Joy Stephens, BS, MAT, MSc, and Jordan Leech, P.G., MSCE, discuss how landfill aerial surveying uses drone technologies like photogrammetry and LiDAR to collect topographic data, each suited to different site conditions and project needs. In their article, they help you choose the right technology depending on the purpose, terrain, landscape, and desired accuracy. Selecting the appropriate drone surveying method depends on site vegetation, terrain complexity, accuracy requirements, budget, and project goals. Clear sites with good visibility and moderate accuracy need favorable photogrammetry, while dense vegetation and high accuracy demand point to LiDAR as the better choice.
Photogrammetry overview: This passive data-collection method stitches overlapping drone images to create 3D models, ideal for cleared areas with minimal vegetation but reliant on good lighting conditions. It uses smaller payloads, allowing longer flights, and is generally more affordable. However, it struggles with dense vegetation and produces lower-density point clouds compared to LiDAR.
LiDAR technology: Originating in the 1960s, LiDAR actively emits laser pulses to measure distances, excelling in dense vegetation and poor lighting conditions. It requires larger drones due to the bulky sensors, but it provides high-density point clouds and centimeter-level elevation accuracy. LiDAR is more expensive and requires slower, low-altitude flights.
Purpose-driven technology choice: Projects not requiring exact accuracy can use photogrammetry for reliable, cost-effective data. In contrast, design-level projects needing precise data benefit from LiDAR’s superior accuracy. Dense vegetation or thick underbrush necessitates LiDAR, while cleared sites with good visibility suit photogrammetry.
Terrain considerations: Landfill sites typically have less complex terrain, but features such as retaining walls or uneven grades can complicate data capture. Proper planning is needed to handle abrupt elevation changes to reduce errors.
Data quality assurance: Both technologies require pre-flight planning and post-processing techniques such as ground control points (GCPs), checkpoints, real-time kinematic (RTK), and post-processed kinematic (PPK) positioning to ensure accuracy. RTK is used during data collection for real-time corrections, while PPK refines data after collection.
Incorporating drones into landfill operations enhances efficiency, reduces worker exposure to hazards, and supports diverse applications, including topographic surveys, volumetric measurements, erosion detection, and gas emissions monitoring. Advances in drone technology have made these tools more accessible and sophisticated—photogrammetry benefits from lower equipment and processing costs, as well as faster flight speeds at varying altitudes. LiDAR has higher costs stemming from its sensor price, specialized software, and slower flight requirements due to its payload weight.
Please feel free to share this article, published in Talking Trash, using your email (icon at left) or social media (icons below).
About the Authors: Joy Stephens is an environmental scientist with strong communication, analytical, and technical skills; she applies these skills across multiple environmental management projects and disciplines, including sustainability, GHG accounting, landfill operations, and energy management.
Jordan Leech has a decade of experience as an environmental consultant. As a Professional Geologist, his knowledge and expertise include consulting with clients on environmental compliance matters under federal/state laws and regulations, including the CAA, CWA, SDWA, CERCLA, RCRA, NEPA, ESA, EPCRA, PPA, and TSCA.
Additional Resources for Landfills:
