FOSS4G, FOSS4G , Seoul Seoul September September 16, 2015 16, - PowerPoint PPT Presentation

Canton of Zürich, Switzerland Building Department, Office for Spatial Development Department of Geoinformation High-Precision Open Lidar Data of Zürich/Switzerland FOSS4G, FOSS4G , Seoul Seoul September September 16, 2015 16, 2015 1 Prisk Priska a Haller Haller

Europe 2 https://commons.wikimedia.org/wiki/File:Blank_political_map_Europe_in_2008_WF_(with_Kosovo).svg?uselang=de

Switzerland 3 https://commons.wikimedia.org/wiki/File:Blank_political_map_Europe_in_2008_WF_(with_Kosovo).svg?uselang=de

Switzerland Department of Geoinformation 8’256’000 41’285 km2 German, French, Italian, Romansh Bern Confederation, consisting of 26 cantons 4 https://commons.wikimedia.org/wiki/File:Kanton_Zürich_auf_der_Schweizer_Karte.png?uselang=de

Canton of Zürich Department of Geoinformation 5 https://commons.wikimedia.org/wiki/File:Kanton_Zürich_auf_der_Schweizer_Karte.png?uselang=de

Canton of Zürich Department of Geoinformation 1’446’100 1729 km2 German Zürich 169 communes 6 https://commons.wikimedia.org/wiki/File:Karte_Kanton_Zürich_2010.png

Department of Geoinformation About us Priska Haller Department of Geoinformation Kanton Zürich Canton of Zürich, Switzerland 7

Department of Geoinformation LIDAR = Li ght d etection a nd r anging First Return Second Return Third Return Fourth Return Last Return 8

Department of Geoinformation The Zürich Lidar-Project  Parent project: «Luftaufnahmen42»  Lidar  Aerial photographs  Scanning period: March / April 2014  Flight altitude: 1400 – 1800 meters a.s.l.  Helicopter + small aircraft (nightly flights above Zürich airport)  260 flight tracks, 20% overlap  62 hours flight time  Scanning angle: -20º / +20º 9

Department of Geoinformation Point Classification  Ground (LAS Code 2)  Low vegetation < 50cm (LAS Code 3)  Medium vegetation < 3 m (LAS Code 4)  High vegetation > 3 m (LAS Code 5)  Buildings (LAS Code 6)  Noise, errors (LAS Code 7)  Bridges, crossings (LAS Code 10)  Overlap points (LAS Code 12)  Open wires, poles, antennas (LAS Code 15)  Other (e.g. vessels) (LAS Code 17) 10

Department of Geoinformation Lidar Data and Products  Point cloud  Format: LAS 1.2 (ASPRS)  Classification: 10 classes  Point cloud of ground points, ASCII text (xyz)  Point cloud of non-ground points, ASCII text (xyz)  GeoTIFF grid for Digital Terrain Model (DTM),  GeoTIFF grid for Digital Surface Model (DSM)  Web Coverage Service DTM + DSM 11

Department of Geoinformation Digital Terrain Model (DTM) / Digital Surface Model (DSM)  Digital Terrain Model (DTM)  Digital Surface Model (DSM) 12 https://commons.wikimedia.org/wiki/File:DOM_DGM.png

Department of Geoinformation Calculation of DTM and DSM  Ground (LAS Code 2) DTM  Low vegetation < 50cm (LAS Code 3) DSM  Medium vegetation < 3 m (LAS Code 4)  High vegetation > 3 m (LAS Code 5)  Buildings (LAS Code 6)  Noise, errors (LAS Code 7)  Bridges, crossings (LAS Code 10)  Overlap points (LAS Code 12)  Open wires, poles, antennas (LAS Code 15)  Other (e.g. vessels) (LAS Code 17) 13

Department of Geoinformation Calculation of DTM and DSM  DTM:  Triangulation of ground points (Delaunay)  LAS Code 2  0.5 m grid-model  DSM:  «Highest hit» of all first returns / grid cell  LAS Codes 2,3,4,5,6,10  Empty cells get the value of the DTM  0.5 m grid-model 14

Department of Geoinformation Special Issues of the Project  Resolution & Accuracy  Scope  Repetition interval  Open Government Data 15

Department of Geoinformation Resolution esolution & & Accur Accurac acy 16

Department of Geoinformation Resolution & Accuracy  Resolution:  Average Point Density: 8 Points/m2  1850 GB storage  Accuracy:  horizontal: +/- 20 cm  vertical: +/- 10 cm 17

Department of Geoinformation Scope Scope 18

Department of Geoinformation Scope  Total coverage: 1900 km2  Area of the canton of Zürich: 1729 km2  Buffer-Zone of 500 m  Cities Zürich and Winterthur  Airport of Zürich  Permission from the Civil Aviation Authority 19

Department of Geoinformation Repetition epetition inter interval val 20

Department of Geoinformation Repetition Interval  Every 4 years: Laserscanning  Every 2 years: Aerial Photos  Spatiotemporal Monitoring Projects! 21

Department of Geoinformation Open Da Open Data ta 22

Department of Geoinformation Swiss Open Government Data Portal opendata.admin.ch WCS with DSM + DTM 23

Department of Geoinformation Data downloadable at maps.zh.ch/?topic=LidarZH DSM/DTM (GeoTIFF) Lidar (laz) Point cloud ground-points (ASCII-xyz) 24

Department of Geoinformation Data Download from Independent Sites 25

Department of Geoinformation What does « open » mean? Licence: CC-BY 26

Department of Geoinformation More about Open Government Data in Zürich / Switzerland Thursday, September 17: « Use case of a dual open strategy in the canton of Zürich, Switzerland » ( Pirmin Kalberer / Priska Haller ) 27

Department of Geoinformation Some use cases … 28

Department of Geoinformation 29 Thanks to Markus Schütz, potree & Martin Isenburg, rapidlasso

Department of Geoinformation 30 Thanks to Markus Schütz, potree & Martin Isenburg, rapidlasso

Department of Geoinformation 31

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Department of Geoinformation 33

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Department of Geoinformation City Model of Uster 35 Thanks to Andreas Neumann, City of Uster / Switzerland

Department of Geoinformation Cada Cadastr stral al Sur Survey: ey: Detec Detection tion of of Dif Differ erent Height Le ent Height Levels els within within Buildings Buildings 36

Department of Geoinformation Source: Google StreetView 37

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Department of Geoinformation Cada Cadastr stral al Sur urvey ey: : Detec Detection tion of of for orest est boun boundaries daries 39

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Department of Geoinformation Archaeology: Detection of Prehistoric Barrows 41

Department of Geoinformation Forestry: Detection of Skid Trails 42

Department of Geoinformation Virtual Reality as a PR Instrument Device: Oculus Rift 43

Department of Geoinformation Virtual Reality as a PR Instrument Device: Oculus Rift 44

Department of Geoinformation Lessons Learned  Acquiring new experience in working with very large datasets  Automatic preprocessing always needs manual postprocessing 45

Department of Geoinformation Lessons Learned  Acquiring new experience in working with very large datasets  Automatic preprocessing always needs manual postprocessing  Example Prime-Tower (126 m) 46

Department of Geoinformation Conclusion  Opening up the dataset was the right decision!  Development of many attractive applications and visualisations  Useful also for the authorities!  Combination of accuracy&resolution, scope, repetition interval und openness makes this dataset unique  Locational advantage for the canton of Zürich  Attractive open datasets help to promote Open Data 47

Department of Geoinformation Open Your Data! 48

Department of Geoinformation Questions? Priska Haller Department of Geoinformation Canton of Zürich, Switzerland priska.haller@bd.zh.ch @GISZentrumZH geoportal.zh.ch Icon credits: Noun project. Erik Johansson 49

Department of Geoinformation Thank you! 50