firing it will also be cearly understood that the rifles can be replaced by any other type of weapon which is adapted to indoor training in the case of the figures which illustrate the present description there has also been shown a single video camera this camera 3 is equipped with a retractable filter 12 this filter absorbs visible light but permits selective traversal by radiations within the same range of wavelengths as the beam produced by the laser emitter it may be assumed by way of example that consideration is given to infrared radiation having a wavelength of 0 9 micron in the active position shown the filter 12 is interposed in front of the camera lens which is therefore sensitive solely to this infrared radiation the filter is mounted on the shaft of a rotating electromagnet 13 which is controlled by the computer and serves to withdraw the filter in a movement of pivotal displacement away from the path of the light rays between the projection screen and the camera this pivotal displacement of the filter is controlled by the computer 8 which also initiates laser emission at the time of firing of the shot a sufficient time interval is nevertheless allowed to elapse between the two actions in order to ensure that the laser beam reflected from the screen is received by the camera and detected in the video signal prior to pivotal displacement of the filter it will be understood that detection by the camera 3 and scanning of the video signal by the computer consequently make it possible in a first stage to detect the position of.