The system (1) is used for the automatic calibration of an imaging-antenna arrangement (2) using an evaluation unit (4). The antenna arrangement (2) transmits signals (6) and receives the signals (6′) reflected from a calibration object (3) of known shape. The calibration object (3, 31, 32) provides at least one diffuse reflector (8). In the evaluation method, position coordinates of the calibration object (3) are entered, and the following method steps are implemented after the measurement of the reflected signals (6′): i. Calculation of the reflections of the calibration object (3, 31, 32), ii. Calculation of calibration data, iii. Preparation of an image of the calibration object with the use of the calibration data, iv. Determination of corrected position coordinates by evaluating the image of the at least one diffuse reflector, v. Implementation of steps i. to iv. with corrected position coordinates.