Drone Mapping: land surveying with drones
We can provide a quick overall snapshot of a site.
An orthographic photo could form part of a progress monitoring report or supplied as just one deliverable of a wider range of land survey mapping or modelling deliverables.
Drone take off and landing area – DJI M300 preparing for take off
Using the correct number and location for Ground Control Points and check points is important for an accurate survey, map & quality control
Drone survey photogrammetry rig. Choosing the right rig for the conditions and the site is an important consideration. Small to large drones have their place as do fixed wing or rotor drones.
Drone mapping has now come into its own. We can measure sites in a fraction of the time of conventional survey operations. That isn’t to say this technique is without limitations. As skilled land surveyors, we know the relative accuracies of data. We understand the limitations of drone technology. As a result, we can maintain precision across a project. While any drone pilot can make a map only a trained land surveyor has the depth of knowledge to deliver precise spatial data. We can map sites quicker than a conventional land survey takes and with better deliverables. As land surveyors, we know quality still counts when carrying out land surveys with drones. We apply this know-how throughout our drone services.
For the ultimate service, we take an integrated approach to data gathering and can provide visually rich and accurate deliverables as 3d models.
Aerial-based Land Surveys offer the best data coverage, accuracy, with highly visual deliverables using Airborne Photogrammetry and Lidar/Laser Scanning.
Drones have brought about a renaissance in Photogrammetry. The origins of Photogrammetry stretch back over 100 years. Photogrammetry, until recently, has been limited to large-scale airborne flights using aeroplanes and helicopters. Yet, Advances in drone technology and the photogrammetry software behind them have revolutionised survey work. Overlapping photographs are used to calculate 3d points in a sparse point cloud, then a dense point cloud before a 3d mesh model is created. The final step is to apply textures to the model.
Lidar surveys have their own limitations but also some unique advantages. Lidar makes many return measurements at various levels. Effectively ‘peaking’ through the gaps in vegetation to measure the ground details below the canopy. This allows us to remove vegetation, revealing hidden ground details. We can then extract survey data in hard-to-reach areas with relative ease. Where required we can infill with traditional topographical survey equipment (total station, GPS etc.) to produce a drone topographical survey.
We are able to produce drone mapping surveys & models of ground survey-grade quality. We have a sound appreciation of data quality. Our skills as Land Surveyors, acquired with over 30 years of working in the trade, allow us to match the survey method to a client’s needs and specifications. For some projects, we can use the full range of methods and apply them to a project. We can combine photogrammetry data, Lidar data and ground survey data as required to produce a quality drone land survey or integrate the survey with a measured building survey for complete coverage of your project.
The most basic deliverable is a rectified and geo-referenced orthographic photograph of a project area. For construction monitoring/progression monitoring this may be sufficient on its own. However, a drone land survey will take the 3d data created and convert that into a survey-grade topographical survey.
Choosing the correct drone for the survey required is an important consideration. The battery life, the camera type, wind resistance, the survey specification and the site itself are all important considerations when choosing which drone to use on-site.