Both LiDAR and photogrammetry create 3D representations of the physical world using fundamentally different approaches. Understanding when to use each technology is essential for your surveying, forestry, or mapping project.
The Fundamental Difference
LiDAR (Light Detection and Ranging)
Active sensing — emits laser pulses and measures return time. Works independently of ambient light. Penetrates vegetation to reach ground.
Photogrammetry
Passive sensing — derives 3D from overlapping photographs. Relies on visible light and surface texture. Cannot see through vegetation.
This fundamental difference drives all practical distinctions in accuracy, cost, and ideal applications.
How Each Technology Works
LiDAR Operation
- Scanner emits rapid laser pulses (millions/sec)
- Pulses travel to target and reflect back
- Sensor measures time-of-flight
- Distance calculated: (Speed × Time) / 2
- Combined with GPS/IMU for 3D coordinates
Key capability: Multiple returns penetrate vegetation
Photogrammetry Operation
- Camera captures overlapping images (60-80%)
- Software identifies matching features
- Bundle adjustment calculates camera positions
- Dense matching generates 3D point cloud
- Structure from Motion (SfM) reconstructs geometry
Key capability: Rich color and texture information
Visual Comparison: Same Area, Different Technologies
See how photogrammetry (RGB imagery) and LiDAR classification capture the same agricultural landscape differently:
RGB Imagery (Photogrammetry)
Rich color and texture — ideal for visual inspection
LiDAR Point Cloud (Classified)
Ground, vegetation, and structures separated
Accuracy Comparison
LiDAR Accuracy
- Airborne: 5-15 cm vertical RMSE
- Drone LiDAR: 3-5 cm RMSE (1-2 cm best case)
- Terrestrial: 1-5 mm
LiDAR accuracy is consistent regardless of surface texture or lighting conditions.
Photogrammetry Accuracy
- Drone: 5-15 cm RMSE (2-3 cm best case)
- Aerial: 10-30 cm RMSE
Photogrammetry accuracy depends on image quality, ground control, and surface texture.
LiDAR in Complex Terrain
In mountainous terrain with steep slopes and dense vegetation, LiDAR excels where photogrammetry struggles. The point cloud elevation data shown here captures ground surface beneath forest canopy — impossible with camera-based methods.
This makes LiDAR the preferred choice for forestry, hydrology modeling, and infrastructure planning in challenging landscapes.
When to Choose Each
Choose LiDAR When
- Vegetation canopy covers the area
- Bare-earth terrain model needed
- Low-light or night operations
- Consistent accuracy required
- Forestry inventory or biomass
- Flood modeling under tree cover
Choose Photogrammetry When
- Budget is primary constraint
- Visual texture/color needed
- Open terrain without vegetation
- Orthophotos are required
- Construction site monitoring
- Mining stockpile volumes
Cost Comparison
Equipment Cost: LiDAR sensors $15,000-150,000+ vs. Survey-grade cameras $5,000-30,000
Per-Project Cost: LiDAR typically 2-3x higher than photogrammetry for equipment and expertise
Processing Cost: Similar for cloud platforms; LiDAR often requires specialized software
Process Your LiDAR Data Easily
LidarVisor automates classification, terrain modeling, and feature extraction for LiDAR point clouds. Generate DTM, DSM, contours, and CAD-ready vectors without specialized software or expertise.