Rotation laser device and method for controlling a laser beam

The rotational laser apparatus (1) has a laser device (3) for producing laser beam (5). A rotating unit (9) is provided for rotating a laser device around rotation axis (4) with specific rotation speed. A measuring device (21) is provided for determining rotation angle of the laser device with respect to rotation axis. A storage device (22) is provided for storing rotation angle of the laser device determined by measuring device. Independent claims are included for the following: (1) method for controlling laser beam; and (2) method for measuring rotation angle.