1. A method for tracking a straight line target, the method comprising: selecting at least two temporally-discontinuous primary frames from a plurality of image frames; creating a detection envelope between a first detection and a second detection, the first detection taken from a first primary frame and the second detection taken from a temporally-discontinuous second primary frame, the first detection and second detection being potential straight line targets; and associating a third detection within the detection envelope with a straight line track between the first detection and the second detection to identify a straight line target.