To bring their maps to the modern viewer (i.e. online), the NLS team needed to fetch up-to-date OS map tiles from a stable source.
The process required substantial technical knowledge, time, computing and storage resources.
The team was required to periodically download large spatial datasets and re-process them, so they could host raster map tiles on their own web servers – taking several days with hosting being an additional cost.
The raster tile service included in the OS Maps API provides the most up-to-date map tiles.
NLS Map Curator Chris Fleet updated a few lines of the code deployed on the NLS map view website. This small update means that Map Viewer users fetch their mapping data directly from OS – not from the map tile server configured and maintained by Chris and his team.
The OS Maps API provides three primary benefits to the NLS web mapping team:
- The NLS site now displays the most up-to-date mapping Ordnance Survey has published – changes in the real world are reflected on their website in a matter of weeks, not years.
- The OS Maps API serves map tiles using new, “significantly improved” OS cartographic styling and enriched map content, including visual consistency across zoom levels and topographic relief.
But perhaps the most important advantage is that the mapping itself is significantly improved in terms of styling and content.
As users zoomed in and out with the previous separate OS OpenData products the contrast in styling when jumping between the layers was quite obvious, whereas now different zoom levels look and feel like a single integrated map.
More important still, especially at larger scales, is the much richer topographic content which, in many of the hillier parts of the country, means that the sense of topography and relief is easier to convey.
There are also a number of styling improvements to land use and text for features, so that things like parkland and woodland are easier to tell apart, more minor street names can be shown in urban areas, and different coloured lettering distinguishes things like schools, hospitals and churches from street names.