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966 results about "Ephemeris" patented technology

In astronomy and celestial navigation, an ephemeris (plural: ephemerides) gives the trajectory of naturally occurring astronomical objects as well as artificial satellites in the sky, i.e., the position (and possibly velocity) over time. The etymology is from Latin ephemeris, meaning 'diary' and from Greek ἐφημερίς (ephemeris), meaning 'diary, journal'. Historically, positions were given as printed tables of values, given at regular intervals of date and time. The calculation of these tables was one of the first applications of mechanical computers. Modern ephemerides are often computed electronically, from mathematical models of the motion of astronomical objects and the Earth. However, printed ephemerides are still produced, as they are useful when computational devices are not available.

Mechatronics small planar phased-array antenna satellite tracking method and device

The invention provides a satellite tracking method and device for a mechanical-electrical integration small planar phased-array antenna, and belongs to the technical field of satellite communication. The method comprises the following steps: starting and electrifying the small planar phased-array antenna and adjusting the small planar phased-array antenna into a preparation attitude; using the central array element to complete satellite searching to obtain ephemeris information; in the satellite and satellite top-crossing tracking stage, the expected beam direction is calculated, the beam direction is controlled in a beam forming and mechanical angle compensation combined mode, and satellite and satellite tracking operation is achieved; and the antenna receives the satellite switching instruction and adjusts the satellite switching instruction to a preparation attitude, and the next round of satellite tracking operation is carried out. According to the invention, mechanical angle compensation is carried out on the wave beam by adjusting the orientation of the antenna array surface, the satellite alignment and tracking performance of the antenna in a low satellite elevation scene is improved, and the consistency of terminal communication performance in the satellite top-crossing process is ensured.
Owner:THE 54TH RESEARCH INSTITUTE OF CHINA ELECTRONICS TECHNOLOGY GROUP CORPORATION

GPS interference phased array monitoring direction-finding antenna system for 1575 frequency band

The invention discloses a GPS interference phased array monitoring direction-finding antenna system for a 1575 frequency band, and relates to the technical field of intelligent antennae, comprising a data integration module for integrating data of satellite ephemeris, carrier attitude and airspace coverage through a weighted average method and generating an environment parameter set, a prediction calibration module for predicting the data of the satellite ephemeris, the carrier attitude and the airspace coverage through a weighted average method and generating an environment parameter set, and a direction-finding antenna module for performing direction-finding on the environment parameter set. The phase drift prediction module is used for inputting an environment parameter set into a bidirectional LSTM network, obtaining a phase drift prediction value, carrying out nonlinear calibration on the phase drift prediction value by adopting a Kalman-particle hybrid filtering algorithm, and synchronously monitoring an IQ signal by utilizing a closed-loop feedback mechanism, and the beam generation module is used for carrying out orthogonal modulation and radio frequency up-conversion processing on the IQ signal, and outputting the processed IQ signal. According to the method, the bidirectional LSTM network is combined with the Kalman-particle hybrid filtering algorithm, so that phase drift caused by factors such as carrier vibration and the like can be accurately predicted and calibrated in real time.
Owner:SHENZHEN RUIXUNTONG INFORMATION TECH CO LTD

GNSS (Global Navigation Satellite System) virtual observation value generation method and system based on real-time precise point positioning

The invention provides a GNSS virtual observation value generation method and system based on real-time precise point positioning, and belongs to the technical field of GNSS positioning, and the method comprises the steps: obtaining ephemeris clock error data and observation data received by a reference station in real time, filling a UCUD PPP observation equation, and solving a non-difference floating point solution of a to-be-estimated parameter of each parameter station; through UPD estimation, non-difference floating point solution ambiguity parameters recover the whole cycle characteristic, and a fixed solution STEC and a fixed solution ZTD are obtained; the STEC is locally fitted into a function about the position, and a regional non-difference ionosphere model is established; the ZTD is locally fitted into a function about the position, and a regional non-difference troposphere model is established; and generating a double-difference atmospheric delay between the main reference station and the virtual reference station based on the non-difference ionosphere model and the regional non-difference troposphere model to obtain a virtual observation value. According to the method, the reliability of GNSS signal atmospheric delay is effectively improved, so that the quality of a virtual observation value is improved.
Owner:CHINA RAILWAY SIYUAN SURVEY & DESIGN GRP CO LTD

Testing framework for UE timing-tracking capabilities over satellite or similar communications

Common delay(s) are set for a base station, the base station and a UE able to communicate via signals and to use the common delay(s) in communication. The common delay(s) correspond to delay in communication of the signals in a path from a simulated satellite to a reference point, which is a point selected between the base station and the simulated satellite. The UE is placed in a known location. Ephemeris values are set for the base station for the simulated satellite and caused to be broadcasted toward the UE. The ephemeris values represent positioning of the simulated satellite through which the signals are supposed to travel. In response to communication over the path by the UE, error is determined corresponding to at least timing at least between the UE and the reference point.
Owner:NOKIA TECHNOLOGIES OY

Space-ground integrated Beidou high-precision positioning method applied to urban canyons

The invention relates to a space-ground integrated Beidou high-precision positioning method applied to urban canyons, and belongs to the technical field of navigation positioning. The method comprises the following steps: deploying a pseudo satellite base station, calibrating coordinates of the base station through carrier phase difference, and monitoring the number of Beidou visible satellites; a master pseudo-satellite is determined, timestamps and ephemeris data are broadcasted to slave pseudo-satellites through Beidou short messages, and the slave pseudo-satellites are combined with bidirectional ranging data to correct a local clock to realize high-precision synchronization; receiving Beidou and pseudo-satellite signals by a user terminal, screening effective observation values through a shielding judgment mechanism, substituting the effective observation values into a non-difference observation equation in combination with pseudo-satellite reference difference data, and resolving a fusion result through an elastic coupling mode; and finally, multi-path interference is identified by using pseudo-satellite double antennas, and historical data is called to construct an error model to correct a fusion result. The space-ground integrated positioning of Beidou and pseudo satellites in an urban canyon scene is realized, the centimeter-level positioning precision is stably output, and the high-precision positioning requirements of urban traffic, surveying and mapping and the like are met.
Owner:SHANGHAI AZIMUTH DATA TECH CO LTD

Method, device and equipment for determining measurement and control orbit of low-orbit satellite and medium

The invention discloses a low-orbit satellite measurement and control orbit determination method, device and equipment and a medium, and the method comprises the steps: obtaining a satellite-borne GNSS pseudo-range observation value and a GNSS broadcast ephemeris, and carrying out the calculation through a pseudo-range single-point positioning algorithm, and obtaining a self-positioning result of a low-orbit satellite; when the number of GNSS satellites used by pseudo-range single-point positioning is lower than a first threshold value, or a satellite space distribution characteristic value of a positioning epoch is greater than a second threshold value, removing a corresponding self-positioning result; polynomial fitting is carried out on the filtered self-positioning results by adopting a sliding window, the self-positioning results with fitting residual errors larger than a third threshold value are removed, then interpolation processing is carried out, and optimized self-positioning results are obtained; and orbit determination is carried out in combination with a dynamic fitting method, and a final low-orbit satellite measurement and control orbit is obtained. The method is low in calculation cost and good in real-time performance, gets rid of the dependence of a ground station, is less affected by low-orbit satellite orbit maneuver, and can reflect a more accurate satellite position.
Owner:CENT SOUTH UNIV

Satellite-assisted user equipment (UE) location techniques

Various approaches for the generation and verification of user equipment (UE) location, using communications and processing capabilities of non-geostationary (NGSO) satellite networks and equipment are discussed. Among other examples, communications between a UE and a low-earth orbit (LEO) satellite may be used to substantiate or corroborate, to a location management function (LMF) of a 5G network, that a UE is located in or at a particular geographical location or area. Additionally, based on this location information and related SV ephemeris data, a satellite coverage area may be determined for a UE at a location at any one moment in time, for coordinating and managing connectivity of the UE with terrestrial and non-terrestrial networks.
Owner:INTEL CORP

PPP-B2b-based Beidou time service delay processing method and device

The invention belongs to the technical field of time service, and relates to a Beidou time service delay processing method and device based on PPP-B2b. The method comprises the following steps: acquiring a navigation signal of a current epoch to obtain an observation value, a broadcast ephemeris and precise point positioning service information; obtaining a precision satellite position and a precision satellite clock error according to the broadcast ephemeris and the precision single-point positioning service information; forecasting to obtain a forecast value; calculating a difference value between the forecast value and the observation value, when the difference value does not exceed a preset threshold value, establishing a satellite pseudo-range and carrier phase ionosphere-free combination observation equation, establishing an antenna position constraint virtual observation equation, and performing resolving according to the combination observation equation and the virtual observation equation to obtain a receiver clock error result; and correcting the pulse per second according to a clock error result of the receiver so as to carry out delay time service. According to the invention, accurate time service can be realized, interference and environmental influence are avoided, and the convergence speed is high.
Owner:HUNAN ZHONGDIAN HUARONG ENTERPRISE MANAGEMENT CO LTD

GNSS (Global Navigation Satellite System) real-time precise single-point positioning ambiguity fixing method for complex environment

The invention relates to the technical field of GNSS (Global Navigation Satellite System) navigation and positioning, in particular to a GNSS real-time precise single-point positioning ambiguity fixing method for a complex environment. The method comprises the steps of obtaining and processing data, obtaining a precision satellite orbit and a precision satellite clock error from original observation data, broadcast ephemeris and an SSR correction number which are originally obtained in sequence, obtaining original frequency point non-difference floating point ambiguity, obtaining fixed integer inter-satellite single-difference wide-lane ambiguity, and obtaining floating point inter-satellite single-difference narrow-lane ambiguity. And finally, selecting the complete set ambiguity according to the precision index of the floating point narrow lane ambiguity, and carrying out iteration to obtain an ambiguity subset meeting the optimal aperture check rule. Through the method, the ambiguity fixing reliability can be further improved, and the convergence time is shortened.
Owner:GUIZHOU BRIDGE CONSTR GROUP

Beidou / GNSS-based real-time high-accuracy sea surface measurement method and buoy

A Beidou / GNSS-based real-time high-precision sea surface measurement method and a buoy, wherein by using free-to-use broadcast ephemeris freely broadcast by GNSS satellites, precise point positioning of China's Beidou satellites, and other high-precision service space signals, real-time centimeter-level element information comprising time, longitude, latitude, water level, wave height, wave period, wave direction, sea surface current velocity and direction, atmospheric water vapor content, and the like can be directly obtained. The information can be stored locally in a buoy or transmitted back by communication, and is suitable for real-time high-precision sea surface measurements in offshore and far-sea scenarios.
Owner:FIRST INSTITUTE OF OCEANOGRAPHY MNR

Method to predict and fit antenna phase center of leo satellite considering attitude information

A method to predict and fit an APC of a LEO satellite considering attitude information is provided, which includes: transforming a spacecraft body-fixed coordinate system, obtaining a transformation matrix from orbital coordinate system to transformed spacecraft body-fixed coordinate system, obtaining rotation angles during a rotation process, obtaining rotation angles in orbit determination time period to predict rotation angles in orbit prediction time period, obtaining a transformation matrix from spacecraft body-fixed coordinate system to Earth-fixed coordinate system of each prediction moment, obtaining a correction vector from a CoM to a phase center of a downlink signal antenna in the Earth-fixed coordinate system at each prediction moment, and obtaining an orbit of the phase center of the downlink signal antenna of a LEO satellite, and performing an ephemeris parameter fitting on the orbit of the phase center of the downlink signal antenna of the LEO satellite in a fitting time period.
Owner:NAT TIME SERVICE CENT CHINESE ACAD OF SCI

Unmanned aerial vehicle positioning and cruising method and system based on satellite-based enhancement

The invention belongs to the technical field of satellite positioning, and discloses an unmanned aerial vehicle positioning cruise method and system based on satellite-based enhancement, and the method comprises the steps: setting an unmanned aerial vehicle cruise region range, a high-coverage cruise route and flight time; and checking software and hardware equipment of the unmanned aerial vehicle, taking off from a safe area, and starting automatic cruise. Observation data, broadcast ephemeris and Beidou B2b and Galileo HAS products are obtained through an unmanned aerial vehicle receiver. Carrying out decoding and correction number matching on the B2b and the HAS messages; correcting the satellite orbit, the clock error and the code and phase deviation according to the correction number provided by the B2b and the HAS; performing gross error elimination, clock jump repair and cycle slip detection on the data; and performing parameter estimation by using Kalman filtering to obtain high-precision position coordinates. If an emergency occurs, an operator can send a return instruction to the unmanned aerial vehicle through a Beidou short message. And after the cruise task is finished or a return instruction is received, the unmanned aerial vehicle completes safe landing at the planned return point.
Owner:KUNMING UNIV OF SCI & TECH

Regional interference signal detection method and device based on Beidou router

The invention provides a regional interference signal detection method and device based on a Beidou router, and the method comprises the steps: obtaining reference broadcast ephemeris data of a network platform and local ephemeris data received by the Beidou router, carrying out the data integrity calculation, and judging whether the local ephemeris data are missing or not; performing same-epoch data comparison on the reference broadcast ephemeris data and the local ephemeris data, and judging whether the local ephemeris data has deception signals or not; calculating a visible satellite integrity rate in a fixed time window based on the observation data of the Beidou router, and judging whether interference signals exist in the observation data or not; analyzing by utilizing the cycle slip ratio and the carrier-to-noise ratio of the observation data, and judging whether interference signals exist in the observation data or not; under the condition that local ephemeris data do not have missing and deception signals and the observation data do not have interference, whether the observation data have the deception signals or not is judged based on pseudo-range single-point positioning and inter-epoch carrier phase difference velocity measurement, and the method can improve the reliability of Beidou signal interference detection.
Owner:WUXI POWER SUPPLY BRANCH OF STATE GRID JIANGSU ELECTRIC POWER CO LTD +1

Beidou satellite ephemeris prediction method and system based on water-wave parallel network

Disclosed is a BeiDou satellite ephemeris prediction method and system based on a water-wave parallel network. The method includes: receiving broadcast ephemeris data; calculating according to the broadcast ephemeris data to obtain a sequence of extrapolation errors and historical extrapolated states; and inputting the sequence of extrapolation errors and the historical extrapolated states into a pre-trained prediction model to output an error prediction result. The system includes: a data receiving module, a dynamical calculation module, an error prediction module and a correction module. The present disclosure allows for accurate ephemeris prediction at a lower computational cost, and can be widely applied in the field of trajectory prediction.
Owner:GUANGDONG UNIV OF TECH

Low-orbit satellite communication system positioning method and terminal

The invention relates to the technical field of satellite internet, in particular to a low-orbit satellite communication system positioning method and a terminal. Comprising the following steps: a user terminal receives satellite broadcast to obtain ephemeris information at the current moment and position information of a wave position center point, and carries out initial time delay estimation and initial frequency offset estimation; then the user terminal carries out time-frequency pre-compensation processing on the PRACH signal according to the initial time delay and frequency offset estimation and sends the PRACH signal to a satellite; and after the satellite captures the PRACH signal, positioning the user terminal corresponding to the PRACH signal according to the residual time delay and the residual frequency offset carried in the PRACH signal and the position of the wave position center point. Therefore, under the condition of not depending on GNSS information, the satellite side can position the GNSS-free terminal.
Owner:CHINA SATELLITE NETWORK INNOVATION CO LTD

Landslide hidden danger point identification method based on aerospace remote sensing fusion neural network

The invention relates to the technical field of landslide geological disaster hidden danger point identification, in particular to a landslide hidden danger point identification method based on an air-space remote sensing fusion neural network, which comprises the following steps: acquiring satellite SAR data, a digital elevation model, a vector boundary map and a precision orbit ephemeris of a research area; carrying out interference processing on the InSAR data, and carrying out deformation rate inversion, terrain residual error correction and atmospheric delay phase modeling and correction; preprocessing an original high-resolution remote sensing image, interpreting a high-resolution image, and outputting spatial distribution of suspected landslide hidden danger points in a research area; planning an aerial survey route of the unmanned aerial vehicle, and performing distortion correction, feature matching, dense point cloud generation and orthoimage generation processing; performing multi-dimensional feature analysis, and performing comprehensive interpretation in combination with an expert knowledge base; according to the method, the key effect of the multi-source remote sensing fusion technology in landslide hidden danger monitoring is displayed from data acquisition to hidden danger recognition.
Owner:GUILIN UNIV OF ELECTRONIC TECH +1

Resource allocation system and method in satellite-ground convergence network

The invention relates to the technical field of communication networks, in particular to a resource allocation system and method in a satellite-ground fusion network, and the system comprises a satellite-ground topology and channel evolution predictor which is used for obtaining satellite ephemeris, user GNSS positioning and moving vectors, ground base station topology and a real-time CQI / RSRP measurement report; generating future link state information; the business QoE impact and switching cost modeling device is used for calculating transient interruption time of a switching action; generating switching cost information; the continuity risk quantification engine is used for generating continuity risk information containing the link maintaining risk probability, the instantaneous impact collapse probability and the link switching risk probability; the risk evasion type resource decision-making device is used for calculating maintenance link comprehensive cost and switching link comprehensive cost; calculating a dynamic switching damping threshold value; generating risk avoidance decision information; according to the invention, the high-frequency ping-pong switching near the edge state point is effectively inhibited, and the signaling overhead caused by invalid switching is reduced.
Owner:NANJING XIANFENG SHUOTONG WIRELESS TECH

GNSS data quality prediction method and device based on fisheye camera, and medium

The invention provides a GNSS data quality prediction method and device based on a fisheye camera, and a medium, and belongs to the technical field of data processing, and the method comprises the steps: determining the satellite orbit information of a future time period with a to-be-evaluated observation station as a reference point based on ephemeris prediction; according to the fisheye sky image shot at the to-be-evaluated observation station and the satellite orbit information, determining satellite feature data of a future time period and the occlusion porosity of the future time period; respectively inputting the occlusion porosity of the future time period and at least part of satellite feature data of the future time period into a general prediction model and an observation station prediction model corresponding to the observation station to be evaluated for data quality evaluation, and obtaining a first data quality evaluation index and a second data quality evaluation index; and determining a data quality prediction result based on the first data quality evaluation index and the second data quality evaluation index. A general prediction model and an observation station exclusive prediction model are introduced to carry out double-model evaluation, and accurate prediction of GNSS observation data quality is realized.
Owner:CHINA INST OF WATER RESOURCES & HYDROPOWER RES

Space debris orbit prediction and avoidance method

The invention relates to the technical field of spacecraft orbit control and space safety, and discloses a space debris orbit prediction and avoidance method, which comprises the following steps that: a ground computing center screens candidate targets and generates enhanced data packets for uploading; the spaceborne computer combines real-time navigation data to carry out geometric feature screening, and an instant high-risk target list is generated; controlling the star sensor to execute optical observation, and resolving an optical measurement relative orbit state by utilizing displacement superposition and Kalman filtering; selecting a high confidence coefficient or a conservative probability threshold according to the optical measurement state acquisition condition, and generating an avoidance instruction when the collision probability exceeds the limit; and the propulsion system responds to the instruction to execute avoidance, verifies the effect by confirming the semi-major axis variation and executes track recovery by selecting an aircraft. According to the method, the ground-air collaborative screening and shift superposition enhancement technology is adopted, the problems that the low-precision ephemeris false alarm rate is high and the detection capability of a satellite-borne sensor on a dark and weak target is insufficient are solved, and the accuracy of evasion decision making and the execution reliability are improved.
Owner:SHANGHAI TAIYI MICRO-SPACE TECHNOLOGY CO LTD

Internet constellation dynamic routing optimization method and system

The invention discloses an internet constellation dynamic routing optimization method and system, and the method comprises the steps: setting orbit plane parameters and satellite parameters, and carrying out the modeling of an orbit and a constellation; performing link visualization and time-varying graph generation according to ephemeris data and the constructed constellation model; defining a related space, a network and a function based on a deep reinforcement learning algorithm; and based on an MADDPG framework, introducing a multi-agent collaborative decision-making mechanism, and outputting action selection and execution results after collaborative optimization. The system comprises a model construction module, an embedding module, a reinforcement learning design module and a collaborative optimization module. By using the method, the dynamic change of the low-orbit satellite network can be effectively dealt with, satellite resources are fully utilized, and efficient and reliable communication is realized. The method can be widely applied to the field of wireless communication.
Owner:SUN YAT SEN UNIVERSITY SHENZHEN +1

Terminal positioning method and device, storage medium and electronic equipment

The invention discloses a terminal positioning method and device, a storage medium and electronic equipment. The method comprises the following steps: determining a single-point positioning result of a target terminal based on a navigation signal; determining a target positioning result based on the communication signal and the single-point positioning result, the target positioning result being determined by at least two corrections in the enhancement information when the target terminal executes the communication service through the broadcast channel, and the target positioning result being determined by at least two corrections in the enhancement information when the target terminal executes the communication service through the service channel. The target positioning result is determined by at least three corrections in the enhanced information, and the at least three corrections comprise atmospheric corrections; and under the condition that the first broadcast ephemeris and the second broadcast ephemeris meet verification conditions, determining positioning information of the target terminal according to the target positioning result. The technical problem of low terminal positioning accuracy is solved.
Owner:CHINA SATELLITE NETWORK SYSTEM CO LTD

Unscented batch processing orbit determination method and system for continuous low-thrust maneuvering satellites

The invention belongs to the technical field of aerospace, and relates to an unscented batch processing orbit determination method and system for a continuous low-thrust maneuvering satellite. The method comprises the following steps: acquiring a radar observation vector according to radar measured data or satellite ephemeris data in combination with radar site coordinates; obtaining an initial orbit state at a to-be-estimated moment by adopting a Lambert algorithm according to the radar observation vector; generating an initial expansion state quantity according to the initial orbit state at the to-be-estimated moment; a simplified orbit kinetic equation containing earth non-spherical perturbation, atmospheric resistance perturbation and constant small thrust acceleration under an RTN coordinate system is constructed under the ECI coordinate system; based on the simplified orbit kinetic equation, obtaining an expansion state quantity precision value of the to-be-estimated moment through the initial expansion state quantity, the radar observation vector and an unscented batch processing filtering method; and substituting the precision value of the expansion state quantity of the to-be-estimated moment into the simplified orbit kinetic equation to carry out orbit forecasting at other moments. According to the method, the orbit determination precision is remarkably improved, and the influence of single-point observation errors is reduced.
Owner:XI AN JIAOTONG UNIV +1

High-precision PPP positioning method based on SSR correction prediction

The invention belongs to the technical field of satellite positioning, and particularly discloses a high-precision PPP (Point-to-Point Protocol) positioning method based on SSR (Simple Sequence Repeat) correction prediction, which comprises the following steps that: a receiver receives and stores an SSR correction in real time to obtain an SSR sequence; inputting the stored SSR sequence into a pre-trained prediction model, and outputting an SSR correction number prediction value in a future time period; the broadcast ephemeris is corrected through the predicted SSR correction number, and a precise satellite orbit and clock correction are obtained; and constructing an ionosphere-free combination model based on the double-frequency observation value, and resolving the position of the receiver through Kalman filtering in combination with the corrected satellite orbit and clock correction. According to the method, long-time-sequence prediction is carried out on the SSR correction number through the prediction model, the problem of positioning precision jump caused by satellite correction data interruption is effectively solved, it is guaranteed that PPP positioning continuously outputs centimeter-level precision results under the scenes of signal shielding, network delay and the like, and the limitation that traditional PPP strongly depends on real-time SSR data is broken through.
Owner:NORTHWEST UNIV

Conduction fusion enhancement method suitable for earth-moon space high-orbit spacecraft

The invention relates to a conduction fusion enhancement method suitable for an earth-moon space high-orbit spacecraft, and the method comprises the steps: transmitting a communication and navigation fusion enhancement signal through a designed and planned HEO satellite constellation, and receiving and processing a Beidou navigation signal and an HEO enhancement signal in a compatible manner on the basis of not changing the hardware structure of an earth-moon space navigation receiver. The number of available navigational stars is increased through an observed quantity combination mode, the geometric distribution of constellations is improved, and the navigation solution accuracy and the positioning precision of earth-moon space are improved. And meanwhile, a communication function of forwarding information such as navigation ephemeris, receiver position and user customized data of uplink injection on the ground through an HEO constellation is supported, auxiliary information is provided for the earth-moon space navigation receiver, the receiving processing performance is improved, and communication and navigation fusion processing is realized. According to the method, the performance and the service capability of the high-orbit satellite navigation receiver can be improved, and the method has certain reference significance for spacecraft conduction fusion and integrated design.
Owner:SPACE STAR TECH CO LTD

Low-orbit navigation constellation autonomous orbit determination method and system under weak inter-satellite topological structure

The invention provides a low-orbit navigation constellation autonomous orbit determination method and system under a weak inter-satellite topological structure, and relates to the technical field of satellite orbit determination, and the method comprises the steps: obtaining various observation data of an inter-satellite link on a predetermined orbit, and carrying out the preprocessing of the various observation data; establishing a synchronous observation equation of orbit and clock correction parameters by adopting a segmented linear polynomial satellite clock correction modeling method, generating orbit, clock correction and related error parameters combining satellite-borne GNSS and inter-satellite link data, and forecasting; based on an error analysis result, multiple key features are extracted from the generated orbit, clock error and related error parameters to serve as input of a parameter prediction model, and a parameter time sequence of four types of prediction including relative weight, inter-satellite link hardware delay, low-orbit satellite clock error and unmodeled error is obtained through output; and uploading the predicted parameter time sequence and the broadcast ephemeris to a main satellite together, and transmitting to each sub-satellite by the main satellite through an inter-satellite link to realize distributed autonomous orbit determination of the sub-satellites.
Owner:SHANDONG UNIV

Satellite Internet of Things distributed node parallel transmission acceleration method

The invention discloses a satellite Internet of Things distributed node parallel transmission acceleration method, which relates to the technical field of satellite Internet of Things, and comprises the following steps: dynamically fragmenting, splitting into N fragments according to a network load rate and a node state, adding a serial number, a check code and redundant information, and marking a head as {INJ}; the intelligent routing is used for distributing fragments to distributed nodes through a scoring function based on satellite ephemeris, node loads and link quality; dynamic path switching: monitoring link and node states, and switching to a better path when the performance does not reach the standard; fault-tolerant recombination is carried out, recombination is carried out according to sequence numbers, if missing fragments are few, erasure codes are used for recovery, and if missing fragments are more, local retransmission is carried out. Through parallel transmission, dynamic switching and fault-tolerant recombination, the transmission rate, throughput and robustness are improved, node loads are balanced, and the performance of the satellite Internet of Things is optimized.
Owner:JIANGSU LEZHONG INFORMATION TECH CO LTD

Satellite tracking method, tracking processing device and satellite tracking system

The invention provides a satellite tracking method, and belongs to the technical field of communication. The satellite tracking method disclosed by the invention comprises the following steps: acquiring track information and antenna attitude information of communication-in-moving equipment in real time; for the target satellite, calculating a theoretical directional angle of an antenna beam according to the orbit parameters of the target satellite and the track information of the communication-in-moving equipment; correcting the theoretical directional angle of the antenna beam according to the antenna attitude information of the communication-in-moving equipment to obtain an actual directional angle of the antenna beam; based on the actual directional angle of the antenna beam, controlling a receiving phased-array antenna in the communication-in-moving equipment to form the antenna beam; in response to the situation that the signal strength of the satellite signal is larger than or equal to a preset value, data information of the received satellite signal is obtained, and the actual directional angle of the current antenna beam is corrected; according to the corrected actual directional angle of the antenna beam, controlling the transmitting phased-array antenna to form the antenna beam; and establishing a communication link, and updating ephemeris data of the target satellite.
Owner:BOE TECHNOLOGY GROUP CO LTD +2

Space-based directional observation method and device based on orbit precision evaluation

The invention discloses a space-based directional observation method and device based on orbit precision evaluation. The method comprises the following steps: acquiring fixed star angular distance measurement data information, a Ka-band inter-satellite link observation value and an L-band satellite-ground link observation value of a Beidou satellite; using the information to construct a multi-dimensional observation matrix and carrying out resolving processing to obtain satellite position parameters corresponding to the three space-based directional observation modes; and performing comparison processing on the satellite position parameters by taking an MGEX precise ephemeris as a comparison baseline to obtain an optimal observation mode. Therefore, three space-based directional observation modes are provided, the orbit precision is used as an evaluation criterion, an observation mode system with high adaptability and high practicability is formed, and the orbit determination precision of the Beidou satellite is improved.
Owner:BEIJING SATELLITE NAVIGATION CENT

Downlink signal sending method and downlink signal processing method

The embodiment of the invention provides a downlink signal sending method and a downlink signal processing method, which are characterized in that a downlink signal is obtained on the satellite side based on a supplementary synchronization sequence, and then time-frequency synchronization is carried out on the terminal equipment side by using the downlink signal from the satellite. In the application, the terminal device can realize time-frequency offset tracking compensation without acquiring satellite ephemeris information and using GNSS (Global Navigation Satellite System) equipment, so that the influence of ephemeris errors and GNSS errors on time-frequency synchronization performance after the terminal device is shut down for a long time is eliminated, and the problem that the time-frequency synchronization performance of the terminal device is influenced in the related technology is solved. The problem of low precision of time-frequency offset tracking compensation in the satellite-ground communication process is solved, and the time-frequency synchronization success rate of satellite-ground communication under the conditions of inaccurate ephemeris and high speed is improved.
Owner:CHINA STAR NETWORK SYST RES INST CO LTD

Single base station PPP-RTK positioning method and device

The invention discloses a single base station PPP-RTK (point-to-point protocol-real-time kinematic) positioning method and equipment. The method comprises the following steps: firstly, according to acquired single base station observation data, single base station accurate coordinates and ephemeris data, satellite end error corrections and atmospheric delay corrections are respectively obtained based on different resolving models, and the satellite end error corrections comprise satellite clock error corrections and satellite orbit error corrections; the atmospheric delay correction number comprises an ionosphere delay correction number and a troposphere delay correction number of the first frequency; calculating an atmospheric delay difference between the single base station and the user based on an empirical model, and substituting the atmospheric delay difference into the atmospheric delay correction number to obtain an atmospheric delay correction number which can be used for the user; obtaining observation values of users to construct a PPP-RTK observation equation so as to eliminate error terms related to a single base station; and the satellite end error correction number and the atmospheric delay correction number are substituted into a user end PPP-RTK observation equation, so that single base station PPP-RTK positioning can be realized.
Owner:HOHAI UNIV +1