Photogrammetry vs. LiDAR: When to Use Each for Surveying and Engineering

When it comes to aerial mapping, two technologies often come up: photogrammetry and LiDAR. Both are powerful tools, but the decision on which to use often depends on the lay of the land, surface conditions, and project goals. In many cases, the best results come from using a hybrid approach that combines the strengths of both.

Photogrammetry: High Accuracy and Dense Point Clouds

Photogrammetry uses overlapping aerial images to create detailed 3D models and point clouds. Modern drone cameras can capture tens of millions of points per flight, producing extremely dense datasets.

• Best for: hard, reflective surfaces such as pavement, rooftops, or bare ground.

• Accuracy: vertical accuracy down to a few hundredths of a foot (hundredths of a foot precision).

• Limitations: can only capture what the camera sees—meaning it records the tops of trees, vegetation, or structures, but not what’s underneath.

LiDAR: Penetrating Vegetation and Complex Terrain

LiDAR (Light Detection and Ranging) uses laser pulses to measure distances and generate point clouds. Modern drone-mounted LiDAR sensors can capture 500,000 to 1.5 million points per second.

• Best for: vegetated areas, forests, or places where you need to see the ground surface beneath the canopy.

• Accuracy: typically within a tenth of a foot on softer or irregular surfaces.

• Limitations: LiDAR does not perform well over water due to light reflection.

Why a Hybrid Approach Often Wins

While photogrammetry provides extremely dense and accurate data on visible surfaces, LiDAR excels at capturing terrain beneath vegetation. By combining the two, you can overcome the limitations of each and deliver the most complete dataset.

Example: 35-Acre River Corridor Project

Recently, our team mapped a 35-acre site bordered by a river. About 90% of the site was covered in dense vegetation, but the client also needed an accurate elevation model of the water surface.

• LiDAR allowed us to capture the terrain beneath the trees.

• Photogrammetry provided precise surface data for the river, where LiDAR struggled with reflection.

By fusing both datasets, we delivered a highly accurate elevation model that met all project requirements.

Final Takeaway

The choice between photogrammetry and LiDAR isn’t always “either/or.” For roads, infrastructure, or hard-surface projects, photogrammetry can provide incredible detail and cost savings. For vegetated or complex terrain, LiDAR is essential. But in many cases, the hybrid method delivers the most accurate, complete, and cost-effective results—helping engineers and surveyors make better decisions and build longer-lasting infrastructure.