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G.I.S. - Frequently Asked Questions

What is GIS

In short GIS (Geographic Information Systems) are maps which have a database attached to them giving the parts of the map extra information.

What is GIS software used for?

Many uses for GIS are obvious, utilities need to know where the pipes and valves are, local authorities need to know where all the land it owns are, and so on. However the uses are very varied - from health care to housing.

What about maps and data?

Like any other piece of software GIS need information to work. Any database is useless with some data to work with. As a word processor is no good at all without a document, so a GIS isn’t much good with a map and/or some data. Data for GIS is now widely available, from many different sources and for a myriad of subjects - from highly localised and specific data to world-wide coverage, it's all available.

Is it expensive?

Looking from a home-user point of view, you would say yes, but in a corporate environment a GIS package is no more expensive than any other piece of specialised software. Data can bump the total cost up, depending on how much and how detailed the data you need is.

Does a GIS look like a road map?

Depending on the data you use, then yes it can do, but that is just one possibility among hundreds. More normally the data is intelligent and known as "vector" data, where as the style of map we know from road atlases is dumb - a scanned image - known as a "raster" data.

Where does the data come from?

It depends on the data. If you have old paper maps or microfiche, then organisations like CDR Group will convert them into digital data. Some data are published by the government, via the Office of National Statistics and the Office of the Deputy Prime Minister. Others are produced commercially and are available through various specialist companies. However the biggest supplier of map data, both paper and digital is Ordnance Survey.

Can I create or use my own data?

Yes, of course. Without this ability a GIS is no different to a journey routing package running on a home P.C. The ability to add or overlay your data is essential. You can either import the data from existing sources (e.g. databases and spreadsheets) or simply start from scratch.

Is it difficult to use my own data?

No. Most GIS software has "wizards" to guide you through the import routines. The better ones will open the data directly without any conversion. Some will even use data sharing technology like OLE or ODBC (see elsewhere for definitions), to access data from other applications.

What about creating my own data?

Creating your own data depends on the exact package you decide upon. Most have a process similar to creating a new database. It's just a matter of deciding on what data you want and how you want it to be presented.