Add a Google Earth Satellite Image in
ArcMap and Geo-Reference
The
following tutorial guides you through the steps of bringing in selected
screenshots from Google Earth into ArcMap.
GOOGLE EARTH
You
will navigate to the location in Google Earth that you want to bring in to
ArcMap. Then, you will add 4 control points on each corner of the image,
record their latitude/longitude coordinates, and export the image as a jpg
file.
1.
Open
Google Earth
2.
In the
Layers panel, turn everything off
3.
Go to
Tools -> Options, and change the “Show Lat/Long” option to “Decimal Degrees”
4.
Navigate
to the area and extent that you want to use in ArcMap.
5.
Press
“r” on your keyboard. This will reset the view angle to be “top down” and
rotates the map so that it is “north up”
6.
Press
F11 to make your map go full screen
7.
Click
on the “add placemark” button
8.
Move
the icon from the middle of the screen to the top left corner of the map
9.
Rename
the icon “Top-left”
10.
Click
the button to change the icon
11.
Choose
this icon:
12. Jot down (or copy and paste) the latitude and
longitude coordinates somewhere you can access later
13. Repeat the process and add icons for
“Top-right”, “Bottom-left” and “Bottom-right”
14. Now it’s time to export the image. Go to
File -> Save -> Save Image and save your file
ARCMAP
To geo-reference,
means to associate something with locations in physical
space. The term is commonly
used in the geographic information systems field to describe the process of
associating a physical map or raster
image of a map with
spatial locations. Georeferencing may be applied to any kind of object or
structure that can be related to ageographical location, such as points
of interest,
roads, places, bridges, or buildings.
Now you
will import your google earth image, and georeference it based on the 4 control
points you created.
1.
Open
ArcMap
2.
Go to
View -> Data Frame Properties and select the Coordinate System tab
3.
Choose
Predefined -> Geographic Coordinate Systems -> World -> WGS 1984
4.
Go to
Customize -> Toolbars -> Georeferencing
5.
Add the
image file from Google to ArcMap. If it prompts you to build pyramids,
click ok
6.
Zoom
into the top left corner of your satellite image
7.
From
the georeferencing toolbar, click the “add control points” button
8.
Hover
over the exact center of the top left icon you created, and LEFT click once
9.
Now,
RIGHT click once and click on “Input X and Y…”
10. Add the correct coordinates for your Top-left
control point
WARNING: Remember that “X” is LONGITUDE and “Y” is LATITUDE
11. Repeat the process for the remaining 3 control
points. If the map has disappeared from your view port, just right click
on the layer, and select “zoom to layer”
12.
To
finish your georeferencing, click on the “Georeferencing” menu item from the
toolbar, and select “update georeferencing”
You
should now be able to overlay additional layers on top of the satellite image.
