Given two trajectory states, computes the two points of closest approach in the transverse plane for the helices extrapolated from these states. 1) computes the intersections of the circles in transverse plane. Two cases: - circles have one or two intersection points;
- circles do not cross; the points used are the points of closest approach of the two circles. 2) computes the corresponding z-coordinates. In the case where the circles have two intersections, the point for which the z-coordinates on the 2 tracks are the closest is chosen.
1.8.14