Radar level gauging using corner reflector formed by product surface and tank wall

A radar level gauge system for determining a filling level of a product in a tank having a tank wall, and a tank atmosphere above a surface of a product in the tank, wherein the radar level gauge system comprises:

• a transceiver for generating, transmitting and receiving electromagnetic signals;
• a signal propagation arrangement coupled to the transceiver for:
• propagating an electromagnetic first transmit signal through the tank atmosphere towards a corner reflector formed by the surface of the product and the tank wall where the surface of the product meets the tank wall, the corner reflector being at a known horizontal distance from the radar level gauge system, and returning to the transceiver an electromagnetic first reflection signal resulting from reflection of the first transmit signal at the corner reflector;
• and
• propagating an electromagnetic second transmit signal vertically from the transceiver through the tank atmosphere towards the surface of the product and returning to the transceiver an electromagnetic second reflection signal resulting from reflection of the second transmit signal at the surface of the product;
• and
• processing circuitry coupled to the transceiver and configured to determine the filling level based on a first timing relation between the first transmit signal and the first reflection signal, a second timing relation between the second transmit signal and the second reflection signal, and the known horizontal distance between the radar level gauge system and the corner reflector.