The design uses active radio frequency identification（ RFID） tag placed at the key point of the tower to send the time-sharing signal

calculate the phase difference between the two after the ground of multiple receive antennas receives the signal

can calculate the coordinates of these points. Use the calculated coordinates to compare with the normal position

timely detection of the deformation of the tower. It monitoring results can be reach 5～ 6 cm measurement precision in a single direction

can reflect size of the deformation about the tower and ensure the reliability of transmission.