Laser tracker (10, 11) for position determination of a target and in particular for progressive tracking of the target, having • a beam source for generating measurement radiation, • a base, which defines a standing axis, • a support, which defines a tilt axis standing essentially orthogonally to the standing axis, wherein ▪ the support is pivotable by a motor in relation to the base about the standing axis and ▪ a horizontal pivot angle is defined by an alignment of the support in relation to the base, • a beam deflection unit (16, 20), which is pivotable by a motor about the tilt axis in relation to the support, wherein a vertical pivot angle is defined by an alignment of the beam deflection unit (16, 20) in relation to the support, ▪ for emitting and aligning the measurement radiation and ▪ for receiving at least a part of the measurement radiation reflected on the target, • angle measuring functionality for determining the horizontal pivot angle and the vertical pivot angle, • distance measuring functionality, and • a photosensitive surface detector for detecting a position of incidence of the reflected measurement radiation on the surface detector and for generating an output signal for controlling a target tracking functionality, characterized in that • the base has a self-calibration unit having ▪ at least one first retroreflective reference target (70, 71) and ▪ at least one optical assembly acting as a reduction objective lens, and • the self-calibration unit can be targeted using the measurement radiation for determining at least one calibration parameter with respect to a position and/or direction of the measurement radiation for the laser tracker (10, 11) such that an optical beam path of the measurement radiation extends through the optical assembly and the measurement radiation is incident on the at least first retroreflective reference target (70, 71), whereby ▪ a first calibration measurement can be carried out using a distance, which is simulated with respect to relevant measured variables for the determination of the at least one calibration parameter, to the at least first retroreflective reference target (70, 71) and ▪ the simulated distance is greater than an actually structurally provided distance (d', d1, d2, dn) to the at least first retroreflective reference target (70, 71). • a beam source for generating measurement radiation, • a base, which defines a standing axis, • a support, which defines a tilt axis standing essentially orthogonally to the standing axis, wherein ▪ the support is pivotable by a motor in relation to the base about the standing axis and ▪ a horizontal pivot angle is defined by an alignment of the support in relation to the base, ▪ the support is pivotable by a motor in relation to the base about the standing axis and ▪ a horizontal pivot angle is defined by an alignment of the support in relation to the base, • a beam deflection unit (16, 20), which is pivotable by a motor about the tilt axis in relation to the support, wherein a vertical pivot angle is defined by an alignment of the beam deflection unit (16, 20) in relation to the support, ▪ for emitting and aligning the measurement radiation and ▪ for receiving at least a part of the measurement radiation reflected on the target, ▪ for emitting and aligning the measurement radiation and ▪ for receiving at least a part of the measurement radiation reflected on the target, • angle measuring functionality for determining the horizontal pivot angle and the vertical pivot angle, • distance measuring functionality, and • a photosensitive surface detector for detecting a position of incidence of the reflected measurement radiation on the surface detector and for generating an output signal for controlling a target tracking functionality, • the base has a self-calibration unit having ▪ at least one first retroreflective reference target (70, 71) and ▪ at least one optical assembly acting as a reduction objective lens, and ▪ at least one first retroreflective reference target (70, 71) and ▪ at least one optical assembly acting as a reduction objective lens, and • the self-calibration unit can be targeted using the measurement radiation for determining at least one calibration parameter with respect to a position and/or direction of the measurement radiation for the laser tracker (10, 11) such that an optical beam path of the measurement radiation extends through the optical assembly and the measurement radiation is incident on the at least first retroreflective reference target (70, 71), whereby ▪ a first calibration measurement can be carried out using a distance, which is simulated with respect to relevant measured variables for the determination of the at least one calibration parameter, to the at least first retroreflective reference target (70, 71) and ▪ the simulated distance is greater than an actually structurally provided distance (d', d1, d2, dn) to the at least first retroreflective reference target (70, 71). ▪ a first calibration measurement can be carried out using a distance, which is simulated with respect to relevant measured variables for the determination of the at least one calibration parameter, to the at least first retroreflective reference target (70, 71) and ▪ the simulated distance is greater than an actually structurally provided distance (d', d1, d2, dn) to the at least first retroreflective reference target (70, 71).