Aerial surveying (also called drone surveying, UAV mapping or aerial geodesy) is land surveying from the air. A drone with precise GNSS positioning and a camera photographs a site, and photogrammetry software turns the images into measurements. The result is an orthophoto, a topographic plan, a 3D model and earthwork volumes, accurate to a few centimetres.
In short, instead of a survey crew spending days on foot with a total station, a drone operator collects data for tens or hundreds of hectares in one or two flights. Below is how it works, what accuracy to expect, what you receive and what to check when you order a drone survey in Georgia.
What Is Aerial Surveying, in Plain Words
Classic surveying measures individual points: an instrument is set up on the ground and coordinates are recorded point by point. Aerial surveying works differently. The drone takes hundreds of overlapping photos, and software reconstructs the shape of the surface from them. This method is called photogrammetry.
Instead of dozens of points you get millions, each with coordinates in the system you need.
There is an important difference from ordinary aerial photography. A good-looking drone shot is an illustration. A survey is a measurement: you can calculate distances, areas, slopes and volumes from it.
How Aerial Surveying Differs from Ground Surveying
- Speed. A site of tens of hectares is flown in one or two flights instead of several days of fieldwork.
- Data density. You get a continuous model of the surface instead of separate survey points.
- Access and safety. Slopes, quarries, active construction sites and vineyard terraces can be surveyed without walking into hazardous areas.
- Limitation. A drone sees only what is visible from above. Ground under dense vegetation or roofs stays hidden.
In practice the two methods complement each other. Ground measurements verify accuracy, and the drone covers everything else.
How a Drone Survey Works, Step by Step
- Brief. We define the goal (plan, volumes, cadastre, monitoring), the required accuracy, the coordinate system and the delivery formats.
- Preparation and permissions. We choose flight height and route, take airspace into account and, where needed, mark ground control points and checkpoints on site.
- Flight. The drone flies a set route and captures the site with overlapping images, while RTK records the coordinates of every photo.
- Processing. The images become a point cloud, an orthophoto and a digital terrain model.
- Quality control and delivery. We compare the result against checkpoints, prepare the data in the formats you need and hand it over.
How Accurate Is a Drone Survey?
There is no single figure. Accuracy depends on flight height, image resolution, quality of RTK corrections, the number of checkpoints and the terrain itself.
As a guide, 1–2 cm is achievable at low altitude with checkpoints. At a typical height for large sites, expect a few centimetres. That is enough for topographic plans, volume calculations and most construction tasks.
Accuracy should be proven, not claimed. Ask for a report showing how far the result deviates from independent checkpoints (usually given as RMSE).
The Equipment We Use
We work with the DJI Matrice 4E, a drone built by the manufacturer for mapping and surveying. Here is what matters about it for a client:
- 4/3-inch, 20 MP camera with a mechanical shutter. There is no rolling-shutter distortion, so images taken in motion keep clean geometry.
- Built-in RTK module. Every photo gets precise coordinates during the flight. This reduces the number of ground control points needed on site, but does not remove the need for checkpoints.
- Multi-angle capture and an interval of about 0.5 seconds. A site is covered faster, and slopes and facades are captured without blind spots.
- Up to 49 minutes of flight time (according to the manufacturer). More area per flight.
The drone is only a tool. Method, checkpoints and processing determine the result, so the aircraft model should not be the only criterion when you choose a provider.
What You Receive After the Survey
Not just nice photos, but data that opens in your CAD, BIM and GIS software:
- Orthophoto (GeoTIFF). A distortion-free image of the site that you can measure on.
- Point cloud (LAS, E57). A 3D base for Revit, AutoCAD and ArchiCAD.
- Digital terrain and surface models. The first shows bare ground, the second includes buildings and vegetation.
- Topographic plan (DXF, DWG). Contour lines, site features and as-built plans for design work.
- 3D model (OBJ, glTF). A textured model for visualisation and viewing in a browser.
- Vector data (GeoJSON). Boundaries and attributes for interactive maps and databases.
- Volume report. Calculation of cut and fill for earthworks and stockpiles.
Where Drone Surveying Is Used
- Construction. Progress control, earthwork volumes and as-built surveys at each stage.
- Municipal work and GIS. Land plot inventories, updated plans and GIS layers, and mapping of infrastructure.
- Agriculture and wine. Slope and aspect maps, irrigation and drainage planning, and monitoring of vineyards.
Limitations to Know in Advance
- Vegetation. Photogrammetry builds the surface from the tops of trees and bushes. To get the ground under a forest you need lidar or ground measurements.
- Weather. Strong wind, rain, fog and low sun reduce quality, and the survey is then rescheduled.
- Uniform and reflective surfaces. Water, snow and glass are hard to reconstruct from images.
- Airspace. Flights in some zones need prior approval, and this is built into the schedule.
How to Choose a Drone Survey Provider
- Ask about accuracy. How is it verified? Are checkpoints used, and will you get a report with numbers?
- Confirm the coordinate system and formats. The data should open in your software without extra conversion.
- Find out how positioning works. RTK from a base station or network, ground control points, and result checks.
- Ask for sample data. It is better to test quality on a small area than on the whole project.
- Agree deliverables and deadlines in advance. What exactly will be handed over, and on which day.
We survey a test area of up to 0.5 ha free of charge, so you can check the data in your own software before the project starts. You can send a request using the form at the bottom of this page.
What Affects the Cost of a Drone Survey
The price is made up of several factors rather than a single rate per hectare:
- site area and shape;
- terrain and accessibility;
- required accuracy and number of checkpoints;
- scope of deliverables: a point cloud takes less work than a finished topographic plan or volume calculation;
- urgency and any required approvals.
To get a quote, tell us the area, the purpose of the survey and the formats you need. We reply within one business day.
Frequently Asked Questions About Drone Surveying
What is the difference between aerial surveying and aerial photography?
Aerial photography gives you an image, while aerial surveying gives you measurable data. In a survey, images are tied to coordinates, checked against control points and turned into plans, models and calculations.
How much area can be surveyed in one flight?
The manufacturer states up to 2.8 km² per flight in ideal conditions. In practice the area depends on height, required resolution, image overlap and wind, and it is usually smaller.
How long does a survey take?
Flying a site usually takes one day. We deliver the data within 24–72 hours after the flight, depending on the volume and the scope of deliverables.
Do drone flights need permits?
Flights are planned with airspace in mind. If the site lies in a restricted zone, the approval process is built into the work schedule.
Can the data be used for cadastre and registration?
That depends on the requirements of the specific authority and type of work. So before the flight we confirm the coordinate system, format and accuracy tolerance, and prepare the data accordingly.
Can you survey a forested site?
Yes, but a camera drone cannot show the ground under the canopy. For such tasks lidar is used, or the survey is supplemented with ground measurements.