Using unmanned aerial systems - drones - for construction and surveying

Unmanned aerial systems (UAS) for construction and surveying are a method of providing a stable platform for mounting a variety of sensors, such as cameras and laser surveying Lidar. (They are also known as drones or unmanned aerial vehicles/UAV.)

They can be operated manually or in semi-automated or assisted mode, following a predetermined path (which can be overridden by the pilot for safety reasons) which use global navigation satellite systems (GNSS), inertial measurement unit (IMU) sensors for positioning and attitude determination and altitude and heading sensors for height and orientation.

Simple hand launch or vertical take-off solutions are preferable to using additional hardware such as catapults and bungees, although damage to the body of the system when landing can be a problem.

Types of UAS

UAS generally fall into two categories, multi-rotor or fixed wing. Further sub-divisions can be made within these categories such as number of rotors, delta wing or traditional wing. Multi-rotor systems are more flexible, often being able to carry heavier payloads and therefore, better sensors.

They are suitable for most applications given below, being capable of automated survey flights, as well as close range inspection work. Whereas fixed wing systems are optimised for surveying and mapping applications.

Applications for UAS in construction

Below is a list of some typical applications for UAS. Appropriate survey methods are given:

L: LiDAR, VP: RGB vertical photography, IRP: infra-red photography, OP: oblique photography.

Note, vegetation coverage will impact upon 3D modelling from VP making it less suitable for some applications.

• Earthwork volumetric surveys and 3D modelling(L & VP)
• Topographic mapping (VP)
• Infrastructure/deformation monitoring (L)
• Infrastructure inspection (OP)
• Asset inventory surveys (VP)
• Visualisation surveys (L & VP)
• "Progress mapping" suitable for BIM (L & VP)
• Environmental surveys (L & IRP)
• Thermal inspection surveys (IRP)

Beyond construction

Non-construction research applications are focusing on autonomous UAS for infrastructure sensing, diagnosis and repair, with the development of advanced robots for deployment in complex live city environments and the robot–human – natural systems interfaces.

Download the full briefing paper written by Mat Kellett (Topcon) and edited by Chris Preston (Geospatial Panel Chair) using the link below. The document also includes:-

• Regulation of UAS in the UK
• Survey accuracies
• Pros and cons of using UAS in construction
• Considerations before using UAS

Useful Links

• CAA Unmanned Aircraft

More detail can be found in the Survey Association Client Guide to Small Unmanned Aircraft Surveys