Since SATPS data gives good results at longer distances, SATPS data is used when {TAIL ~ the distance} is greater than or equal to {HEAD ~ the optical threshold} 
Since SATPS data gives good results at longer distances , SATPS data is used when { TAIL ~ the distance } is greater than or equal to { HEAD ~ the optical threshold }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD