Patent ID: 6891497
Filing Date: 2005-05-10
Classification: G01S

Abstract:
1. For use with an electrical apparatus employing a signal transport path having a first node coupled with a reference frequency signal source that is operative to generate a reference frequency signal that propagates along said signal transport path to a second node, said signal transport path imparting a variable delay of said reference frequency signal employed by said apparatus to operate electrical devices at said nodes, as a result of temperature variation along said signal transport path, a method of providing a measure of delay through said signal transport path between said first node and said second node, said method comprising the steps of: (a) injecting a chirp signal into said signal transport path from said second node of said signal transport path, so that said chirp signal is transmitted over said signal transport path, is reflected from said first node and returned to said second node of said apparatus; (b) receiving said reflected chirp signal at said second node of said apparatus; (c) correlating energy contained in said reflected chirp signal received in step (b) with energy in an auxiliary chirp signal, delayed with respect to that of the chirp signal injected into said signal transport path in step (a); and (d) adjusting said auxiliary chirp signal to maximize the result of correlating in step (c) and thereby provide an output representative of delay through said signal transport path.