This video demonstrates our main Georeferenced maps viewers, and our related Side-by-side viewer for comparing two maps on screen. It illustrates how georeferenced map layers can be found and viewed, and how you can adjust their transparency to compare them to modern day satellite imagery. The various tools for measuring bearings, distances and areas, tracing features, showing heights and elevation profiles, printing and rotating are also shown.
The Georeferenced Maps interface allows you to view a set or series of historical maps seamed together, in one continuous layer.
You can locate the map by searching on a modern placename, National Grid Reference, or historical placename, or by sharing the location of your device.
You can also zoom in on the map by using the plus and minus buttons in the bottom left or using the mouse wheel, or holding the [Shift] button down and dragging a box to zoom to a specific area. On touchscreen devices pinch to zoom in and out.
To select a map in the Georeferenced Maps viewer, choose the historic map series that you would like to view from the left-hand lists, you can switch between different map series at any time using this menu. The lists reflect the area shown in the map, so if you zoom in, fewer layers appear. To close the search boxes to see more of the map, click the X at the top of the box, and to open them again click on the layer tab.
The Georeferenced Maps viewer has several additional features for you to explore.
The transparency slider bar allows you to change the transparency of the historic maps to display the background map behind it.
By default, the background map shows a modern ESRI World Image satellite layer. To change to a different background map, select the drop-down list at the top of the page.
For coordinate details like Latitude and Longitude and National Grid Reference, click on Show coordinates on the bottom bar and then click on the map.
If you would like more information about the symbols on the map, click on the Map Key.
On the right of your screen, there are a set of measurement tools. The first icon is a 'measure bearing' tool, the second is a 'measure area' and the third is 'measure distance'. For example, to measure the area click on the corners surrounding the area you would like to measure. Click on the measurement tool icon to clear the screen or turn off the measurement tool.
If you toggle the Show Height button to ON, then the approximate height of your cursor location is shown. You can switch this OFF by toggling the button back to OFF.
You can also create an Elevation Profile by toggling the ON button in the box below. To draw the profile, click the route on the map. When you double click an elevation profile box will open.
If you would like to see details of the specific map you are looking at, or order a print or image, click on the Display map details? View or order this map link to the lower right.
The Full Screen / Draw viewer provides a tool to mark up or draw on the map layers.
The Draw/Trace features button allows you to choose a feature type and a colour and then draw features. You can change features whilst drawing or delete them.
To print the map on the screen, click on the print icon, to the lower left of the screen. Once opened, you can drag or zoom the map image to make sure it covers exactly the right area and choose orientation and scale. You can then save the image in various formats or copy the image to clipboard. It is also possible to print the map directly to a printer.
You will also find a 3D viewer option. You can fade the transparency and change the vertical exaggeration of the heights/terrain (to make the hills or mountains appear higher).
Finally, use the Spy viewer to view the historic map layer in a spyglass over the background map. You can change the size of the spyglass in the left-hand panel. You can choose the layer inside the spyglass, with the drop-down lists to the lower left, and choose the layer outside the spyglass with the drop-down list at the top of the page.
The Side by Side viewer places georeferenced maps alongside modern maps. Choose the map layers that you would like to view on each side of the viewer. Select the Swipe OFF / Swipe ON buttons in the header to change the central vertical bar, so that it can be moved sideways to compare two maps.
You can rotate the maps by holding down the [Alt] and [Shift] keys and drag with your cursor. On a mobile device or tablet, you can rotate the map using two fingers. To return to the default rotation, click the rotation arrow that appears in the top right of your screen or refresh your page.
There is a detailed Help page which you can view by selecting the orange Help button to the lower left, describing these and other functions in detail.
We hope this video has been helpful - if you have any questions, please get in touch.