US Patent 9541391 Geodetic instruments and methods of operating geodetic instruments

Embodiments provide for a geodetic instrument comprising a scanning head, a reflecting optical element, a radiation source, a control unit and an electronic distance measurement (EDM) unit. The scanning head is rotatable about a first axis. The reflecting optical element mounted in the scanning head and rotatable about the same first axis. The radiation source is adapted to emit light to be output along a light beam path from the geodetic instrument via light reflection against the reflecting optical element. The control unit is adapted to adjust an angular displacement profile of the reflecting optical element about the first axis relative to an angular displacement profile of the scanning head such that an angular displacement of the light beam path about the first axis as a function of time presents a stair-like profile. The EDM unit is adapted to determine a distance to a target during a flat portion of the stair-like profile.