Universal planisphere, sight reduction finder and identifier, guidance and computer system

Planisphere computer structure comprising a central navigation west and navigation east dial having a zero Greenwich indication thereon and navigation west and navigation east scales about the outer periphery thereof proceeding 360.degree. clockwise and counterclockwise from the zero Greenwich indication, a sky map dial on at least one side of the navigation west and navigation east dial and concentric therewith having a ground position sky map thereon and a first point of Aries zero indication thereon and circumferential sidereal hour angle and right ascension sidereal time and degree scales thereon proceeding respectively in a clockwise direction from zero to 360.degree., in a counterclockwise direction from zero to 24 hours, and from zero to 360.degree., which scales are radially inwardly of the navigation west and navigation east scales of the navigation west and navigation east dial, a Greenwich dial concentric with the navigation west and east dial and sky map dial and positioned over the sky map dial on the other side thereof from the navigation west and east dial radially within the sidereal hour angle and right ascension scales on the sky map dial, which Greenwich dial is transparent and has thereon a ground position azimuthal equidistant polar map, a concentric transit indicator dial positioned over the Greenwich dial which is transparent and includes horizon lines for different latitudes thereon and which has peripheral, circumferentially extending meridian angle and meridian time scales thereon reading both clockwise and counterclockwise from one to 180.degree. and from 0 to 12 hours in each direction over 180.degree. respectively, an Aries indicator extending radially outwardly from the sky map dial at the first point of Aries, a Greenwich indicator extending radially outwardly from the Greenwich meridian on the Greenwich dial, a transit scale indicator extending radially outwardly from the sky mask dial including transparent and translucent portions with the transparent portions extending over more than one-half of the circumferential extent of the transit scale indicator, a reference indicator extending radially outwardly from the center of the concentric dials having a reference line thereon, and pivot means extending through each of the dials centrally thereof and through the inner end of the reference indicator for permitting relative rotation of each of the dials about the pivot means and permitting rotation of the reference rule about the inner end thereof.