Drone Overlap Calculator
Check that a flight plan gives photogrammetry enough to work with. Enter the camera, altitude, speed, shutter interval and line spacing, and see the forward and side overlap you will actually get.
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Camera
Flight plan
Sets the forward overlap.
Sets the side overlap.
Work back from a target
Overlap
Fill in the camera and the flight plan to see the overlap.
Recommended overlap by application
| Application | Forward | Side | Notes |
|---|---|---|---|
| 2D Orthomosaic | 75% | 65% | Standard mapping projects, flat terrain |
| 3D Modeling | 80% | 70% | Buildings, structures, volumetrics |
| Urban & Tall Structures | 85% | 75% | Avoids occlusion from buildings |
| Forestry/Vegetation | 85% | 75% | Dense canopy, penetrates canopy gaps |
| Corridor Mapping | 80% | 60% | Roads, pipelines, railways |
| Agriculture (NDVI) | 70% | 60% | Crop monitoring, lower requirement |
| High Precision Survey | 85% | 80% | Construction, engineering surveys |
Understanding image overlap
Image overlap is crucial for photogrammetry processing. Sufficient overlap ensures that software can find common points between images (tie points) to create accurate orthomosaics and 3D models.
Types of overlap
- Forward overlap (endlap): overlap between consecutive images along the flight direction
- Side overlap (sidelap): overlap between adjacent flight lines
Why overlap matters
- Tie point matching: more overlap means more common features between images
- Redundancy: compensates for image quality issues such as blur and shadow
- 3D reconstruction: higher overlap improves depth estimation accuracy
- Gap prevention: ensures no missing coverage in the final output
Photo Interval Formula
Interval = (Footprint × (1 - Overlap%)) / Speed
Where
- Interval
- Time between photos in seconds
- Footprint
- Ground footprint height in meters
- Overlap%
- Desired forward overlap (0.75 for 75%)
- Speed
- Flight speed in meters per second
Worked example
With 150m footprint, 75% overlap, 8 m/s: Interval = (150 × 0.25) / 8 = 4.7 seconds
Frequently Asked Questions About Drone Overlap
Low overlap (<70% front, <50% side) creates 'holes' in orthomosaics where the photogrammetry software cannot find sufficient tie-points. This results in failed processing, distorted 3D models, or areas with no data. Professional projects require minimum 75% front and 60% side overlap.
Yes. While overlap >90% ensures data quality, it significantly increases flight time, battery usage, storage requirements, and processing time. The optimal balance is 75-85% front overlap and 60-70% side overlap for most mapping projects.
Forward overlap (endlap) is the overlap between consecutive images along the flight direction. Side overlap (sidelap) is the overlap between adjacent flight lines. Both are essential - forward overlap connects images in sequence, while side overlap connects parallel flight lines.
For 3D modeling, use 80-85% front overlap and 70-75% side overlap. For complex structures or urban areas with tall buildings, increase to 85% front and 75% side to avoid occlusion issues. Consider adding oblique imagery for better vertical surface capture.
Photo interval = (Footprint Height × (1 - Overlap%)) / Flight Speed. For example, with 100m footprint, 75% overlap, and 8 m/s speed: Interval = (100 × 0.25) / 8 = 3.1 seconds. Our calculator does this automatically.