Drone Mapping vs. LiDAR: Which One Does Your Project Need?

How photogrammetry works

A mapping drone flies a grid pattern, capturing hundreds of overlapping photos. Software matches millions of common points between images and reconstructs the scene in 3D, producing a dense point cloud, a surface model and an orthophoto. It's efficient, and the imagery itself is a deliverable — you get a measurable photo of the whole site.

Its limit is simple: photogrammetry can only measure what the camera can see. On open ground it's excellent. Under trees, it measures the canopy, not the terrain.

How LiDAR works

A LiDAR sensor fires laser pulses — hundreds of thousands per second — and measures their return time. Crucially, some pulses slip between leaves and branches and return from the actual ground. After classification, you get a bare-earth surface even in forest that photogrammetry can't penetrate.

LiDAR sensors and processing are more specialized, so LiDAR generally costs more than a photo flight. It also doesn't produce photographic imagery on its own, which is why many projects fly both together.

The short version

A rule of thumb that holds up well:

• —Open site (cleared land, gravel, stockpiles, construction in progress): photogrammetry
• —Vegetated or forested terrain where the ground matters: LiDAR
• —Corridors through mixed cover (roads, pipelines, trails): LiDAR, often with photos
• —You need imagery people can read: photogrammetry / orthophoto — with LiDAR added if canopy hides the ground

Why this question matters more on Vancouver Island

Much of Vancouver Island is second-growth forest with dense understorey — some of the most demanding mapping terrain in the country. Here, the photogrammetry-vs-LiDAR decision isn't academic: on a treed site, a photo-only flight can miss the ground by metres. It's usually the first question we settle when scoping any large-area mapping job on the Island.