Tag: tutorial

Over one Pyrenean valley, four free 30 m DEMs sat 12 to 18 m above the LiDAR ground under forest. Where to get each DEM free, and how to load it in QGIS.

6,041 bike crashes in Paris mapped three ways in QGIS: Heatmap renderer, kernel density raster and hexagons, then one sentence to an AI agent: 2 min 34 s.

Where to run PyQGIS, a first script, and a test on six tasks: chatbot code always ran, but one result was silently wrong when given only layer names.

Stream Sentinel-2 over STAC with no account, or get the L2A product from Copernicus Browser. Four methods tested on farms in Brazil, with timings.

QuickOSM fetched 4,560 buildings in 5 seconds; the same query on a whole country timed out. When to use QuickOSM, a Geofabrik .pbf or Overpass Turbo.

Layer > Georeferencer, 4 spread points, Polynomial 1. Why an RMSE of zero proves nothing: a thin plate spline hit it on a map 594 m off.

The classified LiDAR HD cloud covered 78.4% of France on 6 September 2026, 30,933 of 34,877 communes. Map per commune, products, clicks in QGIS.

How to use AI Agent in QGIS: install it, write your first request, stay in control, then 5 real tasks, from open data to an HTML report.

Browser panel > XYZ Tiles > double-click OpenStreetMap. Then satellite tiles by URL, QuickMapServices, a national WMS, and the ground size of each zoom.

Flat, watercolor, pencil and glossy, all rendered from one aerial image of Letchworth Garden City. Every prompt in full, and where the model invented water.