Comparar, primero visualmente y después cuantitativamente dos DTM. Por un lado elegimos una fuente muy usual, SRTM con un DTM derivado de Fotogrametría Stereo.
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!”
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)”
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)”
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”
One more video i recorded long ago on geoprocessing Cartography. Landuse, DTM, etc. Hope you like it.
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”
(source: http://dominoc925.blogspot.com/) The height accuracy of the collected LiDAR data can be verified by comparing with independently surveyed ground control points on hard, flat, open surfaces. It is essentially just calculating the height differences for all the control points and then determining the height root mean squared error (RMSE) or differences. Most LiDAR processing software have theContinue reading “Using Excel to calculate the RMSE for LiDAR vertical ground control points”
Barcelona (Spain), Winnipeg (Canada), Las Vegas (USA), Moscow (Russia), Durban (South Africa), Vancouver (Canada) and Tokyo (Japan)… these were some of my Terrain view’s 3D scenarios published by Computamaps, a South African company I worked in not so long ago. By the way it was one of my best professional experiences ever… I enjoyed joiningContinue reading “Some of my 3D scenarios”
I have thought there is something very interesting maybe you guys have never tried… using your Google Earth sesssion not just for navigating, finding your house or the place you are going on holidays to… If you use the WMS protocol to show your map over your 3D scenario you are going to add aContinue reading “WMS in Google Earth.”