he path specified by polar stereographic coordinates <tt>x,y</tt> where <tt>x</tt> and <tt>y</tt> are vectors of equal size in ps71 meters.</p><p><tt>d = pathdistps(...,'km')</tt> simply divides output by 1000 to give distance in kilometers.</p><p><tt>d = pathdistps(...,'ref',[reflat reflon])</tt> references the output to the track coordinate nearest to the location given by a two-element vector <tt>[reflat reflon]</tt>.  This might be useful when analyzing distance along a satellite ground track relative t