Applications of 3D Laser Scanning

ICE Plymouth – 08/10/13

C:\Users\cblake\Desktop\1310 3D Laser Scanning Techniques.docx

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Applications of 3D Laser Scanning Technology in Civil Engineering

1 Introduction

There are 3 main techniques for 3D laser scanning of structures: Terrestrial Laser Scanning,

Airborne Laser Scanning (ALS or Lidar), and Bathymetric Lidar. All three systems are

interchangeable and data can be merged to create complex models of an area. All pieces of

3D laser scanning equipment work using the same principles of sending out a laser beam at

a prescribed angle and measuring the length of time it takes to return back to the 3D

scanning unit.

2 Terrestrial Laser Scanning

• Various levels of accuracy are achievable depending on site and customer

requirements, mm accuracy achievable on plant such as power stations, refineries

etc.

• Can be either stationary or mounted on a vehicle for moving scanning (accuracy will

vary)

• One set up scans 360o, this initial scan will have “data black spots” where the laser

can’t reach. Multiple set-ups are used to fill in these black spots and to capture the

entirety of the structure.

• Data points merged with image data, using RGB values for different data points to

create a rendered 3D model.

• The reflected intensity of the laser can also be set to specific colours to give a

representation of size and shape if image data is not available.

• Possible to convert scan data into 3D and 2D CAD models depending on customer

requirements.

• Autodesk products can be compatible with correct plug-ins.

• Especially effective with BIM systems, as different properties and data can be linked

to specific data points.

3 Airborne Laser Scanning (ALS or Lidar)

• Used for scanning of large areas, either from fixed wing aircraft to cover wide areas

or corridor surveys using a helicopter (ie pipelines, power lines, roads etc.)

Applications of 3D Laser Scanning

ICE Plymouth – 08/10/13

C:\Users\cblake\Desktop\1310 3D Laser Scanning Techniques.docx

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• Accuracy up to ±5mm.

• Able to penetrate foliage, using multiple returns, to allow foliage and structures to be

removed to leave a terrain map of the ground below.

4 Bathymetric Lidar

• Either mounted from aircraft or from a boat.

• Shallow water only, with very low turbidity.

• Normally echo location systems used as currently more versatile.

5 Contacts

Peter Merrett

Merrett Surveys

3 Merlin Business Park,

Fairoak Close,

Exeter Airport,

EX5 2UL

Tel: 01392 362161

Email: pjm@merrettsurvery.com

www.merrettsurvey.com

www.lidar.co.uk