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Posts Tagged ‘3d models’

Remote Sensing, Photogrammetry, Lidar and Landuse IGN Spain

2014/11/18

teledeteccion-fotogrametria-lidar-usos-del-suelo-ign-20141118b

A few more lines for leting you know again that i passed this other course just now in Instituto Geográfico of Spain (IGN).

Remote Sensing, Photogrammetry, Lidar and Landuse, a comprehensive 40h update on relevant information i need tu use on a daily basis. This ‘update’ helps me to better understand what i am working with and this way, being able to properly describe it for my daily analysis,

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HTML High resolution DTM visualization using Quantum GIS (Qgis)

2014/11/03

This QGIS Plugin, Qgis2threejs, exports terrain data, map canvas image and vector data to your web browser!!

3dvisualizatio-DTM-QGIS-20141103

All you have to do is opening the DTM in Qgis (2.4.0 Chugiak), go to plugins library and install Qgis2threejs.

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Once its installed you will see this icon on screen iconand you will need to clic on it.

3dvisualizatio-DTM-QGIS-20141103-04

Then choosing the parameters of the visualization and voilá!!

I have used a 5m DTM which source was LIDAR so the quality is very good

3dvisualizatio-DTM-QGIS-20141103-05

Hope you guys like it. Feedback would be greatly appreciated.

Alberto Concejal
MSc GIS and Quality Control
albertoconcejal [at] gmail.com

DTM from SRTM? Let’s compare sources using RMSE (Root Mean Square Error) and a gaussian kernell density map

2014/10/29

I guess we all can make a DTM out of many sources but SRTM is one of the most common ones, right?. Then let’s learn from this very simple approach how close we are from the SRTM raw data.

  1. Selecting a not very big representative area to be able to handle it,
  2. exporting raster to polygon (from SRTM 3 arcsec/90m) dataset 1
  3. exporting raster to polygon 30m (our DTM dataset) dataset 2
  4. exporting to POIs 30m (our DTM dataset) dataset 2b
  5. Spatial join POIs dataset 2b vs dataset 1
  6. RMSE
  7. visualizing delta using a density map/gaussian kernell +appropriate symbolization

In yellow we see theres a full correspondence between SRTM and our DTM dataset and in blue there’s a ‘hole’ and in red there’s a ‘mountain’, this means it’s in here where the shift is more important.

This way we can highlight if sources are OK.

It’s simple but it works. How do you like it?. Please feel free to send some feedbak.
(Software used: ArcGIS 10.1, Global Mapper 13.2)

Cheers,
Alberto Concejal
MSc GIS, QC

DENSITY-MAP-V1-VS-SRTM-20141021

density maps parameters

rmse-sierra-leone-20141008-02

Spatial join between both DTM datasets

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Density map for highlighting differences between both datasets (ours and SRTM’s)

blog-20141029-03

RMSE. It’s not too big so there’s need to visualize to find potential bizarre spots

blog-20141029-02

bizarre DTM heights

Ever tried Google Earth 3D Building Maker?

2010/02/18

I started modelling 3D buildings quite a few years ago, I used to use 3D StudioMAX… After almost forgetting everything i knew about modelling, 3D and so on Sketch up was released by Google. In a few days i was not just making demos but working and producing!!! Its extremly easy!!!!. Now They have just released something called “Google Earth 3D Building Maker” and its amazing, theres no need to know anything about modelling, you just have to insert polygons and move vertexes…very intuitive indeed!.

place the number of polygons you need…move their vertexes to the proper position.

Directly upload it to your Google 3D warehouse…

And finally take a look at it inside Google Earth… that’s it!.

You can always use Sketchup to perfect it… but it’s good enough…a piece of cake!

http://sketchup.google.com/3dwh/buildingmaker.html

Some of the buildings located in Madrid and Cape Town are mine!

Any questions?, please, don’t hesitate to contact me on:
albertoconcejal [at] gmail.com

Alberto Concejal
3D GIS Technician

News: Amazing Helsinki 3D!

2009/08/13

Navigating all over the world within Google Earth I have just discovered a brand new 3d layer in Helsinki, Finland.  Almost every building around makes this scenario very realistic… You just have to click on ‘3d buildings’  and it will show you this incredible layer… Does anybody know a WMS map to use it here?.

helsinki01

helsinki02

helsinki03

Hope you like them,

Alberto