El láser desvela toda la grandeza de la civilización maya (Fuente: El País)

Esta mañana encontré este interesante reportaje sobre el LIDAR (Laser Imaging Detection and Ranging, detección y localización de imágenes por láser) la tecnología con la que trabajo desde hace años y que a algunos les parece recién inventada, jeje.

LIDAR Madrid LAZ 20cm

Ya van varias veces en el último mes que alguien no especialista en temas geográficos-cartográficos me habla de ‘ese sistema’ de láser para saber ‘la altura del terreno’ y es que la verdad es que LIDAR parece magia. Es bastante increible que pase un avión con una tecnología invisible a ojos humanos y que seContinue reading “LIDAR Madrid LAZ 20cm”

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!”

Risk exposure. Geoprocessing using Open Source Data!! Next steps!!

Now that we have completed a first example, let’s continue with a real-world one. Its important working on a Data Model to define what we understand as a Risk and how important this is. Meaning. High voltage power lines are an actual risk but the closer we are, i guess the bigger the risk is, meaning i.e 3 if we are within 50m and 1 if we are 150m away… It’s only a guess.

Change detection – Detección de cambios en polígonos

THE IDEA: DEMONSTRATING HOW DYNAMIC A CITY IS, THUS HOW IMPORTANT IS HAVING AN UPDATED DATASET THE FACTS: THE CITY OF BOGOTÁ IN COLOMBIA 2012-2014 Overall growth rate: -0.12% ONLY HAVING INTO ACCOUNT THE DIFFERENCE OF BUILDINGS CAPTURED BETWEEN 2012 AND 2014 (We can do this because we have used the same data capture model in both years) (DeContinue reading “Change detection – Detección de cambios en polígonos”

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)”

Remote Sensing, Photogrammetry, Lidar and Landuse IGN Spain

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 andContinue reading “Remote Sensing, Photogrammetry, Lidar and Landuse IGN Spain”

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)”

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”