| description |
The fact that mobile users of location-based services (LBS) have to
be able to go anywhere on earth without changing the application
brings up a major requirement: there has to be one global platform
that provides a transborder and continuous access to the information
necessary for this kind of information systems - and the most
important information source for location-based services is
geospatial data. However, the world of geospatial data is split into
pieces, and the integration of those pieces is a difficult task
since the data are highly heterogeneous: they have been acquired
according to differing conceptual schemas (or application
perspectives), they are available in different formats and scales,
with different accuracies, etc. The main problem concerning spatial
data integration results from the fact that the same real world
objects are stored in multiple, inconsistent representations (MRep)
in different spatial databases. Thus, in order to achieve a common
view on the underlying spatial data within a global information
platform for location-based services, mainly the inconsistencies
between multiple representations have to be considered and dealt
with adequately.
The problem can be depicted by means of a navigation service.
Consider the task of finding the shortest car route between
Stuttgart/Germany and Vienna/Austria. You will not have any problems
to find a solution if you have one single, continuous street data
set comprising the whole query area. However, you will encounter
difficulties in case you have two or more separate, partly
overlapping source data sets (or patches) that you have to assemble
(like a mosaic) in order to form the query area. In this case your
navigation application has to be able to merge (or conflate) the
source data sets that contain multiple conflicting representations
of one and the same real world (street) object in the overlapping
areas to again create one consistent, single representation (SRep)
street database on which the navigation algorithms can operate. The
merge operation, though, is time consuming. This paper describes an
approach to find an optimized solution for the navigation in MRep
street networks by generating explicit relations between multiple
representations and by exploiting them during shortest path search
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