272 results about "Normal waves" patented technology

The invention discloses a sparse Bayesian learning shallow sea target depth and horizontal distance passive estimation method, and the method comprises the steps: calculating a modulus depth function hypothesis space through employing a finite difference method based on a prior sound velocity profile and a horizontal wavenumber hypothesis interval; preprocessing the vertical array data to a frequency domain, constructing a linear underdetermined equation set about the frequency domain vertical array data and a modulus depth function of a hypothesis space under sparse constraint, and solving by using a sparse Bayesian learning algorithm to obtain estimation of a horizontal wave number spectrum; performing spectrum peak search on the horizontal wave number spectrum, estimating the order and the horizontal wave number of an actual excitation mode, and estimating a mode depth function of each order of mode by using a finite difference method; vertical array copy sound fields under different depths and horizontal distances are calculated according to a normal wave sound field formula; and respectively performing conjugate transpose multiplication on the vertical array copy sound field and actual data to obtain a depth-horizontal distance ambiguity surface, and searching the position of the maximum surface value as the estimation of the depth and horizontal distance of the source.

An antenna module is configured to receive a signal from a baseband circuit and to radiate a radio wave. The antenna module includes a dielectric substrate, radiating elements, and a connector. The dielectric substrate includes planar sections having different normal directions. A first radiating element is disposed in or on the planar section. A second radiating element is disposed in or on the planar section. The antenna module is configured to transfer a radio-frequency signal to a third radiating element, which is externally disposed, via the connector. The size of the second radiating element is smaller than that of the third radiating element.

The invention belongs to the technical field of flow velocity measurement, and relates to a 4D millimeter wave radar flow velocity measurement method and system. The method comprises the following steps: emitting frequency-modulated continuous waves to irradiate the water surface by using a 4D millimeter-wave radar; receiving a water surface emission signal and carrying out frequency mixing to obtain a difference frequency signal; performing two-dimensional FFT processing on the difference frequency signal to obtain distance information from the emission point to a river reflection point, mirror image speed information of the reflection point relative to the radar and angle information of the reflection point relative to the emission point; establishing a coordinate system; converting the distance information and the angle information into coordinate data; determining an included angle between the river surface and a transmitted wave of a radar normal corresponding to the reflection point; and determining the flow velocities of a plurality of reflection points on the same straight line of the river surface, and averaging to obtain the river surface flow velocity. According to the invention, through the 4D millimeter wave radar, three-dimensional construction is carried out on the river plane, errors caused by installation errors or equipment aging are avoided, and the effect of accurate measurement is achieved; through information of four dimensions, complete four-dimensional space information is constructed.

The invention provides a water surface / underwater target distinguishing method and system based on normal wave limited energy under an ice region half-sound channel, and the method comprises the steps: converting a time domain signal received by a vertical array in an ice region sea area into a frequency domain, and obtaining the frequency domain data of an array receiving signal; simulating and forecasting a normal wave modal depth function, a horizontal wave number and a phase velocity of the test sea area by using the normal wave model; extracting a normal wave modal amplitude which can be distinguished by test measured data; comparing the sound velocity of the phase velocity with the sound velocity of the critical resolution depth to obtain an order index of the limited mode; calculating the energy of a data extraction result limiting mode as a binary detection statistic; and setting a detection threshold according to the ROC curve, and if the limited modal energy is smaller than the detection threshold, determining that the target is an underwater target. Otherwise, determining the target as a water surface target. Compared with a traditional matching field and matching mode method, the method is small in calculation amount, high in environment tolerance and easy to popularize in an actual sonar platform.

The invention discloses a modal decomposition-based target motion velocity estimation method and a sound velocity profile inversion method, and the method comprises the following steps: 1, obtaining a two-dimensional frequency domain sound field, obtaining a normal wave vertical mode function through singular value decomposition, and obtaining a normal wave horizontal wave number through Fourier transform; 2, substituting the normal wave vertical mode function and the normal wave horizontal wave number into a mode difference equation to obtain a sound velocity profile estimated by each normal wave mode; and step 3, setting a loss function for measuring similarity between sound velocity profiles corresponding to each normal wave mode, setting a target motion velocity search interval, scanning the target motion velocity search interval, and taking a velocity value corresponding to the minimum loss function as a target motion velocity estimation value. According to the invention, target motion velocity estimation and sound velocity profile inversion in an unknown marine environment are realized by using a narrow-band signal radiated by a moving target.

The invention discloses a method for detecting radiation characteristics of a to-be-detected target in a shallow sea waveguide environment, which comprises the following steps of: 1, extracting real normal wave modal parameters of a sound source radiation signal in the shallow sea waveguide environment through an orthogonal constraint modal search method according to data received by a vertical array; 2, according to the real normal wave modal parameters, through a normal wave expression in a waveguide environment, performing inversion to obtain a sound field of the whole shallow sea waveguide; and step 3, acquiring sound field information required in the sound field of the shallow sea waveguide, mapping the sound source information into the free space by using the reciprocity theorem, realizing sound field migration from the shallow sea waveguide to the free space, and further acquiring the radiation characteristics of the target to be measured in the free space. The method is used for obtaining the radiation characteristics of the to-be-measured target in the free space according to the data received by the vertical array.

The invention belongs to the technical field of underwater target detection, and discloses an underwater target depth coherent estimation method and system, and the method comprises the steps: receiving a single snapshot signal radiated by a target through a sensor array carried by an underwater carrier, and constructing a potential normal wave orthogonal mode space of a sound field under the condition that a sound velocity profile is known, estimating normal wave parameters (namely normal wave horizontal wave number and vertical modal function) and depth-related modal characteristics (namely modal amplitude) by using the sparsity of the sound field projected in the orthogonal modal space as a constraint, and coherently estimating the depth of the underwater target by using a modal polarity-based search method. According to the method, target depth coherent estimation is realized in a marine environment with unknown seabed sediment by using a single frequency component in a single snapshot noise signal radiated by the target, the accuracy of polarity estimation is improved by using a theoretical depth ambiguity function learned by the KAN network, and the method can be used for underwater target positioning, identification and the like. The method is suitable for carrier platforms such as vertical array subsurface buoys and vertical array buoys.

The present invention relates to a nanodrone, a method of operating a nanodrone, and a system for operating a nanodrone. The nanodrone comprises a substrate extending perpendicular to a normal direction and two or more nanoantennas arranged on and / or in the substrate. Each of the two or more nanoantennas exhibits an optically addressable resonance at a respective resonance wavelength. The two or more nanoantennas comprise a first nanoantenna and a second nanoantenna, each being configured to scatter circularly polarized light at the respective resonance wavelength that is incident on the nanoantenna along the normal direction such that photons of the scattered light have a mean wavevector (I) and (II) in a plane perpendicular to the normal direction for left- and right-circularly polarized light, respectively, with i=1 for the first nanoantenna and i=2 for the second nanoantenna. The mean wavevector (III) with ji=L or R is non-zero. The mean wavevector (IV) with (V) for ji=R and (VI) for ji=L is substantially zero or substantially anti-parallel to (III). At least one of (VII) and (VIII) is substantially parallel or substantially anti-parallel to one of (IX) and (X).

The invention provides a lens optical fiber array coupling system and a chromaticity measurement system and method, and belongs to the field of chromaticity measurement, and the lens optical fiber array coupling system comprises an imaging lens which is used for obtaining incident light of an object to be measured and guiding the incident light to an array optical fiber; the end face of the array optical fiber is located on the first image plane of the imaging lens, the normal of at least part of the optical fiber end face in the array optical fiber has a deflection angle relative to the normal of the first image plane, and the deflection angle is angle deflection performed by taking the main light ray of the light received by the corresponding optical fiber position as a target reference; and the imaging spectrometer is used for receiving the light information sent by the array optical fiber. By setting the deflection angle of the array optical fiber, the effective receiving area of the optical fiber is maximized, and the change of the transmission efficiency of light of different wavebands is avoided.

A radio-frequency module includes a module substrate, an inductor, and an acoustic wave filter. The inductor overlaps at least a portion of the acoustic wave filter when seen in a plan view from the normal direction of the module substrate. The inductor includes first and second coils connected in series. Each of the first and second coils is a spiral or helical coil that is wound with more than one turn. At least a portion of the first coil overlaps the second coil when seen in a plan view from the normal direction of the module substrate. A direction of a magnetic field generated by the first coil is opposite to a direction of a magnetic field generated by the second coil.

The invention relates to a seabed sediment intelligent discrimination method based on active target echoes, and the method comprises the following steps: 1, building different types of seabed sediment echo simulation data sets based on a normal wave model; step 2, constructing a seabed sediment classification network model; establishing a mapping relation between the echo data and the type of the seabed sediment by using a neural network; step 3, training the seabed sediment classification network; and 4, preprocessing actual echo data to be predicted according to the same preprocessing mode, and inputting the data into the network to obtain an estimation result of the type of the seabed sediment. According to the method, the normal wave approximation under the distance-independent shallow sea waveguide condition is utilized, the seabed sediment needing to be represented by a plurality of parameters is simplified to be represented by a single parameter of the normal wave number capable of being propagated in the waveguide, the parameter quantity is greatly simplified, and the automatic classification of the seabed sediment is realized by utilizing the deep learning technology.

An optical termination device (30) is provided with a first termination waveguide (50). The first termination waveguide (50) includes a curved waveguide (51) and a curved waveguide (52). The curved waveguide (51) includes a unique maximum curvature portion (51m). The curved waveguide (52) includes a unique maximum curvature portion (52m). A first normal vector of the curved waveguide (51) in the maximum curvature portion (51m) and a second normal vector of the curved waveguide (52) in the maximum curvature portion (52m) face the same direction as each other.

A light illumination and collection device (100; 200) for a micro-fluidic system comprises: a flow channel (110; 210) configured to extend in a first plane and allow flow of a sample through the flow channel (110; 210), a light source (120; 220) configured to transmit illumination light along an optical axis extending through a cross-sectional plane of the flow channel (110; 210) for causing light interaction between the illumination light and the sample to form sample information carrying light; a light collecting waveguide (130; 230) configured to extend in a second plane parallel to the first plane, wherein the light collecting waveguide comprises a light inlet (132; 232) configured to receive the sample information carrying light, wherein the light inlet (132; 232) and the light collecting waveguide (130; 232) are rotated in relation to a projection of a normal of the cross-sectional plane onto the second plane.

The invention relates to the technical field of sound source radiation signal power estimation, and discloses a method for estimating sound source radiation signal power by using robust normal waves, which comprises the following steps of: S1, calculating a modal coefficient vector and a modal domain receiving signal by using a sound field model; s2, selecting a robust normal wave reconstruction modal coefficient vector and a modal domain receiving signal vector; and S3, estimating the power of the sound source radiation signal. According to the method, the environment mismatch robustness of the sound source radiation signal power estimation result can be improved only by using the robust normal wave, and the environment mismatch robustness of the sound source radiation signal power estimation result obtained by the RM-SRPE method is higher than that of the C-SRPE method due to the fact that the robust normal wave is less affected by the environment mismatch. As the robust normal wave is selected in the hypothetical marine environment, the environmental mismatch robustness improvement effect of the RM-SRPE method is related to the mismatch degree of the hypothetical marine environment.

The invention discloses a double-seabed horizontal array joint target positioning method based on subspace intersection, and the method comprises the steps: synchronously collecting signals transmitted by an underwater sound source through two seabed horizontal arrays, and constructing a signal receiving model; establishing a two-dimensional rectangular coordinate system based on the spatial positions of the two seabed horizontal arrays; in the sea area where the two seabed horizontal arrays are located, acoustic environment parameters are measured; based on a modal theory, substituting the acoustic environment parameters into the normal wave model, and calculating the horizontal wave number of each order of normal wave in the sound field; screening out an effective mode in each order mode corresponding to the horizontal wave number; constructing a covariance matrix of a horizontal array output signal; performing eigenvalue decomposition on the covariance matrix to construct a signal subspace; constructing a modal subspace; the modal subspace and the signal subspace are combined and orthogonal triangular decomposition is carried out so as to solve the estimation result of the two seabed horizontal arrays on the sound source azimuth angle; and estimating the position of the sound source according to the estimation result of the two seabed horizontal arrays on the azimuth angle of the sound source.

The invention provides a normal wave frequency dispersion mode decomposition and sound source depth estimation method and system. The method comprises the following steps: S1, obtaining a vertical array space-frequency domain signal; s2, obtaining a parameterized model of each order of airspace; s3, obtaining a frequency domain parameterized model; s4, jointly establishing a space-frequency parameterization superposition model of the space-frequency domain signals of the vertical array; s5, optimizing and solving the space-frequency parameter matrix of each order; s6, reconstructing each order of space modal function and each order of frequency dispersion modal response; and S7, constructing a sound source depth estimation index, and performing optimization solution to obtain a sound source depth value. According to the method, parameterized joint modeling is carried out on the spatial modal function and the frequency domain modal response, a complex normal wave frequency dispersion mode can be jointly decomposed in the spatial domain and the frequency domain at the same time, meanwhile, the spatial modal function and the frequency domain modal response of each order are obtained through reconstruction, and compared with a traditional single-frequency-point modal decomposition method and the like, the method has the advantage that the method is more efficient. Rich information of normal waves in space and frequency dimensions can be better utilized, and the modal decomposition effect is better.

The invention relates to the technical field of wave soldering, and discloses a wave soldering wave crest height correction method which comprises the following steps: S1, simulation model establishment: determining preset welding process parameters; s2, preparation before correction is conducted, wherein fault-free operation and normal wave-soldering operation of welding equipment are guaranteed; s3, wave soldering debugging: determining the depth of the PCB simulation board immersed in the soldering flux wave crest; s4, wave-soldering test welding: correcting the height of the wave crest of the welding flux; s5, formal wave-soldering: correcting the wave crest of the soldering flux; and S6, welding quality monitoring and evaluation. The method comprises the following steps: determining preset welding process parameters; determining the depth of the soldering flux wave crest immersed in the PCB analog board; the preheating temperature is continuously adjusted for adjustment, so that the height of the wave crest of the correction solder is corrected; the height, the width and the outline shape of the soldering flux wave crest are monitored in real time, and the soldering flux wave crest is corrected in real time; the wave-soldering quality can be greatly improved, and the reliable and stable soldering quality is ensured.

An antenna module includes: a first substrate having a first surface and a second surface facing each other; a second substrate having a third surface and a fourth surface facing each other and disposed such that the third surface faces the second surface of the first substrate; a radiation element provided on a first surface side of the first substrate; a first ground electrode provided in the first substrate and facing the radiation element in a normal direction of the first substrate; a power inductor provided closer to the second substrate than the first ground electrode in plan view in a normal direction of the first substrate; and an electronic component provided on a fourth surface side of the second substrate and connected to the power inductor.

An information processing device according to one embodiment of the present technology includes: a first flat plate part; a second flat plate part; a housing part; a millimeter wave module; and a drive mechanism. The first flat plate part has a flat plate shape. The second flat plate part has a flat plate shape and is orthogonal to the first flat plate part. The housing part has an internal space surrounded by at least the first flat plate part and the second flat plate part. The millimeter wave module is disposed in the internal space, has a radiation surface, which is a plane, and is rotatable. The drive mechanism is disposed in the internal space and rotates the millimeter wave module between a first position where the radiation surface faces a first direction, which is a direction of a normal line of the first flat plate part, and a second position where the radiation surface faces a second direction, which is a direction of a normal line of the second flat plate part.

The invention relates to the technical field of wave power generation, in particular to floating type wave power generation equipment with a variable energy capturing body structure and a controllable energy conversion system. The device comprises an upper buoy, a power generation cabin and a lower buoy which are sequentially connected from top to bottom, a bottom frame is arranged below the lower buoy, the bottom frame is fixed to the lower portion of the lower buoy through a base frame arranged in the middle of the bottom frame, a plurality of resistance adjusting assemblies are arranged on the periphery of the side wall of the bottom frame, and the outer wall of the upper buoy is movably sleeved with a floating body. The device is reasonable in structural design, mechanical and hydraulic transmission energy conversion modes are adopted, the energy conversion mode of power generation equipment can be changed in time according to the size of a wave condition, and under the normal wave condition, the mechanical and hydraulic hybrid transmission mode is adopted, so that the transmission efficiency is effectively improved; under the extreme wave condition, the floating body dives to the position below the sea surface, so that the impact load borne by the oscillating floating body is effectively reduced, the equipment is prevented from being impacted excessively, the reliability of the equipment is improved, the service life of the equipment is prolonged, and the problems existing in the prior art are solved.

The application discloses an ion cyclotron interface coupling method, and relates to the technical field of magnetized plasma radio frequency coupling. The method comprises the following steps: determining a plurality of discrete parameter combinations comprising a first ion proportion, a background magnetic field, an electron density profile and a tangential wave number component; for each discrete parameter combination, screening a candidate angular frequency based on an interface matching matrix corresponding to the candidate angular frequency, a normal wave number at a normal position in a density transition layer and an ion-ion hybrid margin to obtain a bound operating point frequency corresponding to the discrete parameter combination and construct a relationship table accordingly; and adjusting a vacuum-plasma device and / or a radio frequency source based on the relationship table during operation of the vacuum-plasma device. The method solves the problem that ion cyclotron interface coupling cannot be accurately realized, and realizes accurate identification of an interface bound state and precise regulation and control of ion cyclotron interface coupling.

An aircraft radome and radar assembly includes: a radome arranged on the nose of the aircraft; a radar inside the radome, the radar operating in the millimeter domain and including a transmission antenna for emitting a TM polarized wave and a reception antenna; the radome includes an integrated window in front of the radar, the window being of a material transparent to millimeter waves; the radar being arranged so the angle between the maximum gain direction of the transmission antenna and the normal to the window is within an angular range [θB−θ1; θB+θ2], with OB being the Brewster angle for an air / window interface, θ1 and θ2 determined to obtain reflectivity at said air / window interface less than a predefined threshold; and an isolation partition between the transmission antenna and the reception antenna, the isolation partition being substantially in contact with the window and with the radar.

The embodiment of the present application provides a grating structure, an optical waveguide device and a display device, and belongs to the technical field of display, the grating structure is arranged on the optical waveguide plate, the light in the optical waveguide plate is incident on the grating structure, the grating structure is used for changing the propagation direction of incident light or coupling out the incident light from the optical waveguide plate, the grating structure comprises: a plurality of sub-gratings arranged along a first direction and different in position;Wherein, the light-out angle range of at least two sub-gratings is different, the light-out angle range is the angle range of the light emitted by the sub-grating, and the angle range is the included angle range between the emitted light and the normal direction of the sub-grating. Through the grating structure, the optical waveguide device and the display device provided by the embodiment of the present application, the light efficiency waste caused by the grating structure can be reduced, and the light efficiency of the optical waveguide device is improved.

An antenna substrate includes a substrate including a first main surface and a second main surface, and a coil including a first portion supported on the first main surface, and a second portion supported on the second main surface. A communicating portion is formed in the substrate. The communicating portion communicates the first main surface with the second main surface. The first portion and the second portion are electrically connected to each other, through the communicating portion. A winding direction of the first portion and a winding direction of the second portion are identical, when viewed from a direction along a normal line of the first main surface or a normal line of the second main surface.

The present invention proposes a method, device and medium for calculating the position of a deep-sea convergence zone based on acoustic diffraction phase shift. Based on MRT, the present invention uses a numerical method to introduce an additional functional phase shift at the sound line inversion point, and uses the functional phase shift to obtain the additional horizontal displacement of the sound line at the inversion point, so that the sound line in the deep-sea waveguide and the simple normal wave can establish an accurate equivalent relationship under low-frequency conditions through the WKB method. Here, the reflection phase shift caused when the inversion point in MRT is close to the waveguide interface and the functional phase shift introduced at the inversion point are collectively referred to as acoustic diffraction phase shift. Research has found that only by considering these two types of acoustic diffraction phase shifts at the same time can the span, propagation delay and group velocity of the sound line in the deep-sea waveguide be accurately corrected. On this basis, the present invention proposes a method suitable for calculating the position of a deep-sea convergence zone under low-frequency conditions. Finally, by studying the position of different types of convergence zones in a complete deep-sea sound channel at low frequencies, the formation mechanism of the convergence zone at low frequencies is revealed.

The utility model discloses an optical machine module and a near-to-eye display device. A lighting assembly and a lighting and imaging multiplexing assembly of the optical machine module are located on the two sides of a waveguide sheet. Illuminating light emitted by the illuminating assembly is transmitted in the first direction, transmitted through the waveguide sheet, the fly-eye lens, the first polaroid and the lens set in sequence, then incident to the surface, close to one side of the lens set, of the light modulator and modulated into imaging light through the light modulator to be reflected, and the imaging light is transmitted through the lens set and the second polaroid in the second direction and then emitted to the other side of the light modulator. And after total reflection transmission in the waveguide sheet, the light is emitted from the exit pupil area of the waveguide sheet to the human eyes, and the included angles between the first direction and the normal of the light modulator and between the second direction and the normal of the light modulator are the same. According to the optical machine module provided by the utility model, the volume of the optical machine module can be reduced on the premise of ensuring the performance of the optical machine.

The invention relates to a drilling transient antenna assembly inspection method and system, belongs to the technical field of geophysical exploration, and solves the technical problem that after a drilling transient electromagnetic instrument is assembled, a wiring is packaged in a pipe body, and the correctness of the wiring cannot be directly observed and inspected, so that the potential quality hazard of a product is caused. According to the technical scheme, low-resistance anomalous bodies such as metal bodies are sequentially placed at preset positions in the positive direction of the normal of a receiving coil, an instrument is operated to enable a transmitting coil to transmit electromagnetic waves, the receiving coil collects original signals of a secondary field, wiring correctness is judged according to signal polarity, and a signal positive value indicates that wiring is correct. The technical effects are that wiring can be accurately checked through physical experiments and data analysis without dismounting an instrument, assembling quality is guaranteed, checking efficiency is improved, and detection data abnormity is avoided.

In an embedded optical waveguide structure (100), for example, a waveguide (20) has: a first portion (20-1); a second portion (20-2) narrower than the first portion (20-1); and a third region (20-3) that is adjacent to the first region (20-1) in a third direction, is optically connected to the first region (20-1), and has an end surface in the third direction, the first direction being a crystal orientation [100] direction, the second direction being a crystal orientation [0-11] direction or a crystal orientation [01-1] direction, and the third direction being a crystal orientation [011] direction or a crystal orientation [0-1-1] direction. The normal direction at each position of the end surface (20a) faces the first direction, the second direction, or the direction opposite to the second direction and the third direction, and is inclined with respect to the crystal orientation [111] direction or the crystal orientation [1-1-1] direction.

This antenna module comprises: a dielectric substrate (130) having a first main surface (11) and a second main surface that face each other; an RF pad (20) disposed on the first main surface (11); a first ground pad (40) disposed on the first main surface (11); and a radiation electrode disposed on the dielectric substrate (130) at a position different from the first main surface (11). The dielectric substrate (130) has a resist layer (140) formed on the first main surface (11). In a plan view of the dielectric substrate (130) from the normal direction, the resist layer (140) is not formed on a straight line connecting one point on the RF pad (20) and one point on the first ground pad (40).