Method and device for locating an object in space

Is to be located in space an object (1) carrying marks (3) by a video camera (4). Traces of marks (3) on the image are searched to deduce the directions of the marks (3) in the camera's field of view (4) and the position of the object (1). The used algorithm comprises an approximate location step marks by simple formulas, and then a step to improve the estimation calculation of error minimization. Modeling traces the image is taken to determine their position with great accuracy, less than the no resolution of the camera (4), which does not need to give a clear picture. The marks (3) are preferably passive marks, reflective or not, devoid of light emission. The system is insensitive to stray lighting.