Patent ID: 8326523

Claim:
A method of determining range between first and second objects with relative movement, the method comprising: projecting into space from the first object a grid comprised of a plurality of grid lines from a first origin point on the first object; modulating each grid line to carry a grid word comprised of a number of modulated bits to identify each grid line within the grid by the modulated grid word; detecting the grid lines and the corresponding grid words from at least three locations having a predetermined triangular relationship on the second object, with each location defining a vertex of the triangle, which define three unique pairs of vertices; determining the location within the grid of the three vertices based on the grid word detected at each of the at least three locations; for each unique pair of vertices, determining an angle subtended by a pair of unit vectors extending from the origin based on the location within the grid of each of the vertices, with each unit vector passing through one of the vertices of the unique pair, to form a set of three subtended angles; determining the range between the first and second objects based on the set of subtended angles.