Mention a cartographer and people will think of someone who draws maps. Well, it’s obvious isn’t it? Having spent a few hours talking to various members of our Cartography team though, I’m actually amazed at the breadth of areas they cover. So, if you’ve already read our ‘day in the life of a surveyor’ blogs, read on to find out what happens once that surveyed data gets inside the building.
Our Cartography team, which is really lots of separate teams with different specialisms, is led by Huw, and they are responsible for deriving and maintaining cartographic databases, and providing the finished data for Ordnance Survey national series paper and data products. They do this through the manipulation and enhancement of our core databases. But as well as this ‘core’ work, they work on lots of other projects from specialist maps to innovative work on the effects of colour vision deficiency on mapping.
Sandy leads the Explorer team. Unsurprisingly, they work on the design, editing and updating of databases for our very popular 1:25 000 OS Explorer Map. The team also work on the data for our OS Select bespoke product where customers can centre a map on an area of their choice and on our digital product, 1:25 000 Scale Colour Raster.
The team are programme-led and have a good idea of their workload over the course of a year. Sandy explained that the map sheets for Explorer are split down into tiles and the cartographers work on six tiles at a time, known as 6blocks. So, when a job arrives from Production Control, they order the tiles from the database. When the tiles are on screen, the cartographer will check each tile for any relevant changes by a combination of running reports and visually comparing the data against other datasets.
In rural areas rural areas they’re looking for paths, tracks, fences and other navigational aids which are significant for our users, but in urban areas there can be many changes to buildings, new developments, road changes and so on and it can take from two days to three months to complete an update – although it is much quicker today with computers than in the days of hand scribing the changes.
It quickly makes me realise how much of an attention to detail you need as Sandy and one of her team, Dave, show me the changes needed in one very small area of a tile. Only after completing the 6blocks can the cartographer then work on the actual map sheet. Sheets are compiled from the tile blocks and amended for late information before a proof is printed for Quality Control purposes.
It can then be turned into a PDF and sent to our printers. After this the data needs to be cut back down into single tiles in a variety of formats to be fed back into our database for more products. This is a 36 step process and even an experienced cartographer like Dave works his way down the checklist very carefully.
Small scales team
Next I caught up with Steve from Small Scales. They produce all Ordnance Survey paper and digital products that have a scale smaller than 1:50 000. These include the OS OpenData products 1:250 000 Scale Colour Raster, Strategi, Meridian 2, MiniScale and OS Locator. His team of 12 also produce Ministry of Defence (MOD) training charts, the GB contribution to geographic data for the European Union (Eurostat and the European Environment Agency),National Air Traffic Services (NATS) air charts, covers for our paper mapping, mapping extracts for exam boards, work for the Boundary Commission and a whole range of ad hoc work.
I was intrigued to discover that the team are responsible for updating our Ancient and Roman Britain map. What could possibly change from Roman Britain? But, of course, they update the map as new sites are discovered.
The MOD work also means that the team produce mapping for overseas countries where the armed forces carry out training – these include Germany, Brunei, Jamaica and Kenya. The team do visit the UK-based training sites with the MOD, but sadly not the overseas ones! The last visit was to Salisbury Plain, less than an hour away from our head office.
Steve explained that while each of his team are responsible for a specific product, they are flexible in helping each other out – essential when you are producing mapping for such a large range of internal and external customers.
You can find out more about the work our Cartography teams do next Friday…