1. A method for building a 3D model of an area of interest on the surface of a planet, the method comprising: 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; performing bundle adjustments for the plurality of 2D images; 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 out of two images covering that part of the area of interest, wherein said two images are taken from the at least two images, taken from at least two different angles, out of the plurality of 2D images; establishing point matching correspondence for a set of points for each such combination of two images; combining the sets of points if more than one set of points exists; and building a 3D model of said part of the area of interest based on the combined set of points; and combining the 3D models from each part of the area of interest to a 3D model of the whole area of interest.