Maps on a shelf or floppy discs of data are often out of date as soon as they are made. But accessing the current details is often essential for the engineer.
In response to this demand, one of the biggest growth areas in services available on the Internet is the provision of instant access to the latest geospatial (map-based) data. This can be tailored to the exact place and nature of the work.
Geographical information systems software uses digital information, built up in layers to give as accurate a picture as possible. Satellite imagery, aerial photography, observations on the ground, even historical data can be combined. Such information is increasingly being used to fit designs to the surrounding environment.
But clearly, for it to be of use, engineers need the most up to date information, and a format that is compatible with the software in use.
Many information providers are now offering on-line ordering through their web sites. Major organisations have joined forces with computer companies to aid this process, one of the most notable being British Geological Surveys collaboration with Intergraph (see box).
But while offering paying customers (subscribing on an annual basis or through the use of virtual tickets) the chance to view and order data on screen, the services do not yet offer the option of downloading data directly. Instead, hard copies and digital data in a variety of formats is sent more conventionally through the post.
Despite this obvious drawback, the process is still faster, with data being sent out in a turnaround of a few days.
In the near future however, it should be possible to order and download on line. But this step from virtual shopping basket to physical receipt will only be achieved when the security of the financial transaction can be assured.
A major and seemingly fundamental step in this process has been Ordnance Surveys full digitisation of its map-making. At the end of January, OS completed the training of its 450 field surveyors who all now have handheld pen-operated computers. PRISM (Portable Revision & Integrated Survey Module) uses GIS software designed by Edinburgh based Conic systems and works on Fujitsu machines. Surveyors can simply download digitised maps from the OS central database, go into the field and enter any new features on to the computer. On returning to the office, the data is downloaded on to PC and the new map sent back to the central database.
Digital map information from the OS is thus regularly updated and as this service is offered over the Internet, engineers have rapid access to order and receive the latest maps.