The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 08, 2008
Filed:
Apr. 06, 2005
Thorkell Gudmundsson, San Jose, CA (US);
Jim Waite, Los Gatos, CA (US);
Johan Överby, Sunnyvale, CA (US);
Stevan Polak, Aptos, CA (US);
Niklas Lindstrom, Sunnyvale, CA (US);
Thorkell Gudmundsson, San Jose, CA (US);
Jim Waite, Los Gatos, CA (US);
Johan Överby, Sunnyvale, CA (US);
Stevan Polak, Aptos, CA (US);
Niklas Lindstrom, Sunnyvale, CA (US);
Metrotech Corporation, Inc., Santa Clara, CA (US);
Abstract
A new approach for locating an underground line described herein remains accurate in the face of bleedover by including both amplitude and phase from at least two magnetic field strength sensors in the measurement set. A numerical optimization step is introduced to deduce the positions and currents of each of several cables, of which one is the targeted cable and the others are termed bleedover cables. Furthermore, some embodiments of the method accounts for practical problems that exist in the field that relate to reliable estimation of cable positions, like the phase transfer function between transmitter and receiver, the estimation of confidence bounds for each estimate, and the rejection of false positive locates due to the presence of noise and interference.