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