First attempts to Automatize Generalisation of Electronic - - PowerPoint PPT Presentation
Presentation for the 16 th ICA Workshop on Generalisation and Map Production - Dresden, Germany, 23-24 August, 2013 by Weronika Socha First attempts to Automatize Generalisation of Electronic Navigational Charts Weronika Socha GIMA, Delft
Presentation for the 16th ICA Workshop
Dresden, Germany, 23-24 August, 2013 by Weronika Socha
Weronika Socha – GIMA, Delft University of Technology, The Netherlands Dr Jantien Stoter – OTB Research Institute, Delft University of Technology, The Netherlands
How are ENCs different from topographic maps? What is the project about?
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Source: CARIS B.V.
Highly simplified data model
TOPMAR BCNCAR LIGHTS
Source: CARIS B.V.
5 6 7 8 9 4 3 2
5 6 7 8 4 3 1 2
X,Y,Z, X,Y,Z X,Y,Z, ….....
Source: CARIS B.V.
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Add more
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Specifications Maps Evaluation
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AtoNs On water < 2Nm from Main land Cardinal or Isolated Danger
SELECT all Masters AND Slaves
Other Surrounded by land Do not select Not surrounded by land Light
SELECT all Masters AND Slaves
No light Do not select ≥ 2Nm from Main land
SELECT all Masters AND Slaves
On land BCN*
SELECT all Masters AND Slaves
LNDMRK Light
SELECT all Masters AND Slaves
No light Conspicuous
SELECT all Masters AND Slaves
Not conspicuous Do not select
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LNDARE Point Do not select Area Another LNDARE (area) within 50m Aggregate Smooth Smooth Smaller than 1mm/cs Collapse into point and SELECT SELECT
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BUISGL Convert into BUAARE BUAARE Another BUAARE within 3mm/cs Aggregate Simplify Simplify Small Do not select SELECT
Object group What was done? What went well? What went wrong? AtoNs and Landmarks Selection De-clustering Safe approach Logical selection Not all support structures chosen Manual effort still needed for special cases WRECKS Selection All selected correctly Possibly manual deletions involved UWTROC Selection Removing redundant Safe approach Clusters of objects LNDARE Aggregation Simplification Collapsing Time savings Effective depiction of small islands Generalisation not on the safe side Oversimplification COALNE Create feature based on geometry Buffers Assignation of attributes Time savings Correct attribution Short edges BUAARE Aggregation Simplification Correct shape No differentiation between close to shore and far from shore Need to take more objects into account OBSTRN Enlargement Safe approach Effective depiction Consistent with Approach No OBSTRN points Clusters of other objects on better scale should be transformed into OBSTRN areas on the target chart Miscellaneous Selection Sometimes time savings Difficult to find patterns
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– “very encouraging to see the results ” – “in this area of marine cartography that we lack appropriate tools” – “it is necessary to move the objects "seaward"” – “generalisation should be holistic (more complex) and not theme by theme”
– “land area and coastline not completely desirable” – “the routines for de-cluttering of point objects interesting and with a bit of tweaking could be implemented quite quickly”
– “results look promising” – “it is a pity that the bathymetry was not generalised, because generalisation of bathymetry is a recurring event”
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Presentation for the 16th ICA Workshop
Dresden, Germany, 23-24 August, 2013 by Weronika Socha
Weronika Socha – GIMA, Delft University of Technology, The Netherlands Dr Jantien Stoter – OTB Research Institute, Delft University of Technology, The Netherlands