  This paper presents a method of finding the shortest path for an unmanned
aerial vehicle (UAV) flying from an initial point to a target line at a
constant altitude. The length of a Dubins path is derived as a function of the
final position on the line and then differentiated to obtain its extreme value.
The primary contribution of the study is a simple analytical solution to
determine the minimum-length Dubins path from an initial position to a target
line with initial and final orientations given. The proposed method is
demonstrated with numerical examples.
