Abstract: A locating device disposable on a surface has a housing, a capacitance sensor, a radar sensor, and an inductance sensor. The locating device also has a motion sensor disposed for detecting at least one motion parameter. A controller receives data from the capacitance sensor, the radar sensor, the inductance sensor and the motion sensor, and determines from the data a presence of objects disposed within or behind the surface. A display is used for displaying a graphical representation of the objects disposed within or behind the surface.

Abstract: An apparatus for measuring radiated power of a terminal includes: an enclosure including a pair of couplers configured to couple an electromagnetic field radiated from the terminal or a substitution antenna and a measurement jig configured to rotate the terminal or the substitution antenna, the terminal or the substitution antenna being supposed to be arranged between the pair of couplers, with reference to at least one of X, Y, and Z axes; a driver installed outside the enclosure to drive the measurement jig; a signal generator configured to generate a feed signal transferred to the substitution antenna when the substitution antenna is arranged on the measurement jig; a feed signal transmitter configured to transfer the feed signal generated by the signal generator to the substitution antenna; and a spectrum analyzer configured to measure power of a radiated signal radiated from the terminal or the substitution antenna.

Abstract: The invention relates to the field of electrical exploration and to the methods of determination of subterranean formations properties by means of electric parameters of subterranean formations measuring and separating of the parameters measured. The invention can be applied both in surface and marine electrical exploration using controlled sources of electromagnetic field, and is used in gas and oil exploration for searching and delimitation of oil and gas reservoirs basing on segregation of response from stratum, secondarily changed due to hydrocarbons migration, to split the measured signal to available components. The invention provides for a set of techniques that enable a layer-by-layer determination of geoelectrical parameters values, as well as process characteristics of induced medium polarization and electromagnetic induction.

Abstract: A method is proposed for a marine electromagnetic survey based on the TM mode, for the purpose of prospecting for and detecting subsurface hydrocarbon reservoirs. The method includes an electromagnetic field source (1113) that, in a submerged, essentially vertical transmitter antenna, generates and injects electric current pulses (81,82) with a sharply defined termination. An electromagnetic field generated by these pulses (81,82) is measured by at least one receiver (1109) provided with an essentially vertical receiver antenna (1111) submerged in water, during the interval when the current in the transmitter antenna (1108) of the electromagnetic field source (1113) is switched off. The distance between the electromagnetic field source (1113) and the at least one receiver (1109) is smaller than the depth of the target object. An apparatus is also described, for implementation of the method.

Abstract: Method for removing air wave noise from shallow water controlled source electromagnetic survey data, using only the measured data and conductivity values for sea water (140) and air. The method is a calculation performed numerically on CSEM data and resulting in an estimate of those data that would have been acquired had the water layer extended infinitely upward from the seafloor. No properties of the sub-sea sediments are used. Synthetic electromagnetic field data are generated for (a) an all water model (141) and (b) an air-water model (146-147) of the survey region. These simulated results are then used to calculate (148-150) electromagnetic field values corresponding to a water-sediment model with water replacing the air half space, which represent measured data adjusted to remove air wave noise.

Abstract: A method and apparatus for minimizing direct coupling between transmitters and receivers on a downhole logging tool are disclosed. One embodiment includes a transmitter, a bucking device, and a plurality of receivers, where signals may be directly coupled from the transmitter into the receivers and signals may be indirectly coupled from the transmitter into the receivers through the formation and borehole environment. The bucking device minimizes the magnitude of the signals that are directly coupled from the transmitter into multiple receivers within the plurality. By varying the current in the bucking device, the bucking device minimizes the magnitude of the directly coupled signal of each receiver in the plurality, and each receiver may utilize a common bucking device.

Abstract: A pulse induction metal detector having high efficiency and sensitivity. Within the scope of the invention is a high efficiency hand-held metal detector for detecting a metal object, comprising a coil and a source of current flow in the coil. The source is adapted to produce one or more pulses of current in the coil. Preferably, at least two of the pulses are spaced apart in time at least about 20 microseconds during which current flow in the coil is substantially constant. The metal detector also comprises a detecting circuit for detecting a response to the current pulses, and a sampling circuit for sampling the response at predetermined times at least during the time of one of the pulses.

Abstract: A method is provided for detecting geophysical anomalies. Electrical energy is capacitively accumulated with a charging circuit until a breakdown voltage of a switch is reached. Thereafter, the accumulated electrical energy is discharged by passing a discharge current through a transmitter antenna to transmit an electromagnetic pulse into a geophysical region. This technique allows an increase in the strength of an electromagnetic sounding signal, while simultaneously reducing energy consumption, and thereby also permitting smaller weights and dimensions for the power supply.

Abstract: Systems and methods are provided for adjusting the frequency of an oscillator to compensate for oscillator frequency variations resulting from changes in oscillator parameters. Measurement systems monitor one or more oscillator parameters. The capacitance of the oscillator is selectively adjusted based on the measurement of the one or more oscillator parameters. The change in capacitance compensates for changes in environmental and operating conditions that affect the oscillator parameters, such as temperature and applied voltage, and produces a relatively stable output frequency over a specified operating range.

Abstract: A method and apparatus locates buried objects in conductive soil by creating a direct current in a transmitting loop, periodically terminating the direct current in the transmitting loop to create an eddy current in the conductive soil using time domain induction, receiving a magnetic field resulting from the eddy current running through the conductive soil, and locating the buried object using the received magnetic field.

Abstract: A pulse lamp system has two or more lamps for providing pulses with common electronics to perform processing such as curing coatings, curing adhesives, tilt management, and optical disk initialization.

Abstract: The measurement equipment serves to map the subsurface geology in a terrain by means of electrical profiling. A plurality of drag electrodes are used for this purpose, the electrodes with specific mutual spacing, being hooked together with a tow in the form of, e.g., a rope or a wire which is towed by a towing means. An electrical current which is so low as to constitute no danger to operators, is transmitted into the earth through the current electrodes and the voltage is measured across the voltage electrodes. A single-ended electrode amplifier is incorporated into each of the voltage electrodes. The method is useful for rapid and detailed mapping of deposits of natural resources, moist site areas, sand and clay localities in connection with road construction and building land as well as water magazines and refuse dumps.

Abstract: Magnetic flux guide having tongues and magnetoresistive transducer incorporating said guide. A transducer is provided which includes a magnetic flux guide having first and second parts longitudinally separated by a head gap and a magnetoresistive bar positioned facing and along the head gap. The first and second guide parts are provided on their edges contiguous with the head gap respectively with a first and second series of tongues separated by spacers. The tongues of the first part extend into the spaces of the second part and vice versa.

Abstract: Method and apparatus for measuring apparent earth resistivity, by determining potential drop produced by electric current injected into the ground. Periodic, or very low frequency polarity reversal of direct current is used to eliminate induced voltage errors that might otherwise occur with higher frequency polarity reversal or alternating current. Synchronizing pulses are used to gather and separately store information from each half cycle. A calibrated readout is obtained in which values of the voltages in the two half-cycles are algebraically subtracted and divided by two to measure the potential drop, with automatic compensation for effects of earth currents.

Abstract: In a method of geophysical prospection a transmitter dipole and a receiver dipole which is sensitive to an electromagnetic field are positioned in cooperation with the subsoil. An impulsive excitation current is applied repeatedly to the transmitter dipole, the excitation current comprising a group of pulses of alternate polarity, each followed by zero current. The transient signal, which is produced thereby at the output of the receiver dipole, is repeatedly detected, and the transient signals are processed to obtain a figurative representation of the transient phenomenon which facilitates geophysical interpretation. Time intervals which are consecutive to excitation pulses and simultaneously with the excitation zero current are defined, these time intervals being of a predetermined duration, chosen to substantially cover all the useful parts of the transient phenomenon.

Abstract: In a method of geophysical prospection a transmitter dipole and a receiver dipole which is sensitive to an electromagnetic field are positioned in cooperation with the subsoil. An impulsive excitation current is applied repeatedly to the transmitter dipole, the excitation current comprising a group of pulses of alternate polarity, each followed by zero current. The transient signal, which is produced thereby at the output of the receiver dipole, is repeatedly detected, and the transient signals are processed to obtain a figurative representation of the transient phenomenon which facilitates geophysical interpretation. Time intervals which are consecutive to excitation pulses and simultaneously with the excitation zero current are defined, these time intervals being of a predetermined duration, chosen to substantially cover all the useful parts of the transient phenomenon.