The present invention relates to planning of a trajectory for minimum
threat exposure in a given geographical region. A trajectory is planned
from a start node to a final node in a digital representation of the
geographical region. The threat exposure for a vehicle moving along the
trajectory is determined. Navigation performance of the vehicle along the
trajectory is evaluated. A rate of survival based on threat exposure and
navigation performance along the trajectory is estimated. A new
trajectory is planned from the start node to the final node until a best
rate of survival is established for the planned trajectory.