The filter system filters {HEAD ~ the excursion signal} to remove {TAIL ~ unwanted frequency components} from the excursion signal 
to remove
The filter system filters { HEAD ~ the excursion signal } to remove { TAIL ~ unwanted frequency components } from the excursion signal
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH