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. 15, 1997
Filed:
May. 16, 1995
Gregory W Draper, Perry, OK (US);
Frank S Nickel, Perry, OK (US);
Michael F Gard, Perry, OK (US);
Jian J Jin, Perry, OK (US);
The Charles Machine Works, Inc., Perry, OK (US);
Abstract
An apparatus and method is provided for determining if the signal received from an underground beacon (10) at a locator (22) is a true signal or a ghost signal. Orthogonal horizontal antenna (38) and vertical antenna (40) are used and a ratio is computed of the signal strengths measured by the two antennas. At the true location, the signal strength in the horizontal antenna (38) will be maximum and the signal strength of the vertical antenna (40) will be a null. If the ratio of the signal strength sensed by the horizontal antenna and vertical antenna is large, exceeding a predetermined value, the locator is receiving a valid signal from the beacon and a display of this fact is made on a display on the locator and the depth of the beacon is calculated. If the ratio is less than the predetermined value, a ghost signal is being received and this fact is displayed on the display on the locator (22).