Georeferencing tools

Georeferencing toolbar

The Georeferencing toolbar is used to georeference raster and CAD data.

Georeferencing toolbar
Georeferencing toolbar options and buttons

Button

Name

Function

Update Georeferencing

Saves the transformation with the raster.

Rectify

Creates a new transformed raster dataset.

Fit To Display

Shifts the raster to the current display extent area.

Update Display

Updates the display with the current transformation. This is useful when Auto Adjust is disabled.

Auto Adjust

Updates the display with each link that is created.

Flip or Rotate

Corrects for common scanning distortions.

Transformation

Sets the transformation.

Delete Control Points

Deletes all the control points.

Reset Transformation

Resets the raster back to its original location. The control points are not deleted.

Options

Opens the Georeferencing Options window.

Add Control Points

Add Control Points

Allows you to select control points from a layer and add them to the map.

Auto Registration

Auto Registration

Automatically creates links for your source raster, against a target raster. The source raster must be in a relatively close geographic location in order for the auto registration to work. Please refer to the Georeferencing a raster automatically help topic for steps to perform auto registration.

Select

Select Link

Selects and highlights a link within the display.

Zoom To Selected

Zoom To Selected Link

Centers and zooms in to a selected link. If you want to zoom in farther, you can click this tool multiple times.

Delete

Delete Link

Deletes the selected link.

Viewer

Viewer

Opens a viewer window that only displays the raster that you will be georeferencing. This window will allow you to georeference a raster using two windows.

View Link Table

View Link Table

Shows links and errors in tabular form.

Rotate

Rotate

Rotates the source layer. You can manually rotate the source layer, or you can type a degrees value in the measurement text box.

Shift

Shift

Shifts the source layer. You can manually shift the source layer, or you can type an x,y value in the measurement text box.

Scale

Scale

Rescales the source layer. You can manually rescale the source layer, or you can type a rescale factor in the measurement text box.

measurement text box

Measurement

Type in the rotation angle, x,y shift, or rescale factor.

Georeferencing toolbar buttons described

Georeferencing Options window

The Georeferencing Options window allows you to specify default behaviors while you are georeferencing.

Georeferencing options and their functions

Button

Name

Function

From point symbol

From point symbol

Opens the Symbol Selector window to allow you to choose any point symbol as your from-point.

To point symbol

To point symbol

Opens the Symbol Selector window to allow you to choose any point symbol as your to-point.

Residual line symbol

Residual

Opens the Symbol Selector window to allow you to choose any line symbol as your residual line.

Residual

Check this box to show the residuals and RMS error in the link table. The residual shows you the error in the same units as the data frame spatial reference.

Inverse Residual

Check this box to show the inverse residuals and inverse RMS error in the link table. The inverse residual shows you the error in the pixels.

Forward-Inverse Residual

Check this box to show the forward-inverse residuals and RMS error in the link table. This is a measure of how close your accuracy is, measured in pixels.

First the transformation is used to find a point in the forward direction. Then that point is used with the inverse transformation and mapped back to image space. This second point is then compared to your from point that the link tool created.

Auto complete

Check this box to automatically show the user where the system thinks the corresponding to-point should be. Auto complete only works when you georeference your layer to another raster, after the first two points have been created. When Auto complete finds a more suitable link pair, it may adjust the from-point that you specified. If no corresponding point can be found, you may need to manually specify the to-point.

Georeferencing options described

Image Viewer window

The Image Viewer window is very useful when you are trying to georeference one raster dataset to another by allowing you to see both the source raster and the referenced layers at the same time. This window displays the raster dataset you are trying to georeference in its own window. If you have dual monitors, you can drag the Image Viewer window to the second monitor. If you only have one monitor available, you can use the Split Screen button Split Screen to divide your screen evenly for each window.

Image Viewer window buttons and their functions

Button

Name

Function

Zoom In

Zoom In

Zoom in by clicking once or dragging a box in the Image Viewer window.

Shortcut: Hold down the Z key.

Zoom Out

Zoom Out

Zoom out by clicking once or dragging a box in the Image Viewer window.

Shortcut: Hold down the X key.

Pan

Pan

Pan the ungeoreferenced raster in the Image Viewer window.

Shortcut: Hold down the C key.

Full Extent

Full Extent

Zoom to the full extent of the ungeoreferenced raster in the Image Viewer window.

Fixed Zoom In

Fixed Zoom In

Zoom in on the center of the Image Viewer window.

Fixed Zoom Out

Fixed Zoom Out

Zoom out from the center of the Image Viewer window.

Go Back to Previous Extent

Go Back To Previous Extent

Go to the previous extent of the Image Viewer window when linked to the main data view.

Shortcut: Press SHIFT+<.

Go To Next Extent

Go To Next Extent

Go forward through the sequence of extents that you have been viewing in the Image Viewer window when linked to the main data view.

Shortcut: Press and hold SHIFT+>.

Refresh

Refresh

Redraw the current extent of the Image Viewer window.

Shortcut: Press the F5 key.

Reposition

Reposition

Display both the main ArcMap window and the Image Viewer window, side by side.

Link Windows

Link to Main Display

Link the data view extent with the Image Viewer extent. The navigational buttons will all be disabled on the Image Viewer window. If you navigate the data view, the Image Viewer will show the same extent.

Image Viewer window buttons described

Link Table

Link Table provides information regarding the links that have been created and the residual error associated with the links.

There are several tool that you can use to evaluate your links:

Link Table buttons and their functions

Button

Name

Function

Open link table

Open

Opens a georeferencing link file.

Save link table

Save

Saves a georeferencing link file.

Zoom To Selected

Zoom To Selected Link

Centers and zooms in to a selected link. If you want to zoom in farther, you can click this tool multiple times.

Delete

Delete Link

Deletes the selected link.

Insert link

Insert Link

Opens a viewer window that only displays the raster that you will be georeferencing. This window will allow you to georeference a raster using two windows.

Auto Adjust

Check this box to adjust the raster to immediately show the transformation, after each link is chosen.

Degrees Minutes Seconds

Check this box to show the coordinates in degrees/minutes/seconds. This is only valid when the data frame is using a geographic coordinate system.

Transformation

This drop-down menu allows you to choose a valid transformation. To see more transformations, you may need to choose more links.

Link Table buttons described

Georeferencing keyboard shortcuts

While you are georeferencing, there are several keyboard shortcuts available to help you perform your task easily and quickly. Many of these keyboard shortcuts are commonly used in ArcGIS.

Keyboard shortcut

Function

A

Toggle the visibility of georeferencing layer on and off

B

Continuous zoom/pan

C

Pan

Q

Roam

X

Zoom out

Z

Zoom in

ESC

Cancel link (while creating a link)

DELETE

Delete selected link

SPACE

Disable vector snapping (while pressed down)

Related Topics

5/18/2014