What is the difference between LiDAR and photogrammetry?

LiDAR and photogrammetry are both remote sensing technologies that create 3D data, but they work differently: **LiDAR (Light Detection and Ranging):** - Measures distance directly using laser pulses - Works independent of ambient light - Penetrates vegetation (multiple returns) - Generates sparser but cleaner data - Higher equipment cost - Best for: Forestry, topography, corridors **Photogrammetry:** - Calculates 3D from overlapping photos - Requires good lighting and visibility - Cannot see through vegetation - Creates dense, colorful point clouds - Lower equipment cost - Best for: Construction, quarries, facades **Accuracy Comparison:** - Both can achieve 2-3cm with GCPs - LiDAR more consistent in varied conditions - Photogrammetry can achieve higher density **When to Use Each:** *Choose LiDAR:* - Vegetated terrain - Bare earth required - Power line corridors - Poor lighting conditions *Choose Photogrammetry:* - Clear, visible surfaces - Texture/color important - Budget constraints - Construction sites Many projects benefit from combining both methods.