Acoustic system for measuring the location and depth of underground pipe

摘要

An acoustic method and apparatus for measuring the horizontal surface location and depth of any type of underground pipe or conduit, including nonmetallic or nonconductive pipe, such as sewer, gas, and water pipes, which cannot be detected with electromagnetic locators. A continuous-wave (CW) acoustic signal is injected into and transmitted through the fluid (liquid or gas) in the pipe. The horizontal surface location and depth of the pipe are determined from an analysis of the phase measurements derived from an array of acoustic measurements, which are made at the surface and approximately perpendicular to the direction of the underground pipe.