In aerial mapping applications, the Ground Sampling Distance (GSD) represents the distance, measured on the ground, between the centers of two adjacent pixels within a digital image. For example, an image with 5cm/pixel GSD means the locations of two consecutive pixels are 5cm apart on the ground.
Remind that:
- A higher GSD indicates that less details will be visible from the images since the resolution is lower ("higher GSD => lower resolution")
- GSD is an indicator for the area represented by one pixel. For example a 2cm/px GSD means a pixel accounts for a ground area of 2 cm x 2 cm = 4 sq.cm
The GSD information, in a delair.ai project where a photogrammety process was conducted, is indicated on the Photogrammetry Accuracy Reports. In the example below, the average GSD was 1.7 cm/pixel:
