International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B4. Istanbul 2004 Intei
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Fig.4 The data integration of three different GIS platforms at 3 C
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This system has provided the functions of the spatial data query a
and thematic mapping based on GML and SVG. How to realize of
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the query function? At first, user selects the query feature by
clicking with the mouse at client. In SVG every graphic element
has exclusive ID number for identifying with each other. We can
(b) The thematic mapping function ©
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get the ID number by these mouse response events of being
responded by graphic elements such as “onClick” event through Fig.5 The system’s function of query and thematic mapping
JavaScript language. The attribute data are stored in the GML
document. The ID of attribute data is corresponding with the ID 5. CONCLUSION
of the graphic element. So the attribute data stored in GML
e : As a new developing technology, XML has been used in many
document can be found easily from the relevant graphic ID. The |
; : domains. The superiority of XML in the semantic definition,
result is showed as Fig.5 (a)
data exchange and information search make it be possible to
: - : Wa . apply XML to GIS field and to realize the spatial data
In order to realize the thematic mapping, it is required to
: : : > s : interoperability from many different systems.
ascertain the thematic range of the certain attribute of the feature.
Such as Fig.5 (b), it is the thematic mapping with the "area"
; = ; ; Comparing deeply GML and SVG specification, we can get the
attribute of the layer of BOUNT (the borderline of national
; ce : ; ; N ; result that GML is a geographic mark-up language, and it has
provinces). It is divided into eight levels. The first level is the
: ; almost considered every necessary aspect of GIS application.
range from zero to 15,0000 sq .km, and the second is between
GML object model is designed for all kinds of questions
15,0000 sq .km and 30,0000 sq .km, ....... We can search the
Nga : : ; appearing in GIS application. While SVG is a common planar
“area” attribute value of each feature in the layer of BOUNT in
vector graphic description and it is not direct for the professional
the GML document, reset different symbol colours to the gran p p
PEOR : ento field of GIS. But SVG has the function to browse graphics easily
features in different interval range based on the division above
: : ; - by SVG viewer. Mutually combining the two kinds can
while exporting GML document into SVG format, then browse
: ; : : : completion effectively the interoperability and visualization of
the SVG format in the explore with SVG Viewer. So the
; US ; spatial data.
thematic mapping is realized.
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