Patent ID: 6593746
Filing Date: 2003-07-15
Classification: G01V

Abstract:
An anomaly sensing system, comprising:a transmitter providing for at least one RF-probe signal and one RF-synchronizing signal at substantially different carrier frequencies and yet synchronous to one another; a coherent receiver having a frequency synthesizer able to lock on to said RF-synchronizing signal and providing for synchronous detection of said RF-probe signal; and a measurement device for detecting attenuation and phase shift affects on said RF-probe signal by an anomalous media that intervenes between the transmitter and receiver; wherein, synchronization between the transmitter and coherent receiver is accomplished wirelessly and without a synchronizing cable, and such synchronization provides for the detection and measurement of small sinusoidal signals embedded in electrical noise, and synchronous detection is used in the receiver to measure the attenuation rate (alpha) and phase shift (beta) of an electromagnetic wave propagating between the transmitting and a receiving magnetic dipole antenna can be measured; and wherein, images of geologic structure are constructed by dividing a geologic region into pixels or boxels include a lane or volume between location visited by the receiver and transmitter, and lines between the locations visited represent the edges of the image plane, and the depths width and height of each pixel or boxel is arbitrary, but is usually made unequal to the physical space between each transmitter and receiver location, and the electromagnetic wave propagation constants in each pixel are determined by an image reconstruction process that does not require a straight ray path assumption and that accounts for electromagnetic wave propagation phenomena of refraction, reflection, and scattering in a geologic target.