Patent ID: 8862431

Claim:
A method for determining and retrieving positional information, comprising: locating a plurality of first conductive elements on a surface and a plurality of second conductive elements on said surface to form a first grid having a first plurality of intersections, electrically isolating the plurality of first conductive elements from the plurality of second conductive elements; coupling a second grid to the surface and electrically isolating the second grid from the plurality of first conductive elements and the plurality of second conductive elements, the second grid comprising a plurality of third conductive elements intersecting each other at a plurality of nodes, the plurality of nodes aligned with the plurality of intersections; penetrating the surface with a first projectile; electronically determining a first location of a first penetration of the surface with the first projectile based on a first change in a first electrical measurement of the plurality of first conductive elements and a second change in a second electrical measurement of the plurality second conductive elements; penetrating the surface with a second projectile; electronically generating a plurality of possible penetration points of the second projectile based on the first location; performing a computer simulation of the second grid; performing a plurality of third electrical measurements on a second plurality of locations of the second grid; and electronically determining a second location of a second penetration of the surface with the second projectile based on the plurality of possible penetration points of the second projectile, the computer simulation and the plurality of third electrical measurements.