43results about How to "Solving Phase Blur Problems" patented technology

The invention introduces a microwave device impedance measurement calibration method. The method comprises the following steps: (1), calculating time-delay transmission line transmission parameters through real-time measured data of straight-through calibration member scattering parameters and time-delay calibration member scattering parameters; (2), embedding a newly added virtual transmission line in an original time-delay calibration member, and calculating the transmission parameters of a virtual time-delay calibration member; (3), according to a conventional TRL calibration method, extracting calibration coefficients of a measuring clamp, and performing matrix inversion and multiplication operation to obtain a microwave device de-embedding transmission parameters; and (4), performing impedance normalization transformation on the microwave device de-embedding transmission parameters to obtain normalized microwave device normalization scattering parameters relative to system measurement reference impedance. The method makes up the measurement errors caused by inconsistence of transmission line characteristic impedance and the system measurement reference impedance, and realizes microwave device impedance measurement with an ultra wide band and high precision. At the same time, the improved microwave device impedance measurement calibration method can substantially reduce design processing requirements of a calibration device, thereby having high versatility.

The invention belongs to the technical field of surface topography measurement, and discloses a method and a device for fluorescence interference microscopic measurement based on stimulated radiation. The method includes: firstly, coating surfaces of a measured piece and a reference mirror; secondly, subjecting the measured piece and the reference mirror to stimulation of monochrome detection laser; and finally, resolving interference fringes on a detection surface. The device a laser device, a converging objective lens, a first pinhole, a collimation and beam expanding objective lens, a beam splitting prism, a reference focusing objective lens, the reference mirror, a displacement driver, a detection focusing objective lens, the measured piece, an imaging converging objective lens, a narrow-band filter, a second pinhole and a detector, wherein the converging objective lens, the first pinhole, the collimation and beam expanding objective lens, the beam splitting prism, the reference focusing objective lens, the reference mirror and the displacement driver are disposed on a direct light path of the laser device along a light transmitting direction, the detection focusing objective lens and the measured piece are disposed on a reflected light path of the beam splitting prism, and the imaging converging objective lens, the narrow-band filter, the second pinhole and the detector are disposed on a transmission light path of the beam splitting prism. By the design that surfaces of the measured piece and the reference mirror are coated by the aid of a vacuum evaporation coating method, measurement light is guaranteed to be capable of returning to a detection system after being reflected by a measured surface, high-NA(numerical aperture) and high-slope surface detection is achieved, and the device is applicable to ultra-precise measurement of three-dimensional topographies of high-NA and high-slope spherical surfaces, aspheric surfaces and free-form surfaces.

The invention discloses a method for measuring a TEC value of an ionized layer by utilizing an SAR satellite. After satellite-borne SAR transmission pulse signals penetrate through the ionized layer, the phase of the satellite-borne SAR transmission pulse signals contains complete TEC information of the ionized layer on the propagation path. By means of the method, multiple sub-bands are selected from the SAR signals with a certain band width, so that a freedom degree needed by phase ambiguity resolution is provided. Through the optimized design of parameters of the sub-bands and other technical means, the influence on phase position ambiguity resolution processing from an electromagnetic wave propagation distance phase is eliminated while the estimation accuracy of the TEC value is considered. Finally, a phase ambiguity resolution equation is built, and high-accuracy estimation of the TEC value of the ionized layer is achieved. The estimated TEC value of the ionized layer is utilized to supplement a satellite-borne SAR echo phase, and the satellite-borne SAR imaging quality and interferometry accuracy can be effectively improved.

The invention discloses a carrier synchronization method and device for deep space communication. The carrier synchronization method is characterized in that, a process of only emitting carriers exists in each time of building a communication link, and information in the stage is used for capturing carrier signals; the signals are put into an orthogonal demodulation loop, after matched filtering I and Q branches are respectively subjected to table look-up mapping so as to prevent phase deviation having phase ambiguity; in a synchronous tracking stage, the invention provides a simple and convenient phase demodulation tracking loop design method which utilizes judgment of polarity, and thereby circuit design is simplified; phase deviation information output by the phase demodulation loop is put into a loop filter, and phase changes of local carriers are timely adjusted according to deviation result of the loop filter. The carrier synchronization method and device for deep space communication can solve the problem that common carrier synchronization technologies have phase ambiguity, and is simplified in design of the phase demodulation loop, thus being easy to achieve from the aspect of hardware.

The invention discloses a laser white light compound interference measuring device and method. Monochromatic light phase shift interference can be combined with white light scanning interference to improve the measurement performances of the system. The measurement device comprises a white LED light source, a collimating lens, a filter, an optical microscopic interference module and an image acquisition device. The measurement method comprises the steps of: performing white light scanning interferometry of a measured sample; performing monochromatic light phase shift interferometry, wherein itis only needed to put the filter at front of a beam splitter mirror, and other portions are the same as the white light scanning interference; and combining a white light scanning interferometry andthe monochromatic light phase shift interferometry to solve the phase fuzzy problem in the monochromatic light phase shift interference. Compared to the white light canning interference, a compound interferometry result is higher in precision. Besides, the system provided by the invention employs an Michelson interference structure, the transverse measurement range is far larger than the measurement range of a commerce white light interference Mirau structure, and therefore, the laser white light compound interference measuring device and method has bigger advantage for large-size part surfacedetection.

The invention proposes a radar object positioning method based on machine learning. According to one embodiment of the invention, the method comprises the steps: carrying out the range-direction pulse compression of a target echo signal received by an along-track two-channel SAR (synthetic aperture radar), obtaining an interference phase matrix, sequentially inputting the interference phase vectors corresponding to all distance units in the interference phase matrix into a neural network, and obtaining a result of judgment whether each distance unit has a moving object or not and the orientation position x0 of the moving object. According to the embodiment of the invention, the method avoids problems of complex orientation pulse compression, radial speed estimation and faced phase fuzziness of a conventional ATI (along-track interference) method, thereby solving a problem that the positioning precision of the moving object is decreased because of error accumulation in the above process. The method is higher in positioning precision of the moving object, is lower in time consumption, and can meet the demands of high instantaneity and high positioning precision.

The invention belongs to the technical field of surface topography measurement and relates to a stimulated radiation based Mirau fluorescence interference microscopic measurement device. The measurement device comprises a laser device, a converging objective lens, a first pinhole, a collimation and beam expanding objective lens, a beam splitter, a focusing objective lens, a displacement driver, a reference mirror, a beam splitting prism, a measured piece, an imaging converging objective lens, a narrow-band filter, a second pinhole and a detector, wherein the converging objective lens, the first pinhole, the collimation and beam expanding objective lens and the beam splitter are disposed on a direct light path of the laser device along a light transmitting direction, the focusing objective lens, the displacement driver, the reference mirror, the beam splitting prism and the measured piece are disposed on a reflected light path of the beam splitter, and the imaging converging objective lens, the narrow-band filter, the second pinhole and the detector are disposed on a transmission light path of the beam splitter. Surfaces of the measured piece and the reference mirror are coated by the aid of a vacuum evaporation coating method. By the design that surface properties of the measured piece are changed through coating, measurement light is guaranteed to be capable of returning to a detection system after being reflected by a measured surface, high-NA(numerical aperture) and high-slope surface detection is achieved, and the measurement device is applicable to ultra-precise measurement of three-dimensional topographies of high-NA and high-slope spherical surfaces, aspheric surfaces and free-form surfaces.

The invention provides a radar angle and distance estimation method based on tensor high-order singular value decomposition, and the method comprises the following steps: constructing an MIMO radar receiving array comprising k subarrays, obtaining the receiving data of a target echo through the MIMO radar receiving array, and constructing a third-order tensor signal model; decomposing the three-order tensor signal model by adopting a high-order singular value to obtain tensor-based signal subspaces; extracting a receiving matrix of the signal subspace to realize MIMO radar target DOA parameter estimation; and extracting a signal subspace and an emission matrix corresponding to each subarray, eliminating the phase ambiguity problem caused by the coupling of the target DOD parameter and the distance, achieving the automatic pairing of the target DOD and the distance with the DOA parameter, and finally achieving the estimation of the target DOD parameter and the distance parameter of the MIMO radar.

The invention discloses a single-equipment Wi-Fi indoor multi-user positioning method based on principle of a phased array. The method mainly includes two parts of angle measurement and distance measurement; in an indoor environment, an antenna array is deployed, and then angle measurement is carried out with the idea of the phased array; and by means of scanning from coarse granularity to fine granularity, scanning time is reduced; by means of an equi-signal method, the precision of angle measurement is increased. By means of the steps, angles of all the targets can be acquired; and finally distance measurement to the targets is carried out via a multiple-frequency method, and the angle information and distance information are combined to complete the multi-user positioning.

The invention provides a positioning system and method based on single base station soft position information, and the system comprises a positioning base station which is used for receiving positioning data transmitted by a user terminal, and generating a positioning result based on the positioning data; the user terminal is used for sending positioning data to the positioning base station and receiving a positioning result; the positioning base station comprises an antenna array, a clock synchronization module, a measurement module, a soft position information extraction module, a communication module and a positioning module, and the user terminal comprises a wireless measurement module, a communication module and an inertial measurement unit. The soft position information extraction module is used for extracting soft position information from the measurement information related to the position of the user; and the positioning module is used for estimating the user position according to the soft position information and inertial data of the user terminal. According to the positioning system and the positioning method provided by the invention, the problem of phase ambiguity caused by the fact that the array antenna spacing is greater than the half-wavelength in single base station positioning can be effectively solved, so that the positioning precision can be remarkably improved by increasing the antenna array aperture.

The invention discloses a signal direction-of-arrival estimation method and device based on a sparse symmetric array, and the method comprises the following steps: S1, constructing the sparse symmetric array which consists of a plurality of uniform sub-arrays with unequal array element intervals; S2, calculating and constructing a fourth-order cumulant vector with a uniformly changed phase difference through the fourth-order cumulants of the received data of the different sub-array elements, and constructing a toeplitz matrix equivalent to the uniform linear array covariance matrix through thefourth-order cumulant vector; and S3, estimating azimuth angles of all the information sources by utilizing a sparse reconstruction method based on the constructed toeplitz matrix. Through the method, the problems of array aperture loss and too low information source angle estimation precision of an existing uniform linear array can be solved.

The invention provides a radio frequency direction finding method. The method comprises the following steps of, for an N-element uniform circular array antenna, obtaining a voltage phase difference between each path of antenna and a first path of antenna through a phase discriminator; recording each phase difference as an initial phase difference when an incoming wave enters the circular array antenna at an elevation angle of 0 degree; constructing a complex number corresponding to each antenna according to the voltage phase difference and the initial phase difference; calculating a theoretical phase difference between each antenna and the first antenna according to the elevation angle and the azimuth angle; introducing a vector X and a direction vector G, calculating the difference between the iteration times k+1 and a two-dimensional incident angle of the iteration times k by combining the elevation angle and the azimuth angle of the two-dimensional incident angle of the iteration times k+1 calculated by the constructed complex number, comparing at a threshold value, and entering an output elevation angle and an azimuth angle when the difference is smaller than the threshold value; otherwise, adding 1 to the value of k, and calculating the theoretical phase difference again. The method is advantaged in that complex operation is adopted, a phase ambiguity problem is avoided, direction finding precision is improved, and an iterative algorithm is adopted so that operations such as logic judgment are avoided.

The invention discloses a tamed spread spectrum communication system based on fast Fourier transformation. The tamed spread spectrum communication system comprises a training sequence module, a code phase mapping module, a framing transmitting module, a capturing module, a tracking module, a data interception module, a fast inverse Fourier transformation module, a point multiplication module, a fast Fourier transformation module, a data pseudo code transformation result extraction module and a data demodulation module. By adoption of the tamed spread spectrum communication system, the code length of a spread spectrum code is not limited by the number of correlators, and anti-interference capacity and confidentiality are improved.

The invention discloses a surface acoustic wave positioning system and method fusing intensity and phase information. The surface acoustic wave label is of a double-frequency double-channel structure,and the center distance from the reflecting gratings of the two propagation channels to the interdigital transducer is inversely proportional to the center frequency of the interdigital transducer. The reader is connected with three reader antennas through a one-to-three switch, and the three reader antennas are respectively located at three fixed positions. Before system positioning, a positioning area is divided into a plurality of sub-areas without a phase ambiguity problem, fingerprint points are arranged in geometric centroids of the sub-areas to establish a fingerprint library, the characteristic value of each fingerprint point comprises 12 characteristic values including echo signal intensity and phase, and then the sub-area where a positioning target is located is determined by adopting a fingerprint positioning algorithm. And finally, the unambiguous phase difference of the echo signal is taken as distance measurement information, and thus obtaining a two-dimensional coordinate of the positioning target through a trilateral positioning algorithm. The invention has the characteristics of high positioning precision and low system cost, and not only solves the problem of phase ambiguity, but also eliminates the temperature influence.

The invention discloses a tamed spread spectrum communication system based on fast Fourier transformation. The tamed spread spectrum communication system comprises a training sequence module, a code phase mapping module, a framing transmitting module, a capturing module, a tracking module, a data interception module, a fast inverse Fourier transformation module, a point multiplication module, a fast Fourier transformation module, a data pseudo code transformation result extraction module and a data demodulation module. By adoption of the tamed spread spectrum communication system, the code length of a spread spectrum code is not limited by the number of correlators, and anti-interference capacity and confidentiality are improved.

The invention proposes a radar object positioning method based on machine learning. According to one embodiment of the invention, the method comprises the steps: carrying out the range-direction pulse compression of a target echo signal received by an along-track two-channel SAR (synthetic aperture radar), obtaining an interference phase matrix, sequentially inputting the interference phase vectors corresponding to all distance units in the interference phase matrix into a neural network, and obtaining a result of judgment whether each distance unit has a moving object or not and the orientation position x0 of the moving object. According to the embodiment of the invention, the method avoids problems of complex orientation pulse compression, radial speed estimation and faced phase fuzziness of a conventional ATI (along-track interference) method, thereby solving a problem that the positioning precision of the moving object is decreased because of error accumulation in the above process. The method is higher in positioning precision of the moving object, is lower in time consumption, and can meet the demands of high instantaneity and high positioning precision.

The invention discloses a single-device WiFi indoor human body height detection method based on a phased array principle. The single-device WiFi indoor human body height detection method mainly comprises an angle measurement part and a distance measurement part. According to the technical scheme, in the indoor environment, an antenna array is deployed, angle measurement is conducted by means of the idea of a phased array, scanning time is shortened by means of scanning from coarse granularity to fine granularity, angle measurement precision is improved by means of an equal signal method, and the angles of different parts of the body can be obtained through the steps; and then distance measurement is performed on different body parts by using a multi-frequency method, and angle information and distance information are combined to obtain a body trunk heat map, so that the purpose of height detection is achieved.

The invention discloses a method for measuring a TEC value of an ionized layer by utilizing an SAR satellite. After satellite-borne SAR transmission pulse signals penetrate through the ionized layer, the phase of the satellite-borne SAR transmission pulse signals contains complete TEC information of the ionized layer on the propagation path. By means of the method, multiple sub-bands are selected from the SAR signals with a certain band width, so that a freedom degree needed by phase ambiguity resolution is provided. Through the optimized design of parameters of the sub-bands and other technical means, the influence on phase position ambiguity resolution processing from an electromagnetic wave propagation distance phase is eliminated while the estimation accuracy of the TEC value is considered. Finally, a phase ambiguity resolution equation is built, and high-accuracy estimation of the TEC value of the ionized layer is achieved. The estimated TEC value of the ionized layer is utilized to supplement a satellite-borne SAR echo phase, and the satellite-borne SAR imaging quality and interferometry accuracy can be effectively improved.

The invention belongs to the technical field of surface topography measurement and relates to a stimulated radiation based Michelson fluorescence interference microscopic measurement device. The measurement device comprises a laser device, a converging objective lens, a first pinhole, a collimation and beam expanding objective lens, a first beam splitting prism, a focusing objective lens, a displacement driver, a reference mirror, a second beam splitting prism, a measured piece, an imaging converging objective lens, a narrow-band filter, a second pinhole and a detector, wherein the converging objective lens, the first pinhole, the collimation and beam expanding objective lens and the first beam splitting prism are disposed on a direct light path of the laser device along a light transmitting direction, the focusing objective lens, the displacement driver, the reference mirror, the second beam splitting prism and the measured piece are disposed on a reflected light path of the first beam splitting prism, and the imaging converging objective lens, the narrow-band filter, the second pinhole and the detector are disposed on a transmission light path of the first beam splitting prism. Surfaces of the measured piece and the reference mirror are coated by the aid of a vacuum evaporation coating method. By the design that surface properties of the measured piece are changed through coating, measurement light is guaranteed to be capable of returning to a detection system after being reflected by a measured surface, high-NA(numerical aperture) and high-slope surface detection is achieved, and the measurement device is applicable to ultra-precise measurement of three-dimensional topographies of high-NA and high-slope spherical surfaces, aspheric surfaces and free-form surfaces.

The invention provides a time frequency synchronization unit and method for an OFDM system receiver. The time frequency synchronization unit comprises a frame synchronization controller, a frequency offset compensating controller and a synchronization estimation effective counter. When the count value of the synchronization estimation effective counter is 0, the frame synchronization controller confirms that frame synchronization is carried out for a received signal. When the count value of the synchronization estimation effective counter is 1, the frame synchronization controller confirms that the frame synchronization is not carried out for a next frame received signal, and the frequency offset compensating controller confirms that the frequency compensation is carried out for the next frame received signal based on a fractional frequency offset which is estimated aiming at the current frame received signal. When the count value of the synchronization estimation effective counter is2, the triggering time is synchronous, and the frequency offset compensating controller confirms that the frequency compensation is carried out for the next frame received signal based on a fractionalmultiple frequency offset and an integral multiple frequency offset, which are estimated aiming at the current frame received signal, so that the frequency synchronization is realized.

The invention provides a direction finding method based on a digital interference system, comprising: for an N-element uniform circular array antenna, converting a space electromagnetic wave into a digital voltage signal, and processing the voltage signal to obtain the voltage phase of each antenna; When the incident circular array antenna is 0°, the phase of each antenna is recorded as the test phase; the complex number corresponding to each antenna is constructed according to the voltage phase and the test phase; the theoretical phase of each antenna is calculated according to the initial phase of the elevation angle and azimuth; the introduction vector X and the direction vector G, combined with the constructed complex number to calculate the elevation angle and azimuth angle of the two-dimensional incident angle with the iteration number k+1. Compare, enter the output elevation angle and azimuth angle less than the threshold value; otherwise, add 1 to the value of k, and calculate the phase difference again. The advantage of the method lies in the use of complex number operations, which avoids the problem of phase ambiguity and operations such as logical judgment, and improves the direction finding accuracy.

The invention belongs to the technical field of surface topography measurement, and discloses a method and a device for fluorescence interference microscopic measurement based on stimulated radiation. The method includes: firstly, coating surfaces of a measured piece and a reference mirror; secondly, subjecting the measured piece and the reference mirror to stimulation of monochrome detection laser; and finally, resolving interference fringes on a detection surface. The device a laser device, a converging objective lens, a first pinhole, a collimation and beam expanding objective lens, a beam splitting prism, a reference focusing objective lens, the reference mirror, a displacement driver, a detection focusing objective lens, the measured piece, an imaging converging objective lens, a narrow-band filter, a second pinhole and a detector, wherein the converging objective lens, the first pinhole, the collimation and beam expanding objective lens, the beam splitting prism, the reference focusing objective lens, the reference mirror and the displacement driver are disposed on a direct light path of the laser device along a light transmitting direction, the detection focusing objective lens and the measured piece are disposed on a reflected light path of the beam splitting prism, and the imaging converging objective lens, the narrow-band filter, the second pinhole and the detector are disposed on a transmission light path of the beam splitting prism. By the design that surfaces of the measured piece and the reference mirror are coated by the aid of a vacuum evaporation coating method, measurement light is guaranteed to be capable of returning to a detection system after being reflected by a measured surface, high-NA(numerical aperture) and high-slope surface detection is achieved, and the device is applicable to ultra-precise measurement of three-dimensional topographies of high-NA and high-slope spherical surfaces, aspheric surfaces and free-form surfaces.