Keywords: SVG, goSVG, GIS, Mapping, WebService
Yuji Kobayashi is a winner of the XML WWW Page Contest of JAPAN 1999,2001.He cooperated in holding of Welcome2000XML1PageFesta,As the member of grass-roots activity of XML promotion.
With the conventional web mapping service, GIS engine, a base map, and g-CONTENTS are the Trinity, and for the individual or the organization who holds g-CONTENTS, the expense burden concerning a systems configuration or management is too large-scale, and it is obstruction factor for the spread of g-CONTENTS. Under present condition, it is hard to think that the grass-roots location information which leads to activation of an area circulates. SVG1.1 Tiny Profile is a language for describing two-dimensional graphic in XML that The geographical coordinates and the screen coordinates can be mutually exchanged, and it can be created comparatively easily using an authoring tool etc. G-XML over SVG (goSVG) is the language which extended SVG1.1TinyProfile so that an G-XML element (POI) can be treated as mean as the name, and it is also a language for exchanging g-CONTENTS. By using goSVG as a Exchange base of g-CONTENTS, it is possible to build g-CONTENTS Exchange model independent of specific GIS engine and a specific base map. Therefore, we build a "g-CONTENTS" Aggregation System, prove the usefulness by the hyper-layer ring architecture which is the feature of goSVG, and the usefulness which can utilize XML technology for the maximum, respectively, and further, consider the advantage of using goSVG in technology of exchanging g-CONTENTS.
g-CONTENTS is general term of the information based on the location. The information which can be expressed with a point in it is called POI (Point of Interest).
1. Overview of the experiment
2. Development environment
3. Contents of the experiment
3.1 The comparison of the experimental system
3.1.1 Experiment 1 :appending location informations by DOM ( The generation of goSVG which utilized Web service )
3.1.2 Experiment 2 :Reference of geographical information by HyperLayerring-architecture
3.1.3 Experiment 3 :The system which united experiment 1 and experiment 2
3.2 Display verification by a various browser
3.3 Display by the various terminals
4. Advantage of using goSVG in technology of exchanging g-CONTENTS
4.1 Advantage of goSVG as a g-CONTENTS distribution format
4.2 Advantage of goSVG in the system which aggregate g-CONTENTS
4.3 Advantage of goSVG in g-CONTENTS superposition
5. A future subject
The method of collecting goSVG data is divided roughly into two cases. One is the method of collecting it by the client. Another is the method of collecting it by the server. When collecting on a client side, the hyper-layer ring architecture can be utilized. It is necessary to generate goSVG which refers to a g-CONTENTS distribution server which exists in the Internet by the server side. As for an advantage, there is little load of a server. When collecting on a server side, it is necessary to collect data from a g-CONTENTS distribution server which exists independently separately on the Internet, and to generate and distribute goSVG which combined them. It is effective when the system and user of a client use the Secondary processing. We built a g-CONTENTS aggregation system and it implemented the experiment to append g-CONTENTS at the convenience store in Kawasaki-city, using base map which KDDI R&D Laboratories Inc is providing.
A development environment about this experiment is shown in the figure.
|Operation System||Windows 2000|
|The JAVA execution environment||Java2SDK1.4|
We built the actual proof experiment system about the experiment 1 and experiment 2 which were Figure 1 in the overview of the experiment, respectively. The display by the goSVG browser and each browser by AdobeSVGViewer etc. was verified, and the display etc. was verified in the cellular phone in PC using the goSVG browser as terminals other than PC.
It is the experiment supposing g-CONTENTS aggregator which relays between the sites which cannot be distributed in goSVG format, combines g-contens of various format, and generates and distributes goSVG. It is using Web service for the concentration of the g-CONTENTS.
<!-- The code of a Base Map --> <g id="3524" style="stroke:#8b8378;fill:#cdb7b5;"> <polyline points="423,81 421,84 416,85 414,84 393,62 393,59 387,59 387,56 381,56 381,37 422,36 423,81"/> </g> <g id="3532" style="stroke:#8b8378;fill:#cdb7b5;"> <polyline points="268,62 268,57 276,58 276,59 284,59 284,68 286,67 285,76 269,76 269,62 268,62"/> </g> <!-- The code of a POI --> <g> <use xlink:href="#A01" x="320" y="240"> <desc gxml:poi="point"> <gxml:cat>Asia Air Survey Co.,Ltd Shinyurigaoka Technical Center</gxml:cat> <gxml:time>2004-03-10</gxml:time> <gxml:tel>044-967-6110</gxml:tel> <gxml:balloon>A receptionist is the third floor!</gxml:balloon> <gxml:floor>3F</gxml:floor> <gxml:prop name="url">http://www.ajiko.co.jp</gxml:prop> </desc> </use> </g>
Figure 4: The sample of the SVG code
goSVG downloaded to the client is displayed with reference to geographic information by the hyper-layer ring architecture. goSVG has a role of a container which stores reference information.
<!-- The code which refers to a base map --> <image xlink:href="http://jamaps3.kddlabs.co.jp/jamaps/japan/japan.svg?position=+35.6032+139.5062/&r=250" x="0" y="0" width="500" height="500"/> <!--The code which refers to a POI --> <image xlink:href="http://gcon.survey.ne.jp/gosvg/getHyperLayerPoi.svg?position=+35.6032+139.5062/&r=250" x="0" y="0" width="500" height="500"/>
Figure 7: The sample of the SVG code
An aggregation system is mounted in a portal site server. The server collects POI using Web service and distributes goSVG. By HyperLayerring-architecture, goSVG which is distributed to the client refers to the map.
<!-- The code which refers to a base map --> <image xlink:href="http://jamaps3.kddlabs.co.jp/jamaps/japan/japan.svg?position=+35.6032+139.5062/&r=250" x="0" y="0" width="500" height="500"/> <!-- The code of a POI. --> <g> <use xlink:href="#A01" x="320" y="240"> <desc gxml:poi="point"> <gxml:cat>Asia Air Survey Co.,Ltd Shinyurigaoka Technical Center</gxml:cat> <gxml:time>2004-03-10</gxml:time> <gxml:tel>044-967-6110</gxml:tel> <gxml:balloon>A receptionist is the third floor!</gxml:balloon> <gxml:floor>3F</gxml:floor> <gxml:prop name="url">http://www.ajiko.co.jp</gxml:prop> </desc> </use> </g>
Figure 10: The sample of the SVG code
goSVG is the application language which extended SVG (XML), in order to display geographic information. It is necessary to implement in a browser about the analysis of a figure element, the cooperation with geographical coordinates, and the treatment of the G-XML element and the processing function of a Map request, which is extension from SVG1.1 Tiny Profile. We verified about the handling of goSVG in the two Windows version browsers.
goSVG Browser(KDDI R&D Laboratories Inc is providing for the experiment.) - As a result of using the structure of experiments 1,2,3 and performing display verification by goSVG browser, it has checked that every case was displayed satisfactory. It corresponds also to the G-XML element and the Map Request Protocol.
AdobeSVGViewer- As a result of using the structure of experiments 1,2,3 performing display verification by AdobeSVGViewer it has checked that every case was displayed satisfactory. However, although it is natural, in AdobeSVGViewer, it does not implement about the processing function of the G-XML element,Map Request Protocol which is an extended portion from SVG1.1 Tiny Profile.
The structure of experiments 1,2,3 was used and it verified whether goSVG could be displayed with various terminals. The display with the PC environment could be already confirmed and as the terminals except the PC, this time, it dealt with the cell phone. It used the BREW version browser which is provided for the experiment paying. It made the structure which delivers data by preparing SVG for the link. because it wasn't possible to address, in the version to have used for a experiment.
In the structure of experiment 1, it did not indicate by data in an error. goSVG which turned redundantly by the data addition by DOM in the server side is distributed, and it thinks because the data-processing capacity of application was exceeded. As for the structure of experiment 2, as in the following figure, the data could be displayed.
The following point is mentioned.
Therefore, the client received in goSVG form can perform easily use by the goSVG browser, and processing by the authoring tool. Furthermore, use with the GIS application of the exclusive use which implemented the import function of goSVG is possible.
The following point is mentioned.
In DOM ,the consumption of the memory generally grows because it constructs the tree in the memory based on read XML. To construct such a system, the analyzed data structure should be simple and be reduced. (the base map which KDDI R&D Laboratories Inc is providing is tuned best of the figure according to the delivered area. )
A question will arise,
When dispersed g contents are compounded and displayed,
By using The affine conversion parameter which is the structure of conversion to a geography coordinate system in SVG1.1 as same conversion formula, in each g-CONTENTS After changing into a screen coordinate, it can treat as the same coordinate system.
Figure 14: Superposition of the base map and g contents by the difference between a selection domain and display width
In order to promote spread and circulation of g-CONTENTS, The structure is required that a user uses g-CONTENTS which is not as the add-on of a base map, and can choose a base map according to the scene. It will also be required to have in stock many base maps which can be used from now on.
Figure 15: [Red Relief Image Map] can be used as a base map at the dangerous area in a steep slope.
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