An increasing number of customers are now specifying that light detection and ranging (Lidar) mapping technology be used on their projects, reports aerial survey company Southern Mapping CEO Norman Banks.
In the past, the company had to educate clients about the advantages of Lidar mapping and why it, rather than conventional mapping methods, should be used, he says, adding that Lidar has now become a mainstream application.
Banks says Southern Mapping was the first company to operate Lidar systems in Africa, as well as in the Southern Hemisphere.
The laser system is used to provide high-resolution, accurate elevation models and topographical maps of areas ranging from the size of a mine pit to that of an entire province. “Both of which the company has previously done,” he notes.
The company accurately maps areas by flying an aircraft along a planned route. Its aircraft are equipped with sophisticated equipment, including a global positioning system, an inertial measurement unit and a laser unit capable of measuring up to 200 000 pulses a second, to measure distances, he explains.
Southern Mapping provides its services to many industries.
In the mining exploration industry, Lidar mapping is used for the topographical survey of an entire project area, which is a requirement for resource estimation. “One cannot publish a mineral resource without having an accurate elevation model, typically provided by Lidar mapping,” says Banks.
Operational mines also make use of Lidar mapping for calculating stockpile and pit volumes, as well as mine infrastructure and expansion planning.
Further, Lidar mapping is used in the infrastructure industry for the design of roads, railways, pipelines and power lines.
The company also uses the technology for dam design. “It is very useful, as you can determine the inundation area of the entire proposed dam, and this data can be used for socioeconomic and environmental studies,” he says.
Banks states that the greatest advantages of Lidar mapping is the ability to penetrate vegetation, which gives the client accurate elevations despite a thick canopy of vegetation. This technology is extremely useful in areas that are thickly vegetated, and is particularly effective in tropical Africa, he says.
Lidar mapping provides a dense set of elevation points, delivering a high-accuracy map of the area. “A typical project might have anything between 1 and 20 elevation points a square metre, accurate up to 10 cm or better,” he explains.
Further, the Lidar mapping process has a rapid turnaround time, which enables the company to deliver a completed project in a matter of weeks after flying, says Banks.
In recent years, Lidar has evolved from being an airborne technology to a solution that is mounted on a vehicle or a tripod, he says.
“These three application areas of the technology work well together and are used in a complementary fashion by a range of industries,” he adds.
A major application area of terrestrial Lidar systems, namely vehicle and tripod-mounted systems, is in as-built surveys for process plants. The laser systems can determine the current exact layout of structures at a mine, which is useful as it is usually difficult to find up-to-date plans of a plant with the necessary information, Banks explains.
Southern Mapping is doing airborne laser mapping for a number of projects including railway lines in Mozambique and dams in Tanzania, Uganda, Rwanda and Burundi, says Banks.
The company is also carrying out laser mapping on a mine in the Central African Republic, an agricultural project in Gabon and a mine-audit in South Africa, to create elevation models for the clients.
All these projects will be completed within the next three months, he says.
Further, the company will shortly start work on a carbon-auditing assessment for carbon accounting in the Democratic Republic of Congo. Southern Mapping will be mapping natural forest in this country, Banks states.