Patent ID: 6441599
Filing Date: 2002-08-27
Classification: G01S

Abstract:
A method of locating a reference point located on one side of a structure from the opposite side of the structure, the method comprising:(A) generating an electromagnetic signal using a transmitter that is located at a position that defines the reference point, the transmitter being located on the one side of the structure; (B) sensing the electromagnetic signal using a receiver that is located on the opposite side of the structure, including: (1) providing a first indication when the receiver is within a first distance of the transmitter, wherein the first indicant is one of a group consisting of an audio indication, a visual indication and a tactile indication; and (2) providing a second indication when the receiver is within a second distance of the transmitter, the second distance being less than the first distance, and wherein the second indication is another of the group consisting of an audio indication, a visual indication and a tactile indication.