On 17th March, 23 Questers from Anton U3A visited the Ordnance Survey offices at Southampton.
A series of presentations had been arranged to show how information is collected and processed to produce the popular maps that we buy today. We also were told about the total amount of information that is collected to make different versions of maps for other users giving a variation for their needs and to provide digital data for topography, roads, buildings natural features etc.
The printed maps part of the organisation is only a small function of the business which is owned by the Government but has to make its money from commercial operations. The Government only supplies a small income to support public service requirements such as emergencies.
We were told how they ensure the accuracy of the position of the instrumentation to record data. Mapping is now about digital data and digital processing. This could in extreme emergency situations produce a limited area map in 30 mins from ground and/or air observations to a digital map becoming available. Maps are normally updated about every 3 years, using aerial photography and field surveyors. The field surveyors no longer use a telescope type instrument but a sophisticated pole with a communication device, which communicates with radio beacons (these appear to replace trig points) and of course satellites.
Cartographers produce the coloured map by generalising the raw digital data and photographs to reduce the “clutter” of the raw information into easily understood symbols which enables us read the map.
Future developments were mentioned. The use of Unmanned Aerial Vehicles (drones) to carry out limited area surveys is being investigated. The reduction of raw data through to a printed map without human input is also being developed.
We found it interesting and informative. The demise of the paper map has been predicted for some time, but sales are holding on and apart from their main function of showing where we are going (and significantly the batteries don’t run out), some of them are also works of art.