In
remote sensing
Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object, in contrast to in situ or on-site observation. The term is applied especially to acquiring information about Earth ...
, ground sample distance (GSD) in a digital photo (such as an
orthophoto
An orthophoto, orthophotograph, orthoimage or orthoimagery is an aerial photograph or satellite imagery geometrically corrected ("orthorectified") such that the scale is uniform: the photo or image follows a given map projection. Unlike ...
) of the ground from air or space is the distance between
pixel
In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a raster image, or the smallest point in an all points addressable display device.
In most digital display devices, pixels are the smal ...
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
In physics and geosciences, the term spatial resolution refers to distance between independent measurements, or the physical dimension that represents a pixel of the image. While in some instruments, like cameras and telescopes, spatial resolution ...
or
image resolution
Image resolution is the detail an image holds. The term applies to digital images, film images, and other types of images. "Higher resolution" means more image detail.
Image resolution can be measured in various ways. Resolution quantifies how ...
, that is, the limitation due to
sampling.
GSD is also referred to as ground-projected sample interval (GSI) or ground-projected instantaneous field of view (GIFOV).
[{{cite book
, title = Encyclopedia of Optical Engineering
, author = Ronald G. Driggers
, publisher = CRC Press
, year = 2003
, isbn = 978-0-8247-4251-5
, page = 1392
, url = https://books.google.com/?id=4hBTUY_2BMIC&pg=PA1392&dq=%22ground+sample+distance%22
]
See also
*
Geographic distance
Geographical distance or geodetic distance is the distance measured along the surface of the earth. The formulae in this article calculate distances between points which are defined by geographical coordinates in terms of latitude and longitude. ...
References
Aerial photography
Photogrammetry
Satellite imagery