| 摘要 |
<p>The apparatus includes two independently-movable carriages in the form of transparent plates which are able to be displaced to and fro along the X,Y axes, respectively. On top of the plate a map holder is disposed which receives a micromap insert. A main projector produces an image of a section of the map onto a display screen. Additional working projectors are provided spaced respectively along X,Y axes from a prism mirror in the optical path of the beam from the main projector to the display screen. The marking projectors provide, via plane mirror, respective cross-marked lines on the display screen, each one of the respective divisions representing a nautical mile. The optical line is used to indicate the estimated course relative to the projected image of the map section. The cross marking then represents the position of the last-taken observation. The map section image is caused to move relative to the optical line by manipulation of wheels to provide X,Y displacement of the plates. In a second embodiment movement of a marking projector is caused by pulses from the ship's compass and movement of the map holder is derived from the ship's log and compass via a computer.</p> |
