Scanned Ordnance Survey Maps - A Tutorial

This tutorial will show you how to get a scan of a GB Ordnance Survey map to show up on your phone. I'm no expert, this just toook me a while to figure out so I've posted it here in case it helps anyone out.

Things you need:

• A scanned OS Map (mine is made of 12 A4 scans stitched together in Photoshop, use The GIMP as a free alternative)
  
• OziExplorer
  
• OruxMapsDesktop
  

How to do it:

1. Start OziExplorer Trial
   
2. Go to ‘File’ -> ‘Load and Calibrate Map Image’
   
3. Under the ‘Setup’ tab on the right of the screen, fill in ‘Map Name’ with whatever you want. ‘Map Datum’ should be ‘Ord Srvy Grt Britn’. Under ‘Map Projection’ select ‘(BNG) British National Grid’.
   
4. Click the tab that says ‘Point 1’.
   
5. Choose a point near the top left of the map where two grid lines cross and click it in the main window. Be as accurate as you can. A red circle with ‘1’ next to it should appear.
   
6. On the right hand side of the screen under ‘BNG Coordinates fill in ‘Zone’ with the Zone of your map. This is given on the key of your OS map and will be two letters, mine is ‘SD’.
   
7. Under ‘Easting’ and ‘Northing’ type the grid coordinates of the point you have just marked. So if the coordinates are 80, 73 you would enter ‘80000’ for Easting and ‘73000’ for Northing.
   
8. Continue with three more points in the rest of the corners.
   
9. Once you have finished all four points, click ‘Save’ and a ‘something.map’ file will be generated.
   
10. Load OruxMapsDesktop and click ‘Calibration File’. Browse to your .map file and select it.
    
11. Click ‘Image file’ and browse to your map image file and select it.
    
12. Set the Datum to ‘Ordnance Survey Great Britain 1936: England’.
    
13. Set the Projection to ‘Transverse Mercator’ with the following options:
    
    1. Latitude Origin: 49.0
       
    2. Longitude Origin: -2.0
       
    3. k: 0.9996012717
       
    4. False East: 400000
       
    5. False North: 100000
    
    
14. Change the ‘Destiny Directory’ (sic) to where you would like the file to be saved.
    
15. Hit ‘Create Map’
    
16. Once it has finished processing, copy the output folder to your sd card, by default maps should be in their own folder and the folder should be placed in /sdcard/oruxmaps/mapfiles.
    

Hope this is of help to someone!

Thanks so much for that guide!

I am doing something similar to you except my source maps are from Memory Map - using that I can export an entire (or more than one) map sheet directly to a bitmap.

Then using your method I seem to be able to convert very accurately to use with OruxMaps.

I recently upgraded my phone & so have an old android smartphone. I'm a cyclist & have been considering bike gps, however I'm struggling to justify £300-£500 on this at the moment & decided to convert my old phone for this use. The old phone would no longer be online so I needed an offline mapping/gps function. Oruxmaps seems to fit the bill well, but I have struggled to get OSGB maps calibrated correctly for 3 days now. This article however has proved invaluable & now have my OS map tiles working well. Thank You.