GSD calculator
Work out the Ground Sample Distance for a survey or mapping mission — or work backwards from a target accuracy to the flight height you need.
What is GSD?
Ground Sample Distance (GSD) is the distance between the centres of two adjacent pixels measured on the ground. It is a core measure of accuracy in mapping and remote-sensing operations — a smaller GSD means finer detail and higher accuracy.
How GSD is calculated
GSD is driven by how high you fly, the size and resolution of the sensor, and the focal length of the lens. It can be calculated from the sensor's width or its height — and because these can differ, the conservative approach is to take the larger of the two (the worst case) as your effective GSD.
How GSD is defined
Higher GSD numbers mean less accuracy. For survey deliverables, plan to the worst-case value so your accuracy is never overstated.
Keep reading →GSDh = (sensor height × height × 100) ÷ (focal × image height)
Specifying a survey payload?
Our survey team can help match a sensor and flight plan to the accuracy your deliverable needs — from RTK mapping to LiDAR.