Orthomosaic Mapping — Accurate Aerial Maps from Drone Imagery

An orthomosaic is a geometrically corrected aerial image — stitched together from hundreds of individual drone photographs and processed to remove the distortion caused by camera angle and terrain variation. The result is a scaled, georeferenced map that can be measured directly, overlaid with GIS data, and compared against previous surveys to track change over time.

Unlike a standard aerial photograph, every pixel in an orthomosaic corresponds to a known location on the ground. Distances, areas, and boundaries can be measured with precision. A construction site orthomosaic captured at regular intervals creates a visual record of progress that is both accurate enough for technical use and clear enough for client and stakeholder communication.

Before and after — Berkeley Commons, Berkeley CA

The images below show the same site captured at two different stages of construction — six months apart. Drag the slider to compare.

What orthomosaic mapping delivers

A drone orthomosaic provides an accurate top-down view of the site at a resolution far exceeding satellite imagery — typically 2 to 5 centimeters per pixel depending on flight altitude and camera specifications. This level of detail allows individual features, structures, and site elements to be clearly identified and measured. Orthomosaics can be imported directly into AutoCAD, ArcGIS, QGIS, and other technical platforms for further analysis.

For construction sites, regular orthomosaic surveys provide a timestamped visual record that documents site conditions, tracks earthwork progress, monitors material storage areas, and supports quality assurance. Combined with elevation data from the same flight, orthomosaics also support volumetric calculations and drainage analysis.

Applications

Orthomosaic mapping is used across a wide range of construction and infrastructure projects — site surveys, progress monitoring, as-built documentation, environmental baseline studies, and boundary verification. For large sites where ground-level inspection is time-consuming or impractical, a drone orthomosaic provides a complete picture of the site in a fraction of the time.

Air Actual provides drone orthomosaic mapping throughout the San Francisco Bay Area. All flights are conducted by an FAA Part 107 certified pilot. Get in touch to discuss your project.