Abstract: The present invention features a unique system of interdependent methods to greatly improve data acquired via the Differential Target Antenna Coupling (“DTAC”) method, which transmits electromagnetic (“EM”) fields and measures the primary EM field and the secondary EM fields generated in subsurface targets. These new data correction techniques provide improvements, in orders of magnitude, to the measured DTAC response accuracy. This improvement allows for greater depth of investigation, improved target location, and enhanced target characteristics.

Abstract: The present invention features a unique system of interdependent methods to greatly improve data acquired via the Differential Target Antenna Coupling (“DTAC”) method, which transmits electromagnetic (“EM”) fields and measures the primary EM field and the secondary EM fields generated in subsurface targets. These new data correction techniques provide improvements, in orders of magnitude, to the measured DTAC response accuracy. This improvement allows for greater depth of investigation, improved target location, and enhanced target characteristics.

Abstract: The present invention features a unique system of interdependent methods to greatly improve data acquired via the Differential Target Antenna Coupling (“DTAC”) method, which transmits electromagnetic (“EM”) fields and measures the primary EM field and the secondary EM fields generated in subsurface targets. These new data correction techniques provide improvements, in orders of magnitude, to the measured DTAC response accuracy. This improvement allows for greater depth of investigation, improved target location, and enhanced target characteristics.

Abstract: The present invention features a unique system of interdependent methods to greatly improve data acquired via the Differential Target Antenna Coupling (“DTAC”) method, which transmits electromagnetic (“EM”) fields and measures the primary EM field and the secondary EM fields generated in subsurface targets. These new data correction techniques provide improvements, in orders of magnitude, to the measured DTAC response accuracy. This improvement allows for greater depth of investigation, improved target location, and enhanced target characteristics.

Abstract: The present invention features a unique system of interdependent methods to greatly improve data acquired via the Differential Target Antenna Coupling (“DTAC”) method, which transmits electromagnetic (“EM”) fields and measures the primary EM field and the secondary EM fields generated in subsurface targets. These new data correction techniques provide improvements, in orders of magnitude, to the measured DTAC response accuracy. This improvement allows for greater depth of investigation, improved target location, and enhanced target characteristics.

Abstract: The present invention features a unique system of interdependent methods to greatly improve data acquired via the Differential Target Antenna Coupling (“DTAC”) method, which transmits electromagnetic (“EM”) fields and measures the primary EM field and the secondary EM fields generated in subsurface targets. These new data correction techniques provide improvements, in orders of magnitude, to the measured DTAC response accuracy. This improvement allows for greater depth of investigation, improved target location, and enhanced target characteristics.

Abstract: Sub-surface detection systems include a transmitter antenna and a receiver antenna that is coupled to a receiver circuit. The receiver antenna is rotated to three different orientations, and a reference null field direction is determined. Based on variations in the null field direction at other frequencies or variations in a magnitude of a field component in the reference null field direction, the presence, location, depth, size, and electrical properties of a target can be determined.

Abstract: A new measurement system, with two receiver channels per measurement port, has been developed that provides absolute magnitude and absolute phase relationship measurements over wide bandwidths. Gain ranging is used at RF to provide optimum noise performance and a swept YIG preselector filter is used to avoid spurious signals. A new absolute vector error correction method is used to calibrate the measurement system in order to allow for absolute vector measurements, and it also removes the time-varying responses caused by the swept YIG preselector filters. A quasi-reciprocal mixer with a characterized non-reciprocal ratio is used to provide the absolute calibration standard. The two receiver channels can be adapted to a wide variety of applications, including wide bandwidth vector signal analyzer measurements, mixer measurements, and harmonic measurements. The two-channels can also be used as an absolute calibrated transmitter/reflectometer.

Abstract: A new measurement system, with two receiver channels per measurement port, has been developed that provides absolute magnitude and absolute phase relationship measurements over wide bandwidths. Gain ranging is used at RF to provide optimum noise performance and a swept YIG preselector filter is used to avoid spurious signals. A new absolute vector error correction method is used to calibrate the measurement system in order to allow for absolute vector measurements, and it also removes the time-varying responses caused by the swept YIG preselector filters. A quasi-reciprocal mixer with a characterized non-reciprocal ratio is used to provide the absolute calibration standard. The two receiver channels can be adapted to a wide variety of applications, including wide bandwidth vector signal analyzer measurements, mixer measurements, and harmonic measurements. The two-channels can also be used as an absolute calibrated transmitter/reflectometer.

Abstract: A new measurement system, with two receiver channels per measurement port, has been developed that provides absolute magnitude and absolute phase relationship measurements over wide bandwidths. Gain ranging is used at RF to provide optimum noise performance and a swept YIG preselector filter is used to avoid spurious signals. A new absolute vector error correction method is used to calibrate the measurement system in order to allow for absolute vector measurements, and it also removes the time-varying responses caused by the swept YIG preselector filters. A quasi-reciprocal mixer with a characterized non-reciprocal ratio is used to provide the absolute calibration standard. The two receiver channels can be adapted to a wide variety of applications, including wide bandwidth vector signal analyzer measurements, mixer measurements, and harmonic measurements. The two-channels can also be used as an absolute calibrated transmitter/reflectometer.

Abstract: Sub-surface detection systems include a transmitter antenna and a receiver antenna that is coupled to a receiver circuit. The receiver antenna is rotated to three different orientations, and a reference null field direction is determined. Based on variations in the null field direction at other frequencies or variations in a magnitude of a field component in the reference null field direction, the presence, location, depth, size, and electrical properties of a target can be determined.

Abstract: A new measurement system, with two receiver channels per measurement port, has been developed that provides absolute magnitude and absolute phase relationship measurements over wide bandwidths. Gain ranging is used at RF to provide optimum noise performance and a swept YIG preselector filter is used to avoid spurious signals. A new absolute vector error correction method is used to calibrate the measurement system in order to allow for absolute vector measurements, and it also removes the time-varying responses caused by the swept YIG preselector filters. A quasi-reciprocal mixer with a characterized non-reciprocal ratio is used to provide the absolute calibration standard. The two receiver channels can be adapted to a wide variety of applications, including wide bandwidth vector signal analyzer measurements, mixer measurements, and harmonic measurements. The two-channels can also be used as an absolute calibrated transmitter/reflectometer.

Abstract: A thorough error suppression signal measurement system (20) having a transmitter (300) for propagating a transmission signal to a first probe 100, through a device under test (26), and into a second probe (200), and for propagating reference signals to the probes (100,200). The probes (100,200) extract normalization signals from the reference signals, exchange specific ones of the normalization signals, and combine the normalization signals with data signals derived from the transmission signal to form receiver signals. The probes (100,200) propagate the receiver signals to a receiver (400), where the signals are gain-ranged, digitized, normalized, and compensated for phase-noise.

Abstract: An error-suppression signal measurement system and method therefor is provided. The system transmits a test signal from a first probe, through a device under test, and into a second probe. The probes extract normalization signals from reference signals therein, exchange specific ones of the normalization signals, and combine the normalization signals with data signals derived from the test signal to form receiver signals. The probes propagate the receiver signals to a receiver, where the signals are gain-ranged, digitized, normalized, and compensated for phase-noise.

Abstract: A thorough error suppression signal measurement system (20) having a transmitter (300) for propagating a transmission signal to a first probe 100, through a device under test (26), and into a second probe (200), and for propagating reference signals to the probes (100,200). The probes (100,200) extract normalization signals from the reference signals, exchange specific ones of the normalization signals, and combine the normalization signals with data signals derived from the transmission signal to form receiver signals. The probes (100,200) propagate the receiver signals to a receiver (400), where the signals are gain-ranged, digitized, normalized, and compensated for phase-noise.

Abstract: An apparatus includes a logging tool having electrodes for introducing a current into a downhole formation and for detecting a voltage produced in the formation by the current. The current is provided by a transmitter circuit, and the voltage is received and processed by a receiver circuit including a computer programmed to provide induced polarization and resistivity measurements based on the detected voltage. The electrodes are equidistantly spaced but are adjustable (either on a single logging tool or as between different logging tools) so that various logging runs can be made to obtain different measurements whereby the intrinsic complex resistivity (induced polarization) of formation layers can be suitably resolved. The apparatus also includes a contact resistance measurement circuit for making measurements used by another computer means to determine the contact resistance of each of the electrodes.

Abstract: Method and apparatus for high accuracy simultaneous calibration of electrical measuring systems wherein a calibration signal which has frequency spectra which interleave but do not interfere with the data spectra is injected into the electrical system during data acquisition to simultaneously correct for the response of the particular detection system. In a particular geophysical application, a calibration signal at a source system or receiver system, or both, is injected into each individual system as the data and calibration signals are measured so that an overall system response can be applied to the data signals in order to remove system response effects therefrom.

Abstract: A method and apparatus for electromagnetic hydrocarbon exploration which is accomplished by implanting at least two pairs of electrodes into the ground. One pair transmits a signal into the earth, and the other pair receives the signal. With proper processing the polarization and resistivity of the ground can be calculated. The components are arranged in a manner to insure that the electromagnetic coupling can be determined and can be removed from the measurements. Electrode spacing can be varied to focus on the anomalous stratum. If an anomalous stratum is discovered, it is cored to determine the nature of the material creating the anomaly.

Abstract: A method and apparatus for electromagnetic hydrocarbon exploration which is accomplished by implanting at least two pairs of electrodes into the ground. One pair transmits a signal into the earth, and the other pair receives the signal. With proper processing the polarization and resistivity of the ground can be calculated. The components are arranged in a manner to insure that the electromagnetic coupling can be determined and can be removed from the measurements. Electrode spacing can be varied to focus on the anomalous stratum. If an anomalous stratum is discovered, it is cored to determine the nature of the material creating the anomaly.

Abstract: A target is sensed by an antenna array having a transmitter antenna and a receiver antenna, both of which are caused to be electromagnetically coupled to the target. The antenna array is rotated, and as the array rotates, a change in at least one of the coupling between the transmitter antenna and the target and the coupling between the receiver antenna and the target is detected at multiple rotational orientations of the antenna array.