{TAIL ~ The method} further comprises measuring the first and second components based on {HEAD ~ the error signal} and the repeatable component 
{ TAIL ~ The method } further comprises measuring the first and second components based on { HEAD ~ the error signal } and the repeatable component
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH