Patent ID: 9645239
Date: 2017-05-09
CPC Classifications: G01B,G01S

Claim:
1. A laser tracker for continuously tracking a reflecting target and for determining a distance to the target, the laser tracker comprising: a base defining a vertical axis; a beam guiding unit for emitting measurement radiation and for receiving at least part of the measurement radiation reflected at the target, wherein the beam guiding unit can be pivoted in a motor-driven manner relative to the base about the vertical axis and an inclination axis which is substantially orthogonal to the vertical axis; an interferometer for determining a change in the distance to the target using interferometry having a tunable laser diode configured as the interferometer laser beam source for generating the measurement radiation for the interferometer in such a way that the measurement radiation is coherent and longitudinally single-mode; an absolute distance measurement unit for determining a measurement distance value for a distance to the target; and an angular measurement functionality for determining an orientation of the beam guiding unit relative to the base; a control and evaluation unit configured such that, during execution of a calibration mode, an interferometer wavelength of the measurement radiation is determined by: