The method 2, wherein {HEAD ~ the magnitude} and phase angle of {TAIL ~ both the pseudo tracking servo output signal} and the tracking servo output signal are identical 
of
The method 2 , wherein { HEAD ~ the magnitude } and phase angle of { TAIL ~ both the pseudo tracking servo output signal } and the tracking servo output signal are identical
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH