Automatic Relocation of Ground Control Points in Landsat Imagery

摘要

Images obtained from the Landsat multispectral scanner are not provided in any normally recognised map projection system, so it is often necessary for a transformation to be made. This is usually done with the aid of ground control points, whose locations on the ground (or on a map) are accurately known and which can be accurately located within Landsat images. The initial selection and location of such ground control points is usually performed manually. For repeat - ie multitemporal - imagery, the same ground control points can be used. The positions of these points can be relocated within the repeat image either manually or, as described in this paper, by an almost entirely automatic computer process. This process has been found to work speedily and effectively on many repeat images of Britain, usually giving accurate relocation of well over 90% of ground control points. The process has been developed for use with images of Britain, but it could readily be adapted for worldwide use. (Author)