A position measurement method for position alignment with a vehicle, performed by a charging pad, may comprise performing synchronization with a vehicle entering a vicinity of the charging pad, transmitting low frequency (LF) signals having a same strength through a plurality of LF spots of the charging pad, receiving information on reception strengths of the LF signals from the vehicle, adjusting a transmission strength for the plurality of LF spots according to the information on reception strengths received from the vehicle, and transmitting the LF signals according to the adjusted transmission strength.