“Drone survey” is a broad term that covers several distinct methods, each built around a different sensor and suited to a different deliverable. Choosing the right type is the single biggest factor in whether the data answers your question — so it pays to understand what each one captures before you commission a flight.
The main types of aerial drone survey are:
- Photogrammetry
- LiDAR
- Thermal imaging
- Multispectral imaging
- Inspection survey
Below we explain how each works, what it produces, and the projects it suits.
What is a photogrammetry aerial drone survey?
Photogrammetry is the most common type. The drone captures a series of overlapping high-resolution photographs from different angles, and specialised software matches common points across the images to reconstruct an accurate 3D scene. The outputs are point clouds, textured 3D models and orthomosaics — scaled, distortion-corrected aerial images of the whole site.
It is widely used in construction, urban planning, earthworks and heritage recording, and it underpins terrain modelling, volumetric calculations and site visualisation. Photogrammetry performs best on open, well-textured ground; it struggles with reflective surfaces, water and areas hidden under vegetation. See our photogrammetry survey service for detail.
What is a LiDAR drone survey?
LiDAR (Light Detection and Ranging) replaces the camera with a laser scanner that measures distance directly, returning millions of points per second. Its defining advantage is that the laser penetrates gaps in vegetation, so it can map the true ground surface beneath trees and scrub where photogrammetry sees only the canopy.
That makes UAV LiDAR the method of choice for wooded sites, embankments, flood and drainage modelling, and any project that needs a bare-earth terrain model. It is also less dependent on lighting conditions than photogrammetry.
What is thermal imaging and why would it be used?
Thermal surveys use a heat-sensitive camera to record the infrared energy emitted by objects and surfaces. The resulting imagery reveals temperature variation that the eye cannot see — making it valuable for building heat-loss assessment, flat-roof moisture detection, solar-panel fault finding and electrical or mechanical inspection.
Because it captures condition rather than geometry, thermal imaging is often flown alongside a photogrammetric survey so the heat data can be tied to an accurate spatial record. Our thermal imaging survey service covers these applications.
Why would multispectral imaging be useful?
Multispectral imaging captures light across several wavelength bands, including bands beyond visible light. Comparing how surfaces reflect across those bands reveals information that ordinary imagery cannot — most usefully, the health and vigour of vegetation.
This makes it the standard tool for precision agriculture, forestry and environmental monitoring, where it flags crop stress, disease and irrigation problems early. It also supports habitat assessment and baseline ecological recording.
How does an inspection survey work?
An inspection survey uses the drone as a remote eye rather than a measurement instrument. Fitted with a high-resolution or zoom camera — and sometimes a thermal sensor — the aircraft reaches bridges, façades, chimneys, pylons and other structures that would otherwise need scaffolding, rope access or road closures.
The result is detailed visual evidence of cracking, corrosion, displacement and wear, captured without putting people in hazardous positions or interrupting operations. This data supports condition reporting, planned maintenance and defect tracking. See aerial inspection and, for internal assets, confined-space inspection.
How do I choose the right type of drone survey?
Start from the deliverable, not the technology. Ask what decision the data needs to support:
- Need accurate ground levels and volumes on open terrain? Photogrammetry.
- Surveying through vegetation, or need bare earth? LiDAR.
- Looking for heat loss, moisture or electrical faults? Thermal.
- Assessing vegetation or crop health? Multispectral.
- Checking a structure’s condition? Inspection.
Many projects benefit from combining methods — for example, LiDAR for the terrain model and photogrammetry for the visual record. A chartered surveyor will recommend the combination that meets your accuracy requirement without paying for capture you do not need, and will specify the result against the relevant RICS measured-survey accuracy band (RICS, 2014).
Frequently asked questions
Which type of drone survey is the most accurate? There is no single answer — accuracy depends on ground control, flight planning and processing as much as the sensor. On open ground, well-controlled photogrammetry and UAV LiDAR achieve comparable centimetre-level accuracy; on vegetated ground, LiDAR is more reliable because it reaches the true surface.
Can different survey types be flown in one visit? Often, yes. Many drones can carry, or be swapped between, sensors, so a single mobilisation can deliver photogrammetry and thermal data together. This is usually more efficient than separate visits.
Do I need to know which type I want before contacting a surveyor? No. The more useful conversation is about the outcome you need. Describe the decision the survey has to inform, and the surveyor will match it to the right method.
To discuss which type of aerial drone survey suits your project, contact Angell Surveys and we will scope it around the deliverable you need.