WGS84 gives global latitude and longitude; UTM gives local metres in zones. Learn when each system helps, why layers misalign when they mix, and how to set the right CRS in QGIS.
Archive: 2026
211 stories published in 2026
A choropleth map shades areas by a data value, such as population or rainfall. Follow a beginner workflow in QGIS: prepare clean data, choose a classification, pick a honest colour ramp, and label the result.
Resolution decides what a satellite image can show. Compare 30-metre Landsat, 10-metre Sentinel-2, and sub-metre commercial imagery, and learn which level your project really needs.
Good GIS work starts with good data. Bookmark these free sources for boundaries, elevation, satellite imagery, and OpenStreetMap extracts, and learn how to check licence and date before use.
The best free satellite imagery sources for GIS work, from Sentinel and Landsat to cloud viewers β and how to match resolution, revisit time, and licensing to your project.
Sentinel-2 is sharper and fresher; Landsat reaches back to 1972. Learn when to use each free dataset β and when the best answer is both.
A step-by-step guide to downloading Sentinel-2 imagery into QGIS: account setup, smart searching by cloud cover, choosing Level-2A data, and loading the right band combinations.
WebODM turns drone photos into free orthophotos and 3D models. Learn the flight settings that make it work, how to run your first task, and how to check your results.
NDVI turns satellite imagery into a plant-health map in minutes. Learn the formula, which Sentinel-2 and Landsat bands to use, and how to style and interpret the result honestly.
Overlap, altitude, and speed decide whether a drone mapping flight succeeds. Learn the settings behind good photogrammetry and the pre-flight checklist that prevents failed reconstructions.
Free open aerial imagery is often sharper than satellite data for local mapping. Learn where national programs, OpenStreetMap, and web services offer it β and how to use it legally.
QGIS is free and ArcGIS is the industry standard β but which should a beginner learn first? Compare cost, jobs, and ecosystem, and learn why the underlying skills transfer either way.
Turn a drone elevation model into readable contour lines in QGIS. Learn how to prepare the DEM, choose the right interval, style index contours, and check accuracy.
A GeoTIFF is an image with location tags that place it on the map. Learn how georeferencing works, what cloud-optimized GeoTIFFs change, and how to use them in QGIS.
QGIS is free and powerful, but beginners need a clear path. This step-by-step tutorial covers installing, adding data, styling, querying, and exporting your first map.
Sentinel-2 offers finer detail and frequent revisits; Landsat offers decades of history. Here is how to choose the right free satellite data for your mapping project.
WebODM turns overlapping drone photos into maps and 3D models for free. This beginner workflow covers flight planning, processing, and checking your first orthomosaic.
LiDAR uses laser pulses to build detailed 3D maps of terrain, forests, and cities β even under tree cover. Here is how it works and when to use it.
QGIS print layouts add titles, legends, scale bars, and clean design to your map. Here is how to build, style, and export a professional layout.
QGIS, PostGIS, GeoServer, and Python libraries now cover most GIS work for free. Here is the open-source stack that can replace commercial GIS for most users.
Georeferencing gives a scanned old map real coordinates so it can be compared with modern data. Here is how to pick control points, transform, and check the result in QGIS.
Drone photogrammetry can produce elevation models for flood, construction, and land analysis. Here is the difference between surface and terrain models and how to use them.
Free DEMs from SRTM, ALOS, Copernicus, and national lidar programs cover most of the world. Here is how to choose the right elevation source for your project.
OpenStreetMap lets anyone improve the world's free map. This beginner guide covers editors, tags, accuracy, and using OSM data in your own projects.