Abstract: A method for generating a relief representation model using a plurality of N pairs of stereo images, each of the N pairs of stereo images being associated with a map of photogrammetric disparities which is obtained by correlation calculation based on the pair of stereo images in question, comprises: a calculation of maps of geometric disparities based on a predetermined relief representation model, by projection of the predetermined relief representation model into an epipolar geometry of the pairs of stereo images; a calculation of a cost function, representative of a difference between the geometric and photogrammetric disparities, associated with the predetermined relief representation model; and an updating of the predetermined relief representation model by optimization of the gradient descent type of the cost function, and iteration until a predefined endpoint criterion is reached. Also a computer program and a system.

Abstract: A method (100) for referencing a digital elevation model (10), involving a step of obtaining (110) two SAR images (12, 14) having a common area (15) that their area of overlap (16, 17) shares with the digital model (10); the method (100) involving, for the SAR images (12, 14), steps of: selecting (120) an AOI (18) in the common area (15); calculating (130) a simulated image (22) in the AOI (18); estimating (140) an offset (di,dj) between the simulated image (22) and the SAR image (12); the method (100) involving steps of selecting a reference point (26) in the AOI (18); projecting (160) the reference point (26) into the SAR images (12, 14) to obtain one connection point per SAR image (12, 14); correcting (170) the connection points by the offsets (di,dj); calculating (180) the readjusted reference point (26); referencing (190) the digital model (10).

Abstract: A method for generating a relief representation model using a plurality of N pairs of stereo images, each of the N pairs of stereo images being associated with a map of photogrammetric disparities which is obtained by correlation calculation based on the pair of stereo images in question, comprises: a calculation of maps of geometric disparities based on a predetermined relief representation model, by projection of the predetermined relief representation model into an epipolar geometry of the pairs of stereo images; a calculation of a cost function, representative of a difference between the geometric and photogrammetric disparities, associated with the predetermined relief representation model; and an updating of the predetermined relief representation model by optimization of the gradient descent type of the cost function, and iteration until a predefined endpoint criterion is reached. Also a computer program and a system.

Abstract: A method (100) for referencing a digital elevation model (10), involving a step of obtaining (110) two SAR images (12, 14) having a common area (15) that their area of overlap (16, 17) shares with the digital model (10); the method (100) involving, for the SAR images (12, 14), steps of: selecting (120) an AOI (18) in the common area (15); calculating (130) a simulated image (22) in the AOI (18); estimating (140) an offset (di, dj) between the simulated image (22) and the SAR image (12); the method (100) involving steps of selecting a reference point (26) in the AOI (18); projecting (160) the reference point (26) into the SAR images (12, 14) to obtain one connection point per SAR image (12, 14); correcting (170) the connection points by the offsets (di, dj); calculating (180) the readjusted reference point (26); referencing (190) the digital model (10).

Abstract: A method (100) for referencing an optical image (19) including: obtaining (110, 120) a stereoscopic image pair (19, 23) of the optical image (19) and a SAR image (35), the surface areas covered by the images (19, 23, 35) on the ground having an overlapping area (39); selecting (130) an area of interest (42) in the overlapping area (39); from the area of interest (42): obtaining (140) a 3D model (40); calculating (150) a simulated radar image (44); estimating (160) an offset (di, dj) between the simulated image (44) and the radar image (35); selecting (170) a reference point (46); projecting (180) and shifting (di, dj) the reference point (46) in the radar image (35) to correct the radar connection point (46??); determining (175) a pair of connection points (46?, 46?) in the image pair; and referencing the optical image (19) based on the connection points (46?, 46?, 46??).

Abstract: Method for selecting stereo pairs of satellite or aerial images to generate elevation data for an area of interest, the method being computer-implemented and including a phase of selecting eligible stereo pairs from an initial set of images representing the area of interest, followed by a phase of ranking the selected stereo pairs according to their quality. The method further includes a phase of defining N image clusters, where N is an integer greater than or equal to 2, each grouping images from the initial set according to a similarity criterion, and a phase of selecting the best stereo pairs per cluster on the basis of the ranking established during the ranking phase and on the fact that a pair belongs to a cluster if the two images of the pair belong to the cluster.