🛰️ Ground Sampling Distance Calculator
Enter your sensor width, flight altitude, focal length, and image width to find the ground sampling distance — the size of a single pixel on the ground, in centimetres.
📐 How Sharp Is Your Map?
What is a Ground Sampling Distance Calculator?
It works out the ground sampling distance — the real-world size a single pixel covers — from your camera's sensor width, the flight altitude, the lens focal length, and the image width in pixels. The answer, in centimetres per pixel, is the headline resolution of a drone map.
Use it to plan the altitude that hits a required GSD, compare cameras, and estimate how many flight lines a survey needs. Lower GSD means sharper maps but lower flights and more coverage passes.
❓ Frequently Asked Questions
What is ground sampling distance (GSD)?
GSD is the real-world distance on the ground that a single image pixel covers, expressed in centimetres per pixel. A GSD of 1.3 cm/px means each pixel spans 1.3 cm of ground. It's the standard way to describe the resolution of a drone map or orthomosaic — the lower the number, the sharper the detail.
How do I lower my GSD for sharper maps?
Fly lower, use a longer focal length, or use a camera with a wider sensor and more pixels. Altitude is the easiest lever: halving your height roughly halves the GSD. The trade-off is that lower flights cover less ground per pass, so you need more flight lines and battery time.
Where do I find my sensor width and focal length?
The sensor width in millimetres and the lens focal length are in your camera's specifications; image width in pixels is the horizontal resolution of your photos. Use the true focal length, not a 35 mm-equivalent figure, for an accurate result.
What GSD do I need for a survey?
It depends on the deliverable. General mapping might accept 3–5 cm/px, while inspection or volumetric work often calls for 1–2 cm/px or finer. Clients frequently specify a target GSD in the contract, so plan your flight altitude to meet it before you launch.