chris wright managing consultant chris.wright@1spatial
DESCRIPTION
Chris Wright Managing Consultant [email protected]. The current situation. Assets captured against supplied base data Aligned to the base data As an offset from the base data Base data continuously being updated Often in small discreet areas. What needs to happen. - PowerPoint PPT PresentationTRANSCRIPT
• Assets captured against supplied base data
• Aligned to the base data
• As an offset from the base data
• Base data continuously being updated
• Often in small discreet areas
The current situation
• Update Asset information to match shifts
• Maintain alignment
• Maintain offset
• Needs to be easy and simple to do
What needs to happen
Our process
• Utilises a piecewise triangular warp (Delaunay)
• Create triangular mesh from the shift vector data– Shift vectors may exist– Shift vectors can be created
• Transform between triangles– Delivers smaller more accurate transformations– Nearby co-ordinates have a much bigger effect on transform
Our process
• Why Delaunay ?
– A well-established mathematical algorithm
– Nearby control points have bigger effect than distant control
– Triangles only dependent on set of nearest neighbour control points
– Movements to control points beyond set that have no effect
An exampleThe original
basemap cadastre with original annotation,
together with the current cadastre
shown in blue
An exampleThe original
basemap cadastre with original annotation,
together with the current cadastre
shown in blue and the shift vectors shown in pink
An exampleThe original
basemap cadastre with original annotation,
together with the shift vectors shown
in pink and the shifted original
basemap shown in orange
An exampleThe original
basemap cadastre with original annotation,
together with the shift vectors shown in pink, the shifted original basemap
and shifted original annotation shown
in orange