help you decide which image you want to use with the Lock Raster mosaic method.

Steps:

1. Right-click the Footprint layer and click Open Attribute Table.
2. Click the field under the Raster column.

   The cell in the table displays an arrow button.

3. Click the arrow.

   A dialog box appears allowing you to view the metadata, function, and properties for the raster dataset.

4. Click the Preview tab to preview the raster dataset.

Downloading rasters

There may be times when you want to download the source raster data to your local computer rather than use the mosaic dataset to view the image.

Steps:

1. Click the Select Features By Rectangle button and draw a rectangle, or click a location within the mosaic dataset to select the footprints of the rasters you want to view.

   This selects any rasters within the area you defines. This may include the primary rasters and any overviews.

2. Right-click the Footprint layer, click Selection, then click Reselect Only Primary Rasters.

   This removes any overview footprints that may have been selected.

3. Right-click the Footprint layer, click Data, then click Download Selected Rasters.

   This opens the Download Selected Rasters dialog box where you can select the images and their metadata to download or even clip the source rasters.

4. You can enter a target location to which the raster data will be saved, or click the browse button and navigate to a location.
5. Click the Download button to start downloading the data.
6. Click Close when all the data is downloaded.

Note:

Source files stored using the GRID raster format cannot be downloaded.