Ground sample distance

In remote sensing, ground sample distance (GSD) in a digital photo of the ground from air or space is the distance between pixel centers measured on the ground. For example, in an image with a one-meter GSD, adjacent pixels image locations are 1 meter apart on the ground. GSD is a measure of one limitation to spatial resolution or image resolution, that is, the limitation due to sampling.

GSD is also referred to as ground-projected sample interval (GSI) and is related to the ground-projected instantaneous field of view (GIFOV).