There are a few terms that you will come across whilst on the Layers of London site and project that are explained here:

  • Record - This is what we call each story, memory, history or piece of research on the site.
  • Collection - This is a collection of records which are about the same topic or area.
  • Map Layers - These are the historic map layers that you can fade in and out to discover how an area has changed over time.
  • GIS - Geographical Information Systems are systems or programmes that help you link data or information with somewhere on the globes surface. We use GIS to help us with the map layers on the website and ensure that the maps are perfectly placed over eachother.
  • Geo-referencing - This means connecting a historic map or photo to a modern map, usually by locating a number of points that appear on both. Sometimes this means that the old map is warped because of the way that surveying has been done in different periods. In terms of the Layers of London, we talk about geo-referencing in relation to the volunteer and schools programme we have on offer. We work with Historic England and their fantastic collection of RAF aerial photographs of London taken between 1947-49 to map the damage from WW2 on the city. The public will be able to help us create a new map layer using our specially built geo-referencing tool.  This will be ready through the website soon.