UNSYNCHRONIZED RADIO IMAGING

• US 20120062408A1
• Filed: 11/21/2011
• Published: 03/15/2012
• Est. Priority Date: 06/15/2010
• Status: Active Grant

• Current Assignee: Stolar Incorporated
• Original Assignee: Stolar Research Corporation
• Inventors: Bausov, Igor, Stolarczyk, Gerald, Stolarczyk, Larry G., Sanchez, Tito, Duncan, Joseph
• Granted Patent: US 8,847,813 B2
• Time in Patent Office: Days
• US Class Current: 342/22
• CPC Class Codes: G01S 13/003 Bistatic radar systems; Multistatic radar systems
• CPC Class Codes: G01V 3/12 operating with electromagnetic waves operating with millimetre waves G01V8/005

Abstract

An unsynchronized acoustic or radio-frequency (RF) computed tomography (CT) imaging system with matched, but independent, continuous wave (CW) transmitters and receivers configured to radiate acoustic or RF transmissions in a plurality of vector paths through solid geologic material. A computer calculates and displays tomographic images constructed from individual acoustic or RF path signal travel time or attenuation measurements logged from registered locations from the CW transmitters and receivers after their being shuttled amongst a number of different transmitter and receiver perspectives available around said geologic material to generate data necessary for computed tomography. Each of the transmitters and receivers include independent unsynchronized crystal oscillators rated at 10-ppm or better frequency uncertainty to produce and to detect CW radio frequency (RF) transmissions.

Claims

1. An unsynchronized radio-frequency (RF) or acoustic computed tomography (CT) imaging system, comprising:

at least one pair of matched, but independent, continuous wave (CW) transmitters and receivers configured to radiate acoustic or RF transmissions in a plurality of vector paths through solid geologic material with strategic known transmission and reception points in tunnels, wells, surfaces and/or boreholes;

a computer configured to calculate and display tomographic images constructed from individual acoustic or RF path travel times or signal attenuation measurements logged from registered locations from the CW transmitters and receivers after their being shuttled amongst a number of different transmitter and receiver perspectives available around said geologic material to generate data necessary for computed tomography; and

a device configured to normalize said individual path travel time or signal attenuation measurements such that variations in operating conditions, equipment, and components, do not render as artifacts in tomographic computations and displays;

wherein, each of the transmitters and receivers include independent unsynchronized crystal oscillators rated at 10-ppm or better frequency uncertainty to produce and to detect CW acoustic or radio frequency (RF) transmissions.

2. The unsynchronized acoustic or RF-CT imaging system of claim 1, further comprising:

a local oscillator connected to receiver'"'"'s crystal oscillator and configured to heterodyne with an associated transmitter'"'"'s carrier frequency to produce a baseband signal during detection;

wherein, the frequency error between the local oscillator and the transmitter carrier frequencies produces a beat product of less than one Hertz in frequency and its magnitude is inversely proportional to the path attenuation between the transmitter and receiver.

3. The unsynchronized acoustic or RF-CT imaging system of claim 2, further comprising:

an extremely low-pass filter configured to remove all heterodyne products above one Hertz in the detector;

wherein an extraordinarily high sensitivity results in the highly attenuating depths and distances usual to natural media or coal bed Acoustic and radio imaging.

4. The unsynchronized acoustic or RF-CT imaging system of claim 1, further comprising:

a matched continuous wave (CW) transmitter and receiver for electronically imaging material in between them, wherein signal travel time or attenuation measurements can be collected from a number of different transmitter and receiver perspectives around the material;

a pair of crystal oscillators, one of which is disposed in the transmitter and the other of which is disposed in the receiver, and each crystal oscillator having the same rating for frequency uncertainty better than ten parts per million (10-ppm); and

a local oscillator disposed in the receiver that uses a reference frequency obtained from the receiver one of the pair of crystal oscillators, and configured to produce a local oscillator signal that can beat-down the transmitter'"'"'s carrier frequency to baseband;

wherein, the frequency error between the local oscillator and the transmitter carrier frequencies produces a beat product of less than one Hertz in frequency and its magnitude is inversely proportional to the path attenuation between the transmitter and receiver; and

wherein, a low-pass filter is used to remove everything above one Hertz in the detector to produce an output signal for tomographic processing and display of the material characteristics.

5. The unsynchronized acoustic or RF-CT imaging system of claim 1, further comprising:

an amplitude control device to fix the amplitude of steady-state radio frequency transmissions output by the CW transmitter.

6. The unsynchronized acoustic or RF-CT imaging system of claim 1, further comprising:

a computer data memory for registering a series of predetermined places (P₁, P₂, . . . P_N) visited by each of the CW transmitter and receiver along the fringes of a mass at corresponding known times (t₁, t₂, . . . t_N), and for correlating a series of amplitude measurements (A₁, A₂, . . . A_N) taken by the CW receiver at those places and times.

7. The unsynchronized acoustic of RF-CT imaging system of claim 1, further comprising:

a tomographic processor capable of constructing electronic image representations of the internal character of the materials in said mass from information stored in the computer data memory.