SIG & Territoires is the portal for GIS professionals. It offers information on the latest GIS technologies, training and resources for professionals in the sector. GIS & Territoires is the ideal starting point for professionals wishing to find out more about GIS and how to use it to improve their activities.
- QGIS: A New “SQL Query” Option in the Layer Context Menu
Starting with QGIS version 3.42, a subtle but powerful feature has been added to the context menu of vector layers: the “SQL Query…” option. This improvement provides a direct and user-friendly interface for running SQL queries,… - QGis and geoparquet
History of Parquet and GeoParquet 1. Apache Parquet – The original format History: Objective: GeoParquet – Geospatial extension of Parquet History : Year Event 2021 (April) First exchanges on GitHub and in open source communities to… - ENC maps in QGis with Postgis(1)
This subject comprises two articles. The first deals with importing ENC S57 files into a Postgresql/postgis database. The second deals with setting up an automatic symbology equivalent to nautical charts. You can download all the scripts… - Postgis:table with multiple geometries
List partitioning in PostgreSQL/PostGIS is a declarative partitioning method that divides a large table into several sub-tables, according to the discrete values of a column (e.g. by region, type, year, etc.). This is particularly useful in… - Leaflet: responsive
At the end of the Leaflet introductory course, the final mini-project looked like the following map: With a map displaying geojson data, a mini-map and a title. This screenshot was taken on a PC and looks… - MBtiles & Leaflet
Introduction: What is the MBTiles format? The MBTiles format is a file format for storing map tiles (raster or vector) in a SQLite database, a lightweight, stand-alone database engine. Initially designed by Mapbox, this format has… - Leaflet tutorial: session 6
Session objectives: Creation of a mini-mapping project The aim of this session is to mobilize all the skills acquired in the introductory course to Leaflet to create a complete interactive map. Learners choose a theme from… - Leaflet tutorial: session 5
Slide 1: Key events in Leaflet In Leaflet, events play a key role in making maps interactive and responsive. Indeed, Leaflet can handle a wide range of events that occur on the map, layers or specific… - Leaflet tutorial: session 4
Session 4: Customization and control in Leaflet Objective: enhance the user experience (UX) and customize the appearance of interactive maps. Diapo 1: Customizing markers 1. Introduction: Why customize markers? By default, Leaflet uses a standard blue…
Why do we prefer Open Source software?
Geomatics is a discipline at the crossroads of geography and computer science, which involves using software tools to collect, store, analyze and represent spatial data. In this field, the use of open source software offers many advantages.
First of all, what is open source software? It’s software whose source code is publicly available and can therefore be modified and distributed by anyone. It also means that the software is often free, in the sense that it can be used without license fees. The open source movement was born in the 1990s with the emergence of Linux, an open source operating system based on the Unix kernel. Since then, many other open source software products have emerged, covering a wide range of fields, including geomatics. Licenses play an essential role in the operation of open source software. The GPL. General Public License is one of the most common in the open source world. It guarantees fundamental freedoms for users, including the freedom to use, modify and redistribute the software. Many libraries, frameworks and open source tools used in geomatics are distributed under the GPL license.
One of the major advantages of open source geomatics software is its flexibility. Developers have access to the software’s source code, enabling them to adapt it to their specific needs. For example, if you’re using open source geospatial data visualization software and want to add a specific feature, you can modify the source code to implement it.
Another important feature of open source software is the community of developers that surrounds it. These communities are made up of volunteer programmers who actively contribute to the development and improvement of open source software. They share their knowledge, resolve bugs and provide support to users. This ensures the software’s longevity and scalability, as new versions and features are continually developed.
Among the most popular open source geomatics software are GIS-based geographic information systems such as QGIS, which offer a user-friendly graphical interface and powerful spatial analysis functions. There are also libraries such as GDAL and proj, which can be used to manipulate geospatial data in a wide range of formats. As far as geospatial databases are concerned, PostgreSQL with the PostGIS extension is a popular open source solution. It enables efficient storage and processing of spatial data. In addition, open source tools such as Geoserver or MapServer can be used to publish this data on the web. In the field of cartography, the free and open source Mapnik software offers a powerful solution for custom map creation and tile generation. In addition to geomatics-specific software, more general open source solutions such as Python, R and Java can also be used to analyze and manipulate geospatial data.
In conclusion, using open source software in geomatics offers many advantages. They are flexible, scalable and benefit from an active community of developers. What’s more, they offer genuine interoperability with other software and can be used in a variety of environments, including Windows, MacOS and Linux. However, it should be remembered that the use of open source software does not mean that all software used in a geomatics project must be open source. It is common practice to integrate proprietary software into an open source environment, using open protocols and data formats to ensure greater interoperability.
In short, the open source world offers a multitude of solutions for geomatics, allowing users to access, modify and redistribute software source code according to their specific needs. This fosters freedom, innovation and collaboration within the community of open source geomatics software users and developers.