Orthophotos are aerial photographs that have been geometrically corrected (orthorectified) to eliminate distortions caused by terrain relief, lens distortion, and camera tilt. Unlike raw aerial imagery, orthophotos have a uniform scale and accurate geometry, making them suitable for cartography, measurements, and visual analysis. This specific dataset includes historical orthophotos from 1947 and 1948, derived from aerial surveys carried out by the National Geographic Institute (NGI). During this period, only analogue aerial photographs are available. The analogue images were scanned at high resolution and orthorectified. The resulting orthophotos were assembled into mosaics and georeferenced in the Lambert 2008 coordinate system. All orthophotos are panchromatic (black and white). The ground resolution (GSD) is 50 cm.

Orthophotos are digital aerial photographs in which the systematic distortions caused by the central projection, terrain relief and an image acquisition axis that is not always perfectly vertical have been corrected. The national orthophoto coverage is renewed annually. This dataset always contains the most recent operational orthophoto mosaics for the entire territory of Belgium. When the most recent acquisition campaign does not provide full coverage, the dataset is composed of the last one or two campaigns. In the current version of the dataset, the most recent national orthophoto coverage consists of a combination of the 2023 and 2024 campaigns. The orthophotos have a spatial resolution of 25 cm in Wallonia and 12.5 cm in Flanders and the Brussels-Capital Region. The source data are supplied by the Belgian administrative Regions. NGI harmonises these regional datasets (geometrically and radiometrically) into a single national mosaic, georeferenced in Lambert 2008 (EPSG:3812) and tiled according to the MapIndex1 grid. The dataset is INSPIRE-compliant and can be downloaded as compressed JPEG2000 files (JP2) per MapIndex1 tile, with the corresponding world file (.j2w) and metadata describing the extent of the tiles.