Start with PostgreSQL / Postgis -Introduction to pgAdmin 4

Following up a previous article (Débuter avec Postgres/Postgis ), we will address an introduction to Postgres/postgis database management. We will load a shapefile, connect and load the Postgis layer from QGis.

The most  suitable method to manage PostgreSQL databases is by using the pgAdmin4 GUI.

This tool is setup automatically during PostgreSQL installation. You can launch it from the programme bar:

Continue reading “Start with PostgreSQL / Postgis -Introduction to pgAdmin 4”

Use of Landsat images (free) in your GIS

When we think of accessible data to integrate into our GIS, we hardly think of satellite data. And yet, it is possible, and just a few clicks away.

Let’s see an example. The following images represent the state of the vegetation for the islands of the Gulf of Morbihan, on the left for July 2014, on the right for March 2015. If we wish, we can obtain images every 15 days, the most just one week old.

ndvi juillet morbihan

ndvi mars morbihan

Findin, recovering and processing them in just 5 minutes. So, why deprive yourself?  Continue reading “Use of Landsat images (free) in your GIS”

How to join data from Excel to an attribute table in QGis

The present topic is meant as a brief review since the possibility of loading and attach Excel tables was introduced by QGis 1.8.
As we do not follow the general logic, for new users it is not easy to find the answer. So, step by step, how to make a join between a spatial layer (we’ll take an example here with a shapefile) and a non-spatial table like Excel (with or without XY fields). Continue reading “How to join data from Excel to an attribute table in QGis”

The ArcGis spatial temporal :2-hot and cold spots

In the Previous article ( The ArcGis Spatial-Temporal Cube : 1- discovery ) we discussed how to create a spatial-temporal cube from a cloud of XYZ points.
Le cube spatio-temporelThe points are grouped into ” boxes ” (bins) corresponding to 3D pixels.
We have seen how to represent the in a 3D scene from ArcGis Pro. In this article we are going how to analyze temporal trends in bins values, using analysis of hot spots emergingLes points sont regroupés en “boîtes” (bins) correspondant à des pixels 3D.
Nous avons vu comment le représenter dans une scène 3D d’ArcGis Pro. Dans cet article nous allons voir comment analyser les tendances temporelles des valeurs des bins, en utilisant l’analyse des points chauds émergents.
Continue reading “The ArcGis spatial temporal :2-hot and cold spots”