identifying a deviation from the intermediate point to a new intermediate point such that {HEAD ~ the new intermediate point} has a cumulative threat risk value lower than or equal to {TAIL ~ the allowable threat risk} per grid cell 
equal to
identifying a deviation from the intermediate point to a new intermediate point such that { HEAD ~ the new intermediate point } has a cumulative threat risk value lower than or equal to { TAIL ~ the allowable threat risk } per grid cell
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH