34 results about "Satellite visibility" patented technology

A method and system for creating a sky visibility map, using data from a vehicle and its neighbors. A host vehicle with satellite-based navigation capability measures the quality of signals it receives from available satellites, where azimuth and elevation angles of the satellites are known from an ephemeris or almanac. The host vehicle also receives satellite signal data from surrounding vehicles via vehicle-to-vehicle communication. Using data from all of the vehicles, a sky visibility map is constructed, indicating where obstructions to satellite visibility exist for different locations. The sky visibility map is used to anticipate satellite signal quality. A driving environment classification can be used to configure other vehicle systems. The sky visibility map can also be constructed without using data from surrounding vehicles; the host vehicle can store its satellite signal data long-term and use it to estimate satellite visibility when returning to a location previously visited.

A method and system for creating a sky visibility map, using data from a vehicle and its neighbors. A host vehicle with satellite-based navigation capability measures the quality of signals it receives from available satellites, where azimuth and elevation angles of the satellites are known from an ephemeris or almanac. The host vehicle also receives satellite signal data from surrounding vehicles via vehicle-to-vehicle communication. Using data from all of the vehicles, a sky visibility map is constructed, indicating where obstructions to satellite visibility exist for different locations. The sky visibility map is used to anticipate satellite signal quality. A driving environment classification can be used to configure other vehicle systems. The sky visibility map can also be constructed without using data from surrounding vehicles; the host vehicle can store its satellite signal data long-term and use it to estimate satellite visibility when returning to a location previously visited.

The invention discloses a satellite visibility analysis method considering satellite occlusion conditions, comprising the following steps: S1, measuring the occlusion elevation angle Ei of a satellite at a target point; S2, calculating the spatial position of the satellite and carrying out coordinate transformation; and S3, in a station center coordinate system with a ground survey station R as the origin, calculating out the instantaneous elevation angle e and azimuth angle A of the satellite; calculating the occlusion elevation angle Ei at corresponding time and at corresponding azimuth A; comparing the elevation angle e of the satellite with the occlusion elevation angle Ei at the corresponding time and at the corresponding azimuth; if e<=Ei, judging that the satellite is not visible, and removing the satellite; if e>Ei, judging that the satellite is visible, and keeping the satellite; and filtering satellites according to the method, and obtaining an accurate satellite visibility result. The precision factor of a single survey station is evaluated according to the satellite visibility analysis result, and thus, ephemeris prediction is realized. The method of the invention is suitable for carrying out ephemeris prediction of GNSS observation in alpine and gorge regions and in regions difficult to observe under the effect of city buildings. The problem that the traditional ephemeris prediction result is inconsistent with the actual observation conditions is solved.

The invention discloses a quite-weak GNSS signal receiving high-orbit-satellite orbit positioning method. By means of the method, a GNSS ephemeris and celestial navigation information are used, the GNSS satellite visibility is analyzed, and a GNSS signal Doppler frequency range is estimated; the technology that an 8*20-ms coherent integration time matched filer is combined with a navigation message for estimation is used, influences of overturning of the navigation message are avoided, data of the navigation message can be correctly obtained, the problem that a coherent integration value is attenuated due to the code Doppler effect is solved, and open-loop-structure quite-weak GNSS signals with the signal intensity as low as -158 dBm can be accurately captured. Meanwhile, ionized layer delay is compensated, the super-long pseudo-range ambiguity is constructed, and accurate orbit positioning of a high-orbit satellite is achieved. The super-long coherent integration time is used, the signals can be intermittently and accurately captured, the weak signal capturing sensitivity is greatly improved, and the energy losses are reduced.

The invention provides an analysis method of constellation compatibility and interoperability of navigation satellites and relates to a definition and analysis method for the constellation compatibility and the interoperability of the navigation satellites. The compatibility is analyzed mainly from two aspects of long-term evolution and collision probability. Shot effects and long-term evolution rules of satellites on the medium orbit are given and a calculation method of the collision probability is provided. The interoperability is analyzed mainly from aspects of satellite visibility, position precision factors and positioning service availability, and calculation methods and effect factors of the satellite visibility, the position precision factors and the positioning service availability are provided respectively. According to the invention, the provided definitions of the constellation compatibility and the interoperability are different from definitions of common signal, time and coordinate compatibility and interoperability, and the provided analysis method is highly realizable in engineering.

The invention provides a rapid task planning method for a multi-source earth observation satellite. The rapid task planning method comprises the following steps: performing calculating to obtain satellite ephemeris data; establishing an Index in a space-time two-dimensional mode, establishing a data structure, and storing ephemeris data in a KEY-VALUE type database; Performing discontinuous ephemeris data screening in the candidate range, performing satellite visibility calculation, and performing calculation to obtain a point target visible window; Processing the region target by adopting a greedy snake algorithm to obtain a region target visible window, and generating a meta-task window according to the region target visible window; And optimizing and arranging the meta-task window by adopting a pluggable task planning optimization and evaluation method to obtain a relatively optimal planning scheme. According to the invention, rapid access of data can be ensured, unified mode high-speed processing of common satellites and agile satellites is realized, and high-quality task planning is realized in a multi-satellite and multi-task combined planning scene.

The invention provides a window calculation method for a low-orbit satellite tracking a non-orbiting highly dynamic target. Known conditions, constrained conditions and a calculation optimization target of a satellite tracking window are made clear; primary screening and fine screening are carried out; the window of the low-orbit satellite that tracks the highly dynamic target is calculated and optimized by taking a satellite orbit, a movement track of the highly dynamic target, the relative geometric relation between the satellite and the target, satellite visibility condition of a ground measurement and control station, space weather condition, and interference of the sun and moon on a satellite star sensor into consideration comprehensively; problems that the window of the satellite ischangeable and hard to determine are solved; and calculation is simple and the engineering availability is high.

The invention relates to a method and a device for judging satellite visibility under carrier rotating condition. The method mainly includes: building a carrier coordinate system, calculating carrier rotating angles, and calculating satellite positions in the carrier coordinate system according to the carrier rotating angles; and calculating satellite elevation angles according to the satellite positions in the carrier coordinate system, comparing the satellite elevation angles and satellite screening angles, and judging satellite visibility according to comparison results. In an embodiment of the method and the device, the carrier coordinate system is built, positions of satellites in a horizontal coordinate system are shifted into the carrier coordinate system and the satellite elevation angles are calculated, and accordingly the satellite visibility can be effectively judged according to the satellite elevation angles under carrier rotating condition.

The invention discloses a satellite visibility analysis method for Beidou differential reference station layout. The method is used for calculating the satellite visibility of a reference station at some moment through DEM (Digital Elevation Model) data and almanac data. The method comprises the steps: (1) calculating the azimuth angle alpha and altitude angle beta of a satellite; (2) calculating the coordinates P of a point of intersection between the direction from the reference station to the satellite and a DEM valid data boundary; (3) calculating the coordinates of a barrier point; (4) calculating the altitude angle of the barrier point; (5) judging satellite visibility. By the method, on-graph previewing work can be carried out on reference station layout, and the method has the advantages of simplicity and practicability.

The invention discloses a shadow matching improved algorithm based on a Beidou GEO satellite, comprising the following steps: establishing a Beidou GEO satellite shadow model; performing initialization positioning by using a GPS and a BDS satellite to obtain an initial position P0; judging the visibility of the Beidou GEO satellite by using a non-line-of-sight signal detection technology; settingcandidate positions for shadow matching and positioning, and removing the candidate positions which do not accord with the shadow model; carrying out satellite visibility prediction at each candidateposition according to the determined candidate positions; acquiring the carrier-to-noise ratio of each satellite by utilizing satellite NMEA-0183 format data received by a receiver in an urban canyonenvironment, and performing satellite visibility observation according to the carrier-to-noise ratio; performing matching scoring on satellite prediction and observation visibility by using an SM scoring scheme; and scoring each candidate position after matching scoring, and obtaining an SM final positioning result according to the scores and the candidate positions. The positioning precision of satellite positioning in the urban canyon environment is improved.

The invention discloses a Beidou Ka complex phased-array antenna tracking visible report generation algorithm. The algorithm is specifically implemented according to the following steps: 1, establishing a position attitude model about a satellite-borne Ka phased-array antenna and a ground-based Ka phased-array antenna; 2, proposing an inter-satellite visibility judgment algorithm; and 3, proposinga tracking visible report generation algorithm. According to the method, the mutual visibility between the stars is calculated through the satellite space geometrical relationship, and then the star-star visibility report is generated. Through complex beam forming of the Ka phased-array antenna, a satellite-earth visible report is obtained. Through the visible report generation algorithm, omnibearing tracking of a ground Ka station on a Beidou satellite can be achieved, and the method has the advantages of being simple, practical and high in engineering realizability.

The present invention provides a method for carrying out positioning in-orbit test authentication based on a navigation satellite leakage signal. Firstly, an in-orbit test flight height is determined, the relative position relation among a detector, a navigation satellite and the Earth is calculated, the angle of an any position relative to Earth vector and detector vector of the navigation satellite is calculated according to the position relation of the detector, the navigation satellite and the Earth, and the visibility of the navigation satellite is judged. According to the navigation satellite visibility judgment result, the height range of boot working and boot time of a satellite-borne navigation receiver are determined, according to the navigation visibility judgment result, an in-orbit flight attitude is analyzed, and the wave beam angle range of a GNSS navigation receiving equipment receiving antenna is determined. The receiving condition of the navigation leakage signal and a navigation positioning result are recorded in an orbit test. The receiving ability of the navigation leakage signal of the GNSS navigation receiver and the influence on the navigation performance are compared and analyzed. The problems of the comprehensive functional performance testing of the navigation satellite leakage signal receiving equipment of deep-space exploration and high-Earth orbit satellite navigation satellites and the system design of positioning by using the navigation satellite leakage signal are solved.

The disclosed embodiments use 3D city models and shadow mapping to improve altitude fixes in urban environments. In an embodiment, a method comprises: generating a set of three-dimensional (3D) candidate positions in a geographic area of interest; predicting global navigation satellite system (GNSS) signal visibility at selected ones of the 3D candidate positions; receiving GNSS signals at a current location of the mobile device; determining observed satellite visibility based on the received GNSS signals; comparing the predicted satellite visibility with the observed satellite visibility; determining a position fix based on a result of the comparing; determining an indoor environment where the mobile device is located based at least on an altitude component of the position fix; obtainingstructural data for the identified indoor environment; and determining a floor lower bound for the current location of the mobile device based on the altitude component and the structural data.

The invention relates to a positioning method and device, computer equipment, a storage medium and a computer program product. The method can be applied to various scenes such as cloud technology, artificial intelligence, intelligent traffic and auxiliary driving. The method comprises the following steps: acquiring an initial position of a terminal based on inertial navigation data acquired by a current epoch terminal; performing region search based on the initial position to obtain candidate positions of the terminal, determining a reference position from the candidate positions according to the satellite visibility, and determining a visual satellite observed by the current epoch at the reference position and the base station together; a position observation equation constructed based on a reference position, a double-difference observation equation constructed by positioning observation data of a visual satellite based on a current epoch and a tightly-combined state error equation are solved, and positioning information obtained by inertial navigation data collected by a terminal is corrected according to an obtained state error. By adopting the method, the positioning accuracy can be improved.

The invention discloses a satellite search method and a receiver. The satellite search method comprises steps: a spatio-temporal lattice collection and satellite visibility corresponding to the spatio-temporal lattice collection are determined; according to confidence of each spatio-temporal lattice in the spatio-temporal lattice collection where the receiver is located and the satellite visibility, a search optimization level of a to-be-searched satellite is determined; and the satellite is searched according to the search optimization level of the to-be-searched satellite. According to the satellite search method and the receiver, the search sequence of the satellite can be determined according to the confidence and the satellite visibility, the hit rate of capture is improved, and the satellite search efficiency is further improved.

The invention discloses a satellite visibility judgment method combined with terrain influence. The method comprises the following steps of step 1, selecting an observation area, determining a stationpoint, calculating a satellite elevation angle by utilizing satellite coordinates and position coordinates of the station point, and judging the visibility of a satellite in the observation area; andstep 2, introducing topographic influence, calculating elevation angles of topographic sampling points, performing comparative analysis with elevation angles of satellites, and judging the visibilityof satellites again. The method is advantaged in that after terrain shielding of the experimental area is considered, the number of visible satellites and positioning accuracy of the satellites are obviously reduced compared with those when terrain shielding is not considered.

The invention discloses an urban canyon positioning method based on GNSS / vision / Lidar fusion. The method comprises the following steps: 1, judging satellite visibility through a fisheye camera; 2, further judging a satellite signal type based on a supervised learning mode; 3, determining the weight of a satellite, and carrying out multi-constellation positioning calculation based on the weight of the satellite to obtain an initial positioning solution; 4, correcting the initial positioning solution, and generating a candidate position; 5, screening the candidate position and calculating the weight of the candidate position according to the conformity degree of the satellite visibility of the candidate position and the recognized visible satellite in the step 1; and 6, calculating based on the candidate position weight to obtain a final positioning result. According to the method, the precision of the cross-street direction and the along-street direction in urban canyon GNSS positioning is effectively improved, and better real-time performance and convenience are achieved.

The invention relates to an inter-satellite link optimization method in the technical field of aerospace. The method comprises four steps of satellite orbit computing, satellite visibility judgment, inter-satellite transmission rate computing and optimum path selection. An inter-satellite link optimization comprises two parts of a data preprocessing module and a link selection module. The two modules are carried out according to a sequence, namely, the data preprocessing module is carried out firstly, and then the link selection module is carried out. According to the method and the system, aninter-satellite link optimization problem is divided into a time layer and a link layer. In a two-layer circulation mode, a transmission path with the maximum transmission rate at each moment withintask time is determined rapidly, the problem that a conventional optimization method is high in operation quantity and slow in solution speed is overcome, and the global optimum solution also can be ensured. According to the method and the system, through adoption of a modular thought, the inter-satellite link optimization system is provided. The system is simple in construction process and clearin input output interface. An inter-satellite link can be rapidly optimized.

The invention provides a vehicle localization integrity monitoring method based on wireless information interaction. The method includes that a vehicle receives and analyzes observation information of a navigational satellite through a satellite positioning receiver, an adjacent vehicle state information packet of vehicle networking is received and analyzed through a dedicated short range communication (DSRC) transmission unit that is carried by the vehicle, overall PL of the vehicle are determined according to the navigational satellite observation information and the adjacent vehicle state information packet, integrity state is evaluated according to the overall PL and AL of vehicle networking of the vehicle, and an adjusting scheme of a positioning structure of the vehicle is determined according to an evaluated result of the integrity state. A moving adjacent vehicle node is used as a reference target, observation information of automatic integrity monitoring that is implemented by the vehicle-mounted satellite positioning receiver is extended, and thereby, requirements of integrity monitoring for satellite visibility conditions can be lowered.

The invention relates to a method and a device for judging satellite visibility under carrier rotating condition. The method mainly includes: building a carrier coordinate system, calculating carrier rotating angles, and calculating satellite positions in the carrier coordinate system according to the carrier rotating angles; and calculating satellite elevation angles according to the satellite positions in the carrier coordinate system, comparing the satellite elevation angles and satellite screening angles, and judging satellite visibility according to comparison results. In an embodiment of the method and the device, the carrier coordinate system is built, positions of satellites in a horizontal coordinate system are shifted into the carrier coordinate system and the satellite elevation angles are calculated, and accordingly the satellite visibility can be effectively judged according to the satellite elevation angles under carrier rotating condition.

Embodiments of the present invention provide a link flooding attack protection method and device, wherein the method includes: obtaining each traffic transmission requirement of the satellite network, the inter-satellite visibility relationship between each satellite in the satellite network, and the The number of beams; based on the inter-satellite visibility relationship between the satellites and the number of beams of each satellite, determine several candidate transmission paths corresponding to each traffic transmission requirement; based on the respective traffic transmission requirements and their corresponding For several candidate transmission paths, determine the final transmission paths corresponding to the respective traffic transmission requirements and perform traffic allocation. The method and device provided by the embodiments of the present invention realize the balanced distribution of network traffic in the satellite network and ensure normal communication between the target area and the external network.

The invention discloses a quite-weak GNSS signal receiving high-orbit-satellite orbit positioning method. By means of the method, a GNSS ephemeris and celestial navigation information are used, the GNSS satellite visibility is analyzed, and a GNSS signal Doppler frequency range is estimated; the technology that an 8*20-ms coherent integration time matched filer is combined with a navigation message for estimation is used, influences of overturning of the navigation message are avoided, data of the navigation message can be correctly obtained, the problem that a coherent integration value is attenuated due to the code Doppler effect is solved, and open-loop-structure quite-weak GNSS signals with the signal intensity as low as -158 dBm can be accurately captured. Meanwhile, ionized layer delay is compensated, the super-long pseudo-range ambiguity is constructed, and accurate orbit positioning of a high-orbit satellite is achieved. The super-long coherent integration time is used, the signals can be intermittently and accurately captured, the weak signal capturing sensitivity is greatly improved, and the energy losses are reduced.

The invention discloses a positioning method, a positioning device and a computer readable storage medium, and relates to the field of wireless communication. The positioning method comprises the following steps of determining a satellite coverage function according to a reference station variable and the number of base stations to be selected, wherein the reference station variable represents whether the base station to be selected is used as a reference station or not; according to the reference station variable, and the time period during which a satellite can be observed by each base station to be selected, determining a satellite visibility function; determining an optimized objective function according to the satellite coverage function and the satellite visibility function; and determining the to-be-selected base station serving as a reference station when the optimized objective function value is the maximum, so as to carry out positioning according to the determined referencestation. Therefore, modification and upgrading can be carried out on the basis of an existing base station, so that the positioning function is achieved, and the positioning precision is improved on the basis that the station distribution cost is reduced as much as possible.

The method of the present invention proposes an on-orbit test verification method for positioning based on navigation satellite leakage signals. First, determine the flight height of the on-orbit test, calculate the relative positional relationship between the detector, the navigation satellite and the earth, and calculate the relative position of any position according to the positional relationship among the three. The angle between the earth vector of the navigation satellite and the detector vector is used to judge the visibility of the navigation satellite; according to the judgment result of the navigation satellite visibility, determine the altitude range and the startup time of the spaceborne navigation receiver, and according to the judgment result of the navigation visibility , analyze the flight attitude on orbit, and determine the beam angle range of the receiving antenna of the GNSS navigation receiving equipment; on-orbit test records the reception of navigation leakage signals and navigation positioning results; compare and analyze the receiving ability of GNSS receiver navigation leakage signals and its performance on navigation The method of the present invention solves the comprehensive functional performance test of the navigation satellite leakage signal receiving equipment of deep space exploration and high-orbit earth satellites and the system design problem of using the navigation satellite leakage signal for positioning.

The invention discloses a satellite visibility analysis method considering satellite occlusion conditions, comprising the following steps: S1, measuring the occlusion elevation angle Ei of a satellite at a target point; S2, calculating the spatial position of the satellite and carrying out coordinate transformation; and S3, in a station center coordinate system with a ground survey station R as the origin, calculating out the instantaneous elevation angle e and azimuth angle A of the satellite; calculating the occlusion elevation angle Ei at corresponding time and at corresponding azimuth A; comparing the elevation angle e of the satellite with the occlusion elevation angle Ei at the corresponding time and at the corresponding azimuth; if e<=Ei, judging that the satellite is not visible, and removing the satellite; if e>Ei, judging that the satellite is visible, and keeping the satellite; and filtering satellites according to the method, and obtaining an accurate satellite visibility result. The precision factor of a single survey station is evaluated according to the satellite visibility analysis result, and thus, ephemeris prediction is realized. The method of the invention is suitable for carrying out ephemeris prediction of GNSS observation in alpine and gorge regions and in regions difficult to observe under the effect of city buildings. The problem that the traditional ephemeris prediction result is inconsistent with the actual observation conditions is solved.

The embodiment of the invention provides a link flooding attack protection method and device. The method comprises the following steps: acquiring each flow transmission demand of a satellite network,an inter-satellite visibility relationship among satellites in the satellite network and the number of wave beams of each satellite; based on the inter-satellite visibility relationship between the satellites and the beam number of the satellites, determining a plurality of candidate transmission paths corresponding to each flow transmission demand; and based on each flow transmission demand and the plurality of candidate transmission paths corresponding to each flow transmission demand, determining a final transmission path corresponding to each flow transmission demand and carrying out flowdistribution. According to the method and the device provided by the embodiment of the invention, the balanced distribution of the network flow in the satellite network is realized, and the normal communication between the target area and the external network is ensured.

The invention provides an analysis method of constellation compatibility and interoperability of navigation satellites and relates to a definition and analysis method for the constellation compatibility and the interoperability of the navigation satellites. The compatibility is analyzed mainly from two aspects of long-term evolution and collision probability. Shot effects and long-term evolution rules of satellites on the medium orbit are given and a calculation method of the collision probability is provided. The interoperability is analyzed mainly from aspects of satellite visibility, position precision factors and positioning service availability, and calculation methods and effect factors of the satellite visibility, the position precision factors and the positioning service availability are provided respectively. According to the invention, the provided definitions of the constellation compatibility and the interoperability are different from definitions of common signal, time and coordinate compatibility and interoperability, and the provided analysis method is highly realizable in engineering.

The method involves regulating the power of transmission between first and second stations in a multiple satellite visibility satellite telecommunication network. The method comprises the following cyclic steps: regulation, for each of said N channels, of an isolated transmit power level command signal such that when it commands the power at which the first station transmits the first isolated signal in each channel the quality level of the corresponding isolated second signal received by the second station is equal to a reference quality level, and regulation, for all of the N channels, of N combined transmit power level command signals such that when they command the levels at which the first station respectively transmits the N first combined signals on the N channels the quality level of the global signal received formed from the N combined second signals is equal to the reference quality level.