A scan sensor emits detection beams for detecting objects in a scanning area within a scanning plane. The position of the scanning plane is changed by pivoting the sensor device in a scanning area, to produce multiple detection planes. Detection points of objects in the surroundings of the sensor device are detected by the detection beams in the detection planes. Lines are extracted from the detection points of a respective detection plan. Measuring points are determined at the intersection points of the lines with one or more predetermined measuring planes. The measuring points in a respective measuring plane are classified into blocks and lines are extracted on a block basis from the measuring points of the blocks generated, as a result of which structures of objects in the measuring planes are determined.