Hardware

Data acquisition

Data can be acquired by various tools and methods. New data can be collected in the field by means of surveying and remote sensing devices. Nowadays these acquisition systems are often directly connected to a GIS by means of a mobile device or notebook, enabling the operator to verify the data directly in the field. Data collection is usually done by governments, organisations or private companies. The data is stored on database servers, where it can be accessed and downloaded over the internet or the data can be purchased on storage media.

In the beginning of GIS, and still today, maps, plans or photos often exist, and make digitizing necessary, without the need to collect new data. In the case of a paper map, this can be done by using a digitizer tablet, where an operator traces the outline of objects, such as roads, streams or boundaries with the mouse and the tablet captures the coordinates of its position. However, this method is increasingly replaced by a process known as "heads-up" digitizing, where the data collector traces a map or image right on the screen with the mouse. This means that the maps have to be digitized beforehand using a scanner or, in case of photos, with a photogrammetric device. The automatic interpretation of images instead of manually tracing geometrical objects is currently one of the major research tasks in photogrammetry and related disciplines.

Data management and analysis

A Geographic information system runs on different kinds of computer categories, from a simple PC to a specialized database server. The exact needs depend on the amount of data and the complexity of the processing to be done. The faster the computer (resp. the CPU) and the more RAM, the better the working performance. In order to store the often vast quantities of data you need mass storage devices and means of backing up the data. For communication between devices, a network is needed.

Data output and presentation

There are several ways of outputting data. Probably the most common way is to display your data in the form of a map on a screen. Other means are sending the data to a printer or plotter. However, if you want to continue handling the geographic information with other programs and tools, or if you want to keep up with the development of new methods and applications, the spatial data needs to be exported in digital form. Output can then either be done on storing media or over a network. Often the data is published on a web- or database server, where other users can access and query the same data. Today, this form of output is getting more and more important, which demands for the establishment of technical as well as communication standards for interfaces and procedures.

Solve the puzzle below to get an idea of the different hardware devices and their function in a GIS.