Changing {HEAD ~ the area} upon which AGC adjustments are applied permits {TAIL ~ better scene selection} according to the present invention 
permits
Changing { HEAD ~ the area } upon which AGC adjustments are applied permits { TAIL ~ better scene selection } according to the present invention
OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH