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:
An automatic frequency control is used to keep a continuous wave (CW) transmission tuned to the resonant frequency of a resonant microwave patch antenna (RMPA). Changes in loading and the bulk dielectric constant of the mixed media in front of the RMPA will affect its resonant frequency and input impedance. A significant shift in the measured input impedance is interpreted as an object moving nearby, and the phase angle of the measured input impedance is used to estimate the direction of an object's movement.
摘要:
An underground radio communications and personnel tracking system uses a cap-lamp 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:
An underground tunnel detection system does not employ radar. Instead, an automatic frequency control is used to keep a continuous wave (CW) transmission tuned to the resonant frequency of a resonant microwave patch antenna (RMPA). Changes in loading and the bulk dielectric constant of the mixed media in front of the RMPA will affect its resonant frequency and input impedance. A significant shift in the measured input impedance is interpreted as a possible tunnel, and the phase angle of the measured input impedance tends to indicate a slightly forward or aft position relative to the detection system rolling over it on the ground surface.
摘要:
A movement detection system includes a microwave antenna able to transmit microwave frequency signals into a space. An electronics controller is connected to the microwave antenna, and is configured to continually measure the impedance of the microwave antenna while it transmits microwave frequency signals into the space. An interpretive device is connected to receive impedance measurements from the electronics controller, and is configured to interpret and report changes in the magnitude and phase angles of individual impedance measurements as the passing of things and their direction through the space.
摘要:
An underground tunnel detection system does not employ radar. Instead, an automatic frequency control is used to keep a continuous wave (CW) transmission tuned to the resonant frequency of a resonant microwave patch antenna (RMPA). Changes in loading and the bulk dielectric constant of the mixed media in front of the RMPA will affect its resonant frequency and input impedance. A significant shift in the measured input impedance is interpreted as a possible tunnel, and the phase angle of the measured input impedance tends to indicate a slightly forward or aft position relative to the detection system rolling over it on the ground surface.
摘要:
A movement detection system includes a microwave antenna able to transmit microwave frequency signals into a space. An electronics controller is connected to the microwave antenna, and is configured to continually measure the impedance of the microwave antenna while it transmits microwave frequency signals into the space. An interpretive device is connected to receive impedance measurements from the electronics controller, and is configured to interpret and report changes in the magnitude and phase angles of individual impedance measurements as the passing of things and their direction through the space.
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 coal bed anomaly detection and imaging system comprises a synchronous transmitter and receiver that are separated by a geologic structure with embedded and hidden anomalies. The transmitter sends out two signals from magnetic dipole antennas. Such signals are widely separated in frequency but synchronized internally in the transmitter to one another. The higher frequency is used to make phase shift and attenuation measurements at the receiver by synchronous detection. The lower frequency is used at the receiver to synchronize the receiver to the transmitter. The higher frequency signal is measurably affected by anomalies in the intervening geologic structure. The lower frequency signal is fixed low enough so it is not substantially affected by the intervening geologic structure. Geologic modeling tools are preferably downloaded by geoscientists to their personal computers. The total attenuation and phase shift measurements are plugged into a two-dimensional and three-dimensional full-wave inversion code (FWIC) process. A hypothetical model is uploaded for processing by a forward solver so the nature of the anomalous geologic structure can be estimated. A resulting reconstructed image of the anomalies in silhouette is then downloaded for interpretation of the image by the geoscientist.
摘要:
A method utilized with an underground conductor detection system for calibrating a downhole transmitter to compensate for detuning of the transmitter antenna by geologic formations. The method comprises sending a synchronization signal to the transmtter antenna, measuring the current flow through the transmitter antenna and adjusting the current to a constant level, and measuring the phase difference between the transmitter antenna current and the synchronization signal. A receiver transmitter is calibrated by sending a synchronization signal to a radiating antenna in the receiver that in turn sends a calibration signal to the receiver antenna that is directed over the entire signal pathway back to surface located signal processing equipment. Another method of underground conductor detection sends a surface wave to the downhole receier to cancel the effect of the surface wave modulation on a target wave being radiated by the underground detector. Another method of underground conductor detection utilizes a receiver tuned loop antenna oriented orthogonal to the magnetic dipole of the transmitter antenna for discriminating against reception of a primary wave. Another method of detecting anomalous geological zones such as tunnels, utilizes a low to medium frequency tomographic scan to cancel the effect of geological conductivity noise in a high to very high frequency tomographic scan of a region suspected of containing ther anomalous geological zone.