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*** Presented by Christopher Barron at State of the Map 2013 *** For the video please see http://lanyrd.com/2013/sotm/scphkr/ *** Full schedule also available at http://wiki.openstreetmap.org/wiki/State_Of_The_Map_2013 For the purpose of data quality evaluation OSM is almost always compared with reference datasets. However, these datasets are not always accessible due to the lack of availability, contradictory licensing restrictions or high procurement costs. An OSM-Full- History Dump can serve as an alternative source for quality evaluations. Using so-called intrinsic indicators the quality of OSM datasets can be assessed with the help of the data's history. We will present why and how the history of OSM objects matter and which tools were used. For this purpose, examples for selected cities around the world are analysed and compared with each other to reveal differences in terms of OSM data quality based on the history of the dataset's objects.
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Christopher Barron, Geoinformatics Research Group, Institute of Geography, Heidelberg University
Using the History of OSM for Quality Assessment
Christopher Barron, Pascal Neis, Alexander Zipf
Geoinformatics Research Group,
Institute of Geography Heidelberg University
Christopher Barron, Geoinformatics Research Group, Institute of Geography, Heidelberg University
How can we evaluate OSM datasets without a reference dataset?
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Christopher Barron, Geoinformatics Research Group, Institute of Geography, Heidelberg University
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Christopher Barron, Geoinformatics Research Group, Institute of Geography, Heidelberg University
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Christopher Barron, Geoinformatics Research Group, Institute of Geography, Heidelberg University
Methods for Quality Analysis based on an OSM-Full-History- Dump Intrinsic Approach
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Christopher Barron, Geoinformatics Research Group, Institute of Geography, Heidelberg University
iOSMAnalyzer - Architecture
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Christopher Barron, Geoinformatics Research Group, Institute of Geography, Heidelberg University
Examples
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Christopher Barron, Geoinformatics Research Group, Institute of Geography, Heidelberg University
Total Road Network Length (1/6)
Assumption (Neis et al. 2012):
1) Motorways/Highways
2) Secondary/Tertiary Roads
3) Residential Roads
4) Tracks, Paths, etc.
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Map
pe
d c
om
ple
tely
Christopher Barron, Geoinformatics Research Group, Institute of Geography, Heidelberg University
Total Road Network Length (1/6)
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Madrid Yaoundé
Christopher Barron, Geoinformatics Research Group, Institute of Geography, Heidelberg University
Positional Accuracy of Junctions (2/6)
Helbich et al. (2012)
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Christopher Barron, Geoinformatics Research Group, Institute of Geography, Heidelberg University
Positional Accuracy of Junctions (2/6)
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Madrid
Christopher Barron, Geoinformatics Research Group, Institute of Geography, Heidelberg University
Buildings & House Numbers (3/6)
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Salzburg
Christopher Barron, Geoinformatics Research Group, Institute of Geography, Heidelberg University
Buildings & House Numbers (3/6)
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San Francisco
Christopher Barron, Geoinformatics Research Group, Institute of Geography, Heidelberg University
Buildings & House Numbers (3/6)
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Yaoundé
Christopher Barron, Geoinformatics Research Group, Institute of Geography, Heidelberg University
Topological Errors (4/6)
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San Francisco
Christopher Barron, Geoinformatics Research Group, Institute of Geography, Heidelberg University
Currentness of Data (5/6)
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Salzburg
Christopher Barron, Geoinformatics Research Group, Institute of Geography, Heidelberg University
Roads without a name or ref Tag (6/6)
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Yaoundé
Christopher Barron, Geoinformatics Research Group, Institute of Geography, Heidelberg University
Summary
• Q = {V1, V2 … Vn-1}
• OSM quality analyses …
– based on OSM-Full-History-Dumps;
– are possible without reference datasets;
– are arbitrarily repeatable.
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Christopher Barron, Geoinformatics Research Group, Institute of Geography, Heidelberg University
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https://github.com/zehpunktbarron/iOSMAnalyzer GNU GPL Version 3
Christopher Barron, Geoinformatics Research Group, Institute of Geography, Heidelberg University
Thank you for your attention!
Christopher Barron
Geoinformatics Research Group
Heidelberg University http://giscience.uni-hd.de
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