摘要:
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.
摘要:
An underground radio communications and personnel tracking system uses a portable communications device worn by a miner when underground in a mine. A cap-lamp transceiver provides voice and text communication on ultra-low frequency (ULF) to ultra-high frequency (UHF) carrier frequencies and modulation adapted by programming of a software defined radio to making selective and agile radio contacts via through-the-earth, conductor/lifeline, coal seam, tunnel, and ionosphere/earth-surface waveguides for transmission of electromagnetic waves. These waveguides comprise layered earth coal and mineral deposits, and manmade mining complex infrastructures which serendipitously form efficient waveguides. Ultra-Low Frequency F1/F1 repeaters are placed underground in the mine, and providing for extended range of communication of the cap-lamp transceiver with radios and tracking devices above ground of the mine.
摘要:
A slickline data transmission system for a high pressure oil-field well comprises inductive couplers at opposite ends of a slickline in order to establish real-time radio communication between down-the-hole logging toolstrings and supervisory control and data acquisition equipment on the surface. A frequency shift keyed (FSK) carrier centered around radio is used to send data up to the surface and commands back down to the toolstring. The toolstring itself can be a conventional one with a TDMA interface originally intended to be memory-dumped when the toolstring is returned to the surface.
摘要:
A non-invasive method of buried-utility-mapping includes using a long wavelength gradiometric ground penetrating radar to “see” patches of conductive material below ground and buried pipes and electrical conductors that are all constantly radio-illuminated by local AM radio broadcasts. The underground infrastructure of entire cities can be surveyed this way, point-by-point over time. A short wavelength part of the gradiometric ground penetrating radar operates shoulder-to-shoulder with the magnetic part and is able to improve shallow object resolution, map moisture build-ups under roads, and spot contaminated soils. Two gradiometric ground penetrating radar technologies, cameras, and navigation receivers can be mounted on city vehicles and a daily collection of their data batch transformed by digital processing algorithms into detailed and automatically updating false-color maps of the underground utilities of the whole city and other buried infrastructures.
摘要:
A beat-product radio imaging method (RIM) system uses a matched continuous wave (CW) transmitter and receiver to electronically image material in between. Signal attenuation measurements are taken from a number of different transmitter and receiver perspectives around the material. The transmitter and receiver each have a crystal oscillator rated at 10-ppm or better frequency uncertainty. The receiver's crystal oscillator is used as a local oscillator to beat down the transmitter's carrier frequency to baseband. 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. An extremely low-pass filter is used to remove everything above one Hertz in the detector. The receiver sensitivity is therefore extraordinarily high.
摘要:
A ground-penetrating radar comprises a software-definable transmitter for launching pairs of widely separated and coherent continuous waves. Each pair is separated by a constant or variable different amount double-sideband suppressed carrier modulation such as 10 MHz, 20 MHz, and 30 MHz Processing suppresses the larger first interface reflection and emphasizes the smaller second, third, etc. reflections. Processing determines the electrical parameter of the natural medium adjacent to the antenna.The modulation process may be the variable or constant frequency difference between pairs of frequencies. If a variable frequency is used in modulation, pairs of tunable resonant microstrip patch antennas (resonant microstrip patch antenna) can be used in the antenna design. If a constant frequency difference is used in the software-defined transceiver, a wide-bandwidth antenna design is used featuring a swept or stepped-frequency continuous-wave (SFCW) radar design.The received modulation signal has a phase range that starts at 0-degrees at the transmitter antenna, which is near the first interface surface. After coherent demodulation, the first reflection is suppressed. The pair of antennas may increase suppression. Then the modulation signal phase is changed by 90-degrees and the first interface signal is measured to determine the in situ electrical parameters of the natural medium.Deep reflections at 90-degrees and 270-degrees create maximum reflection and will be illuminated with modulation signal peaks. Quadrature detection, mixing, and down-conversion result in 0-degree and 180-degree reflections effectively dropping out in demodulation.
摘要:
A coal-mining machine uses a ground-penetrating radar based on a software-definable transmitter for launching pairs of widely separated and coherent continuous waves. Each pair is separated by a constant or variable different amount double-sideband suppressed carrier modulation such as 10 MHz, 20 MHz, and 30 MHz. Processing suppresses the larger first interface reflection and emphasizes the smaller second, third, etc. reflections. Processing determines the electrical parameter of the natural medium adjacent to the antenna. Deep reflections at 90-degrees and 270-degrees create maximum reflection and will be illuminated with modulation signal peaks. Quadrature detection, mixing, and down-conversion result in 0-degree and 180-degree reflections effectively dropping out in demodulation.
摘要:
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.
摘要:
A radio power output amplifier comprises a balanced radio power output that differentially drives a dipole antenna or other balanced load. One half of the differential power output drives one side of the antenna from ground to the maximum positive rail, while the other half of the differential power output drives the opposite side of the antenna from the maximum positive rail to ground. The result is a voltage swing across the antenna that is twice that which would occur if a single ended output was driving an unbalanced load. Since the power output is the square of the voltage divided by the load impedance, the result is four times the power output.
摘要:
Acoustic heterodyne radars use accurately surveyed or otherwise known locations to repetitively launch at least two, intense acoustic tone soundwaves (F1, F2) into an underground area of search. An acoustic receiver is tuned to receive either the sum (F1+F2) or difference (|F1−F2|) heterodynes and is configured to measure and log the overall relative attenuation and roundtrip travel times of the soundwaves, like a typical radar. Any acoustic heterodynes received are assumed to be the work of non-linearities and stresses in the search area. A full-waveform three dimensional tomography algorithm is applied by a graphics processor to the collected and logged data to generate maps and profiles of objects beneath the ground which are interpreted to have produced the acoustic heterodynes.