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The fusion process of LiDAR and map data to generate 3D city and landscape models. Sander oude elberink Geospatial world forum 16 May 2013. Generation of nationwide 3D city and landscape models using national datasets: 1:1.000, BGT, fused with AHN-2 (~8 p/m^2)
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The fusion process of LiDAR and map data to generate 3D city and landscape models Sander oude elberink Geospatialworld forum 16 May 2013
Generation of nationwide 3D city and landscape models using national datasets: • 1:1.000, BGT, fused with AHN-2 (~8 p/m^2) • 1:10.000, TOP10, fused with AHN-2 (~8 p/m^2) Fusion process Research questions Hydrocity (1:1.000) 3DIMGeo (1:1.000) 3DTOP10NL (1:10.000)
Which lidar points have to be used to transfer the height to an object? How to use the semantics of the map data? How to assign a height to a point, boundary or surface? What is the quality of that height? How to deal with noise in both the map and lidar data? The questions
Transfer height from selected points to map point In general resulting in at least 2 heights per map point. What to do with the differences? Semantics between classes Select laser points per map point, per polygon
See also presentation of Mark Kroon Neo Aim was to keep small relative height differences (but not the ones caused by ‘noise’) Curbstones Boundary between 2 infrastructural polygons (road, sidewalk). Function of object in addition to class label Hydrocity Produce 3d model forhydrologicalapplications
Per object: height, infiltration capacity, surface roughness Interpolated to grid for run off modelling Hydrocity Object based
As a product of 3D Pilot, start of 3D SIG NL (see presentation of Jantien Stoter). Based on IMGeo, CityGML standards. Workbench in FME, in cooperation with con terra GmbH (Christian Dahmen). LoD0, LoD1 and LoD2. 3DIMgeo 1:1.000
Use FME to (summary) • Read andvalidate source data: CityGML 2D IMGeo + LiDAR (AHN-2) • 'Point-On-Polygon' operation (assign laser data topolygons) • Run + manage the complete workflow -> Single User Interface Use '3D IMGeo tools' developedbyU Twente to: • Preparemap data and laser data for the 3D reconstruction. • Assignheightto the map boundariesfor a LoD0 terraindescription. • Assigna heightdescriptioninside the 3D polygons. Results are TIN surfacesat LoD0. • CalculateLoD1 or ‘LoD2’ buildings andforest • Use FME againtowriteresult data: CityGML 3D IMGeo FME - 3DIMGEO tools - FME
1:10.000 Fused with AHN-2 (~8 p/m^2) 3Dtop10nl
TOP10NL: topographic representation, geometric accuracy 2 m AHN-2: geometric 3D representation, geom acc < 0.5 m, 8-10 p/m2 Aim for selecting ‘correct’ points Do we need all laser points? Implications of fusion
Which lidar points have to be used to transfer the height to an object? • Depends on the object. How to use the semantics of the map data? • Depends on the map/application. How to assign a height to a point, boundary or surface? • Depends on the object. What is the quality of that height? • Depends on the workflow. How to deal with noise in both the map and lidar data? • Deal with it. The questions And the frustrating answers
Kadaster will go for 3DTOP10NL 3D IMGeo tools are open (since April 2013) and integrated into FME Nice link between Geo practice and research Nearfuture