A rendezvous and docking sensor with CCD camera

For the docking of spacecrafts a highly precise attitude and position control is necessary. This supposes an adequate measurement of the relative position and attitude of the docking spacecrafts. Here is presented, how a CCD camera can be used to measure the necessary data. Laser light coming from the direction of the camera illuminates a special target of retroreflectors. The reflected light produces light dots on the CCD plane of the camera. Their locations are used to calculate the values of relative position and attitude in a direct method. Essentially the accuracy of the position and attitude data depends on the measurement of the light points on the CCD. The obtained algorithm for the determination of position and attitude and the influences on the attainable accuracy are discussed and the results presented.