When you georeference your raster dataset, you define its location using dataset that you want to align with your projected data in ArcMap. The general steps for georeferencing a raster dataset are: Add the raster dataset that aligns with the projected data. – Add control points that link known raster. This tutorial will explain how to georeference a raster image in ArcGIS so it can then be used as an overlay or for digitizing purposes. In this example, a historic.

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Keep in mind that your georeferenced data is only as accurate as the data to which it is aligned.

If you have dual monitors, you can drag the Image Viewer window to the second monitor. Persist the georeferencing information You can permanently transform your raster dataset after georeferencing it by racmap the Save to New command on the Georeference tab or by using the Warp tool.

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This transformation is useful when the control points are important, and it is required that they be registered precisely. Opens the Symbol Selector window to allow you to choose any line symbol as your residual line. If possible, you should spread the links over the entire raster dataset rather than concentrating them in one area. If you navigate the data view, the Image Viewer will show the same extent.

Shifts the source layer. The adjust transformation performs a polynomial transformation using two sets of control points and adjusts the control points locally to better match the target control points using a TIN interpolation technique.

Adjust requires a minimum of three control points.

How do I georeference an image in ArcGIS? – Community Contributions – Hermes

The forward-inverse residual is a measure of how close your accuracy is, measured georefsrence pixels. Opens a viewer window that only displays the raster that you will be georeferencing. The georeferencing tools on the Georeference tab allows you to georeference any raster dataset. When Autocomplete finds a more suitable link pair, it may adjust the from-point that you specified.


See Georeferencing a raster automatically for steps to perform autoregistration. The source raster must be in a relatively close geographic location in order for the autoregistration to work. Saving the georeferencing will store the transformation information in external files-it will not create a new raster dataset, which happens when you permanently transform your raster dataset.

This is useful when Auto Adjust is disabled. Any more than three control points introduces errors, or residuals, that are distributed throughout all the control points. The number of links you need to create arcma on the complexity of the georefernce you plan to use to transform the raster dataset to map coordinates.

The projective transformation can warp lines so that they remain straight. Email gishelp at mit. Add a control point to a place that will be easy to find in the reference layer, such as a road intersection, bend in a river, administrative boundary, etc.

The first-order polynomial transformation is commonly used to georeference an image. Go to the previous extent of the Image Viewer window when linked to the main data view. There are several tool that you can use to evaluate your links: Arcjap a minimum of three control points, the mathematical georrference used with a first-order transformation can exactly map each raster point to the target location. The similarity transformation is a first order transformation which tries to preserve the shape of the original raster.

The Zoom To Selected Link tool can zoom in on the highlighted link. Rotates the source layer. You can georeference a raster dataset, a raster layer that contains raster functions, an image service, or a mosaic layer.


This drop-down menu allows you to choose a valid transformation. Pan the ungeoreferenced raster in the Image Viewer window. Zoom out from the center of the Image Viewer window. Zoom to the full extent of the ungeoreferenced raster in the Image Viewer window. This is commonly used when your data is already georeferenced, but a small shift will better line up your data.

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

Georeferencing a raster to a vector

If, however, the raster dataset must be bent or curved, use a second- or third-order transformation. You can also use the Shift and Rotate tools to move the raster dataset as needed. It may be a good idea to create a few control points, then choose the one that looks the most accurate. The process involves identifying a series of ground control points—known x,y coordinates—that link locations on the raster dataset with locations in the spatially referenced data.

How To: Georeference an image to align with other data

Instructions provided describe how to georeference raster data to align correctly with other data. Add control points using the georeterence with two crosses connected by a line: Go forward through the sequence of extents that you have been viewing in the Image Viewer window when linked to the main data view. Deletes the selected link.

Corrects for common scanning distortions. A column can be clicked to order the values in ascending or descending order.