Orthomosaic mapping is one of those terms that sounds more technical than it is. In practical terms, it's a highly accurate aerial map — geometrically corrected and scaled — produced by stitching together hundreds of overlapping drone photographs. The result is a single overhead image that you can measure from, export to CAD or GIS, and use in planning applications.
How it works
The drone flies a systematic grid pattern over the site, capturing photographs with 70–80% overlap in all directions. Photogrammetry software then processes those images — matching thousands of common points between overlapping frames — to produce a 3D point cloud, a digital elevation model (DEM), and the final orthorectified mosaic.
Ground control points (GCPs) — physical targets surveyed with a GNSS receiver — are placed across the site before the flight. These anchor the processed data to real-world coordinates, achieving horizontal accuracy of 2–3 cm and vertical accuracy of 3–5 cm with a high-quality GNSS setup.
What you receive
- GeoTIFF orthomosaic — a georeferenced aerial image, measurable and scalable
- Digital elevation model (DEM) — a surface model showing terrain height across the site
- Point cloud (.las / .laz) — raw 3D data compatible with most survey and engineering software
- Contour data in DXF or shapefile format
- Volume calculations if required (stockpiles, earthworks, cut and fill)
When do you need it?
Planning applications
Local planning authorities accept georeferenced orthomosaics for site location plans, topographic surveys, and landscape context assessments. For sites with complex topography or where a traditional ground survey would be prohibitively expensive, an orthomosaic is often the most cost-effective route to a planning-compliant survey.
Land management and boundary disputes
An accurate, scaled overhead image of a site — with real-world coordinate data embedded — is extremely useful for boundary disputes, agricultural land management, and estate planning. We've produced orthomosaics used directly in Land Registry applications and party wall matters.
Construction and civil engineering
Volume calculations from drone surveys are used routinely in quarry management, road construction, and earthworks projects. A drone survey can calculate stockpile volumes or cut-and-fill quantities across a large site in a morning — work that would take a ground survey team several days.
Orthomosaic mapping isn't just for large sites. We regularly produce orthomosaics for sites as small as a single development plot — particularly where the client needs a scaled, georeferenced image for a planning submission or architect's brief.
Orthomosaic vs regular aerial photography
Regular aerial photography — a single drone photograph or video — is not georeferenced and cannot be measured from. It's useful for marketing and visual reference but not for any application that requires scale accuracy. An orthomosaic is a survey product, not a photograph. The distinction matters.
