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

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

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

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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 Prisk Priska a Haller Haller

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

Europe

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

Switzerland

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Department of Geoinformation

Switzerland

https://commons.wikimedia.org/wiki/File:Kanton_Zürich_auf_der_Schweizer_Karte.png?uselang=de

41’285 km2 German, French, Italian, Romansh Bern 8’256’000 Confederation, consisting of 26 cantons

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

Canton of Zürich

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Department of Geoinformation

Canton of Zürich

1729 km2 1’446’100

https://commons.wikimedia.org/wiki/File:Karte_Kanton_Zürich_2010.png

German Zürich 169 communes

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Department of Geoinformation

About us

Kanton Zürich

Priska Haller Department of Geoinformation Canton of Zürich, Switzerland

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Department of Geoinformation

LIDAR = Light detection and ranging

First Return Second Return Third Return Fourth Return Last Return

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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

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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)

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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

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Department of Geoinformation

Digital Terrain Model (DTM) / Digital Surface Model (DSM)

 Digital Terrain Model (DTM)  Digital Surface Model (DSM)

https://commons.wikimedia.org/wiki/File:DOM_DGM.png

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Department of Geoinformation

Calculation of DTM and DSM

 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) DTM DSM

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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
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Department of Geoinformation

Special Issues of the Project

 Resolution & Accuracy  Scope  Repetition interval  Open Government Data

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Department of Geoinformation

Resolution esolution & & Accur Accurac acy

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Department of Geoinformation

Resolution & Accuracy

 Resolution:

  • Average Point Density: 8 Points/m2
  • 1850 GB storage

 Accuracy:

  • horizontal: +/- 20 cm
  • vertical:

+/- 10 cm

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Department of Geoinformation

Scope Scope

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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
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Department of Geoinformation

Repetition epetition inter interval val

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Department of Geoinformation

Repetition Interval

 Every 4 years: Laserscanning  Every 2 years: Aerial Photos

  • Spatiotemporal Monitoring Projects!
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Department of Geoinformation

Open Da Open Data ta

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Department of Geoinformation

Swiss Open Government Data Portal

  • pendata.admin.ch

WCS with DSM + DTM

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Department of Geoinformation

Data downloadable at maps.zh.ch/?topic=LidarZH

DSM/DTM (GeoTIFF) Lidar (laz) Point cloud ground-points (ASCII-xyz)

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Department of Geoinformation

Data Download from Independent Sites

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Department of Geoinformation

What does «open» mean?

Licence: CC-BY

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Department of Geoinformation

More about Open Government Data in Zürich / Switzerland

Thursday, September 17: « Use case of a dual open strategy in the canton

  • f Zürich, Switzerland »

(Pirmin Kalberer / Priska Haller)

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Department of Geoinformation

Some use cases …

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Department of Geoinformation

Thanks to Markus Schütz, potree & Martin Isenburg, rapidlasso

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Department of Geoinformation

Thanks to Markus Schütz, potree & Martin Isenburg, rapidlasso

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Department of Geoinformation

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Department of Geoinformation

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Department of Geoinformation

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Department of Geoinformation

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Department of Geoinformation

Thanks to Andreas Neumann, City of Uster / Switzerland

City Model of Uster

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Department of Geoinformation

Cada Cadastr stral al Sur Survey: ey: Detec Detection tion of

  • f

Dif Differ erent Height Le ent Height Levels els within within Buildings Buildings

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Department of Geoinformation Source: Google StreetView

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Department of Geoinformation

Cada Cadastr stral al Sur urvey ey: : Detec Detection tion of

  • f for
  • rest

est boun boundaries daries

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Department of Geoinformation

Archaeology: Detection of Prehistoric Barrows

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Department of Geoinformation

Forestry: Detection of Skid Trails

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Department of Geoinformation

Virtual Reality as a PR Instrument

Device: Oculus Rift

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Department of Geoinformation

Virtual Reality as a PR Instrument

Device: Oculus Rift

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Department of Geoinformation

Lessons Learned

 Acquiring new experience in working with very large datasets  Automatic preprocessing always needs manual postprocessing

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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)

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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

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Department of Geoinformation

Open Your Data!

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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

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Department of Geoinformation

Thank you!