Some embodiments described herein include a laser tracker for continuously tracking a reflective target and for determining the distance with respect to the target. The laser tracker may include beam directing unit for emitting a measurement radiation and for receiving at least part of the measurement radiation reflected at the target. The laser tracker additionally comprises an interferometer for determining a change in distance with respect to the target. A control and evaluation unit is designed in such a way that an interferometer wavelength of the measurement radiation is determined by defined sample measurements being carried out with variation of the distance with respect to the target, wherein the sample measurements are effected for at least two different distances with respect to the target, the measurement radiation is constantly oriented towards the target and with the interferometer wavelength being kept stable.