In remote sensing

Remote sensing

Remote sensing is the acquisition of information about an object or phenomenon, without making physical contact with the object. In modern usage, the term generally refers to the use of aerial sensor technologies to detect and classify objects on Earth by means of propagated signals Remote sensing...

, ground sample distance (GSD) in a digital photo (such as an orthophoto

Orthophoto

An orthophoto, orthophotograph or orthoimage is an aerial photograph geometrically corrected such that the scale is uniform: the photo has the same lack of distortion as a map...

) of the ground from air or space is the distance between pixel

Pixel

In digital imaging, a pixel, or pel, is a single point in a raster image, or the smallest addressable screen element in a display device; it is the smallest unit of picture that can be represented or controlled....

 centers measured on the ground. For example, in an image with a one-meter GSD, adjacent pixels image locations that are 1 meter apart on the ground. GSD is a measure of one limitation to image resolution

Image resolution

Image resolution is an umbrella term that describes the detail an image holds. The term applies to raster digital images, film images, and other types of images. Higher resolution means more image detail....

, that is, the limitation due to sampling

Sampling (signal processing)

In signal processing, sampling is the reduction of a continuous signal to a discrete signal. A common example is the conversion of a sound wave to a sequence of samples ....

.

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