25
Feb
2011
0

Focus on Cartography – part two

If you missed last week’s blog, catch up now before finding out a little more about what goes on behind the scenes in our Cartography teams…

My next stop was with Jim in Landplan. His team of 20 are responsible for the revision and update of the 1:10 000 database. This covers OS Landplan, 1:10 000 Scale Colour Raster and 1:10 000 Scale Black and White Raster, OS Street View and more recently, OS VectorMap Local.

Jim told me that the Landplan vector editing system was developed in-house during the mid 1990s. The capture programme started in September 1996 and the 10 587 tiles in the initial database were completed in 2001. It was the first production system in Ordnance Survey to use auto generalising algorithms to do Cartographic generalising for a derived product.

One of the Landplan team at work

One of the Landplan team at work

When a 1:10 000 tile needs updating, a job request makes its way to a cartographer. They will add new detail, delete unwanted detail and check the data meets the specification for the product. As with Sandy’s Explorer team, the time this takes depends on the tile. It could be as little as two hours for a mountain or moorland area or upwards of 17 hours for an urban area. Each year the team update around one third of the tiles. When a 5 km by 5 km tile has gone through the revision process it is databanked. This action starts the automatic generation of various 1:10 000 products, raster files for both 1:10 000 Scale Colour and Black and White Raster, as well as the generation of a revised OS Street View raster tile.

Since revision has started, Landplan has been active in chasing prestige sites such as the M6 Toll road, the Channel Tunnel Rail Link, the Eden Project, the Scottish Parliament building and so on. Jim’s team also follow customer needs by updating the major urban areas, whilst not forgetting the more remote areas of the Highlands and islands.

My next visit was with Rick’s Cartographic Design and Quality team. As their name suggests, they carry out ad-hoc design work and quality assurance – particularly on our derived products, data products, and more recently, our printed maps. The team of five also cover any technical customer enquiries passed on from our Customer Service Centre as well as producing special printed plots of our mapping for selected guests to our head office.

 

Gary explained that the team is responsible for the quality assurance (QA) of paper products such as OS Landplan, OS Explorer Map and OS Landranger Map and data products such OS VectorMap District, OS VectorMap Local, Strategi and Meridian 2. Due to the outsourcing of printing to Butler, Tanner and Dennis, the team have recently been made responsible for ensuring our printed maps meet the high standards expected of Ordnance Survey.

 

A large chunk of work comes though our customers or partners too. This could be mapping extracts needed for websites, mapping for charitable events such as the British Heart Foundation tour, work on specialist maps for the Thames Gateway and much more. The team have to interpret the customer requirements to make sure they deliver the right end product with minimum fuss for the customer.

The Olympic Park

The Olympic Park – view a pdf

When Chris Evans ran his Children in Need Ferrari Drive, Rick’s team provided the bespoke maps for the drivers. They’ve also produced the mapping for the Tour of Britain and the Olympic map featured on our blog last year.

 

Ed has become involved in a colour vision deficiency (CVD) project for the team. I was amazed to find that 8-10% of the population can have difficulty with interpreting a map through this. In the US it is actually a legal requirement to make the maps widely accessible and it’s something we would be interested in doing too. The project ties in with the RNIB’s Wayfinder project which is about getting from A to B – in terms of the actual place you might need to visit within a building – and includes tactile and audio work as well as CVD styling. Ed’s work is around producing formulas for our vector products as the styling is more flexible to work with. We could produce a stylesheet for each product and a CVD version too.

 

The team have to be very flexible in how they approach their work, always working on something different relying on each others knowledge, skills and experience to ensure they meet customers’ needs as effectively and efficiently as possible.

 

Last but not least I caught up with Dave in our Landranger team.

It’s particularly apt, as it brings me full circle…part of Dave’s team work on the 1:50 000 OS Landranger Map, the partner of Sandy’s 1:25 000 OS Explorer Map product that started my blog post last week. While many of the processes the team follow are similar, there are also many differences. 

Dave’s team are working on what is our oldest national mapping series, as it is derived from our one inch maps from over a century ago. His modest team of seven follow a revision programme to produce the printed 204 OS Landranger Maps (which include the Isle of Man), the 1:50 000 Scale Colour Raster product and, uniquely in the Cartography teams, the 1:50 000 Scale Gazetteer. These products provide a mapping picture of the country as opposed to the many vector data products we also offer. 

An array of computer screens to work on in the Landranger team

An array of computer screens to work on in the Landranger team

The team work on Landranger sheets or continuously revise 10 km tiles as opposed to the 6blocks in Sandy’s team. These are revised following a programme agreed with the Product Manager. As in the Explorer team, the 1:50 000 data is compared against other information to ensure all available changes are added. This can take from tens of hours to hundreds of hours depending on the amount of change – areas such as central Birmingham or London will take the most time to update.

Once Dave’s team are sure they’ve captured all available change their work passes through to quality control to ensure we maintain our quality and consistency of product. Completed sheets are then passed on to our printers to meet their print schedule before appearing in a shop near you as one of our OS Landranger Map series. 20 km tiles are made and converted into different resolutions and become available to customers as data.

Of course, these are just some selected activities that our Cartography team get up to. You can find out more about cartography from the British Cartographic Society or if you’d like to know more about any of the topics covered here, let us know and we could feature it in another blog entry in the future.

Next week we’ll be looking at how cartography has changed over the last 40 years through the eyes of John, one of our longest-serving Cartography team members.

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