Merrett Survey Limited

Topographic Survey Services

We meet the needs of our clients by providing a high quality cost effective topographical survey service.

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Airborne & terrestrial laser scanning

We can provide or source lidar surveys for you based on an independent appraisal of your requirements. We also provide independent quality control, confirming the accuracy of LiDAR data sets.

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We have worked all over the world

Based in England we have expanded to work throughout the world in over 50 countries.

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What We Do?

We specialise in providing topographical site surveys, terrestrial laser scanning and airborne LiDAR services. We have many years of experience with pipeline mapping and have developed a means of mapping pipelines from the surface without an IMU.

service 1

We use the latest tech

From terrestrial and airborne laser scanners to UAV drones, we use the latest and most efficient technology.

service 2

We work in all environments

From the deserts of Algeria and Oman to snow covered Greenland, we can survey in all conditions.

service 3

We deliver high quality

From CAD drawings to complex 3D models, Merrett Survey have provided quality products to clients for over 25 years.


These are just some of the projects that we have worked on recently

project 1

Complex Plant

We have recently carried out terrestrial laser scanning of a power station which was needed to determine how to install new equipment ensuring clash avoidance. A 3D model of the power station was created from the scan data and delivered to engineering firms who carried out the FEED (Front End Engineering and Design) study. We can scan your plant or factory to ensure that retrofit design projects are carried out efficiently by reducing clashes and rework.

project 2

Deformation analysis

The image shows a laser scan survey of a storage tank with visible shell deformation. We are able to accurately report and monitor the out of roundness of the storage tank.

By unfurling the tank shell, we can create difference images and contours to show areas of deformation. Dents are coloured blue and bulges are coloured red. Areas where the there is no deformation are coloured green.

Tank settlement can cause various changes to the shape of the bottom shell and can tilt the tank in certain circumstances. Our strapping tables not only incorporate accurate circumference and height measurements but also all internal deadwood.

Merrett Survey Limited - Airborne LiDAR

Airborne LiDAR

Contact us with details regarding the laser scanning survey that you require. We can provide or source lidar surveys for you based on an independent appraisal of your requirements. We also provide independent quality control, confirming the accuracy of LiDAR data you may purchase from other providers. We can write the specifications for the laser scanning survey work and ensure they are adhered to.

If you provide laser scanning services, we can provide independent confirmation of your accuracies and offer ground GPS control services - worldwide. LiDAR processing services include coordinate transformation services for both plan and height data. Also, we can process the LiDAR data to produce a variety of digital products, including: Digital Elevation Models, contour models, vector maps for showing water drainage & more.

Merrett Survey Limited - Terrestrial Laser Scanning Heritage

Heritage - Engineering

This 22-span Grade II listed structure was originally constructed in 1860. We laser scanned the existing historic timber bridge and provided 2-D sections and a complete 3-D model of the bridge. The data was also used by engineers who were building the new bridge as well as providing an historic record of the structure.

The benefits provided by laser scanning historic structures are significant when considering large buildings and when recording detail at height is important, such as cathedrals, tall facades and historic civil engineering structures. We do not usually require special access at height in order to record dimensional details, so long as we have line of sight to the structural detail that needs to be recorded.

Merrett Survey Limited - Terrestrial Laser Scanning Heritage

Heritage - Restoration

The image shows an historic building which was badly fire damaged, by using our laser scanner we were able to provide the architects with a true picture of what remained - allowing them to reconstruct faithfully.

The precise shape of a historic structure, from bulges in a wall or the irregular spacing of timbers across a ceiling can all be measured from ground level at millimetric accuracy. From the scan data, we can create highly detailed complex meshes of a surface (from which contours can be generated). By repeating a scan at a later date and overlaying one scan over the other, three dimensional movement in the surfaces can be detected by subtracting one complex mesh from another. This provides an invaluable tool for monitoring structural behaviour, given that it can be achieved without physical access to the walls.

Merrett Survey Limited - Terrestrial Laser Scanning Ships Hull

Hull deformation monitoring

By laser scanning ships hulls and decks, we can rapidly survey and deliver 2D line drawings or a complete 3D model of your vessel.

Scanning can be beneficial for a wide variety of applications as it allows us to deliver "as built drawings and 3D models". This can be useful for restoration projects, new construction, reverse engineering, hull fairing or modification projects. Some work such as scanning an engine room, superstructure detail or compartments can be carried out at sea

Laser scanning is fast, accurate and non-intrusive, it produces very accurate data of a ships actual dimensions. Our clients have requested laser scanning and GPS surveys to determine a vessel's centreline and to calibrate it's on-board gyro. We also determined a means of calculating the heading for a recently installed ROV on a cable laying ship.

Merrett Survey Limited - Airborne LiDAR surveys

Aerial Imagery

We can provide very high quality aerial imagery, down to 5cm per pixel resolution. Often, we combine high resolution aerial images with LiDAR data to create a rich 3D data set by 'draping' the imagery over the high resolution Digital Terrain Model.

The image (left) shows high resolution aerial imagery that was combined with LiDAR data for monitoring mud flats where a new container port was under construction.

Merrett Survey Limited - Cliff Monitoring

Cliff Monitoring

Terrestrial or airborne laser scanning surveys are ideal for studying erosion / movement monitoring of coastal slopes. The combination of airborne LiDAR data and GIS technology facilitates the rapid production of geomorphological maps.

LiDAR is ideal for studying fluvial features on floodplains.  Digital Elevation Models (DEM's) can produced, which accurately represent landform surface variability and offer an important opportunity to measure and monitor morphological change and sediment transfer across a variety of spatial scales.

Merrett Survey Limited - Bathymetric Surveys

Bathymetric Surveying

In Oman, we coupled terrestrial laser scan data of cliffs with bathymetric data to generate a map of Sidab harbour in Oman. The image shows the topographic CAD drawing merged with the point cloud from the laser scan and the spot heights and contours generated from the bathymetric survey.

We also generated complex contours for the rock face.

  • project 1

    Complex Plant

    3D Revit BIM models

  • project 2

    Storage Tanks

    Surveying and modelling storage tanks

  • project 3

    Aerial LiDAR

    We provide airborne mapping services

  • project 4


    Surveying historic structures

  • project 5

    Building surveys

    Surveying for architects

  • project 6

    Hull modelling

    Complex modelling of ships hulls

  • project 7

    Aerial Imagery

    High resolution ortho-photos

  • project 8

    Cliff Monitoring

    Monitoring cliff recession

  • project 9

    Bathymetic LiDAR

    Harbour surveying in Oman

About Us

The company started trading in 1982, so in August 2012 Merrett Survey celebrated 30 years of topographical survey business. Based in the South West of England we have expanded to work throughout the world in over 50 countries including Australia, New Zealand, Algeria, France, Guinea, Bermuda, Philippines and the USA to name but a few. 

Merrett Survey was one of the first commercial organisations to invest in GPS technology so we have built up a mass of experience and knowledge. More recently we have been applying the latest surveying technologies including airborne and land based laser scanning ( LIDAR ).

It is the aim of Merrett Survey to meet the needs of our clients by providing a high quality and cost effective service. We will advise and put forward innovative ideas and new technology to benefit all parties by working in Partnership.

Click here for our Company Policy Statement

Merretts put forward innovative ideas and use new technology. We offer a wide range of survey services.

Our Clients

Our client list includes:-
    World Bank / Asian Development Bank
Environment Agency (UK)
Ordnance Survey (UK's National Mapping Agency)
IGN ( France's National Mapping Agency )
DPWH (Department of Public Works and Highways, Philippines)
UN (United Nations)

"Their deep understanding of GPS & rigid quality controls has particularly impressed us"

  GE Oil & Gas Client

"Merretts have shown themselves to be technically very capable, providing a positive professional approach"

  Ordnance Survey Client

"Merretts provided an excellent service when called upon. They were responsive, helpful, innovative and effective and worked well as part of the overall team delivering emergency response to the South West of England."

 The Environment Agency Client

Contact Us

3, Merlin Business Park, Fairoak Close,
Exeter Airport, EX5 2UL, UK

For UK and 'rest of the world' use-
Telephone    +44 (0) 1392 362161
Fax    +44 (0) 1392 362289

3, Merlin Business Park, Fairoak Close, Exeter Airport, EX5 2UL, UK

+44 (0) 1392 362161

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