Instructions

Working with Georeferencer 4

With our most recent map upload we have switched to a new version of Georeferencer (v. 4).

1. To get started, click here or on the button at the homepage and sign in with email, Facebook, Google or Twitter account. If you want another map click on the ‘Next‘ button in the lower right corner.

2. Enlarge the old and modern maps to find matching town names, street names or other places and assign common points to each maps. At least three points are required, and the more points you assign, the better the georeferencing will be. Use the search box in the modern map to find places listed on the old map. Spread you points over the largest possible area.

3. After assigning at least three points, click on the ‘Clip‘ button in the old map window to draw blue lines around the content area of the map. The Clip lines should be just inside the border of the map.

4. When finished, click on the ‘Save‘ button (although the map will save automatically). Then choose the View This Map or the Overlay & Compare page to see the map.

5. In the View This Map page chose 2D or 3D or Image views. For the 3D view you need to sign in (or set up free account).

6. In the Overlay & Compare page (Georeferencer Compare) you can view one map or search for maps from various sources, and then compare them using several different views – Overlay, Grid, Swipe, and Spy glass.

7. From the This Map pages, use the GeoEditor to locate and measure areas, distances, locations, and more. The Transcribe feature can be used to annotate the maps.

8. For more detailed Help, see the Georeferencer Help Page of the David Rumsey Map Collection, or the help page of Utrecht University (in Dutch). If you find bugs or problems, use the drop down menu in the upper left corner of all screens to send us a message about the problem with the Send Feedback tab. More detailed information on the new features of Georeferencer 4 can be found here.