Patent ID: 6836449
Filing Date: 2004-12-28
Classification: G01S,Y10S

Abstract:
A method for distance measurement comprising the steps of:establishing two spatially different points from which a distance is measured or monitored by acoustical measuring devices between each said point and a center of a reflecting area on a target object such that a substantially perpendicular line could be drawn through said first point and said center of said reflecting area on said target, and an angled line could be drawn through said second point and said center of said reflecting area on said target, thereby these two lines and a line drawn through said two points define a right triangle denoted &Dgr;ABC with its hypotenuse denoted CB between said second point and said center of said reflecting area of said target; measuring an approximate length of a vertical leg AB of said triangle; measuring an approximate length of said hypotenuse CB of said triangle; and obtaining a distance defined, between the said first point and said center of said reflecting area on said target through the application of the functional relationship between said distance and a ratio between the approximate length of said vertical leg AB of said triangle and the approximate length of said hypotenuse CB of said triangle, whereby said distance measurement is invariant to changes in the speed of sound propagation through the medium.