A navigational plotter in which a geographical map or chart has marked thereon lines of position corresponding to the Omega or Loran navigation system aids, for example. The intersections of the lines of position with a base line on the chart are recorded in coded form on a separate strip of the chart....http://www.google.fr/patents/US4135190?utm_source=gb-gplus-shareBrevet US4135190 - Navigational plotter
