A computer system, comprising: a first interface adapted to receive geo-positional data of a movable object, wherein the geo-positional data is associated with an indicator (OL i,l i); a second interface adapted to receive a sequence of frames from at least one camera, wherein at least one frame (f 10,f 23,f 30,f 90) has a picture of the movable object with an optically recognizable structure and with an optically encoded version (122, I i ') of the indicator (I i); a decoder component configured to obtain the indicator ((f j,l i)) associated with the at least one frame (f 10,f 23,f 30,f 90) by decoding the optically encoded version ((f j,l i ')) of the indicator (l i) of the at least one frame (f 10,f 23,f 30,f 90); a matcher component configured to obtain the geo-positional data ((OL i,f j)) of the movable object which is in the picture of the at least one frame (f 10,f 23,f 30,f 90) by matching the indicator (l i) associated with the geo-positional data ((OL i,l i)) of the movable object and the decoded indicator ((f j,l i)) associated with the at least one frame (f 10,f 23,f 30,f 90); and a transformer component configured to obtain at least one reference point ((R j1,R j2,..,f j)) of the at least one frame (f 10,f 23,f 30,f 90) by analyzing the optically recognizable structure in the picture of the at least one frame (f 10,f 23,f 30,f 90), and to obtain camera calibration data of the at least one camera by applying a geometric transformation on the at least one reference point ((R j1,R j2,..,f j)) and its associated geo-positional data ((OL i,f j)) of the movable object which is in the at least one frame (f 10,f 23,f 30,f 90). a first interface adapted to receive geo-positional data of a movable object, wherein the geo-positional data is associated with an indicator (OL i,l i); a second interface adapted to receive a sequence of frames from at least one camera, wherein at least one frame (f 10,f 23,f 30,f 90) has a picture of the movable object with an optically recognizable structure and with an optically encoded version (122, I i ') of the indicator (I i); a decoder component configured to obtain the indicator ((f j,l i)) associated with the at least one frame (f 10,f 23,f 30,f 90) by decoding the optically encoded version ((f j,l i ')) of the indicator (l i) of the at least one frame (f 10,f 23,f 30,f 90); a matcher component configured to obtain the geo-positional data ((OL i,f j)) of the movable object which is in the picture of the at least one frame (f 10,f 23,f 30,f 90) by matching the indicator (l i) associated with the geo-positional data ((OL i,l i)) of the movable object and the decoded indicator ((f j,l i)) associated with the at least one frame (f 10,f 23,f 30,f 90); and a transformer component configured to obtain at least one reference point ((R j1,R j2,..,f j)) of the at least one frame (f 10,f 23,f 30,f 90) by analyzing the optically recognizable structure in the picture of the at least one frame (f 10,f 23,f 30,f 90), and to obtain camera calibration data of the at least one camera by applying a geometric transformation on the at least one reference point ((R j1,R j2,..,f j)) and its associated geo-positional data ((OL i,f j)) of the movable object which is in the at least one frame (f 10,f 23,f 30,f 90).