10 results about "Dipole source" patented technology

This invention discloses a method for calculating electromagnetic anomalies in fracturing fractures of a charging conductor, comprising the following steps: S1, establishing a fracture model by monitoring the well location, burial depth, fracture size, power supply current, and frequency settings; S2, calculating the formation equivalent resistivity using multi-layer profile parameters; S3, dividing the charging conductor into Nd electric dipole sources and obtaining the vector potential and scalar potential Φ of each electric dipole source at the surface; S4, obtaining the E and H values ​​of the electric dipole sources at the surface according to the electric field and magnetic field calculation formulas, determining the reference point N, and obtaining the electric field E in the MN direction. MN and magnetic field H MN S5. Based on the principle of vector superposition, the electromagnetic fields of all the segmented electric dipole sources are superimposed to obtain the electromagnetic fields before and after fracturing, and the electric field anomaly E caused by the fracturing fracture is obtained by differential calculation. a and magnetic field anomaly H a The present invention aims to construct a model of a charging conductor crack to obtain electromagnetic anomalies generated by fracturing cracks, providing a theoretical basis for electromagnetic monitoring and crack identification.

The application discloses a high-resistivity formation borehole correction method based on high-frequency electromagnetic wave resistivity logging, which comprises the following steps: s1, establishing a high-resistivity formation electromagnetic wave resistivity logging method; s2, developing a magnetic dipole source electromagnetic field pseudo-analytical fast algorithm based on different borehole columnar layered formation models in the high-resistivity formation; s3, simulating and analyzing the problem of formation resistivity anomaly caused by the existence of the borehole; s4, selecting different borehole factor parameters under the high-resistivity formation condition, and determining the data range contained in the borehole correction database; s5, carrying out forward simulation and analysis on the borehole influencing factors such as mud resistivity, hole diameter, eccentricity and relative dielectric constant; s6, detailing the change rule of the response results of different influencing factors in the high-resistivity formation; and s7, combining the data obtained from the simulation results and establishing a borehole correction database, thereby forming the high-resistivity formation borehole correction method based on the high-frequency electromagnetic wave resistivity logging.

The disclosure relates to a system for tracking an object that is at least partly buried in seabed, the system comprising: An Autonomous Underwater Vehicle (AUV) having a hull, a controlled electric dipole source mounted on the hull of the AUV; first sensor assembly mounted on the hull in the proximity of starboard side of the AUV (1); second sensor assembly mounted on the hull in the proximity of port side of the AUV; wherein the first and the second sensor assemblies are configured to measure magnetic field from electromagnetic energy transmitted from the controlled electric dipole source. The disclosure further relates to a method of tracking an object that is at least partly buried in seabed.

The invention discloses a broadband spin splitting light field generation method and device based on magneto-optical super atoms and a dipole source, a program and a storage medium, and belongs to the field of micro-nano photonics. The method comprises the following steps: establishing a space rectangular coordinate system; a dipole source is used for exciting magneto-optical super atoms in a wide frequency band to generate an electric dipole moment and a magnetic dipole moment; when the magnetic dipole moment meets the spin splitting condition, an equivalent circular polarization spin dipole source is formed, and a spin splitting light field with left-handed and right-handed circularly polarized light space reverse separation is generated in a far field through spin locking scattering; and the stability in the broadband is verified through normalized Stokes parameters. The limitation that spin splitting can only be achieved at a single frequency point in a traditional scheme is overcome, a stable and pure spin splitting light field in a wide frequency band is achieved through a simple structure, and the device has the advantages of being wide in frequency band and easy to integrate and can be applied to the fields of nanometer optical sensing, polarization precision measurement, spin-dependent photonic devices and the like.

This invention discloses a sound source identification method and system based on the nonlinear harmonic phase conjugation method (PCD). The method involves acquiring the sound pressure gradient time-domain signal of the target sound source using a pre-constructed planar microphone array. After performing a fast Fourier transform on the sound pressure gradient time-domain signal to obtain the sound pressure gradient frequency-domain signal, a sound pressure gradient frequency-domain signal that meets the resolution requirements for reconstructing the sound field is selected as the higher harmonic sound pressure gradient signal. The sound field of the target sound source is reconstructed by establishing the phase conjugation method and the higher harmonic sound pressure gradient signal using dipole source emission based on the sound pressure gradient time-domain signal. This allows personnel to identify the target sound source through the reconstructed sound field. This method improves the resolution of sound field reconstruction by using the nonlinear harmonic phase conjugation method for sound source identification and is not limited by the near-field limitation of evanescent waves.

This invention discloses a method and system for measuring apparent resistivity based on a horizontal grounded dipole source using magnetic field frequency gradient. The method involves supplying power to the underground by laying a horizontal grounded dipole source on the surface, and setting up measuring points at a distance *r* from the horizontal dipole source to measure the radial and tangential magnetic field strengths. Based on the analytical expression of the magnetic field frequency gradient generated by the horizontal dipole source on a uniform half-space surface, the frequency difference between the radial and tangential magnetic field strengths is calculated using a differential algorithm, suppressing the primary field and highlighting the secondary field. The actual field value frequency difference is equivalently represented by the field value frequency gradient of the uniform half-space, and the apparent resistivity is solved using a numerical iteration method. This invention, by calculating the magnetic field frequency gradient to extract apparent resistivity, enables electromagnetic sounding under conditions of low induction numbers, effectively reflecting the deep electrical structure.

The application provides a local sensor array design method for brain magnetic source positioning. The method comprises the following steps: obtaining a scalp surface and a cortex surface of a subject based on a head nuclear magnetic resonance image, obtaining a grid of the scalp surface by using a three-dimensional reconstruction technology, and further generating a candidate sensor array; selecting a dipole source of a brain functional area of interest based on a Brodmann partition system, and calculating array sensitivity corresponding to the selected dipole source by using a Frobenius norm; determining an initial position of the local sensor array based on the array sensitivity, and determining the volume of the sensor and the distance between adjacent sensors based on a size radius and a spacing radius. The local sensor array design method realized by the application is simple and efficient, has strong practicability and universality, and can obtain more accurate source estimation under the condition that the number of sensors is limited.

The invention belongs to the technical field of geophysical exploration, and provides a whole-region tensor electromagnetic observation method and system based on three-source staggered-frequency transmission, and the method comprises the steps: arranging three independent galvanic couple sources, and configuring high-order pseudo-random signals with different fundamental frequencies for each transmission source for synchronous transmission; arranging a plurality of receiving stations along the measuring line, wherein each receiving station records an electric field signal and a magnetic field signal which are perpendicular to each other; and according to the frequency component of the transmitted signal, distinguishing polarization modes, extracting data of a corresponding field source, selecting one group with the best quality in the three groups of tensor impedances, and calculating the tensor impedance of the whole region. According to the method, the limitation of multi-source time-sharing observation is broken through, and three groups of current signals with similar frequency components and staggered specific frequency values (staggered frequencies) are synchronously transmitted through the three electric dipole sources, so that synchronous excitation and high signal-to-noise ratio tensor electromagnetic exploration in an omnibearing range are realized, and the effective detection range of a tensor artificial source electromagnetic method is effectively expanded.

A method (200) for determining target magnetic field data d(Rβ,ω) is disclosed. The method (200) comprises selecting empirical magnetic field data d(Rω) that is associated with an influence region 105ω; fitting synthetic magnetic dipole source moments m(rω,s) to the empirical magnetic field data d(Rω): and determining target magnetic field data d(Rβ,ω) using the synthetic magnetic dipole source moments m(rω,s). A method (300) for determining target magnetic field data d(Rβ,ω) is also disclosed. The method (300) comprises selecting empirical magnetic field data d(Rω) that is associated with an influence region 105ω; determining empirical covariance data Yω based on the empirical magnetic field data d(Rω); determining an optimised value of one or more parameter of a covariance function C by fitting the covariance function C to the empirical covariance data Yω; and determining target magnetic field data d(Rβ,ω) using the covariance function C.

The application discloses a kind of based on bismuth telluride super surface nano hole array subwavelength infrared antenna structure and preparation method thereof, it is related to super surface antenna design and infrared waveband application field.The structure with bismuth telluride as core material, by high-energy electron beam in transmission electron microscope 12×12 super surface nano hole array is prepared as subwavelength infrared antenna.The antenna is excited by the dipole source in array center, and is designed using full-wave finite-difference time-domain simulation optimization.Infrared waveband has 15dBi directivity coefficient, 14.5dBi gain and 93% radiation efficiency, and because of the high refractive index characteristics of bismuth telluride, subwavelength size design is realized.The application solves the problem of large ohmic loss and large size of traditional metal super surface antenna in infrared waveband, realizes miniaturization, high directivity and adjustable radiation characteristics, and has polarization adjustable potential.It can be widely applied in infrared communication, sensing and imaging and other fields.