Measurement system for determining six degrees of freedom of an object

A measurement system for determining six degrees of freedom (α, β, d, φ, χ, ψ) of a reflector (2) or of an object (3) on which the reflector (2) is arranged, said measurement system comprising:

• an angle and distance measurement apparatus (1) emitting a laser beam as a measurement beam (4), the reflector (2) being designed for a parallel reflection of the measurement beam (4) and comprising an apical opening or surface (6);
• a light-sensitive surface (7) arranged behind the reflector apex in a manner such that a part of the measurement beam (4) directed onto the reflector (2) passes through the apical opening or surface (6) of the reflector (2) and is incident on the surface (6), which is light sensitive;
• an optically detectable addition element (10) which is stationary relative to the reflector (2) and is detected from the angle and distance measurement apparatus (1), or is stationary relative to the angle and distance measurement apparatus (1) and is detected from the object (3), the optically detectable addition element (10) defining a direction (21) or a line which does not lie on a reflector axis (A) nor on the measurement beam (4);
• and
• a computer (8) being equipped for computing five degrees of freedom (α, β, d, φ, χ) of the reflector (2) or the object (3), from the measurement data produced by the angle and distance measurement apparatus (1) and by the light-sensitive surface (7) and for computing the sixth degree of freedom (ψ) of the reflector (2) or the object (3) from measurement data obtained by the detection of the addition element (10).