I want to georeference a downloaded map.

enter image description here

In the downloaded map there is no graticule but I know the projection which was used to make this map.

I also know the the location (x, y coordinates) of four points.

However, I cannot identify this location on the map.

Can anyone help with advice on how to register such a map?

  • 2
    What version of arcgis do you have access to? Is the map an image? – Barbarossa Jan 20 '14 at 22:18
  • Arcgis 10. Yes this map is in jpeg format. – Sushanta Gupta Jan 20 '14 at 22:26
  • The map you linked to in a Comment to an Answer below looks like it has a number of points that you should be able to look up coordinates for in a gazetteer making this simple to georeference. Would you be able to review the Georeferencing Help and then edit your Question to show the steps you have tried and where you are blocked, please? – PolyGeo Jan 20 '14 at 22:59
  • Would an answer about doing this using QGIS be of interest? – djq Jan 21 '14 at 3:21

I would trim the jpg to the edge of the map. With a simple image software (irfanview).
Removing marginalia.
Start a new arcmap document.
Insert vector data for as much similar data as you can find. Physical infrastructure (roads, highways) and boundaries (international, district) municipalities etc.
Set the document coordinate system to the one mentioned in your question. This will be the output projection.
Insert the image and zoom to the vector location covered by the image.
This is where you want the image to go.
Turn on the georeferencing toolbar.
Be sure your jpg is the selected image and fit to screen. Now locate intersections of roads and boundaries along the outside edge of the image.
Use the match points tool.
Best practice is clockwise and don't veer too deeply inside the image.
Start with at least 4 match points spread evenly around. To see if it aligns easily. If not you can open the match point list and delete.
Do this back to 1 point and start over if need be.
Also you can export the list of points.
With knowing the exact projection you should be able to accomplish with few points, to place scale, rotate and done.
After this it is your choice of...

  1. Update georeferencing. Probably sufficient if you get a good match.
  2. Rectify. This completely re-writes the image.

NOTE that you should at the least update the referencing and then rectify. As the match points disappear after either.

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