Abstract: A flight trajectory measuring and observing theodolite wherein the stand portion which essentially comprises a socket element, a stand element, and intermediate element and a leveling stand arranged at the center and the measuring components which essentially contains a yolk element and two housings attached thereto for mounting optical devices, are each constructed as a separate horizontally positionably mountable unit. The stand portion is mounted upon a ring-shaped support element which is non-rotatably connected with the foundation. The connection of the stand portion with the ring-shaped support element is accomplished by means of a foot portion of the leveling stand which is provided at one end with a spherically constructed support surface. Further, the stand portion is radially adjustable and fixable in position in order to horizontally position the stand portion-azimuth rotational axis.