MODELLING: GIS
Much more than mapping
A commercial GIS system goes much further than allowing you to view points in space; it allows you to give them meaning. GIS provides a framework for gathering and organising spatial data, and for analysing spatial relationships. It consists of three major components: an information system or database; an analytical framework; and a mapping/visualisation component. Maguire draws an analogy to financial software; you can use a spreadsheet program to handle many basic functions, but those who want to do serious enterprise resource planning, customer relationship management, or product lifecycle management turn to packages such as SAP. Similarly, Google Earth and Bing Maps provide basic mapping functions, but for serious work you’ll turn to a commercial GIS package. Even with consumer maps as a background, scientists still need to store and analyse their own data and associate it with other data in a meaningful way. With the heart of a GIS being its database, it’s no surprise that the database supplier Oracle is involved in this field. Some other GIS suppliers use Oracle Spatial for their database, and others interface directly into it. Just as many applications have date/time as
standard datatypes, Oracle Spatial adds 2D and 3D geometry types. With built-in commands you can easily perform a proximity analysis or containment or topology studies as naturally as you can do data arithmetic. An SQL query can determine how far it is from location A to location B and get the results in metres.
This multiple-view image made with Manifold shows Bing Maps satellite data (upper left), calculated digital elevation with the slash showing the San Andreas Fault (lower left), calculated contour lines (middle) and the contours overlaid on Bing Maps image (right).
cent of the applications. This is possible with the help of other tools such as Microsoft SQL Server 2008, which includes spatial datatypes and geometric datatypes, exposes vector and raster data, is compliant with OGC and can read/write GML (Geographical Markup Language) data. But for spatial mining and analysis applications, he agrees that users will need to turn to higher end GIS products. For some interesting examples of what’s possible with Bing Maps, Kebek first points to
‘Even with consumer maps as a background, scientists still need to store and analyse their own data and associate it with other data in a meaningful way’
Oracle provides all the functionalities of
GIS minus visualisation, but has APIs for that task. The firm explains that its open platform complements other GIS technologies, and you can access it from any application level. A chief advantage is the scale factor; the Oracle database is designed for very large datasets, which scientists are generating and that are becoming more widely available. Johannes Kebek, a Bing Maps technical specialist at Microsoft, agrees to some extent about the place of general-purpose visualisation tools. For simple spatial analysis, in what you might think of as the traditional uses of GIS, he believes that Bing Maps can cover 80 per
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the Environmental Atlas of Europe, for which he is credited with the web development, in which the authors visualise evidence of climate changes. Another one is the Worldwide Telescope by Microsoft Research, where you can examine objects in the night sky; Kebek mentions that soon it will be possible to pick a spot on the earth and see a view of the skies in the past and in the future.
Full-featured packages
For high-end GIS tasks, Bing Maps are closely tied into software from ESRI, which includes those maps in its product offering. Indeed, when it comes to full-featured GSI software,
most industry observers point to ESRI as the market leader. The company launched its first commercial GIS software in 1982. Today it has 4,500 employees, 300,000 seats and between one and two million estimated users. The firm’s core product is ArcGIS, which
comes with its own spatial database, but also works directly with its own spatial datatypes in an Oracle database (but not Oracle Spatial datatypes). The product ships with approximately 26GB of data, including imagery and basemaps, both public domain and purchased. It has meanwhile built up 30 TB (and growing) of data in ArcGIS Online, some of which is free and some of which is a subscription service that ensures regular updates to the basemaps plus access to higher resolution maps or additions such as meteorological data. The main module is ArcGIS Desktop, but additional products are available throughout the enterprise on servers and mobile devices, as well as online services and custom applications. ESRI also has a free downloadable geobrowser called ArcGIS Explorer. It is a 3D globe with a built-in map gallery, including Bing Maps, and users can add their own content or connect to additional resources such as geodatabases, layer files or GIS services. It is intended for someone who has domain expertise, but no GIS expertise. In the next couple of months GIS Explorer Online will become available,
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