THE PROCEDURE: Centroids of buildings; Spatial join showing presence-absence, considering a 10m accuracy threshold, meaning if the centroid has not moved more than 10m, its the same building. If the centroid in 2012 is not in 2014, its considered as demolished. If a new centroid appears its considered new building.
Tag Archives: sig
La geográfica cabecera de ‘Up in the air’ con George Clooney
Para alguien que maneja mapas a diario es una sorpresa interesante cruzarse con esta cabecera de la película de Jason Reirman protagonizada por George Clooney ‘Up in the air’. Nubes, campos de cultivo, ciudades en 2D, 3D. Qué bien he elegido mi profesión:-) Para alguien que viaja mucho, salvando las distancias, este vídeo, también delContinue reading “La geográfica cabecera de ‘Up in the air’ con George Clooney”
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)”
Pearson correlation and GIS
Do these two variables have a correlation?. To answer this important question first of all we have to know that only if it’s a linear relationship and there are no outliers we can take advantage of Mr Pearson’s correlation statiscal tool. If i love chocolate, does this mean i have tendency of being chuby? orContinue reading “Pearson correlation and GIS”
‘Reality Checks’, also called ‘Ground Truth Tests’
Comparing all kind of Geodata (i.e 3D Buildings, DTM, DHM, DSM, Land Use, vectors,…) to background sources as Google Earth/ Bing, available sources from the country we are working on or WMS available sources, etc. Figuring out if the data requested and we want to deliver is consistent enough compared to the so called “Truth”. SomeContinue reading “‘Reality Checks’, also called ‘Ground Truth Tests’”
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”
PISA report SPAIN 2012 by Comunidades Autónomas Trends North-South and West-East
I wanted to take advantage of the latest ‘advanced course on Statistical Analysis’ followed in the spanish IGN and show you how North-South and West-East trends impact on this report. As you can see, the higher the values, the most likely to be in the North and the East of the country. This doesn’t meanContinue reading “PISA report SPAIN 2012 by Comunidades Autónomas Trends North-South and West-East”
Analyse des emplacements réservés à la livraison sur voirie: NANTES
*Désole pour mon français, si vous voulez on peut parler en anglais ou espagnol. La première chose qu’il faut faire c’est télécharger le jeu de données au site: http://data.paysdelaloire.fr/donnees/ Thématique : Mobilité Le jeu propose la géo-localisation des emplacements réservés à la livraison sur voirie dans un secteur limité de la ville de Nantes. Ces aires permettentContinue reading “Analyse des emplacements réservés à la livraison sur voirie: NANTES”
Visualization will endure these difficult years of CRISIS!!
I have already worked as a building cleaner, data capture operator, copywriter, photographer, graphic designer, video editor, technical salesman… and seriously, I think i’m too old to make a living in something else now… GIS has been working for me the last 8 years and i want to stay like this!!!:-) I have just read inContinue reading “Visualization will endure these difficult years of CRISIS!!”
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”
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