A method for building a 3D model of an area of interest on the surface of a planet, the method comprising: a) providing a plurality of 2D images from satellites, where each 2D image out of the plurality of 2D images at least partly covers the area of interest, and where each subarea of the area of interest is covered by at least two images, taken from different angles, out of the plurality of 2D images; b) performing bundle adjustments for the plurality of 2D images; c) dividing the area of interest into parts, and for each part of the area of interest: - taking at least one combination and preferably all possible combinations of two images out of the at least two images covering that part of the area of interest, taken from at least two different angles, out of the plurality of 2D images; and - establishing point matching correspondence for each such combination of two images so that a set of points for each such combination is achieved; further characterised in that: - if more than one set of points exists, combining the sets of points for which point matching correspondence was established so that a final set of points is achieved; - if only one set of points exists, taking said one set of points as the final set of points; - building (240; 340) a 3D model of said part of the area of interest based on the final set of points; and d) combining the 3D models from each part of the area of interest to a 3D model of the whole area of interest, further including the steps of - providing at least one additional image after a 3D model was built, said at least one additional image being originally provided by at least one satellite which has less accuracy in determining its pointing direction than the satellites which originally provided the images used for building the 3D model, and said at least one additional image being not included in the plurality of 2D images; - using the built 3D model to rectify said at least one additional image; and - rebuilding the 3D model according to the steps a)-d), where the plurality of 2D images now also includes said at least one additional image. a) providing a plurality of 2D images from satellites, where each 2D image out of the plurality of 2D images at least partly covers the area of interest, and where each subarea of the area of interest is covered by at least two images, taken from different angles, out of the plurality of 2D images; b) performing bundle adjustments for the plurality of 2D images; c) dividing the area of interest into parts, and for each part of the area of interest: - taking at least one combination and preferably all possible combinations of two images out of the at least two images covering that part of the area of interest, taken from at least two different angles, out of the plurality of 2D images; and - establishing point matching correspondence for each such combination of two images so that a set of points for each such combination is achieved; further characterised in that: - if more than one set of points exists, combining the sets of points for which point matching correspondence was established so that a final set of points is achieved; - if only one set of points exists, taking said one set of points as the final set of points; - building (240; 340) a 3D model of said part of the area of interest based on the final set of points; and - taking at least one combination and preferably all possible combinations of two images out of the at least two images covering that part of the area of interest, taken from at least two different angles, out of the plurality of 2D images; and - establishing point matching correspondence for each such combination of two images so that a set of points for each such combination is achieved; further characterised in that: - if more than one set of points exists, combining the sets of points for which point matching correspondence was established so that a final set of points is achieved; - if only one set of points exists, taking said one set of points as the final set of points; - building (240; 340) a 3D model of said part of the area of interest based on the final set of points; and - if more than one set of points exists, combining the sets of points for which point matching correspondence was established so that a final set of points is achieved; - if only one set of points exists, taking said one set of points as the final set of points; - building (240; 340) a 3D model of said part of the area of interest based on the final set of points; and d) combining the 3D models from each part of the area of interest to a 3D model of the whole area of interest, - providing at least one additional image after a 3D model was built, said at least one additional image being originally provided by at least one satellite which has less accuracy in determining its pointing direction than the satellites which originally provided the images used for building the 3D model, and said at least one additional image being not included in the plurality of 2D images; - using the built 3D model to rectify said at least one additional image; and - rebuilding the 3D model according to the steps a)-d), where the plurality of 2D images now also includes said at least one additional image.