Tag Archives: 3d

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”

RSME comparing LIDAR data with a third party’s 3D dataset

I would like to share with you an easy analysis i have been working in the last days. I had a vector dataset of buildings and i knew how high they were (there was a field called ‘AGL’ or Above Ground Level) and a LIDAR 2m resolution dataset over the city of London. My aimContinue reading “RSME comparing LIDAR data with a third party’s 3D dataset”

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”

Solar + Shadows analysis on Rue Massillon, Nantes (France)

This is the beautiful building in from of my house in Nantes… Let’s model it first using Sketchup. Also I have used a non standard style only for visualization purposes… If we have the North behind us this means we are going to have a lot of light… but so far we are just guessing… Now weContinue reading “Solar + Shadows analysis on Rue Massillon, Nantes (France)”

Shadow analysis en Puerta de Arganda, Madrid.

Hoy publico en español puesto que los datos son en español y yo soy español:-) but if you guys have any doubt dont hesitate to ask… even if you are french I will be around to answer you back “en français”, quand même !!!. La idea era hacer un estudio de sombras de para mi propio usoContinue reading “Shadow analysis en Puerta de Arganda, Madrid.”

ViewTec’s State-of-the-art 3D visualization

Good news!!!! They’ve probably released this Geovisualization Engine long time ago (It used to be an ‘in-house’ software) but I have just realized. I worked with this state-of-the-art TerrainView 3D software for six months while I was working as a GIS Specialist in Cape Town (South Africa)… What does this software has that no oneContinue reading “ViewTec’s State-of-the-art 3D visualization”

Visualizing LAS LIDAR data with sketch-up

While trying to figure out the way to get a 3D model from raw Lidar data, I first opened my LAS file in Global Mapper, exported it to DXF, imported then into Sketch-up and after recording a few scenes, I saved the animation… this is it!. Alberto

Using Excel to calculate the RMSE for LiDAR vertical ground control points

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 the reporting function built-in. However, plain Microsoft Excel can also do the job (except for extracting the elevation from the LiDAR data).

Data acquisition: How do I know if this river is been well acquired?

I’ve already entered my river but my imagery was in 2D so… was it well acquired?…  First of all, I import my shape (shp) file into Global Mapper (what a great sofware!) and export my vector file as a KML. Import my river.kml file into my brand new Google Earth 5.2 or just double-click itContinue reading “Data acquisition: How do I know if this river is been well acquired?”