GSD Calculator – Ground Sample Distance
Calculate ground sample distance for aerial photography, surveying, and drone mapping
Calculate Ground Sample Distance
Physical width of the camera sensor
Height of camera above ground
Camera lens focal length
Image width in pixels
Results
Formula used: GSD = (S × A) / (I × F)
Where: S = Sensor Width, A = Altitude, I = Image Width, F = Focal Length
GSD Analysis
Example Calculation
Drone Survey Example
Sensor Width: 13 cm
Flight Altitude: 100 m
Focal Length: 10.62 mm
Image Width: 5000 pixels
Calculation
GSD = (13 cm × 100 m × 1000) / (5000 px × 10.62 mm)
GSD = 1,300,000 / 53,100
GSD = 2.45 cm/pixel
Coverage
Ground width: 2.45 cm/px × 5000 px = 122.5 m
Coverage area: 122.5 m × 122.5 m = 1.5 hectares
GSD Applications
Agriculture
Crop monitoring and yield estimation
Mapping
Topographic and cadastral surveys
Construction
Site planning and progress monitoring
Environmental
Monitoring and conservation
GSD Tips
Lower GSD values mean higher image resolution
Flying lower increases resolution but reduces coverage
Longer focal length improves resolution at same altitude
Consider overlap requirements for photogrammetry
Weather conditions affect image quality
Understanding Ground Sample Distance (GSD)
What is Ground Sample Distance?
Ground Sample Distance (GSD) is the distance between the centers of two adjacent pixels measured on the ground. It represents the real-world distance that each pixel covers, determining the spatial resolution of aerial imagery.
Why is GSD Important?
- •Determines image resolution and detail level
- •Affects accuracy of measurements and mapping
- •Influences survey planning and mission requirements
- •Determines file sizes and storage requirements
GSD Formula Explanation
GSD = (S × A) / (I × F)
- GSD: Ground Sample Distance (length/pixel)
- S: Sensor width (physical size)
- A: Altitude or flight height
- I: Image width (pixels)
- F: Focal length of camera lens
Key Insight: Smaller GSD values indicate higher resolution and greater detail, but also smaller coverage area per image.
GSD Resolution Guide
| GSD Range | Resolution Level | Best Applications |
|---|---|---|
| < 1 cm/pixel | Ultra High | Precision agriculture, detailed inspections |
| 1-2 cm/pixel | Very High | Construction monitoring, archaeology |
| 2-5 cm/pixel | High | Mapping, surveying, urban planning |
| 5-15 cm/pixel | Medium | Large area mapping, forestry |
| > 15 cm/pixel | Low | Regional monitoring, preliminary surveys |