Cable location method and apparatus using modeling data

• US 6,215,888 B1
• Filed: 06/10/1998
• Issued: 04/10/2001
• Est. Priority Date: 06/10/1998
• Status: Expired due to Term

• Current Assignee: AT&T Corporation (AT&T, Inc.)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Huffman, John Sinclair, Eslambolchi, Hossein
• Primary Examiner(s): Bella, Matthew C.
• Assistant Examiner(s): CHOOBIN, BARRY
• Application Number:
  US09/095,238
• Time in Patent Office: 1,035 Days
• Field of Search: 340/566, 324/326, 324/133, 324/233, 324/529, 342/459, 342/22, 342/28, 361/119, 505/164, 436/56, 382/100, 378/88, 378/21
• US Class Current: 382/100
• CPC Class Codes: G01V 3/02 operating with propagation of electric current

Abstract

More accurate location of a buried utility conveyance (10) is obtained by first detecting, via a detector (34) the actual pattern of radiation (26, 28) of a locating signal impressed on the conveyance. The actual pattern of radiation is compared, by a processor (36) to each of a plurality of reference patterns stored in a database (38), each pattern representing the radiation for a conveyance having a known location. The processor selects the reference pattern that most closely the actual pattern and then provides an indication of the conveyance location associated with the selected reference pattern.

Claims

1. A method for facilitating location of a buried utility conveyance of interest that carries a locating signal that has a particular radiation pattern, comprising the steps of:

detecting the actual pattern of radiation emanating independently from the conveyance of interest by virtue of the locating signal carried thereby;

comparing the actual pattern of radiation to each of a plurality of reference patterns, each representing a model pattern of the radiation emanating independently from the conveyance of interest under different conditions, and each reference pattern having a true conveyance location associated therewith,

selecting, based on said comparing, the reference pattern that most closely matches the actual pattern; and

determining, from the true conveyance location associated with said reference pattern most closely matching the actual pattern, the location of the conveyance of interest.

2. The method according to claim 1 wherein:

the detecting step includes the step of detecting actual peak and null patterns of radiation associated with said conveyance of interest.

3. The method according to claim 2 wherein the comparing step includes the step of comparing the actual peak and null patterns to corresponding peak and null reference patterns, respectively.

4. The method according to claim 3 wherein the selecting step includes the step of selecting the peak and null reference patters that most closely match the actual peak and null reference patterns, respectively.

5. The method according to claim 1 wherein the reference patterns are established by computer modeling.

6. A method for facilitating location of a buried utility conveyance of interest that carries a locating signal that has particular null and peak radiation patterns, comprising the steps of:

detecting the actual peak and null patterns of radiation associated with the conveyance of interest;

comparing the actual peak and null patterns of radiation to each of a plurality of peak and null reference patterns, each peak and null representing a model pattern associated with the peak and null radiation, respectively, for the conveyance of interest under different conditions, and each peak and null reference pattern having a true conveyance location associated therewith,

selecting, based on said comparison, the peak and null reference patterns that most closely match the actual peak and null patterns, respectively; and

determining, from the true conveyance location associated with said peak and null reference patterns most closely matching the actual peak and null patterns, respectively, the location of the conveyance of interest.

7. The method according to claim 6 wherein the peak and null reference patterns are established by computer modeling.

8. Apparatus for facilitating location of a buried utility conveyance of interest that carries a locating signal that has a particular radiation pattern, comprising the steps of:

means for detecting the actual pattern of radiation associated with the conveyance of interest;

means for comparing the actual pattern of radiation to each of a plurality of reference patterns, each representing a model pattern associated with the radiation for the conveyance of interest under different conditions, and each reference pattern having a true conveyance location associated therewith,

means for selecting, based on said comparing, the reference pattern that most closely matches the actual pattern; and

means for determining, from the true conveyance location associated with said reference pattern most closely matching the actual pattern, the location of the conveyance of interest.

9. Apparatus for facilitating location of a buried utility conveyance of interest that carries a locating signal that has particular null and peak radiation patterns, comprising:

means for detecting the actual peak and null patterns of radiation emanating independently from the conveyance of interest by virtue of the locating signal carried thereby;

means for comparing the actual peak and null patterns of radiation emanating independently from the conveyance of interest to each of a plurality of peak and null reference patterns, each peak and null reference pattern representing a model pattern associated with the peak and null radiation, respectively, emanating independently from the conveyance of interest under different conditions, and each peak and null reference pattern having a true conveyance location associated therewith,

means for selecting, based on said comparison, the peak and null reference patterns that most closely match the actual peak and null patterns, respectively; and

means for determining, from the true conveyance location associated with said peak and null reference patterns most closely matching the actual peak and null patterns, respectively, the location of the conveyance of interest.