Is A Drone Survey Accurate?

October 18, 2024 Peter Merrett Drone Surveys

Can a drone survey be accurate, the short answer is YES!

But the accuracy of a drone survey is dependent on a number of factors including the amount of overlap between photos, the flight speed, the resolution of the camera and the type of lens used.

What do we mean by accuracy?

In any type of surveying, accuracy and precision is critical in determining the success of a project and there are two terms that you will hear about:

• Relative Accuracy: This refers to the precision of measurements relative to each other within the dataset.
• Absolute Accuracy: This ensures that the data collected is closely coordinated to a known coordinate system.

As surveyors, we are concerned with recording precise and accurate measurements, and we go about achieving this by using the latest technology and ensuring that we can verify our data.

How can we ensure that our data is accurate and precise?

To ensure our data is precise, we fly with a high overlap between images and use high resolution cameras. We ensure that the flight height allows us to achieve a GSD (ground sampling distance) that is appropriate for the work. Here at Merrett Survey Limited, we use drones with RTK GPS modules, and we record data at a GPS base station, so that we can get very accurate coordinates for the image centres. We lean towards post processing the data to get the best possible accuracy. We also survey Ground Control and Ground Check points so that we can improve and check the accuracy of our data.

For a typical topographic survey, our data is accurate to approximately 2cm. However, this can be improved to sub-centimeter if required (for example, when surveying a building facade).

Why Carry Out a Drone Survey?

Drone surveys are used for a wide range of applications, from rapid site mapping to inspecting hard-to-reach structures. Common uses include:

• Mapping: producing large-area topographic maps, Digital Terrain Models and ortho-images in a fraction of the time traditional methods take.
• LiDAR: penetrating foliage to record ground shape beneath tree canopy, without the need for difficult rope access.
• Asset Management: inspecting roofs, bridges, chimneys and other hard-to-access structures safely and accurately.
• Visualisation: capturing high-quality video and imagery for construction progress updates, site overviews and 3D models.
• Volumetric Surveys: measuring stockpile and earthworks volumes faster and more cost-effectively than traditional survey methods.

For the full range of what our aerial survey team can do, see our aerial survey service.

We Work Worldwide!

As dedicated surveyors at Merrett Survey, utilising UAV surveys means that we collect only the most precise results for our clients, that can improve the operator’s ability to perform their job.

Conducting UAV Surveys In Greenland

Merrett Survey Limited surveyed 25 square kilometres of Greenland at a resolution of 2.5cm per pixel using a UAV equipped with a high resolution camera to create photogrammetric point clouds, contours, Digital Terrain Models and more. We use the latest technology to deliver stunning results.

If you are looking to source a UAV survey, then contact Merrett Survey Limited. Our geodesy knowledge means that we can provide accurate and detailed mapping. Our drone pilots have worked in many different environments and we can provide the best and most cost effective solutions.

Book Your Free UAV Survey Quote at Merrett Survey Today

With our honed aerial survey methods, latest technology and skilled-set team of engineers, contact us on +44(0)1392 362161 or send us an email to info@merrettsurvey.com to enquire about our successful UAV surveys.