Surveying land covered with dense trees, shrubs, or tall grass poses a common challenge in land development projects. Creating accurate topographic maps is crucial for planning and design, but traditional methods can be time-consuming and expensive. Drone LiDAR offers a quick, cost-effective solution for capturing precise land contours and design surfaces, even in heavily vegetated areas.
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When compared to piloted airborne LiDAR data, the UAV-LiDAR vertical errors were 2–3 times lower in every vegetation type. Factors likely contributing to these differences include the lower scanning range, smaller footprint size, and increased point density of the UAV-LiDAR data.
Even in dense and varied vegetation, drone LiDAR efficiently produces detailed ground models, achieving results much faster than traditional on-foot surveys. This is especially valuable in wooded areas where visibility is limited, terrain is challenging, and GPS signal acquisition can be difficult. Additionally, LiDAR reduces the need for field crews to navigate through hazards such as ticks, poisonous plants, and thorny underbrush, allowing them to focus on critical measurements, such as inverts and boundary corners, that require on-site precision.
Drone LiDAR Point Cloud of Construction Site Limit of Disturbance
A Basic Understanding of Drone LiDAR
Drone LiDAR works by emitting laser pulses that bounce off surfaces and return to the sensor, measuring the distance between the drone and the ground. This allows it to create highly accurate 3D models of the terrain. LiDAR can penetrate obstacles like tree canopies, tall grass, and shrubs, making it ideal for mapping terrain hidden beneath vegetation, where traditional aerial imaging often fails to provide accurate ground contours.
What's included in YOUR GUIDE...
A Proven Roadmap of Success for Implementing Drones in Construction.
A List of Red Flags to Avoid When Hiring Drone Service Providers.
How to Persuade Your Leadership Team to Leverage Drones on Every Jobsite.
New Development Site Covered in Tall Grass
Can Drone LiDAR Penetrate Vegetation?
Drone LiDAR can pass through gaps in leaves, branches, and certain types of grass to map the ground beneath, but its success depends on both the type of vegetation and the sensor being used. Dense tree canopies, for example, are easier to penetrate than thick, tall grasses, as the laser pulses can pass through openings between leaves and branches. However, thick grasses pose a greater challenge, especially where sunlight struggles to reach the ground, which often means LiDAR cannot effectively penetrate. Certain species of grass may also complicate data capture, making accurate ground contours harder to achieve in these areas.
In forested areas, LiDAR performs well by capturing multiple returns from laser pulses, allowing it to differentiate between vegetation layers and the ground surface and produce accurate topographic maps. Even in dense forests, LiDAR accuracy typically reaches within a tenth of a foot, making it highly effective for detailed land surveys. In areas with thick grasses or where LiDAR coverage is incomplete, a small amount of targeted fieldwork can efficiently fill any data gaps, ensuring a consistently accurate surface model.
With a scan rate of up to 1.4 million points per second the system can penetrate gaps in the canopy to hit the ground and other features in the landscape. This provides a high level of detail which other survey techniques such as photogrammetry are unable to do. It is also better for identifying surface hazards like crags or large, loose boulders. These can be hidden from view and may need to be made safe in case they are dislodged during the felling works.
The ability of LiDAR to penetrate vegetation also depends on the type of sensor being used. Some sensors are better suited for handling dense vegetation, while others may struggle. Matching the right sensor and drone together is crucial for achieving the most accurate results in areas covered by thick vegetation and grass.
Pump Removing Water from Drainage Basin
Can Drone LiDAR Penetrate Water or Snow?
While drone LiDAR is highly effective at penetrating vegetation, it cannot penetrate water or snow. Both water and snow scatter the laser beams, making it impossible for the sensor to detect the ground beneath ponds, creeks, or snow-covered areas, leaving these surfaces invisible to LiDAR technology. For example, if you require a topographic survey of drainage basins at a construction site that are filled with water after a recent rainstorm, you would need to either pump out the water or wait for it to dry up before conducting the drone survey.
Weather conditions such as rain, fog, and heavy clouds can also degrade the quality of LiDAR data. These atmospheric conditions can scatter the laser pulses, leading to reduced accuracy, especially in vegetation-heavy areas.
Related Article – What is a Drone LiDAR Point Cloud? (.LAS/.LAZ)
Drone LiDAR Point Cloud for Vegetation Management of High Voltage Powerlines
For optimal results, drone LiDAR should be used in clear weather and at an ideal altitude. While this depends on the sensor, entry-level LiDAR sensors typically work best at altitudes between 150–200 feet. Higher-end sensors can be flown at higher altitudes while maintaining greater accuracy. Clear weather and proper flight conditions will ensure that LiDAR captures the most precise data for topographic mapping required for the survey.
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Drone LiDAR Survey Point Cloud of Future Construction Site
Crew Setting Up Ground Control for Drone Survey
Getting Started with Drone LiDAR Mapping
Drone LiDAR is an essential tool for accurate and efficient topographic mapping of vegetated land. Without utilizing this technology, companies will find it increasingly difficult to accurately survey land covered in dense vegetation, limiting their ability to deliver precise results in challenging environments. While LiDAR has limitations, such as its inability to penetrate water or snow, it remains a key asset for surveying in heavily vegetated areas.
Now is the perfect time to integrate drone LiDAR into your surveying strategy. Partnering with a skilled drone service provider ensures your projects meet compliance standards and achieve precise results. At The Drone Life, our FAA-licensed and OSHA-certified pilots bring years of experience to every project, delivering top-quality service. Schedule a free consultation with us today, and let The Drone Life to learn how we can support your next project.
What's included in YOUR GUIDE...
A Proven Roadmap of Success for Implementing Drones in Construction.
A List of Red Flags to Avoid When Hiring Drone Service Providers.
How to Persuade Your Leadership Team to Leverage Drones on Every Jobsite.
