Method, system and computer program product for ranging RFID tags

The invention relates to a method for ranging a radio frequency tag, comprising measuring the modulated backscattering response of the tag at a plurality of frequencies using reader and determining the dispersive properties of the tag from the amplitude of the measured backscattering response. Further, the method comprises determining a position parameter of the tag from the measured modulated backscattering response and the determined dispersive properties of the tag.