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77 results about "Coordinate time" patented technology

In the theory of relativity, it is convenient to express results in terms of a spacetime coordinate system relative to an implied observer. In many (but not all) coordinate systems, an event is specified by one time coordinate and three spatial coordinates. The time specified by the time coordinate is referred to as coordinate time to distinguish it from proper time.

Method and apparatus for improved dual channel operation and access point discovery in wireless communication networks

A method and apparatus of coordinating Time Division Multiple Access operation of wireless communication devices is disclosed. The method comprises an access point announcing a Quiet Period to one or more clients of the access point and transmitting as part of Target Beacons and probe responses an indication to the one or more clients that the access point will be absent from the communication channel for a period of time. The method also comprises the one or more clients establishing a connection with the access point after the Quiet Period when the access point is present on the communication channel on the basis of the indication.
Owner:INTEL CORP

Software time synchronization method for position and orientation system

The invention provides a software time synchronization method for a position and orientation system (POS). The POS comprises an inertial measurement unit, a POS navigation computer, a GPS (Global Positioning System) receiver and the like. The time synchronization method comprises the following steps of: firstly synchronizing system time of the POS navigation computer to world coordinated time by using a GPS second pulse sent by the GPS receiver and a time counter; and synchronizing the data acquisition time of the inertial measurement unit with the world coordinated time through a method of correcting a frequency division period of a data acquisition pulse clock of the inertial measurement unit so as to complete the time synchronization of the POS. In the invention, the problem of reducing of synchronization accuracy of the POS in a short time due to the clock drift is solved through the method of changing the frequency division period of the data acquisition pulse clock, and the software time synchronization method has the characteristics of high accuracy and high anti-interference capacity.
Owner:BEIHANG UNIV

Method and device for coordinating interference

The present invention provides a method and a device for interference coordination. The method comprises: determining mutually interfering wave beams between a cell of a first base station and a cell of a second base station based on first interference information and second interference information, the first interference information comprising a first cell set, the first cell set comprising a first interference cell to which the interference wave beam of a wave beam of the cell of the first base station belongs, the second interference information comprising a second cell set, and the second cell set comprising a second interference cell to which the interference wave beam of a wave beam of the cell of the second base station belongs; coordinating time-frequency resources, time domain resources or frequency domain resources occupied when the mutually interfering wave beams between the cell of the first base station and the cell of the second base station are sent, so as to reduce interference. The technical solution may provide a method for interference coordination. By coordinating, wave beams of the cells of the base stations are sent in a staggered manner in terms of the time-frequency resources, the time domain resources or the frequency domain resources, thereby reducing the mutual interference between the wave beams of the cells of the base stations without increasing uplink costs.
Owner:HUAWEI TECH CO LTD

Method for acquiring noise models of coordinate time series of regional GPS (global positioning system) reference stations

The invention provides a method for acquiring noise models of coordinate time series of regional GPS (global positioning system) reference stations. The method includes steps of 1, collecting data; 2, selecting a plurality of groups of combined noise models according to a basic principle that the noise models cover integral frequency bands of noise frequencies; 3, respectively analyzing noise of the coordinate time series of the GPS reference stations and noise of environmental-load-corrected coordinate time series of the GPS reference stations by the aid of a maximum likelihood estimation process according to the various combined noise models, and acquiring MLE (maximum likelihood estimation) values of the various combined noise models at components of the coordinate time series of the GPS reference stations; 4, acquiring the optimal noise models at the components of the coordinate time series of the GPS reference stations according to the MLE values of the combined noise models. The method has the advantages that the optimal noise models of the regional GPS reference stations can be effectively built, nonlinear movement is taken into consideration of the optimal noise models, accordingly, actual movement of the observation stations can be effectively represented as compared with existing models, and noise signals which are reflected by the coordinate time series can be reasonably explained.
Owner:WUHAN UNIV

GNSS base station crustal movement velocity estimation method in consideration of nonlinear change

InactiveCN109188466AOvercoming excessive punishmentReduce spurious motionSatellite radio beaconingSingular spectrum analysisEstimation methods
The invention discloses a GNSS base station crustal movement velocity estimation method in consideration of nonlinear change. In consideration of the influence on the base station velocity estimationby the GNSS base station nonlinear change, a random model and like, the latest resolving strategy is adopted to acquire a GNSS base station coordinate time sequence under an ITRF2014 framework, a timesequence model for performing separation on the nonlinear change of the base station coordinate time sequence is established by combining a real physical correction model, abnormal location gross error and step detection and like methods; and a GNSS base station coordinate time sequence background noise model determination technology based on the singular spectrum analysis method is adopted, andan improved Bayes information minimum criterion noise model estimation method is proposed base on above conditions, a GNSS base station crustal movement velocity field estimation method is provided, thereby providing accurate and reliable velocity field data basis for the crustal movement velocity field estimation.
Owner:EAST CHINA JIAOTONG UNIVERSITY

Periodic detection method and system for GNSS observation station coordinate time sequence

The invention provides a periodic detection method and system for a GNSS observation station coordinate time sequence. The method comprises the steps of acquiring a GPS observation station coordinatetime sequence observed value, removing gross errors and correcting an antenna phase center deviation; performing preliminary spectrum analysis on the GPS observation station coordinate time sequence by using a periodogram method; acquiring a plurality of major cycle frequencies of a corresponding observation station, and sorting according to the amplitudes of main frequencies; describing the GPS observation station coordinate time sequence by using a harmonic function, acquiring a harmonic function model of the GPS observation station coordinate time sequence, and building a harmonic functionmodel matrix; using the main frequencies as prior constraints, and acquiring the standby frequencies of a plurality of periodic signals; resolving the harmonic function model based on a least squarescriterion, acquiring optimal frequencies and verifying the standby frequencies by using a hypothesis testing method, and building the harmonic function model including the plurality of optimal frequencies; and according to the standby frequency after hypothesis testing is performed, resolving the harmonic function model matrix based on the least squares criterion, and acquiring a detection resultof any GNSS observation station periodic signal.
Owner:WUHAN UNIV

Method for stability analysis of reference point for GNSS automatic deformation monitoring

The invention discloses a method for stability analysis of reference point for GNSS automatic deformation monitoring, which comprises the following steps: calculating the GNSS observation data to obtain the coordinate residual time series of the reference point; detecting and removing rough errors in the coordinate residual time series of the reference point; extracting and removing the linear trend and the cyclical term in the series; conducting interpolation to the time series if there exist missing data in the coordinate residual time series after the removal of the trend and the cyclical term; extracting the common-mode error of the residual time series and removing the common-mode error from each residual series; and finally, using a quantification calculating method to determine whether the remaining residual series follows a normal distribution or not. If it is, then the reference point is regarded as stable; otherwise, instable. According to the invention, it can effectively eliminate the common error of a station, improve the signal-to-noise ratio of the coordinate time series, and finally make the main error of the coordinate time series of the station limited to observed random noise to judge whether the station is stable or not.
Owner:CENT SOUTH UNIV

Clock synchronizing method and first part and second part using this method

This invention relates to clock synchronous method to fulfill synchronous clock between first and second parts, which comprises the following steps: a, second part receives clock message from first part with current time in the message; b, the second part coordinates time according to second part. This invention also discloses one first and second part of this method.
Owner:NEW H3C TECH CO LTD

Method for removing colored noise in GPS coordinate time sequence

ActiveCN109709585APreserve nonlinear motion characteristicsAccurate measurement of station motion parametersSatellite radio beaconingLinear motionCoordinate time
The invention provides a method for removing colored noise in the GPS coordinate time sequence. The method comprises steps that S1, a residual sequence of the GPS base station coordinate time sequenceis obtained, and the variance of white noise in the residual sequence is estimated; S2, the white noise is simulated according to the variance of the white noise; S3, the simulated white noise and the residual sequence are simultaneously subjected to wavelet decomposition; S4, an information entropy of wavelet coefficients of the simulated white noise and the information entropy of wavelet coefficients of the residual sequence are obtained; S5, the information entropy of the wavelet coefficients of the colored noise is obtained; S6, wavelet coefficients of the colored noise are obtained according to the information entropy of the wavelet coefficients of the colored noise; S7, the wavelet coefficients of the colored noise are reconstructed to obtain the colored noise; and S8, the obtainedcolored noise is subtracted from the GPS coordinate time sequence, and the time sequence that is unaffected by the colored noise is finally obtained. The method is advantaged in that influence of thecolored noise in the GPS coordinate time sequence can be effectively removed, and non-linear motion characteristics of the GPS coordinate time sequence are preserved.
Owner:CHINA RAILWAY SIYUAN SURVEY & DESIGN GRP

Method for accurately quantifying influence of thermal expansion effect on GPS coordinate time series

The invention discloses a method for accurately quantifying influence of a thermal expansion effect on a GPS coordinate time series. The method includes collecting a surface temperature time series of an IGS reference station, and collecting observation station information; calculating the total influence of the thermal expansion effect on an IGS reference station coordinate time series, i.e., Sequence A; adopting a surface mass load redistribution model to calculate a vertical direction displacement time series of the IGS reference station caused by environmental loads, i.e., Sequence B; adopting a GPS precise data processing model to obtain a coordinate time sequence of the IGS reference station, i.e., Sequence C; deducting Sequence B from Sequence C to obtain Sequence C-B; deducting Sequence A from Sequence C-B to obtain Sequence C-B-A; and based on the Sequence C-B and Sequence C-B-A, proposing that numerical value indexes are utilized to qualify the influence of the thermal expansion effect on the GPS coordinate time series. The method for accurately quantifying the influence of the thermal expansion effect on the GPS coordinate time series can obtain actual motion in the vertical direction of the IGS reference station caused by temperature variation, and adopts the numerical value indexes to accurately quantify the influence of the thermal expansion effect.
Owner:WUHAN UNIV

GPS coordinate time sequence discontinuity complementing method based on common-mode error

The invention discloses a GPS coordinate time sequence discontinuity complementing method based on a common-mode error, and the method comprises the steps: S1, selecting a medium- and small-scale GPS network, and selecting a plurality of continuity measurement stations from the continuity measurement stations in the medium- and small-scale GPS network; S2, obtaining the residual error coordinate time sequence of the continuity measurement stations according to the coordinate time sequence observation data of the continuity measurement stations; S3, selecting any one measurement station from the plurality of selected continuity measurement stations as a reference base station, and determining the common epoch of the reference station and the common continuity measurement stations in the medium- and small-scale GPS network; S4, obtaining the common-mode error that all common continuity measurement stations in the medium- and small-scale GPS network jointly act on the reference station; S5, complementing the GPS coordinate time sequence of a discontinuity measurement station in the medium- and small-scale GPS network through the common-mode error. According to the invention, the method achieves the complementing of the discontinuous data through employing the similarity of the continuous data residual error time sequence of the spatial distribution in the medium- and small-scale range, and improves the derivative quality based on the GPS coordinate time sequence.
Owner:WUHAN UNIV

A quantitative method for influences on a GPS coordinate time series by a higher-order item ionospheric delay

The invention discloses a quantitative method for influences on a GPS coordinate time series by a higher-order item ionospheric delay. The method comprises the steps of collecting original observation data of a GPS base station; obtaining a GPS coordinate time series considering only the first order term of the ionospheric delay based on the historical observation data and recording the GPS coordinate series as sequence A; calculating the GPS coordinate time series corrected by the ionospheric high order term based on the historical observation data and recording the series as sequence B; aligning the series A and the series B in a time domain and subtracting the series A and the series B to obtain a high-order term ionospheric delay influence time series of the GPS base station and recording the series as sequence C; and separately subjecting the sequence A, sequence B and sequence C to noise analysis to obtain the observation station speed, noise characteristics and seasonal information corresponding to each sequence so as to quantify the influence of the high-order term ionospheric delay. The quantitative method of the invention can quantitatively determine the influence of the high-order ionospheric delay on the observation station coordinate time series, and can better explain the non-linear variation source presented in the GPS coordinate time series.
Owner:WUHAN UNIV

GNSS observation station nonlinear motion modeling method and device

The invention provides a GNSS observation station nonlinear motion modeling method and device, and belongs to the technical field of global positioning navigation systems. The method comprises the steps of obtaining an original coordinate time sequence of a GNSS observation station; performing wavelet decomposition and reconstruction on the original coordinate time sequence to obtain a low-frequency part and a multi-layer high-frequency part; performing singular spectrum decomposition and reconstruction on the low-frequency part and each layer of high-frequency part; synthesizing the low-frequency part after singular spectrum decomposition and reconstruction and the high-frequency part of each layer to obtain a fitting sequence of an original coordinate time sequence; and modeling the fitting sequence. The method comprises the following steps: an original coordinate time sequence is decomposed into relatively single and smooth low-frequency parts and high-frequency parts of all layersby utilizing wavelet decomposition and reconstruction; and then singular spectrum decomposition and reconstruction are performed on each part, so that the probability that part of periodic items suchas seasonal periodic items and monthly periodic items are rejected as noise is reduced to a certain extent, and the modeling precision is improved.
Owner:PLA STRATEGIC SUPPORT FORCE INFORMATION ENG UNIV PLA SSF IEU

Test bed for braking performance of automobile/train

The invention discloses a test bed for the braking performance of an automobile/a train. The test bed is characterized in that a signal acquisition part of a sensor is composed of a left detection unit group and a right detection unit group which are formed by linearly arranging a plurality of detection units, and the left detection unit group and the right detection unit group are in symmetric distribution. A braking detection unit comprises a braking sand-adhering plate; the braking sand-adhering plates on the left detection unit group and the right detection unit group are independent, with a distance of 8 mm; each braking detection unit and each weighing detection unit work independently to respectively realize acquisition of braking data and weight data and are independently connected with a signal acquisition processing device; and the signal acquisition processing device is electrically connected with a data processing system. The automobile/train is subjected to multi-axial overall online detection, so that the braking time sequence of the vehicle, the dynamic braking power of the entire vehicle, the poor braking process, the coordinate time and the like of the entire vehicle can be detected in one braking process, therefore, the labor intensity of detection is alleviated, the detection efficiency is improved, and the braking performance of the vehicle can be reflected more truly.
Owner:SHENZHEN ANCHE TECH

GNSS imaging method based on inter-station correlation spatial structure function construction

ActiveCN109581441AOvercoming the lack of time resolutionTake advantage ofCharacter and pattern recognitionSatellite radio beaconingCorrelation coefficientGeodesics on an ellipsoid
The invention provides a GNSS imaging method based on inter-station correlation spatial structure function construction. The method comprises the steps that coordinate time sequence observation valuesof GNSS observation stations and the velocity and velocity uncertainty of each GNSS observation station are input; in combination with geologic and geodetic results of a research region, clustering is performed on the observation stations in a GNSS network to obtain cluster regions; the correlation coefficient of an observation station pair formed by two arbitrary observation stations in each cluster region is calculated, data pool division is performed according to the correlation coefficients of the observation stations, and a plurality of data pools in each cluster region and the GNSS observation station pairs in each data pool are acquired; in each cluster region, the mid-value and absolute median deviation of the correlation coefficients of all the observation station pairs in each data pool are calculated, a spatial structure function of each cluster region is constructed, and a final spatial structure function of the whole GNSS network is formed according to a standard; and according to the velocity uncertainty and the spatial structure function, the weights of all the observation stations within the research range are determined, a spatial interpolation method is utilizedto perform spatial interpolation, and then an image is formed.
Owner:WUHAN UNIV
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