Web map services became a very popular web services following the trend called Web2.0. Those web map services has played a role of a platform for various geographical web content. One of the main functionality of that are offering the map used as a background, and the functionality which superimposes thematic geographical content on it. Occasionally, it may be superimposed on two or more subjects. This can already be called one of the styles of the hyper-document which connects various content on WWW.
Nevertheless, there is almost no compatibility in these web map platforms. As a result, those geographical content must depend on specific web map services strongly. This promotes dividing into sections of hyper-documents. So, the time when the WWW standards which realizes the hyper-document for a map should be established may be arriving.
SVG Map is a specification for the map service platform on WWW that uses SVG. It offers the essential functions for interoperability of Map Services as a basic function by fully applying the hyper-document that is the basic structure of WWW.
A dynamic web server is not indispensable for SVG Map. Of course, it is possible to use it as an option. Because it is possible to construct it as a set of a mere files, even http is not indispensable either. Therefore, SVG Map is also possible stand-alone operation using local file system. This characteristic is the same as HTML that is the basis of the Web architecture. It may turn out that this feature is important by investigating the REST architecture thoroughly. And, it might dramatically decrease the cost of the map data publication and map services.
The basis of the protocol for SVG Map is simply a file access by URI. SVG Map doesn't restrict anything for it. Even query-part of URI which often becomes the argument in REST is not limited at all. Furthermore "file:" is acceptable as a scheme of URI. In other words, various REST-based map services with different query rules and even local files can cooperate in SVG Map easily.
Interoperability that is the most important functionality for Web Mapping platform is realized by hyper-documents (SVG documents linked by hyper-link). Needless to say, hyper document is the most essential characteristic of WWW.
Moreover, composition of the tegular contents (tiling) is always used for the map with a vast area. And tiling can be considered as one type of the hyper-documents, because it is one of the presentations of the relation between a lot of contents.
SVG Map achieves following important functions of map services without a dynamic server.
- Not only raster map but also vector map support
- Geographic coordinates identification
- Tiling by hyper-document
- Layering (MashUp, Interoperation of map services) by hyper-document
- Stand-alone operation
The basic architecture of SVG Map was designed in 1996. Its part was standardized as SVG1.1 (Geographic Coordinate Systems) that had been recommended by W3C in 2003. (See also, SVG Mobile Requirements - Usage Scenarios , SVG 1.1 and SVG Mobile FAQ) And SVG Map Consortium to promote it was established in 2007, and the reference implementation of the viewer was published.
The specifications of SVG Map are very compact by depending on SVG. Therefore the specifications for SVG Map may be called Tiling and Layering Module for SVG.
The latest specification for SVG Map is published at following URL by SVG Map Consortium.
In addition, please pay attention to standardization in the W3C. JSTF
Note: The full potential of SVG Map will be shown by native implementation on the Web browser. Implementation to WebKit is in progress.
Because the server of the minimum implementation is not dynamic, the minimum implementation is a mere map data file itself. Therefore, you can view the examples of such static map data which were shown below. There are some examples which used well known dynamic services.
In addition, tool which converts shapefile into SVG Map is shown.