A method for estimating values for a set of parameters of an imaging system, where the set of parameters comprises one or more of the following parameters: field of view, radial distortion, tangential distortion, focal length, offset of optical axis, the method comprising - taking at least two pictures with the imaging system, where the at least two pictures are taken from different positions and where the at least two pictures comprise an at least partially overlapping area, - sending out pulses to the at least partially overlapping area, - detecting the reflected pulses and calculating distances between a sender of the pulses and the respective point where the pulses were reflected based on the travel time of the pulses, and - associating positioning data to the pictures and to the calculated distance between the points where the pulses were reflected and the sender of the pulses, said positioning data comprising a position and pointing direction of the imagining system and the sender of the pulses, - calculating first information about the at least partially overlapping area, based on the at least two pictures, the first information comprising at least one quantity of the at least partially overlapping area, the at least one quantity comprising size and/or position, - calculating second information related to the calculated distances to the at least partly overlapping area, the second information comprising at least one quantity of the at least partially overlapping area, the at least one quantity comprising size and/or position, - comparing values for the quantities contained in the first and second information, - if the value for at least one quantity of the at least partially overlapping area obtained from the first information differs from the value for the corresponding at least one quantity of the at least partially overlapping area obtained from the second information, calculating values and/or an error estimate for the set of parameters of the imaging system based on the difference. - taking at least two pictures with the imaging system, where the at least two pictures are taken from different positions and where the at least two pictures comprise an at least partially overlapping area, - sending out pulses to the at least partially overlapping area, - detecting the reflected pulses and calculating distances between a sender of the pulses and the respective point where the pulses were reflected based on the travel time of the pulses, and - associating positioning data to the pictures and to the calculated distance between the points where the pulses were reflected and the sender of the pulses, said positioning data comprising a position and pointing direction of the imagining system and the sender of the pulses, - calculating first information about the at least partially overlapping area, based on the at least two pictures, the first information comprising at least one quantity of the at least partially overlapping area, the at least one quantity comprising size and/or position, - calculating second information related to the calculated distances to the at least partly overlapping area, the second information comprising at least one quantity of the at least partially overlapping area, the at least one quantity comprising size and/or position, - comparing values for the quantities contained in the first and second information, - if the value for at least one quantity of the at least partially overlapping area obtained from the first information differs from the value for the corresponding at least one quantity of the at least partially overlapping area obtained from the second information, calculating values and/or an error estimate for the set of parameters of the imaging system based on the difference.