System for measuring the trajectory of a target object , comprising: a measuring apparatus for measuring the trajectory of a target object ; and a radar device separate from the measuring apparatus for radiating radar radiation as first electromagnetic radiation of a first wavelength, wherein the measuring apparatus comprises: a receiving device with a primary mirror and a secondary mirror ; a first detector for detecting the first electromagnetic radiation ; a second detector for detecting second electromagnetic radiation of a second wavelength; a radiation unit which is designed to radiate electromagnetic radiation with the second wavelength in the direction of an optical axis of the receiving device ; wherein the radiation unit is a laser unit and is fixed to the receiving device ; wherein the primary mirror is designed to reflect the first electromagnetic radiation and the second electromagnetic radiation and to direct said radiation on to a focal region; wherein the secondary mirror is arranged between the primary mirror and the focal region and is designed to reflect only the second electromagnetic radiation in the direction of the second detector ; wherein the first detector is arranged behind the secondary mirror in the focal region of the primary mirror . a measuring apparatus for measuring the trajectory of a target object ; and a radar device separate from the measuring apparatus for radiating radar radiation as first electromagnetic radiation of a first wavelength, wherein the measuring apparatus comprises: a receiving device with a primary mirror and a secondary mirror ; a first detector for detecting the first electromagnetic radiation ; a second detector for detecting second electromagnetic radiation of a second wavelength; a radiation unit which is designed to radiate electromagnetic radiation with the second wavelength in the direction of an optical axis of the receiving device ; wherein the radiation unit is a laser unit and is fixed to the receiving device ; wherein the primary mirror is designed to reflect the first electromagnetic radiation and the second electromagnetic radiation and to direct said radiation on to a focal region; wherein the secondary mirror is arranged between the primary mirror and the focal region and is designed to reflect only the second electromagnetic radiation in the direction of the second detector ; wherein the first detector is arranged behind the secondary mirror in the focal region of the primary mirror . a receiving device with a primary mirror and a secondary mirror ; a first detector for detecting the first electromagnetic radiation ; a second detector for detecting second electromagnetic radiation of a second wavelength; a radiation unit which is designed to radiate electromagnetic radiation with the second wavelength in the direction of an optical axis of the receiving device ; wherein the radiation unit is a laser unit and is fixed to the receiving device ; wherein the primary mirror is designed to reflect the first electromagnetic radiation and the second electromagnetic radiation and to direct said radiation on to a focal region; wherein the secondary mirror is arranged between the primary mirror and the focal region and is designed to reflect only the second electromagnetic radiation in the direction of the second detector ; wherein the first detector is arranged behind the secondary mirror in the focal region of the primary mirror . <EOS>