The method 7, wherein a portion of said {HEAD ~ non SATPS position determination data} is acquired by {TAIL ~ an instrument} for sensing a magnetic field 
The method 7 , wherein a portion of said { HEAD ~ non SATPS position determination data } is acquired by { TAIL ~ an instrument } for sensing a magnetic field
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH