LiDAR guide · an IPR project
LiDAR and land surveying
DGT's LiDAR changed the starting point for anyone studying land in Portugal. It does not replace the surveyor: it changes when you need to call one.
What LiDAR gives
A continuous reading of the relief of a whole property, or a catchment, with 50 cm pixels. DGT states 10 cm vertical and 30 cm horizontal accuracy. Enough for contour lines, slope, watercourses and study volumes, before anyone visits the site.
What a topographic survey gives
Points measured on site, with GNSS or a total station, tied to the geodetic network, with stated tolerances and a responsible professional. It sees what the flight cannot: thresholds, floor levels, pipes, boundary markers, detail under closed canopy.
How they fit together
| Stage | Source |
|---|---|
| Choosing land, early study | LiDAR |
| Outline design of water, tracks, planting | LiDAR, with spot checks on site |
| Permits, cadastre, works with tolerances | Topographic survey |
| After the works | A survey or a new flight |
The date matters
The flight is from 2024 and 2025. Tracks, ponds, fills or buildings made later are not in the data.