The digital rectification of multispectral images

Mathematical approaches for digital rectification are considered. In the first step of the rectification procedure, the orientation parameters are determined for the entire image which is to be corrected. In the second step, the correction parameters obtained are applied to the image points. An employment of the direct method for an evaluation of Landsat magnetic-tape data is briefly reported. The direct method, however, permits only an iterative consideration of terrain altitudes. A description is given of the procedures of the indirect method. The effectiveness of the described method is illustrated with the aid of two photographs which show a picture obtained, on the basis of multispectral scanner data, with and without the use of digital rectification.