Shows how to simplify the discussion of the trivial ambiguity (a.k.a. rank-1 ambiguity) problem associated with the polarization-angular coherence structure (PACS) of a tripole antenna by defining a new coordinate system where the two signals of concern both lie in the same coorainate plane, along with a theoretical demonstration indicating that the involved coordinate rotation has no effect on the study of the problem under consideration. The identified situations suffer from the trivial ambiguity are foun...