The two pairs of signals are signal processed to enhance {HEAD ~ resolution} of {TAIL ~ the ring laser} readout 
of
The two pairs of signals are signal processed to enhance { HEAD ~ resolution } of { TAIL ~ the ring laser } readout
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH