Abstract: A plurality of electrochemical corrosion protection systems (30) for underground buried structure installed geographically dispersed are utilized so as to predict an earthquake. Changes in amounts of current flowing through closed loop electric circuits (W) for electrochemical corrosion protection in the electrochemical corrosion protection systems (30) are detected and an earthquake is predicted based on the detected changes in the amounts of current.

Abstract: A lead attachment assembly for attaching a lead to an outer surface of a metal pipe includes a lead fitting having an inner surface, an outer surface, and opposing ends. At least one magnet is carried by the inner surface of the lead fitting. The end of a lead wire is fixed to the inner surface of the lead fitting. A conductive epoxy applied to the inner surface of the lead fitting contacts the outer surface of the pipe when positioned. The magnets hold the lead fitting in position while the epoxy cures.

Abstract: A system includes a plurality of magnetometers that are each configured to generate a vector measurement of a magnetic field. The system also includes a central processing unit that is communicatively coupled to each of the magnetometers. The central processing unit is configured to receive from each of the plurality of magnetometers the respective vector measurement of the magnetic field. The central processing unit is further configured to compare each of the vector measurements to determine differences in the vector measurements and to determine, based on the differences in the vector measurements, that a magnetic object is near the plurality of magnetometers.

Abstract: The present invention relates to a device and a method for, while moving, acknowledging the laying path of an electric line and simultaneously acknowledging the increasing point of ground potential, thereby being capable of updating information of the laying path of the electric line and simultaneously obtaining maintenance data. The present invention has developed a logic capable of classifying and determining a detection signal current when the detection signal current is distributed in several paths and flows according to association between multiple earthling of a neutral line and a new renewable energy source, and has specified a method for analyzing a signal generation and a signal reception for accurately distinguishing the magnetic field signal direction and logic.

Abstract: A system for detecting an object in a subsurface environment includes a first recorder of a vertical electromagnetic component, including first pair of polarization orientation components, of an electromagnetic field in a region of interest, a second recorder of an orthogonal electromagnetic component, including second pair of polarization orientation components, of the electromagnetic field in the region of interest, at least one processor configured to derive a pair of transfer functions that relates the vertical electromagnetic component and the orthogonal electromagnetic component of the electromagnetic field for each of the polarization orientation components, at least one processor configured to determine a simulation of the pair of transfer functions for a given impedance distribution, and at least one processor configured to infer a subsurface impedance map using the pair of transfer functions of the recorded data and the simulation of the pair of transfer functions.

Abstract: A carpet probe for detecting leaks in underground gas pipes, including a handle (12), a wheel (16) connected to the handle (12), and a flat carpet element (14) connected to the wheel (16) and including a sniffing inlet (28) connected to a gas sensor (18), is characterized in that the wheel (16) is the only wheel (16) of the carpet probe adapted for rolling on a ground surface.

Abstract: The present invention presents a comprehensive advanced geological detection system carried on a tunnel boring machine.

Abstract: The invention relates to a method for measuring a current or voltage output quantity of a switched-mode power supply circuit (H), referred to as a chopper circuit, of period T and of cyclic ratio ?, belonging to the interval]0; 1[, such that, at each period, the supply current is non-zero during an “ON” phase of duration ?T, and zero during an “OFF” phase of duration (1??)T. The measurement method includes the following steps: measuring the value Gon of an image of the output quantity during an “ON” phase; measuring the value Goff of an image of the output quantity during an “OFF” phase; calculating the difference ?G=Gon?Goff; and using the difference ?G for evaluating the output quantity.

Abstract: Various embodiments include apparatus and methods to make resistivity measurements in a borehole using tool having an array of electrodes operable to provide focused currents and measure corresponding voltages to determine resistivity. Tools can be configured with a main electrode having a number of spaced apart electrodes within the main electrode such that the spaced apart electrodes are arranged azimuthally with respect to an axis of the tool. Generation of current from the spaced apart electrodes and control of current from additional electrodes on each side of the main electrode can provide for focused measurements. Additional apparatus, systems, and methods are disclosed.

Abstract: Disclosed are apparatus and methods for determining characteristics of a target region which is embedded in background material below a body of water. In accordance with one embodiment, a resistivity background is determined. In addition, characteristics of an electric dipole due to the target region are determined. A resistance for the target region is then computed using the characteristics of the electric dipole and the resistivity background. Other embodiments, aspects and features are also disclosed.

Abstract: Downhole tools and techniques acquire information regarding nearby conductors such as pipes, well casing, and conductive formations. At least some method embodiments provide a current flow along a drill string in a borehole. The current flow disperses into the surrounding formation and causes a secondary current flow in the nearby conductor. The magnetic field from the secondary current flow can be detected using one or more azimuthally-sensitive antennas. Direction and distance estimates may be obtainable from the azimuthally-sensitive measurements, and can be used as the basis for steering the drillstring relative to the distant conductor. Possible techniques for providing current flow in the drillstring include imposing a voltage across an insulated gap or using a toroid around the drillstring to induce the current flow.

Abstract: A passive listening acoustic system and method of use may include source means for providing continuous, pulsed, or pulse coded acoustic signals at two or more frequencies and at least two acoustic sensors or hydrophones which detect and record a signal for use within a Seabed Logging system to determine the position and/or orientation of instruments in the system.

Abstract: An electromagnetic sensing system operates either in land environments or in marine environments on the floor of a body of water to measure electromagnetic fields. The sensing system has electrodes that provide capacitive coupling to the local environment where measurements are being made. A new method of deployment in water provides considerable size and weight reductions. The size and weight reductions also facilitate deployment and rapid repositioning on land. The system is particularly beneficial for surveying sites adjacent to bodies of water.

Abstract: An integrated current sensing apparatus includes a magnetic-field sensing element, a power supply circuit, an offset adjustment circuit, a gain adjustment circuit and a regulating unit. The magnetic-field sensing element is configured for sensing magnetic field, and correspondingly generating a sensing voltage. The power supply circuit is electrically coupled to the magnetic-field sensing element, for generating a constant current to the magnetic-field sensing element to control the sensing voltage. The offset adjustment circuit is electrically coupled to the magnetic-field sensing element, for adjusting an offset of the sensing voltage. The gain adjustment circuit is electrically coupled to the offset adjustment circuit, for amplifying the sensing voltage to a rated output voltage. The regulating unit is electrically coupled to the power supply circuit, the offset adjustment circuit and the gain adjustment circuit, for controlling the constant current, the offset and a gain value.

Abstract: A method for marine electromagnetic surveying includes transmitting a first electromagnetic field oriented in a first direction into a body of water. A second electromagnetic field oriented in a second direction is transmitted into the body of water, wherein the second direction is substantially transverse to the first direction. A parameter related to electromagnetic field amplitude is detected at a plurality of longitudinally and laterally spaced apart positions behind a vessel. The components of the detected electromagnetic field parameter are resolved into components along the first and second directions by using the geometrical symmetries and asymmetries of the transmitting source. Systems for implementing such methods are also provided.

Abstract: A three dimensional (3D) dipole antenna system with spiral leg is described used to measure oscillatory electric field strengths. The system relies on spiral dipole leg segments of limited length attached to a cylinder. It is designed to improve the sensitivity to oscillatory electric signals in the range of 0.01 Hz to 10,000 Hz. The antenna system is connected to an object (a survey platform) that is stationary or moving in an area of interest in air, over land, on water or under water. Such antenna system is generally used as part of a prospecting survey system for water, minerals or hydrocarbons.

Abstract: An apparatus for estimating a property of an earth formation penetrated by a borehole, the apparatus having: a carrier configured to be conveyed through the borehole; a transmitter disposed at the carrier and configured to transmit electromagnetic energy at a first frequency into the formation; a first antenna disposed at the carrier and configured to receive electromagnetic signals from the formation as a result of the transmitted electromagnetic energy interacting with the formation; and an active filter coupled to the antenna and configured to filter electromagnetic signals received by the antenna to let the electromagnetic signals at the first frequency pass for processing to estimate the property.

Abstract: An apparatus includes a conductive plate operable to generate a reference signal and a shield configured to surround at least a portion of the conductive plate and to attenuate at least a portion of a horizontal electromagnetic signal. The apparatus also includes an electrode configured to be electrically coupled to the shield and to a ground, where the electrode is responsive to a vertical electromagnetic signal, and the vertical electromagnetic signal generated by a subsurface earth formation in response to an electroseismic or seismoelectric conversion of a passive electromagnetic source signal. The apparatus also includes an amplifier comprising a first input and a second input, where the first input is configured to electrically couple to the conductive plate and the second input is configured to electrically couple to the electrode.

Abstract: A current detecting device includes a second fixed part to which the harness is fixed and electrically connected, a bus bar as a resistor inserted between a first fixed part and the second fixed part, a circuit board in which a current detection circuit is mounted, the current detection circuit detecting current flowing through the bus bar based on a potential difference between two points along an energizing direction of the bus bar, and a case accommodating the bus bar and the circuit board. The second fixed part to which the harness is fixed and electrically connected is disposed within a battery upper surface area.

Abstract: Methods, systems, and apparatuses for measuring an electric potential in the earth, which includes a first sensor are disclosed. The first sensor includes a sensing plate for placement in an environment in close proximity to the earth. The sensing plate has an operative capacitive coupling with the earth and measures the earth's electric potential. The sensor also includes a barrier providing electrochemical segregation between the sensing plate and the earth and an amplifier having at least one stage for receiving and amplifying a first signal carrying the potential measured by the sensing plate. The sensor also includes a first connection carrying the first signal from the sensing plate to the amplifier; and a reference voltage for application to the first stage of the amplifier, the reference voltage providing a reference against which the potential measured by the sensing plate is compared. Other embodiments are described and claimed.

Abstract: A method and apparatus for sensing conditions in a subsurface geologic formation heated for the extraction of hydrocarbons is disclosed. A time domain reflectometer in conjunction with an open wire transmission line is employed in real time to determine impedance discontinuities in the geologic formation. These impedance discontinuities correspond to physical conditions in the geologic formation. The open wire transmission line can include pipes running into the subsurface geologic formation or other conductors, including a split tube well casing. The method may operate in the low frequency window for subsurface electromagnetic propagation.

Abstract: A method for determining orientation of an electrically conductive formation proximate an electrically substantially non-conductive formation includes measuring multiaxial electromagnetic induction response within the substantially non-conductive formation using an instrument disposed in a wellbore drilled through the formations. A difference from zero conductivity is determined for each component measurement of the multiaxial electromagnetic induction response. The differences are used to correct the measured response of each component measurement in the electrically conductive response. The corrected component measurements are used to determine the orientation of the conductive formation.

Abstract: A follower amplifier with power supply biased by a controlled voltage source such that the power supply potentials are, for the frequencies of interest, as close as possible to the potential of the follower output. There is proposed a front-end electronic circuit for biopotential and impedance measurements with outstanding performances (very high input impedance and gain very close to unity). Preferably, the explicit guard electrode and the explicit electronic unit at the belt are no longer necessary; all electronics is embedded in units placed directly at the measurement sites. Moreover, the proposed front-end electronic circuit allows a drastic simplification of the cabling and connectors since all units are connected to only one wire (the theoretical minimum) for potential reference and current return. Preferably, this wire does not even require an electrical isolation and can be easily embedded in the textile of a shirt, in a garment, mesh, belt, etc.

Abstract: Cost-effective compact magnetometers can be deployed across large ocean areas to record magnetic field strengths. Each magnetometer has a canister containing a magnetometer sensor at its upper end to detect magnetic field strengths of magnetic influence sweep systems and provide representative data signals. Each magnetometer also has sensors to collect data representative of the orientation of the magnetometer as well as temperature and depth to aid in post operational evaluation of the gathered magnetic strength data. A computer processor connected to the sensors controls receipt of the data signals and stores them in a memory device. Batteries at the canister's lower end supply power for the sensors, processor, and memory. An anchor release mechanism causes an anchor to separate from the canister, allowing it to float to the surface for recovery or to transmit data via a UHF transceiver.

Abstract: Disclosed herein is a three dimensional small bin electromagnetic consecutive array data acquisition method used in oil exploration comprising the steps of recording data using small bin lattices on execution of arrangement electrodes, each acquisition station (Ex, Ey) records the natural electromagnetic field time series data with the same acquisition parameter simultaneously; interference is removed first, for recorded data processing to get interference-free data; for border points and center point, the recording point serves as center point, and the same component from adjacent two points to total points area added together to obtain the average value of electric field data at time domain for each observation point; for corner points, the average values of the same electric field component from adjacent two points to total survey points toward bin direction is calculated; the electric field components acquired in maximum space serve as the new electric field values respectively; new time series data acqui

Abstract: Method for real time monitoring of the waveform transmitted by an electromagnetic survey source, using a near-source monitoring receiver to measure electromagnetic field and transmitting the measured signal in real time to a control location.

Abstract: The present invention relates to an autonomous underwater vehicle (“AUV”) for monitoring underwater fluid currents by detecting electrical currents induced by the flow of a conductive liquid through the Earth's magnetic field. More particularly, the present invention relates to the gathering of data related to underwater fluid currents and the control of AUV motion during data gathering.

Abstract: The system and method provided modify a conventional seafloor long-wire electromagnetic (LEM) receiver by increasing the number of discrete antennae placed on the long wire. Two dipoles of electric field data are positioned exactly adjacent to each other, providing input to the same data logger system located within a seafloor survey unit to which the long wire is connected. Highly precise electric field gradients can be obtained by taking the difference of the measurements of the two electrodes, both for amplitude and phase. Any common-mode source of noise, such as magnetotelluric signals and receiver instrument noise will be rejected when the signals from the two electrodes are differenced. An acoustic navigation system utilizes a plurality of transponders to permit triangulation for accurate source-receiver ranging.

Abstract: A sensor device and a method for the geoelectrical prospecting of the location, the (stratographic) arrangement, and the course of raw mineral deposits and of the adjoining rock delimiting these deposits, particularly in the continuous working of the mineral deposits, having a sensor head whose front surface forms the sensor measuring surface, and at least one electrode. The sensor head can make contact with a ground surface, and a central electrode and a plurality of outer electrodes distributed geometrically uniformly around the central electrode are arranged on the sensor measuring surface, the central electrode and the outer electrodes being electrically conductive and electrically separated from one another.

Abstract: A method for designing a controlled-source electromagnetic survey that will discriminate between a defined deep marginal-interest reservoir (2) and specified false positive resistivity structures of concern (3, 4, 5). A reservoir model and a false positive model are constructed for each false positive scenario. The resistivity of the false positive model may be tuned to give electromagnetic data similar enough to the reservoir model when forward modeled that any differences fall in the model null space. A null-space discriminating ratio (“NSDR”) is defined, for example as the peak normalized difference of the two related modeled electromagnetic field data sets. An area coverage display of NSDR values (6) allows determination of such additional data as may be needed to distinguish the false positive body, and a survey design is developed accordingly (7). Reduction of the number of variables affecting the area coverage displays is a key feature of the method.

Abstract: A method of ocean property forecasting. The method includes generating one of a magnetic field prediction and an electric field prediction between a first observation point and a plurality of uniform ocean cells by generating a vector sum of magnetic field contributions from a plurality of magnetic field vectors and a vector sum of electric field contributions from a plurality of electric field vectors, respectively. The method further includes generating one of a magnetic field forecast and an electric field forecast of the ocean volume at a second observation point in the ocean volume by re-using the magnetic field vectors and electric field vectors and scaling one of the plurality of magnetic field vectors and the plurality of electric field vectors by a plurality of tri-axial equivalent electrical currents with identical geometry to the first observation point.

Abstract: A technique for drilling a borehole includes obtaining data from a tool in the borehole for a plurality of positions in the borehole that is being drilled to form acquired data indicative of directional electromagnetic propagation measurements. The technique includes identifying a plurality of distances to a boundary between formations in ground from the plurality of positions in the borehole based on the measurements; identifying a trajectory of the borehole using the plurality of distances; and deciding whether to change the trajectory of the borehole using a change in the plurality of distances between the trajectory and the boundary. The trajectory of the borehole may be changed in both inclination and azimuth.

Abstract: A subsurface imaging cable includes a plurality of sensor modules, wherein the plurality of the sensor modules are flexible and each of the plurality of the sensor modules is spaced apart on the subsurface imaging cable at a selected distance; and a flexible medium connecting the plurality of the sensor modules, wherein the subsurface imaging cable is flexible and adapted to be wound on a reel. A method for subsurface images includes acquiring direct-current measurements at a plurality of sites in a survey area; acquiring a first set of electric and magnetic measurements from natural electromagnetic fields at the plurality of sites; acquiring a second set of electric and magnetic measurements using controlled electric and magnetic sources at the plurality of sites; and determining a subsurface conductivity distribution from the direct-current measurements and the first set and the second set of electric and magnetic measurements.

Abstract: A survey module includes at least one sensing element to measure a first electromagnetic (EM) field along a first direction, and circuitry to derive a second EM field along a second, different direction based on the first EM field.

Abstract: A method for removing a static frequency domain, by (1) installing multiple sampling devices; (2) performing conventional processing whereby obtaining conventional observation curves; (3) adding electric-filed components of two adjacent observation points, those of three adjacent observation points, and adding electric field components of up to n adjacent observation points whereby obtaining electric fields of different polar distance, i.e. a sequence of electric field components of topology points; (4) using the sequence of the electric field components and the encrypted topology points sequence as an observation field value to perform power spectrum analysis and impedance tensor estimate; (5) drawing a resistance-variation of polar distance curve of a single frequency point of the record point; observing and analyzing a variation rule of resistivity, editing and deleting static interference resistance; and (6) repeating the previous step to complete edition of all frequency points of all record points.

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 of determining an orientation of a data acquisition system deployed on a seafloor includes measuring horizontal magnetic fields using detectors on the data acquisition system while the data acquisition rotates and descends to the seafloor or rises from the seafloor. Resting horizontal magnetic fields are measured after the data acquisition system is on the seafloor. A heading of the data acquisition system on the seafloor may be determined based on maximum and minimum horizontal magnetic fields measured during the descent and the resting horizontal magnetic fields.

Abstract: A method of tracking seismic activity through monitoring sunspots and sun disturbances and correlating them with a developed model in order to map out specific locations where an earthquake will consequently appear is provided (FP). The method of comprises mapping coordinates of electromagnetic disturbances on the sun, calculating the coordinates while taking into consideration Earth/sun geometry and relative positions (FP). These coordinates are consequently mapped to a location and time on earth wherein the location and time predicts the location and approximate time of the earthquake, which will consequently occur on earth.

Abstract: A sensor cable system for measuring electromagnetic response of the Earth's subsurface includes a sensor cable deployable on the bottom of a body of water. The sensor cable has a plurality of electromagnetic sensing devices thereon at spaced apart locations. A system control unit is in signal communication with the sensing elements. The system control unit includes a transceiver for communicating signals to and from a corresponding sensor cable system. The system control unit includes a global positioning system signal receiver. The system control unit includes a processor configurable to receive signals detected by sensing elements in the corresponding sensor cable system. The processor is configurable to compute stacked signals from the sensing elements in the sensor cable and from sensing elements in the corresponding system. The processor is configurable to calculate a statistical measure of the stacked signals. The system control unit is disposed in a flotation device.

Abstract: A method of electromagnetic surveying of an area of seafloor that is thought or known to contain a subterranean hydrocarbon reservoir is described. The method includes broadcasting an EM signal from a horizontal electric dipole (HED) transmitter and obtaining vertical electric dipole (VED) response data at a remote receiver in response thereto. Survey data are analyzed by comparing the VED response data with background data which are not sensitive to the postulated hydrocarbon reservoir. Accordingly, differences between the VED response data and the background data allow for the identification of buried hydrocarbon reservoirs. The background data may be provided by magneto-telluric surveying, controlled source electromagnetic surveying or from direct geophysical measurement.

Abstract: Systems and methods for marine surveying of strata beneath a seafloor are disclosed, including, in certain aspects, systems employing one or more cables with a plurality of opto-electrical detector electrodes and an electrical wire with a fixed reference potential imposed thereon along the cable length. In a multi-cable system, the same fixed reference potential is applied to all wires in all cables. This abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims, 37 C.F.R. 1.72(b).

Abstract: A method for measuring a resistivity of a subsurface formation that includes transmitting continuously a signal at a first fundamental frequency at full power for a first period of time within a single window of time causing electromagnetic energy to propagate in the subsurface formations, transmitting continuously the signal at a second fundamental frequency at full power for a second period of time within the single window of time causing electromagnetic energy to propagate in the subsurface formations, measuring variations in the electromagnetic energy propagated through the subsurface formations at receivers at the first and the second fundamental frequencies, and determining the resistivity of the subsurface formations using the measurements of the variations in electromagnetic energy at the receivers.

Abstract: A marine electromagnetic survey cable includes a reference electrode extending substantially along the entire length of the cable. A plurality of spaced apart measuring electrodes is disposed along the cable and each is electrically insulated from the reference electrode. A voltage measuring is circuit functionally coupled between each measuring electrode and the reference electrode.

Abstract: The invention a method and device for carrying out geoelectric mappings. The device includes electrodes, a power supply and a voltage measuring device, for carrying out the method. The electrodes are disposed apart from one another on ground to be investigated and electric current is supplied by certain electrodes to the ground and electric potential is measured by remaining electrodes using the voltage measuring device. The device and method carry out a continuous, geoelectric mapping, with which accurate measurements are achieved. The device is embodied such that the electrodes are disposed at a outside of an endless loop and that this endless loop revolves continuously at the same rate at which the device is moving over the ground to be investigated during the mapping, so that at least two supplying and two potential electrodes rest on the ground investigated during each individual measurement.

Abstract: A sensor cable system for measuring electromagnetic response of the Earth's subsurface includes a sensor cable deployable on the bottom of a body of water. The sensor cable has a plurality of electromagnetic sensing devices thereon at spaced apart locations. A system control unit is in signal communication with the sensing elements. The system control unit includes a transceiver for communicating signals to and from a corresponding sensor cable system. The system control unit includes a global positioning system signal receiver. The system control unit includes a processor configurable to receive signals detected by sensing elements in the corresponding sensor cable system. The processor is configurable to compute stacked signals from the sensing elements in the sensor cable and from sensing elements in the corresponding system. The processor is configurable to calculate a statistical measure of the stacked signals. The system control unit is disposed in a flotation device.

Abstract: An inventory control system, comprising a blister pack having a pierceable sheet that includes a plurality of printed circuits overlying each of the compartments of the blister pack. The printed circuits are in electrical communication with a connector assembly, the connector assembly being in electrical communication with a removable header. The header is in communication with a microprocessor controlled device having a memory; wherein the microprocessor controlled device determines the contents of the blister pack. The blister pack and connector assembly are removed from the substantially fixed header so the contents can be distributed. As the contents are distributed from the blister pack, the printed circuits are broken. When the connector assembly is reattached to the blister pack, electrical signals transmitted through the connector assembly and the blister pack determines the number of broken circuits, indicative of the contents of the blister pack.

Abstract: A constant contact reference wheel system includes a vehicle carrying a water reservoir, and a constant contact reference wheel. The constant contact reference wheel includes a frame having a first end and a second end, an attachment mechanism carried by the first end removably coupling the frame to the vehicle, a wheel structure having a rim for rolling contact with a soil surface, and a reference cell carried by the frame. A water pathway extends from the water source to the rim. The rim exudes water for contact with the soil surface, and the reference cell is in fluid communication with the water pathway.

Abstract: A method for measuring magnetotelluric response of the Earth includes measuring transient controlled source electromagnetic response of the subsurface below a body of water over a plurality of actuations of an electromagnetic transmitter. The transient response measurements are stacked. The stacked transient responses are subtracted from measurements of total electromagnetic Earth response over a time period including the plurality of transient response measurements to generate the magnetotelluric response. A method for determining a component of electric field response to a time varying electromagnetic field induced in the Earth's subsurface, includes measuring magnetic field gradient in at least two orthogonal directions in response to the induced electromagnetic field and determining an electric field response in a direction normal to the magnetic field gradient measurements.

Abstract: A receiver for electromagnetic measurements includes a polyhedron structure having m faces, where m?4 and m?6: n electrodes each disposed on one face of the polyhedron structure, wherein 3?n?m; and at least one circuitry connected to the n electrodes for signal measurement. A method for electromagnetic measurements includes obtaining a plurality of electric current measurements using a plurality of electrodes each disposed on a surface of a polyhedron receiver, wherein the plurality of electric current measurements comprise at least three different measurements; and determining electric field components in a three dimensional space from the plurality of electric current measurements by using a number of matrices that correlate orientations of surfaces of the polyhedron receiver to a coordinate system in the three dimensional space.

Abstract: The invention relates to an apparatus and method for performing passive geophysical prospecting. More particularly, the present invention relates to an improved apparatus and method for locating and selected subsurface Earth material deposits or geologic formations bearing hydrocarbons, oil, gas, or commercially important ore deposits, precious metals, as a function of impulse discontinuities in the near surface atmosphere of the invention. A passive geophysical prospecting method and apparatus are provided. The apparatus has a magnetic component antenna for detecting electromagnetic radiation naturally emanating from the Earth's surface and an electrical signal from the detected electromagnetic radiation while traversing the Earth's surface by a vehicle traveling over land or water or in an airplane.