Patent ID: 7685722
Filing Date: 2010-03-30
Classification: G01C

Abstract:
1. A celestial navigation device comprising: a ring comprising a transparent annular tubular structure having a gravity indicating device moving freely within said transparent annular tubular structure to indicate the highest or lowest point in said transparent annular tubular structure; said ring having a rotational axis perpendicular to a plane of said ring; a first gnomon attached to said ring; an analemma pattern attached to said ring across a diameter of said ring from said first gnomon; a time scale imprinted around said ring; wherein said ring is oriented with a rotational axis in a north-south plane and said ring is adjusted by tilting the rotational axis within said north-south plane and said ring is further adjusted by rotating said ring around said rotational axis to place a shadow of said first gnomon on said analemma pattern at a point on said analemma pattern corresponding to a current calendar date; whereupon achieving said placement of said shadow, a current sun time is indicated by said gravity indicating device with reference to said time scale.