Comparación de DTM usando Global Mapper 17.0.1

Comparar, primero visualmente y después cuantitativamente dos DTM. Por un lado elegimos una fuente muy usual, SRTM con un DTM derivado de Fotogrametría Stereo.

Descargas del CNIG. Open Source bien hecho!

Hola amigos del GIS, Por motivos de trabajo que no vienen al caso, he tenido que bucear de manera sistemática la web de descargas del CNIG. http://centrodedescargas.cnig.es/CentroDescargas/inicio.do Una maravilla. Por motivos que tampoco viene al caso, he de hacer esto mismo de vez en cuando en todos los Institutos cartográficos del mundo y el delContinue reading “Descargas del CNIG. Open Source bien hecho!”

DTM validation using Google Earth (and RMSE extraction)

Hi guys, Surfing the internet is great when you need to figure out something. I needed to validate some DTM from unknown sources against an also unknown source (but at least a kind of reliable one, Google Earth). All we need is Google Earth TCX converter ARcGIS Excel This is the procedure i have followed:Continue reading “DTM validation using Google Earth (and RMSE extraction)”

HTML High resolution DTM visualization using Quantum GIS (Qgis)

This QGIS Plugin, Qgis2threejs, exports terrain data, map canvas image and vector data to your web browser!! All you have to do is opening the DTM in Qgis (2.4.0 Chugiak), go to plugins library and install Qgis2threejs. Once its installed you will see this icon on screen and you will need to clic on it. Then choosingContinue reading “HTML High resolution DTM visualization using Quantum GIS (Qgis)”

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

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. Selecting a not very big representative area to be able to handle it, exporting raster to polygon (fromContinue reading “DTM from SRTM? Let’s compare sources using RMSE (Root Mean Square Error) and a gaussian kernell density map”

Projets éoliens en Loire-Atlantique

C’est vraiment magnifique l’ouverture des données publiques… Je vais décrire mon itinéraire pour mieux comprendre: Télécharger des données (Projets éoliens en Loire-Atlantique) Telecharger DTM (SRTM v4) Faire Carte d’ombrage (ArcGIS), Orientations (ArcGIS) et Inclinations (ArcGIS) pour mieux comprendre l’emplacement des moulins Faire Carte de densité (en mesurent la puissance du parc) Et maintenant la carte de densité en Global Mapper…Continue reading “Projets éoliens en Loire-Atlantique”

Creating DEM/DTM

It was 2007 when i finished my master’s degree and wanted to show some videos of procedures. At that moment in time i wanted to find a job -any job- involving GIS and i finally found it dealing with the Geovisualization department within a GIS company… now i happen to deal with DEMs. DTM, etcContinue reading “Creating DEM/DTM”