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Use this Ground Sample Distance (GSD) Calculator to understand your drone’s mapping accuracy at different altitudes. Learn more about GSD and how it applies to drone mapping & modeling work.
Everything you need to know about GSD and how it affects quality in aerial photogrammetry projects.
Ground Sample Distance (GSD) is the distance between the centers of two consecutive pixels measured on the ground. A GSD of 2 cm/px means each pixel in your image represents 2 cm of the real world. It is the key metric that determines the spatial resolution of aerial imagery.
GSD directly impacts the accuracy of your drone photos. For construction surveys, a GSD under 2 cm/px is typically required. Agriculture monitoring may only need 5-10 cm/px. Matching the right GSD to your project ensures you capture enough detail without wasting flight time or storage.
Flying lower gives you a smaller GSD (higher resolution) but covers less ground per image, requiring more flight passes and longer mission times. Flying higher covers more area quickly but at the cost of detail. The trick is finding the right balance between altitude and resolution.
GSD (cm/px) = (Flight Altitude (m) x 100 x Sensor Width (mm)) / (Focal Length (mm) x Image Width (px))
Flight Altitude — The height above ground level (AGL) at which the drone flies.
Sensor Width — The physical width of the camera sensor in millimeters.
Focal Length — The lens focal length in millimeters. Shorter focal lengths give wider coverage.
Image Width — The horizontal resolution of the camera in pixels.
