Method for locating leakage of substances from subterranean structures
First Claim
1. A method for producing an image representative of a pattern of leakage of a fluid from a structure buried in the ground, comprising the steps of:
- translating an antenna array over an area of said ground having said structure buried therein;
transmitting and receiving a signal having a discrete frequency selected from a predetermined range of frequencies at each of a plurality of points in said area;
storing complex reflectance values having phase and intensity components in a computer memory, each said reflectance value representative of said signal received at one of said points;
Fourier transforming said stored complex reflectance values to form a received spatial spectrum;
propagating said received spatial spectrum to a predetermined depth;
inverse Fourier transforming the propagated spectrum to form a calculated image representative of said pattern of leakage of said fluid; and
displaying said calculated image.
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Accused Products
Abstract
A method for imaging substances leaking from underground structures using continuous-wave signals includes translating an antenna array over the ground, transmitting a continuous-wave signal into the ground at an array of points, detecting the amplitude and phase of the reflected signal at each point, transforming the reflectance values into the frequency domain, propagating this reflectance spectrum to a predetermined depth, and transforming the propagated spectrum into an image in the spatial domain at that depth. An image representing the underground structure containing the substance may be overlayed on the calculated image to detect differences that represent leakage. Successive images of the same area may be produced over a period of time and the differences compared to determine the rate of leakage.
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Citations
12 Claims
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1. A method for producing an image representative of a pattern of leakage of a fluid from a structure buried in the ground, comprising the steps of:
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translating an antenna array over an area of said ground having said structure buried therein; transmitting and receiving a signal having a discrete frequency selected from a predetermined range of frequencies at each of a plurality of points in said area; storing complex reflectance values having phase and intensity components in a computer memory, each said reflectance value representative of said signal received at one of said points; Fourier transforming said stored complex reflectance values to form a received spatial spectrum; propagating said received spatial spectrum to a predetermined depth; inverse Fourier transforming the propagated spectrum to form a calculated image representative of said pattern of leakage of said fluid; and displaying said calculated image. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method for determining a leakage rate, comprising the steps of:
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forming successive calculated images at successive times during a predetermined period in response to continuous-wave signals directed toward the ground, each said calculated image representative of a pattern of leakage of a fluid from a structure buried in the ground, said forming step comprising the steps of; translating an antenna array over an area of said ground having said structure buried therein; transmitting and receiving a signal having a discrete frequency selected from a predetermined range of frequencies at each of a plurality of points in said area; storing complex reflectance values having phase and intensity components in a computer memory, each said reflectance value representative of said signal received at one of said points; Fourier transforming said stored complex reflectance values to form a received spectrum; propagating said received spectrum to a predetermined depth; and inverse Fourier transforming the propagated spectrum to form a calculated image representative of said pattern of leakage of said fluid; and simultaneously displaying all said calculated images and a predetermined image representative of a pattern of said fluid in said structure, thereby illustrating the progression of leakage during said predetermined period. - View Dependent Claims (12)
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Specification