Methods for calculating a relative change in percent voids using electromagnetic wave reflection coefficients
AssigneeGeophysical Survey Systems, Inc.
InventorRoger Roberts
Life of this patent
Estimating the term…
Abstract
A method for calculating the change in percent voids between a reference location and a second location in a medium. The method includes obtaining a reference reflection coefficient of an electromagnetic wave reflection at the reference location, and a second reflection coefficient of an electromagnetic wave reflection at the second location. The obtained reflection coefficients are used to calculate a percent change in reflection coefficient. A reflection conversion factor correlating the change in the reflection coefficient to a change in percent voids in the medium is calculated and is used to calculate a change in percent voids between the reference and second locations based on the calculated percent change in reflection coefficients.
Claims5
A method for determining calculating a change in percent voids between a reference location and a second location in a medium, the method comprising:
- (a) using a radar system having a transmitting antenna and a receiving antenna, transmitting and receiving at least one electromagnetic wave to obtain a reference radar measurement for a reference location of a medium, the at least one electromagnetic wave being transmitted at a predetermined incidence angle;
- (b) using the predetermined incidence angle, an effective dielectric of the medium, and the reference radar measurement, calculating a transmission angle of the electromagnetic wave through the medium at the reference location and calculating a reference reflection coefficient of an electromagnetic wave reflection at the reference location;
- (c) using the radar system transmitting and receiving another electromagnetic wave to obtain a second radar measurement at a second location in the medium, the another electromagnetic wave being transmitted at the predetermined incidence angle;
- (d) using the predetermined incidence angle, the effective dielectric of the medium, and the second radar measurement, calculating a transmission angle of the electromagnetic wave through the medium at the second location and calculating a second reflection coefficient of the electromagnetic wave reflection at the second location;
- (e) calculating a percent change of reflection coefficients between the reference reflection coefficient and the second reflection coefficient;
- (f) graphically generating a % void-percent reflection coefficient (PV-PRC) plot and extracting from the plot a reflection conversion factor correlating changes in reflection coefficient to changes in percent voids in the medium;
- (g) using the reflection conversion factor, calculating the change in percent voids between the reference location and the second location based on the determined percent change of reflection coefficients;
- (h) repeating steps (c) to (g) for multiple sample locations in an area of the medium, each sample location comprising a said second location;
- and
- (i) generating a spatial distribution map of the area of the medium, the spatial distribution map indicating the change in percent voids at the multiple sample locations in the area of the medium.
Dependencies are inferred from the claim text.