Abstract: A time-differenced carrier phase (TDCP) measurement value-based navigation system according to one embodiment of the present invention comprises: a satellite navigation system information reception unit for acquiring satellite navigation system information including a carrier phase measurement value; an initial position determination unit for determining an initial position of a target on the basis of the satellite navigation system information; a TDCP acquisition unit for acquiring a TDCP measurement value; a relative position determination unit for determining a relative position of the target on the basis of the TDCP measurement value; and an absolute position determination unit for determining an absolute position of the target by accumulating relative positions according to time of the initial position of the target.