how_to_georeference_google_earth_images_in_arcmap

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					                    Georeferencing Google Earth images in ArcMap.



Google Earth

      1. In Google Earth zoom into the area you want to study. Save that image as a .jpg.
      Make sure to hide the navigation tools on the screen.

      2. Create 4 pushpin placemarks in Google Earth at each corner of the area you are
      studying. Make sure to use identifiable areas such as cross streets (corners). Name
      each pushpin 1, 2, 3 and 4. Make sure Google Earth is set to decimal degrees.




Notepad

      1. Open Notepad (Start>All Programs>Accessories>Notepad)

      2. Save the document that opens in your working directory as CornerPoints.txt. Now
      type name, ycoordinate, and xcoordinate for the headers. Be sure to separate the
       headers with Tab. Next, copy the data for each of the four Placemarks you added in
       Google Earth.




ArcMap

1. Add the Georeferencing toolbar. To do this, go to Tools>>Customize and check the box next
to Georeferencing.

2. Add the San Diego local roads layer from the Student Share>Burgess>Sandag>local roads

3. Now, go to Add Data, and add the data for the four corner points, CornerPoints.txt.

4. Go to Tools>>Add X Y Data. In the wizard, select CornerPoints.txt, and make sure the X
Field and y Field contain the correct columns. Click OK.
5. Select a Geographic Coordinate System>World>WGS 1984 and choose OK. Your control
points should match up with the local roads file.

6. Add Data and add your .jpg (aerial photo) to the map.

7. Now zoom in to the area bounded by the four points. Zoom in so the four points fill most of
the screen. Then Under the Georeferencing menu of the Georeferencing toolbar, select Fit to
Display. The aerial photo should now show up in nearly the right place. To finally adjust the
image, use the Add Control Points button in the georeferencing toolbar. First click on the JPEG
image where your point should be, then click on the corresponding point. When you have added
control points for all four intersections, the image should automatically have zoomed and rotated
and should now match the roads in the Roads layer.

8. When you have added control points for all four intersections, the image should automatically
have zoomed and rotated and should now match the roads in the Roads layer. Now under the
Georeferencing dropdown screen in the georeferencing toolbar, select update georeferencing,
to permanently create spatial references for the JPEG file.
(12) If you right click on the JPEG and go to properties, you will see that geospatial data for the
image is now included under the source menu.

				
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