An aerator that allows the operator to make a turn with the machine while the tines are still in contact with the turf through the use of a differential shaft and brakes that enhance the maneuverability of the machine. By means of a defined arrangement of a carrying arm proceeding from a support mount at the X-ray device and a defined arrangement of an X-ray calibration phantom at the carrying arm, the coordinate transformation between a coordinate system allocated to the support mount and a coordinate system allocated to the X-ray calibration phantom is known. The invention detects sequences of test sound frames having distortion levels that are greater than a temporal distortion threshold and calculates an average length and a maximum length of these sequences. An interpolation component interpolates pixel intensity data from adjacent pixels based on the position of the mirror when a pixel clock arrives.