What is Formula for calculating GSD?

The Ground Sampling Distance (GSD) can be calculated using the formula:

[ \text{GSD} = \frac{\text{Altitude} \times \text{Sensor Width}}{\text{Focal Length} \times \text{Image Width}} ]

Where the altitude is the height above the ground, the sensor width is the width of the camera sensor, the focal length is the lens focal length, and the image width is the width of the captured image. This formula helps determine the spatial resolution of aerial imagery.