How Is Airborne Lidar Used Within Coastal Zone Surveys?
At Merrett Survey, we specialise in providing our clients with expert coastal and marine hydrographic surveys. Located in the beautiful South West, we are fortunate to have undertaken many projects along picturesque coastlines, applying airborne lidar across the majority for optimum results. This technology is key to maximise the accuracy and efficiency of the sites surveyed, only providing our clients with the best results.
The History of Airborne Lidar
Airborne lidar originally emerged in the mid 1980’s, after NASA found land-based remote sensing began in the 1970’s which centred around airborne prototypes for spaceborne sensor deployment. GPS survey services then rapidly developed into companies providing new airborne kinematic GPS solutions, leading to laser scanners that could project 2,000 to 25,000 pulses per second in the mid-1990s. These were mainly used for topographic mapping applications, with the technology paving the way for the future and being used by surveyors and engineers across the globe. As in the last twenty years, Lidar has evolved so greatly that it can now project over one million points per second with 5mm accuracy, making it an ideal surveying solution for all coastal and marine projects.
What Is Airborne Lidar?
Airborne lidar is when a laser scanner is fixed to an aircraft (full sized fixed wing or drone) during the flight, creating a 3D point cloud model of the ground. Once activated, light is emitted towards the land surface, before returning to the sensor straight away and giving a very precise measurement of the distance.
The surface data is acquired with high-tech laser scanners, meaning that the technology can collect millions of data points across a specific area, without the need for access to the entire area, creating a comprehensive ground digital terrain model.
How Airborne Lidar Is Used By Surveyors In Coastal Zone Surveys
Airborne lidar is integral for our bespoke coastal zone surveys at Merrett Survey, as the devices installed can fly up high above the land / water surface and capture a broad view of the scanned environment. Using specific laser light some scanners can penetrate the water and measure water depths from an airborne platform, such airborne lidar is able to scan both underwater sites and land elevations at the same time, creating a full scanned set of the coastal site and build this into a Digital Terrain Model (DTM).
Our Greenland Case Study at Merrett Survey
Airborne Laser Scanning
We recently surveyed a mining prospect two-hundred and forty miles North of the Arctic Circle in Greenland, which presented a multitude of challenges for us to tackle. However, airborne lidar allowed us to conduct a rapid and extensive survey which enabled the design of a new open pit mine, as well as access to and from the coastal camp and mineral processing location, six hundred metres below.
The Advantages to Airborne Lidar
Much safer than traditional coastal surveying methods, airborne lidar is highly effective for surveying the surroundings in great detail and accuracy. This ultimately means that airborne lidar can capture topographic and bathymetric data in a single survey, making it an extremely useful tool for gaining a wide spectrum of data. Here are the top five advantages to aerial lidar:
1. Accuracy
The accuracy of the lidar technology is always increasing. The data collected can have its accuracy increased further by survey ground control. These are points or an area surveyed using ground survey methods. The lidar data can then be adjusted to fit the control and the accuracy is increased. Merrett sometimes assists other aerial survey companies in providing ground control for their aerial survey projects.
2. Speed
Detected at a fast speed of 16 km/h to 320 km/h, the LiDAR sensor is extremely fast at collecting data, saving surveyors time and money so they can get projects completed in an even faster time. The use of aerial platforms such as full sized fixed wing aircraft or helicopters, or UAV / drones to carry the lidar enables large areas to be surveyed rapidly.
3. Cost-Effectiveness
Airborne lidar can result in remarkable cost savings for very large projects, such as the London Gateway project, where we completed six monthly aerial lidar surveys of the intertidal zone of nearly 400 square kilometres, or for small projects where we have applied lidar mounted on a drone to monitor coastal slope stability.
4. Versatility
Using airborne lidar enables the survey of many sites that cannot be accessed on the ground, such as inter-tidal mudflats, coastal marshes, steep and overgrown coastal slopes and even cliffs.
5. Coverage
With Lidar’s millions of data points, large areas can be covered that include not only the site of interest but its surroundings as well.
The Future For Airborne Lidar
Airborne lidar is a narrow market in the hydrographic survey industry, however, there is significant demand for this technology that is growing because of the high-precision that comes alongside the speed of the survey technique. The high-degrees of accuracy that this technology holds makes it highly beneficial for coastal zone mapping because of its environmental and economic benefits.
With significant growth, the global airborne LiDAR market is thought to reach over $ 24 billion by 2030. This proves how fundamental airborne lidar is, with many surveyors and engineers relying on the technology to conduct the most efficient surveys.
Enquire About Our Airborne Lidar Surveys Now At Merrett Survey
From bathymetric to topographic surveys, airborne lidar is a crucial technology that we use throughout our aerial surveys at Merrett Survey. If you would like to find out more about this, then please contact us by phoning us on 01392 362161 or emailing us at info@lidar.co.uk.
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Peter Merrett - Owner & CEO
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