LiDAR vs. Photogrammetry: Which is best for Forestry Applications

 LiDAR and photogrammetry are two of the most widely used technologies in aerial mapping and surveying. Though they can produce similar results, their underlying technologies, costs, and complexities differ significantly. In forestry applications, where accurate terrain data is critical, the choice between these two methods can have a big impact. This article compares LiDAR and photogrammetry, exploring which is best suited for forestry. 

What is LiDAR? 

LiDAR (Light Detection and Ranging) is an active remote sensing technology that uses laser pulses to measure distances. By emitting a laser beam and measuring how long it takes for the light to reflect back to the sensor, LiDAR generates a detailed 3D surface model known as a point cloud. Unlike traditional surveying, where a single point is captured at a time, LiDAR collects millions of points over the same surface, providing a far more detailed model. Each point in the LiDAR point cloud comes with precise X, Y, and Z coordinates, making it a powerful tool for topographical mapping. 

LiDAR’s ability to generate its own light source allows it to collect data regardless of lighting conditions. Moreover, its ability to penetrate vegetation makes it especially useful in forestry, where dense tree canopies might obscure the ground. Although LiDAR sensors can integrate with RGB cameras to add color to the point cloud, these images are often only used to colorize the point cloud.

What is Photogrammetry? 

Photogrammetry is a passive sensing technology that uses RGB images to create 2D or 3D models. By capturing a series of overlapping images, photogrammetry software stitches these images together using “tie points” to create a model of the surveyed area. The results are highly accurate, high-resolution models that capture not only the shape and elevation but also their colors and textures—similar to how Google Earth presents imagery. 

While photogrammetry excels in creating visually appealing and accurate models, it relies on reflected sunlight, making it ineffective in low-light conditions or beneath dense vegetation. It’s also not ideal for homogeneous surfaces like forests or snowfields, as the software struggles to find distinguishing features for stitching the images together. 

LiDAR Vs. Photogrammetry data. 

 This is an example of a Photogrammetry data set that has been processed into a point cloud and overlayed

Key Differences: Accuracy, Cost, and Ease of Use 

Photogrammetry offers a lower cost of entry and can be conducted with almost any drone equipped with a camera. Ideal drones for this application feature RTK (Real-Time Kinematic) capabilities and a global shutter camera for higher accuracy. Photogrammetry is often preferred for its ease of use and lower processing complexity, making it an excellent option for smaller projects or urban environments where vegetation isn’t an issue. 

LiDAR, on the other hand, requires more expensive equipment and a higher level of expertise to process the data. While photogrammetry provides high accuracy for surfaces visible to the camera, LiDAR shines when you need to map beneath forest canopies or through vegetation. However, additional equipment like ground control points and GPS survey tools are often required for precise data correction. 

Both LiDAR and photogrammetry drones utilize flight automation software, making the data acquisition process relatively straightforward. Companies like DJI offer automated flight planning, enabling the drone to autonomously follow a flight path and land after completing the mission. 

When to Use LiDAR vs. Photogrammetry 

Use Photogrammetry When: 

• Mapping urban environments or areas with little vegetation 

• You require a photorealistic 3D model that is easier to interpret 

• Cost and ease of use are primary concerns 

Photogrammetry is a great entry point for drone mapping due to its lower cost and simpler workflows. It's ideal for capturing detailed visual models of infrastructure, buildings, or landscapes where the ground is unobstructed by dense vegetation. 

Use LiDAR When: 

• Mapping forested areas or environments with dense vegetation 

• You need to capture terrain data beneath tree canopies or foliage 

• High-detail, ground surface models are required for applications like forestry management, road planning, or water flow analysis 

LiDAR’s strength lies in its ability to penetrate vegetation and capture detailed ground-level data. While it cannot “see through” foliage where no light passes through, LiDAR’s multiple scan angles help capture ground points even under thick canopies. This makes it the preferred choice for forestry applications or heavily vegetated environments. 

LiDAR and Photogrammetry: Complimentary Tools 

While these two technologies have different strengths, they can also complement each other in mapping projects. Photogrammetry can provide the visual detail necessary for interpretation, while LiDAR offers precise terrain data, even in challenging environments. Together, they offer a more complete view of a given area. 

LiDAR and Photogrammetry Packages: Our Offerings and Training 

At Candrone, we offer complete training solutions tailored to your organization's needs, from drone pilot certification to in-depth data processing. Whether you're a beginner or a seasoned professional, we can help you master LiDAR or photogrammetry workflows. Explore our range of packages to find the right fit for your applications: 

• LiDAR 101 Course 

• Entry Photogrammetry Package: Mavic 3 Enterprise Mapping Starter Kit 

• Advanced Photogrammetry Package: DJI Mavic 3E Photogrammetry Mapping Kit 

• Professional Photogrammetry Package: DJI Photogrammetry Mapping Kit 

• Advanced LiDAR Kit: DJI LiDAR Drone Kit 

• Professional LiDAR Drone Kit: LiDAR Drone Surveyor Kit 

Conclusion 

Choosing between LiDAR and photogrammetry depends on your specific needs. Photogrammetry is great for visually rich, easier-to-process models in low-vegetation environments, while LiDAR excels in providing detailed terrain data, especially in heavily forested areas. Contact our consultants at Candrone to guide you through the best solutions for your project, saving you time and effort in research. Reach out today!