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Exercise – 20 / Geo Referencing of Google Earth Images in QGIS తెలుగులో నేర్చుకుందాం

Exercise – 20 /  Geo Referencing of Google Earth Images in QGIS

Georeferencing of Aerial Image.


In the exercise Georeferencing of Google Imagery will be covered as the basic process of georeferencing in QGI S(Process for Georeferencing of Topo Sheets and Scanned Maps remains the same). That method involved reading the coordinates from google images / topo sheets / scanned map and inputting it manually. Many times, though you may not have the coordinates printed on your map, or you are trying to georeference an image. In that case, you can use another georeferenced data source as your input. In this exercise, you will learn how to use existing open data sources in your georeferencing process.


How to download image from Google


  • Open Google earth and search for the area to save image.
  • Choose Tools → Options from Menu bar

Figure 184 - Google Earth Option Window


  • Select Universal Transverse Mercator from Show Lat/Long 
  • Select Meters/Kilometers from units of measurements
  • Click on Apply and OK
  • Click on   to add place marks and save the values of Easting & Northing in excel sheet.

Figure 185 - Google earth window with the values of placemarks saved in excel sheet

  • Choose File → Save → Save Image
  • Click on Map Option and uncheck Title and description, Legend, Scale & Compass
  • Click on Resolution and select Maximum (4800x2220)
  • Click on Save Image and save the image in the destination folder.
  • Open QGIS choose Layer→ Add Layer → Add Raster Layer
  • Click on to browse the saved google image and Add to canvas

Figure 186 – QGIS with saved google image

Georeferencing of Google earth Image

  • Choose Plugins → Manage and Install Plugins
  • Select Georeferencer GDAL and close

Figure 187 - Manage and Install Plugins window

  • In Raster menu Georeferencer is added successfully.

Figure 188 - Raster menu with Georeferencer

  • Click on Georeferencer to open Georeferencer window
  • Click on to open raster data
  • After raster data added to Georeferencer window choose Settings → Transformation Settings
  • Select Transformation Type – linear
  • Resampling method – Nearest neighbor
  • Click on to select CRS and provide Target SRS–(Ex: EPSG:4326 – WGS 84)
  • Provide output path to save Output raster
  • Depends upon the requirements select remaining option andClick OK
  • Zoom to Point 1 in theGeoreferencer window and click on to add x & y values (See Figure 197 for saved coordinates in excel)
  • Add X & Y values from excel and click on OK

Figure 189 – adding X & Y values to placemarks in georeferenced window

  • Add X & Y values for remining 3 points from excel

Figure 190 - added X & Y values to all 4 placemarks in georeferenced window

  • Click on to start georeferencing with provided X & Y values

Figure 191 – georeferenced window with Georeference Successful message

  • Click on to open output raster data

Figure 192 – Georeferenced image

  • In layers panel right click on the Georeferenced Image and open Propertiesand click on information to view the CRC information about the layer.

Figure 193 – CRS information of the georeferenced image



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