Abstract: A missile is guided onto a target by means of a laser beam, so that the missile can determine and correct its displacement from the boresight of the laser beam. This leads to greater accuracy of guidance, and avoids the need for very narrow beams which could be lost by the missile.

Abstract: The invention concerns charge coupled devices and the problems of dark current effects. In an arrangement including a charge coupled device utilized as a storage element for data a second charge coupled device is provided. Data is applied to the first device during one half of the storage period, the content of the first device transferred to the second during the second half of the storage period and at the end of the storage period the stored contents of both devices are subtractively combined. In one particular case the arrangement is a CCD television camera of the field transfer type where the normally provided one charge coupled device is replaced by first and second charge coupled devices and the optical image from the optical section of the camera is directed first to one device and then to the second device and the contents of the two devices are exchanges at the end of a storage period.