The apparatus includes a first or reference station that provides {HEAD ~ a reference} for the survey and whose location is determined with {TAIL ~ high accuracy}, and a second or mobile station that is spaced apart from the first station and acts as a mobile measurement unit for the survey 
The apparatus includes a first or reference station that provides { HEAD ~ a reference } for the survey and whose location is determined with { TAIL ~ high accuracy } , and a second or mobile station that is spaced apart from the first station and acts as a mobile measurement unit for the survey
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH