Drone surveying in the UK: commercial drone survey services

A drone survey involves systematically capturing overlapping aerial imagery or sensor data across a site. That captured information is then processed into measurable digital outputs, with the method chosen to suit the accuracy, equipment and deliverables the project actually needs. No two sites are surveyed in exactly the same way.

• Flight planning. The pilot sets the flight lines, altitude and camera angles for the site boundary, obstacles and airspace in question.
• Image overlap. Photographs are captured with deliberate forward and side overlap so that each point on the ground appears in multiple images.
• Ground sampling distance. The real world size represented by one image pixel, driven mainly by flight altitude and sensor. A lower ground sampling distance means finer detail.
• Georeferencing. Imagery is tied to real world coordinates so outputs can be measured and placed correctly.
• Photogrammetry processing. Overlapping images are matched to reconstruct surfaces and generate mapping and 3D outputs.
• RTK or PPK where appropriate. Satellite correction positioning can improve georeferencing and reduce the amount of ground control needed on suitable sites.
• Ground control points where appropriate. Surveyed reference markers placed on site to improve or independently validate spatial accuracy.
• Processing and quality checks. Outputs are reviewed for coverage, residual errors and fitness for the agreed purpose before delivery.

Photogrammetry

Overlapping photographs are processed to reconstruct site surfaces and produce mapping, elevation and 3D outputs. It suits most site, land and progress surveys where open ground and structures need measuring.

RTK and PPK

Some pilots operate RTK or PPK capable equipment, which records precise aircraft positions in flight (RTK) or corrects them afterwards (PPK). This may support higher accuracy georeferencing where appropriate to the project, and can reduce the amount of ground control required. RTK and PPK are not available on every assignment.

Ground control points

Ground control or check points may be used depending on the required accuracy and survey methodology. Surveyed reference points are placed and measured across the site, then used in processing to improve or independently validate spatial accuracy.

LiDAR

LiDAR can be appropriate for certain specialist surveying and mapping applications, such as vegetation penetration, complex terrain and bare earth modelling. Availability depends on a suitably experienced and equipped pilot being available for the assignment.

Where an assignment requires specialist equipment or capability, Drone Assisted assesses the requirement and confirms whether a suitably equipped pilot is available before the job is accepted.

For land surveys on farms and estates, including crop mapping and multispectral capture, see our agricultural drone services.

The outputs available depend on the purpose of the assignment, the agreed scope and the capability and equipment required. Not every output below is produced on every survey, and some depend on the method, sensor and control used.

• Orthomosaic. A single geometrically corrected aerial image of the whole site that can be measured like a map.
• Point cloud. Millions of coordinated points describing the surfaces captured, used for measurement and modelling.
• 3D model. A textured mesh built from the point cloud for visualisation, design context and stakeholder review.
• Digital Surface Model. An elevation surface that includes buildings, plant and vegetation.
• Digital Terrain Model. A bare earth elevation surface with above ground features removed, produced where the methodology and site conditions allow.
• Elevation data. Height values across the site for levels, drainage and earthworks assessment.
• Contours. Interpolated height lines at an agreed interval for design and planning drawings.
• Stockpile and volume calculations. Cut, fill and stockpile volumes derived from the surface model against an agreed base.
• Site progress imagery. Repeatable aerial photography and video for programme records and reporting. For ongoing build programmes, see construction progress monitoring.
• CAD and GIS compatible files. Exports in agreed formats for use in your own design or asset systems, where agreed in advance.

Not every output is included in every assignment. Required deliverables are agreed before the job is confirmed. Depending on the customer brief, deliverables may include imagery, processed data, mapping outputs, annotations or other agreed files. Where a specific reporting format is required, this should be identified and agreed before the assignment.

Delivery times depend on the size of the site, capture requirements, processing required and agreed outputs. The expected timescale will be confirmed when the assignment is scoped.

Mapping outputs such as orthomosaics, contours and volumetrics can be produced as part of these surveys where the project methodology supports it. See our drone mapping services for more on photogrammetry, orthomosaics and three dimensional outputs.

Depending on the project, aircraft, sensor, flight methodology and positioning technology used, drone surveys can achieve highly accurate outputs. For suitably designed projects using appropriate equipment and control methods, centimetre level accuracy may be achievable.

There is no single accuracy level that applies to every drone survey. Where accuracy is important, the required tolerance should be agreed before the assignment so that Drone Assisted can confirm whether suitable pilot, equipment and methodology are available. Achievable accuracy depends on:

• Flight altitude and resulting ground sampling distance
• Camera or sensor quality and calibration
• Use of RTK or PPK positioning
• Quantity, distribution and survey quality of ground control
• Terrain, vegetation and surface texture
• Weather, light and wind on the day
• Processing methodology and software settings
• Required coordinate system and transformation
• The quality control method used to verify the result

Centimetre level outputs can be achievable with an appropriate survey design, equipment and control methodology, but accuracy requirements should be agreed for each project rather than assumed. We will tell you plainly where a brief needs ground control, a different sensor or a different method to meet the stated tolerance.

Drone capture can provide valuable aerial site data, but where a project requires formally certified measurements, legal boundary determination, engineering sign off or professional surveying opinion, an appropriately qualified specialist may also be required.

Drone Assisted assesses each enquiry individually. The location, required output, aircraft or sensor capability, pilot experience, relevant competency and operating requirements are considered before an assignment is confirmed.

The more of this you can supply up front, the faster we can confirm the right pilot, method and price.

• Site address and boundary, ideally as a plan, shapefile or marked map
• Approximate area in hectares or acres
• Required outputs, for example orthomosaic, contours or volumes
• Required accuracy, and how it will be checked
• Coordinate system where relevant, for example OSGB36 with OSTN15
• Intended use of the data, such as design, planning, reporting or claims evidence
• Required completion date
• Site access arrangements, permits and induction requirements
• Known hazards, live plant, overhead lines and restricted areas
• Airspace considerations, such as nearby aerodromes or restricted zones
• Existing control data or previous survey data where relevant

Discuss your drone survey and check survey pilot availability. Availability is confirmed per assignment rather than guaranteed nationwide.

This page covers drone surveying across the UK: site, land and topographic capture and the survey deliverables that can come with it. Mapping outputs such as orthomosaics and 3D models can be produced as part of these surveys where the agreed scope and equipment support it.

• Need orthomosaics, three dimensional models or other spatial outputs? See drone mapping services.
• Need visual imagery for marketing or records? See drone photography and videography.
• Need condition evidence of a structure rather than measurement data? See drone inspection services.
• Ready to start? Hire a UK drone pilot and we will confirm availability for your site.

Pilots are verified for the competency relevant to the assignment, completed where required through a CAA approved training provider, and hold current registrations on the CAA drone and model aircraft register.

Survey deliverables such as orthomosaics, point clouds, volumetrics and topographic outputs can be supplied in formats compatible with RICS qualified surveyors where agreed in advance, and the network follows the professional standards promoted by ARPAS UK, the UK drone industry association.