This is a compound module in which two components are aggregated. An overview of these constituent modules is given in a brief module summary.
This module corresponds to the Introduction in the original article, without coinciding entirely with it. The details on the theoretical methods included in the Introduction are omitted from the module Positioning, as well as the announcement that a discrepencancy has been found between the measurements and the calculations and that this problem could be solved by taking into account rotational coupling. We have expanded the references to previous articles from the same research project.