A LIDAR system, including a transmitting unit that includes a polarization device, the polarization device being configured to set a polarization of a scanning beam, a receiving unit that is configured to receive the scanning beam after it has been reflected on a point in the surroundings of the LIDAR system, the receiving unit including a polarization recognition device that is configured to recognize a polarization of the reflected scanning beam, and an evaluation unit that is configured to ascertain a polarization difference, based on a difference between the polarization that is set by the transmitting unit and the polarization that is recognized by the receiving unit.