CN111239777B - Satellite cluster hierarchical positioning method based on position fingerprint - Google Patents
Satellite cluster hierarchical positioning method based on position fingerprint Download PDFInfo
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
- G01S19/01—Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
- G01S19/13—Receivers
- G01S19/24—Acquisition or tracking or demodulation of signals transmitted by the system
- G01S19/25—Acquisition or tracking or demodulation of signals transmitted by the system involving aiding data received from a cooperating element, e.g. assisted GPS
- G01S19/258—Acquisition or tracking or demodulation of signals transmitted by the system involving aiding data received from a cooperating element, e.g. assisted GPS relating to the satellite constellation, e.g. almanac, ephemeris data, lists of satellites in view
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F17/00—Digital computing or data processing equipment or methods, specially adapted for specific functions
- G06F17/10—Complex mathematical operations
- G06F17/16—Matrix or vector computation, e.g. matrix-matrix or matrix-vector multiplication, matrix factorization
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/70—Reducing energy consumption in communication networks in wireless communication networks
Abstract
The invention provides a satellite cluster hierarchical positioning method based on position fingerprints, which comprises the steps of firstly calculating sparse Radio maps at larger reference point intervals so that the sparse Radio maps occupy smaller storage space and realize coarse positioning of member satellites; and determining a fine positioning area by taking the coarse positioning result as a center, dividing the fine positioning area by fine reference points, calculating a Radio Map of the fine positioning area according to the current moment, and carrying out fine positioning on the member star to obtain a final positioning result of the member star. The method can reduce the storage space by increasing the online calculation time and reduce the influence of time offset on the positioning precision. The method can reduce the influence of time offset on positioning accuracy, greatly reduce the storage space and can be better applied to practical engineering.
Description
Technical Field
The invention belongs to the technical field of signal processing, and particularly relates to a satellite cluster hierarchical positioning method based on position fingerprints.
Background
Satellite clusters refer to a distributed satellite system consisting of a plurality of satellites. One or a plurality of satellites are selected as reference satellites, and the rest satellites are member satellites. The reference star flies along a preset orbit, and the member star accompanies the reference star. As a distributed satellite system, a relatively stable distribution is maintained among satellites in a satellite cluster, and information interaction is realized among the satellites through inter-satellite links, so that the satellites cooperate with each other to jointly complete one or more tasks. Compared with the defects of long design period, high cost and the like of a large satellite, a small satellite has the advantages of high integration level, short design period, low cost and the like, so that the small satellite has the irreplaceable advantages.
Conventional autonomous positioning of satellite clusters is mainly directed to two satellites or small-scale satellite clusters. With the continuous development of task demands of aerospace tasks, the number of satellite cluster members is continuously increased, the size is further reduced, and functions tend to be specialized, so that a quick, low-cost and cluster-autonomous positioning navigation technology needs to be researched. The positioning method based on the position fingerprint is a mature positioning method, and the fingerprint positioning system has the characteristics of low cost and simple structure, so that the fingerprint positioning method is expanded to satellite cluster positioning, the development cost can be effectively reduced, and the method has important significance for the cooperative control of satellite clusters and the development of satellite technology.
Disclosure of Invention
The invention aims to solve the problems in the prior art and provides a satellite cluster hierarchical positioning method based on position fingerprints.
The invention is realized by the following technical scheme, and provides a satellite cluster hierarchical positioning method based on position fingerprints, which comprises three stages: constructing a coordinate system stage, an off-line stage and an on-line stage; establishing an LVLH coordinate system and a reference star body coordinate system in the stage of establishing the coordinate system; in the off-line stage, a sparse Radio Map is calculated from the ground and stored in a member star; the online phase is divided into three sub-phases: a member star rough positioning stage, a fingerprint library online calculation stage and a member star fine positioning stage; in a member star coarse positioning stage, a member star selects an RSS matrix at the latest moment according to the current moment and the sparse Radio Map, and performs coarse positioning by combining an RSS vector obtained in real time; in the on-line calculation stage of the fingerprint library, the member star calculates a dense Radio Map according to the coarse positioning result; and in the member star fine positioning stage, the member star carries out fine positioning according to the RSS vector acquired in real time and the calculated dense Radio Map to obtain the final estimated position of the member star.
Further, the stage of constructing the coordinate system specifically comprises the following steps:
the number of the reference satellites in the satellite cluster is 4, the rest satellites are member satellites, the reference satellites are in pair and fly around, the center of the flying around is called as a center satellite, and the center satellite is a virtual point and is not a satellite in practice; the member star carries out accompanying flight nearby the reference star;
LVLH coordinate system origin O L The 'center star' located in the satellite cluster meets the right hand rule between coordinate axes; o (O) L X L The axial direction is the tangential direction of the movement of the center star, O L Y L The axis pointing from the central star to the earth centroid, O L Z L The axis being perpendicular to X L Y L A plane;
origin O of reference star body coordinate system B The coordinate axis direction is related to the gesture of the reference star; o (O) B X B The axis is the 0 degree direction of the antenna pattern, O B Y B The axis is the 90-degree direction of the antenna pattern, O B Z B The axis being perpendicular to X B Y B Plane, O B X B Shaft and O B Y B The shaft meets the right hand rule; and a corresponding reference star body coordinate system needs to be established for all the 4 reference stars.
Further, the off-line stage comprises the following specific steps:
step 1, determining the side length as l under the LVLH coordinate system 0 Is uniformly divided into n coarse positioning areas with side length of l 1 Each side is l 1 The central position of the grid of the (c) is used as a reference point of the coarse positioning area to obtain a reference point position vector L:
wherein, (x) j ,y j ,z j ) J=1, 2,3 … n is the coordinate of the jth reference point in the coarse positioning area under the LVLH coordinate system;
step 2, dividing the movement period T of the reference star into m time periods at intervals delta T, wherein the central moment of each time period is as follows:
T 1 ,T 2 ,…,T m (2)
obtaining T according to a reference star motion equation i I=1, 2, … m time instant 4 reference star position vectors:
step 3, obtaining the kth reference star through preset parameters, wherein k=1, 2,3,4, and at T i Transmit power at time of dayThe kth reference star has a coordinate (x) in the LVLH coordinate system k (T i ),y k (T i ),z k (T i ) A) the rotation angle of the kth reference star body coordinate system relative to the LVLH coordinate system is +.> θ k (T i )，ψ k (T i ) The rotation angles of the three coordinate axes are respectively corresponding;
calculate at T i Position of the jth reference point relative to the kth reference point in the time coarse positioning area:
step 4, calculating at T i The moment LVLH coordinate system is transformed into a rotation matrix of a kth reference star body coordinate system:
wherein, the liquid crystal display device comprises a liquid crystal display device,
step 5, calculating the j-th reference point at T i Rectangular coordinates of the kth reference star body coordinate system at the moment:
in order to calculate the transmission loss using the antenna pattern, it is necessary to transform rectangular coordinates into spherical coordinates, and the transformation formula from rectangular coordinates to spherical coordinates is:
thus, the jth reference point is at T i The spherical coordinates in the kth reference star body coordinate system at the moment are expressed as:
wherein r is k (T i ) Is the j-th reference point at T i The distance between the moment and the kth reference star; θ G,k (T i ) At T for the jth reference point i The moment is relative to the zenith angle of the kth reference star;at T for the jth reference point i Azimuth angle of moment relative to kth reference star;
step 6, calculating at T according to the spherical coordinates i Time antenna gain:
wherein G is max For the maximum gain of the transmitting antenna,f is the directivity function of the antenna max Is the maximum of the antenna directivity function;
calculating the transmission loss of a signal transmitted by a reference star to a member star:
wherein f is the antenna transmission frequency, G R Is the gain of the satellite receiving antenna;
thus T is i The received signal strength RSS of the kth reference star received at the jth reference point at the moment is:
step 7, repeating the steps 1 to 6 to obtain T i The RSS of the 4 reference satellites received at all reference points at the moment, constitutes T as follows i Time RSS matrix:
wherein, the liquid crystal display device comprises a liquid crystal display device,is T i A vector composed of RSSs of 4 reference points is received at the j-th reference point at the moment;
step 8, repeating the steps 1 to 7 to obtain T 1 ,T 2 ,…,T m RSS matrix of time:
R 1 ,R 2 ,…,R m (16)
thus, a sparse Radio Map is obtained:
M＝[L R 1 R 2 … R m ] (17)
the sparse Radio Map is calculated in advance by the ground and stored in each member star, and the member star is called when being positioned.
Further, the member star coarse positioning stage specifically comprises the following steps:
the member star acquires the RSSs of the 4 reference stars received at the current moment:
acquiring the current time T according to the satellite clock, and at the time T 1 ,T 2 ,…,T m A time T closest to the current time T is selected * T is obtained according to formula (17) * Sparse Radio Map at moment:
RSS and T obtained on line by member star * RSS in the sparse Radio Map at the moment is matched, and the coarse positioning result of the member star is obtained according to a kNN algorithm:
further, the fingerprint library online calculation stage and the member star positioning stage specifically include:
determining a member star fine positioning area according to a member star coarse positioning result: the member star coarse positioning result is taken as the center, and the side length is determined to be l 2 Is used as a member star positioning area;
dividing the fine positioning area into w sides with length of l according to uniform division 3 Each side is l 3 The central position of the grid of the (c) is used as a reference point of the fine positioning area;
obtaining a reference point position vector of the fine positioning area:
according to the operation parameters of the reference star, the emission power of 4 reference stars at the current moment, the coordinates under the LVLH coordinate system and the rotation angle of the reference star body coordinate system relative to the LVLH coordinate system are obtained, so that the RSS matrix of the precise positioning area at the current moment is calculated:
thus, dense Radio Map is expressed as:
matching the RSS vector obtained by the member star on line with the RSS of each reference point in the dense Radio Map at the current moment, and obtaining the accurate positioning result of the member star according to the nearest neighbor algorithm, wherein the accurate positioning result is as follows:
according to the satellite cluster hierarchical positioning method based on the position fingerprint, firstly, the sparse Radio Map is calculated at larger reference point intervals, so that the sparse Radio Map occupies smaller storage space, and coarse positioning of member satellites is realized; and determining a fine positioning area by taking the coarse positioning result as a center, dividing the fine positioning area by fine reference points, calculating a Radio Map of the fine positioning area according to the current moment, and carrying out fine positioning on the member star to obtain a final positioning result of the member star. The method can reduce the storage space by increasing the online calculation time and reduce the influence of time offset on the positioning precision. Experimental results show that when the side lengths of the fine positioning areas are respectively 20m, 30m, 40m and 50m, the probability of positioning errors smaller than 5m respectively exceeds 60%, 75%, 80% and 85%; the method can reduce the influence of time offset on positioning accuracy, greatly reduce the storage space and can be better applied to practical engineering.
Drawings
FIG. 1 is a schematic view of a satellite cluster;
FIG. 2 is a schematic diagram of a coordinate system;
FIG. 3 is a schematic diagram of coarse positioning region gridding and reference point selection;
FIG. 4 is a schematic diagram of rectangular coordinates and spherical coordinates in a reference star body coordinate system;
FIG. 5 is a schematic diagram of a fine positioning area selection;
FIG. 6 is a schematic diagram of fine positioning region gridding and reference point selection;
FIG. 7 is a flow chart of a method for hierarchical positioning of satellite clusters based on location fingerprints;
FIG. 8 is a timing offset diagram;
FIG. 9 is a schematic diagram of a positioning error CDF curve;
fig. 10 is a schematic diagram showing the effect of time offset on positioning error.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
With reference to fig. 7, the invention provides a satellite cluster hierarchical positioning method based on position fingerprints, which comprises three stages: constructing a coordinate system stage, an off-line stage and an on-line stage; establishing an LVLH coordinate system and a reference star body coordinate system in the stage of establishing the coordinate system; in the off-line stage, a sparse Radio Map is calculated from the ground and stored in a member star; the online phase is divided into three sub-phases: a member star rough positioning stage, a fingerprint library online calculation stage and a member star fine positioning stage; in a member star coarse positioning stage, a member star selects an RSS matrix at the latest moment according to the current moment and the sparse Radio Map, and performs coarse positioning by combining an RSS vector obtained in real time; in the on-line calculation stage of the fingerprint library, the member star calculates a dense Radio Map according to the coarse positioning result; and in the member star fine positioning stage, the member star carries out fine positioning according to the RSS vector acquired in real time and the calculated dense Radio Map to obtain the final estimated position of the member star.
The construction of the coordinate system comprises the following steps:
in a satellite cluster, a reference star is responsible for coordination and control of the whole satellite cluster, and a member star is responsible for data acquisition and forwarding. The standard star has large volume and mass, and can determine the accurate orbit position through ephemeris or high-precision positioning equipment; the satellite is much smaller in size and mass and limited in load, so that the positioning equipment capable of being carried is limited. The number of the reference satellites in the satellite cluster is 4, the rest satellites are member satellites, the reference satellites are in pair and fly around, the center of the flying around is called as a center satellite, the center satellite is a virtual point, and the satellite is not actually a satellite; the member star flies nearby the reference star, as shown in fig. 1;
referring to FIG. 2, LVLH coordinate system origin O L The 'center star' located in the satellite cluster meets the right hand rule between coordinate axes; o (O) L X L The axial direction is the tangential direction of the movement of the center star, O L Y L The axis pointing from the central star to the earth centroid, O L Z L The axis being perpendicular to X L Y L A plane;
origin O of reference star body coordinate system B The coordinate axis direction is related to the gesture of the reference star; o (O) B X B The axis is the 0 degree direction of the antenna pattern, O B Y B The axis is the 90-degree direction of the antenna pattern, O B Z B The axis being perpendicular to X B Y B Plane, O B X B Shaft and O B Y B The shaft meets the right hand rule; and a corresponding reference star body coordinate system needs to be established for all the 4 reference stars. The satellite cluster autonomous positioning algorithm is to determine the relative positions of the member satellites in the satellite cluster, so that the positions of the reference satellites and the member satellites are represented under an LVLH coordinate system.
The off-line stage comprises the following specific steps:
step 1, determining the side length as l under the LVLH coordinate system 0 Is uniformly divided into n coarse positioning areas with side length of l 1 As shown in FIG. 3, each side is l 1 The central position of the grid of the (c) is used as a reference point of the coarse positioning area to obtain a reference point position vector L:
wherein, (x) j ,y j ,z j ) J=1, 2,3 … n is the coordinate of the jth reference point in the coarse positioning area under the LVLH coordinate system;
step 2, dividing the movement period T of the reference star into m time periods at intervals delta T, wherein the central moment of each time period is as follows:
T 1 ,T 2 ,…,T m (2)
obtaining T according to a reference star motion equation i I=1, 2, … m time instant 4 reference star position vectors:
step 3, obtaining the kth reference star through preset parameters, wherein k=1, 2,3,4, and at T i Transmit power at time of dayThe kth reference star has a coordinate (x) in the LVLH coordinate system k (T i ),y k (T i ),z k (T i ) A) the rotation angle of the kth reference star body coordinate system relative to the LVLH coordinate system is +.> θ k (T i )，ψ k (T i ) The rotation angles of the three coordinate axes are respectively corresponding;
calculate at T i Position of the jth reference point relative to the kth reference point in the time coarse positioning area:
step 4, calculating at T i The moment LVLH coordinate system is transformed into a rotation matrix of a kth reference star body coordinate system:
wherein, the liquid crystal display device comprises a liquid crystal display device,
step 5, calculating the j-th reference point at T i Rectangular coordinates of the kth reference star body coordinate system at the moment:
in order to calculate the transmission loss using the antenna pattern, it is necessary to transform the rectangular coordinates into the spherical coordinates, and as shown in fig. 4, the transformation formula from rectangular coordinates to spherical coordinates is:
thus, the jth reference point is at T i The spherical coordinates in the kth reference star body coordinate system at the moment are expressed as:
wherein r is k (T i ) Is the j-th reference point at T i The distance between the moment and the kth reference star; θ G,k (T i ) At T for the jth reference point i The moment is relative to the zenith angle of the kth reference star;at T for the jth reference point i Azimuth angle of moment relative to kth reference star;
step 6, calculating at T according to the spherical coordinates i Time antenna gain:
wherein G is max For the maximum gain of the transmitting antenna,f is the directivity function of the antenna max Is the maximum of the antenna directivity function;
calculating the transmission loss of a signal transmitted by a reference star to a member star:
wherein f is the antenna transmission frequency, G R Is the gain of the satellite receiving antenna;
thus T is i The received signal strength RSS of the kth reference star received at the jth reference point at the moment is:
step 7, repeating the steps 1 to 6 to obtain T i The RSS of the 4 reference satellites received at all reference points at the moment, constitutes T as follows i Time RSS matrix:
wherein, the liquid crystal display device comprises a liquid crystal display device,is T i A vector composed of RSSs of 4 reference points is received at the j-th reference point at the moment;
step 8, repeating the steps 1 to 7 to obtain T 1 ,T 2 ,…,T m RSS matrix of time:
R 1 ,R 2 ,…,R m (16)
thus, a sparse Radio Map is obtained:
M＝[L R 1 R 2 … R m ] (17)
the sparse Radio Map is calculated in advance by the ground and stored in each member star, and the member star is called when being positioned.
The member star coarse positioning stage specifically comprises the following steps:
the member star acquires the RSSs of the 4 reference stars received at the current moment:
acquiring the current time T according to the satellite clock, and at the time T 1 ,T 2 ,…,T m A time T closest to the current time T is selected * T is obtained according to formula (17) * Sparse Radio Map at moment:
RSS and T obtained on line by member star * RSS in the sparse Radio Map at the moment is matched, and the coarse positioning result of the member star is obtained according to a kNN algorithm:
the fingerprint library online calculation stage and the member star positioning stage specifically comprise the following steps:
determining a member star fine positioning area according to a member star coarse positioning result: the member star coarse positioning result is taken as the center, and the side length is determined to be l 2 Is used as a member star positioning area; as shown in fig. 5;
dividing the fine positioning area into w sides with length of l according to uniform division 3 Each side is l 3 The central position of the grid of the (c) is used as a reference point of the fine positioning area; as shown in fig. 6;
obtaining a reference point position vector of the fine positioning area:
according to the operation parameters of the reference star, the emission power of 4 reference stars at the current moment, the coordinates under the LVLH coordinate system and the rotation angle of the reference star body coordinate system relative to the LVLH coordinate system are obtained, so that the RSS matrix of the precise positioning area at the current moment is calculated:
thus, dense Radio Map is expressed as:
matching the RSS vector obtained by the member star on line with the RSS of each reference point in the dense Radio Map at the current moment, and obtaining the accurate positioning result of the member star according to the nearest neighbor algorithm, wherein the accurate positioning result is as follows:
simulation experiment
In the autonomous positioning process of the member star, a certain time offset exists between the moment of the member star and the discrete moment of the sparse Radio Map construction, as shown in fig. 8.
In fig. 8, triangles represent times when the sparse Radio Map is established, diamonds represent current positioning times, and Δt represents time intervals when the sparse Radio Map is established. And the member star can select one sparse Radio Map time closest to the current positioning time to position. In the actual positioning process, since deltat is always greater than 0, there is a deviation deltat between the current autonomous positioning moment of the member star and the moment in the sparse Radio Map. The smaller the time offset, the closer the positioning time is to the establishment time of the sparse Radio Map, and the closer the position of the positioning time reference star is to the position of the reference star in the establishment of the sparse Radio Map.
Let l 0 ＝1000m，l 1 ＝20m，l 3 When the time offset is 0, the method and the traditional method of the invention have a positioning error Cumulative Distribution Function (CDF) curve and a storage space along with the side length l of the accurate positioning area 2 The variation of (2) is shown in fig. 9.
As can be seen from fig. 9, when the time offset is 0, the positioning accuracy of the conventional method is highest, the positioning accuracy of the method of the present invention is lower than that of the conventional method, and the accuracy is improved as the range of the fine positioning area increases, but as can be seen from table 1, the method of the present invention can greatly reduce the storage space, and the storage space is basically unchanged as the edge of the fine positioning area changes. This is because the method of the present invention has two processes of establishing the Radio Map. The establishment of the sparse Radio Map is the same as the traditional mode, but the interval of the reference points is large at the moment, the accurate positioning result cannot be obtained, only a rough range can be obtained, but the storage space of the sparse Radio Map is smaller; the reference point spacing of the dense Radio Map is very small, but the range of the dense Radio Map is limited in the positioning range determined by coarse positioning, and the range is far smaller than the initial positioning range, so that the dense Radio Map occupies only a small storage space. Therefore, the whole storage space of the positioning method provided by the invention is very small, and the positioning method can be applied to practice.
TABLE 1 memory space for the methods and conventional methods of the present invention
Fixing the side length of the precise positioning area 2 =30m, Δt=30s, the time offset Δt is from-15 s to 15s, the positioning error at the confidence probability of 67% is counted, and compared with the conventional method, as shown in fig. 10.
As can be seen from fig. 10, the conventional method is more affected by the time offset, and the larger the time offset is, the larger the positioning error is. This is because the position of the positioning time reference star is different from the position where the Radio Map constructs the time reference star due to the influence of the time offset, and thus a positioning error is generated. The larger the time offset is, the larger the difference between the true position of the reference star and the position of the reference star at the Radio Map construction time is, thereby causing an increase in positioning error. While the method of the present invention is also affected to some extent by time shifts, it can be seen from the figure that the method of the present invention is much less affected by time shifts, especially when the time shifts are larger. This is because: the sparse Radio Map is established at a certain time interval, and the coarse positioning result is affected by the time offset, but the dense Radio Map is established according to the current positioning time, so that the influence caused by the time offset can be reduced to a certain extent.
The above describes in detail a satellite cluster hierarchical positioning method based on location fingerprint, and specific examples are applied to illustrate the principle and implementation of the present invention, and the above description of the examples is only used to help understand the method and core idea of the present invention; meanwhile, as those skilled in the art will have variations in the specific embodiments and application scope in accordance with the ideas of the present invention, the present description should not be construed as limiting the present invention in view of the above.
Claims (2)
1. A satellite cluster hierarchical positioning method based on position fingerprints is characterized by comprising the following steps of: the method is divided into three stages: constructing a coordinate system stage, an off-line stage and an on-line stage; establishing an LVLH coordinate system and a reference star body coordinate system in the stage of establishing the coordinate system; in the off-line stage, a sparse Radio Map is calculated from the ground and stored in a member star; the online phase is divided into three sub-phases: a member star rough positioning stage, a fingerprint library online calculation stage and a member star fine positioning stage; in a member star coarse positioning stage, a member star selects an RSS matrix at the latest moment according to the current moment and the sparse Radio Map, and performs coarse positioning by combining an RSS vector obtained in real time; in the on-line calculation stage of the fingerprint library, the member star calculates a dense Radio Map according to the coarse positioning result; in the member star fine positioning stage, the member star carries out fine positioning according to the RSS vector acquired in real time and the calculated dense Radio Map to obtain the final estimated position of the member star;
the off-line stage comprises the following specific steps:
step 1, determining the side length as l under the LVLH coordinate system 0 Is uniformly divided into n coarse positioning areas with side length of l 1 Each side is l 1 The central position of the grid of the (c) is used as a reference point of the coarse positioning area to obtain a reference point position vector L:
wherein, (x) j ,y j ,z j ) J=1, 2,3 … n is the coordinate of the jth reference point in the coarse positioning area under the LVLH coordinate system;
step 2, dividing the movement period T of the reference star into m time periods at intervals delta T, wherein the central moment of each time period is as follows:
T 1 ,T 2 ,…,T m (2)
obtaining T according to a reference star motion equation i I=1, 2, … m time instant 4 reference star position vectors:
step 3, obtaining the kth reference star through preset parameters, wherein k=1, 2,3,4, and at T i Transmit power at time of dayThe kth reference star has a coordinate (x) in the LVLH coordinate system k (T i ),y k (T i ),z k (T i ) A) the rotation angle of the kth reference star body coordinate system relative to the LVLH coordinate system is +.> θ k (T i )，ψ k (T i ) The rotation angles of the three coordinate axes are respectively corresponding;
calculate at T i Position of the jth reference point relative to the kth reference point in the time coarse positioning area:
step 4, calculating at T i The moment LVLH coordinate system is transformed into a rotation matrix of a kth reference star body coordinate system:
wherein, the liquid crystal display device comprises a liquid crystal display device,
step 5, calculating the j-th reference point at T i Rectangular coordinates of the kth reference star body coordinate system at the moment:
in order to calculate the transmission loss using the antenna pattern, it is necessary to transform rectangular coordinates into spherical coordinates, and the transformation formula from rectangular coordinates to spherical coordinates is:
thus, the jth reference point is at T i The spherical coordinates in the kth reference star body coordinate system at the moment are expressed as:
wherein r is k (T i ) Is the j-th reference point at T i The distance between the moment and the kth reference star; θ G,k (T i ) At T for the jth reference point i The moment is relative to the zenith angle of the kth reference star;at T for the jth reference point i Azimuth angle of moment relative to kth reference star;
step 6, calculating at T according to the spherical coordinates i Time antenna gain:
wherein G is max For the maximum gain of the transmitting antenna,f is the directivity function of the antenna max Is the maximum of the antenna directivity function;
calculating the transmission loss of a signal transmitted by a reference star to a member star:
wherein f is the antenna transmission frequency, G R Is the gain of the satellite receiving antenna;
thus T is i The received signal strength RSS of the kth reference star received at the jth reference point at the moment is:
step 7, repeating the steps 1 to 6 to obtain T i The RSS of the 4 reference satellites received at all reference points at the moment, constitutes T as follows i Time RSS matrix:
wherein, the liquid crystal display device comprises a liquid crystal display device,is T i A vector composed of RSSs of 4 reference points is received at the j-th reference point at the moment;
step 8, repeating the steps 1 to 7 to obtain T 1 ,T 2 ,…,T m RSS matrix for time of day：
R 1 ,R 2 ,…,R m (16)
Thus, a sparse RadioMap is obtained:
M＝[L R 1 R 2 … R m ] (17)
the sparse RadioMap is calculated by the ground in advance and stored in each member star, and the member star is called when being positioned;
the member star coarse positioning stage specifically comprises the following steps:
the member star acquires the RSSs of the 4 reference stars received at the current moment:
acquiring the current time T according to the satellite clock, and at the time T 1 ,T 2 ,…,T m A time T closest to the current time T is selected * T is obtained according to formula (17) * Sparse Radio Map at moment:
RSS and T obtained on line by member star * RSS in the sparse Radio Map at the moment is matched, and the coarse positioning result of the member star is obtained according to a kNN algorithm:
the fingerprint library online calculation stage and the member star positioning stage specifically comprise the following steps:
determining a member star fine positioning area according to a member star coarse positioning result: the member star coarse positioning result is taken as the center, and the side length is determined to be l 2 Is used as a member star positioning area;
dividing the fine positioning area into w sides with length of l according to uniform division 3 To each side lengthIs l 3 The central position of the grid of the (c) is used as a reference point of the fine positioning area;
obtaining a reference point position vector of the fine positioning area:
according to the operation parameters of the reference star, the emission power of 4 reference stars at the current moment, the coordinates under the LVLH coordinate system and the rotation angle of the reference star body coordinate system relative to the LVLH coordinate system are obtained, so that the RSS matrix of the precise positioning area at the current moment is calculated:
thus, dense Radio Map is expressed as:
matching the RSS vector obtained by the member star on line with the RSS of each reference point in the dense Radio Map at the current moment, and obtaining the accurate positioning result of the member star according to the nearest neighbor algorithm, wherein the accurate positioning result is as follows:
2. the method according to claim 1, characterized in that: the construction of the coordinate system comprises the following steps:
the number of the reference satellites in the satellite cluster is 4, the rest satellites are member satellites, the reference satellites are in pair and fly around, the center of the flying around is called as a center satellite, and the center satellite is a virtual point and is not a satellite in practice; the member star carries out accompanying flight nearby the reference star;
LVLH coordinate system origin O L The 'center star' located in the satellite cluster meets the right hand rule between coordinate axes; o (O) L X L The axial direction is the tangential direction of the movement of the center star, O L Y L The axis pointing from the central star to the earth centroid, O L Z L The axis being perpendicular to X L Y L A plane;
origin O of reference star body coordinate system B The coordinate axis direction is related to the gesture of the reference star; o (O) B X B The axis is the 0 degree direction of the antenna pattern, O B Y B The axis is the 90-degree direction of the antenna pattern, O B Z B The axis being perpendicular to X B Y B Plane, O B X B Shaft and O B Y B The shaft meets the right hand rule; and a corresponding reference star body coordinate system needs to be established for all the 4 reference stars.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2685753A1 (en) * | 2012-07-11 | 2014-01-15 | Forsvarets Forskningsinstitutt | Large-scale peer-to-peer discovery mechanism for frequency allocation |
| WO2017021218A1 (en) * | 2015-07-31 | 2017-02-09 | Avanti Communications Group Plc | Satellite operations support system |
| CN109459016A (en) * | 2018-11-15 | 2019-03-12 | 上海航天控制技术研究所 | A kind of micro-nano satellite cluster relative positioning method based on location fingerprint |
Family Cites Families (32)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA714200A (en) * | 1965-07-20 | J. Herzl Peter | Coarse-fine positioning system | |
| US5038333A (en) * | 1989-05-05 | 1991-08-06 | International Business Machines Corporation | Positioning systems including reliable track crossing detection for high speed relative motions |
| US5153494A (en) * | 1990-04-06 | 1992-10-06 | International Business Machines Corp. | Ultrafast electro-dynamic x, y and theta positioning stage |
| AU7118896A (en) * | 1995-09-28 | 1997-04-17 | Lockheed Martin Corporation | Techniques for optimizing an autonomous star tracker |
| DE59701839D1 (en) * | 1996-11-15 | 2000-07-13 | Contraves Space Ag Zuerich | Method and arrangement for maintaining the position of a geostationary swarm of satellites using an optical satellite connection |
| JPH10300835A (en) * | 1997-04-25 | 1998-11-13 | Lockheed Martin Corp | Quick and accurate specification of geographical position for cellular telephone using gps satellite system |
| US6313786B1 (en) * | 1998-07-02 | 2001-11-06 | Snaptrack, Inc. | Method and apparatus for measurement processing of satellite positioning system (SPS) signals |
| US7363044B2 (en) * | 2002-09-30 | 2008-04-22 | Motorola, Inc. | System and method for aiding a location determination in a positioning system |
| US7592908B2 (en) * | 2003-08-13 | 2009-09-22 | Arbitron, Inc. | Universal display exposure monitor using personal locator service |
| EP1626288A1 (en) * | 2004-08-13 | 2006-02-15 | Frédéric Henry | Hybrid positioning system |
| JP2007263637A (en) * | 2006-03-28 | 2007-10-11 | Mitsubishi Electric Corp | Apparatus and method for positioning, and program |
| US7839331B2 (en) * | 2007-03-30 | 2010-11-23 | Sirf Technology, Inc. | Satellite clock prediction |
| US9366763B2 (en) * | 2009-02-04 | 2016-06-14 | Qualcomm Incorporated | Method and apparatus for position determination with hybrid SPS orbit data |
| US8089398B2 (en) * | 2008-06-06 | 2012-01-03 | Skyhook Wireless, Inc. | Methods and systems for stationary user detection in a hybrid positioning system |
| TWI384201B (en) * | 2008-08-21 | 2013-02-01 | Mstar Semiconductor Inc | Identification tag navigation system and method of the same |
| CA2928283A1 (en) * | 2008-09-10 | 2010-03-18 | Nextnav, Llc | Wide area positioning system |
| CN101672653A (en) * | 2008-09-12 | 2010-03-17 | 晨星软件研发(深圳)有限公司 | Navigation system, navigation device and navigation method for identifying labels |
| WO2010052496A1 (en) * | 2008-11-04 | 2010-05-14 | The University Court Of The University Of Edinburgh | Improvements to assisted positioning systems |
| JP5354717B2 (en) * | 2008-11-06 | 2013-11-27 | 学校法人東京理科大学 | Displacement measurement system, satellite signal receiving apparatus, and satellite positioning method |
| US8660577B2 (en) * | 2009-12-04 | 2014-02-25 | Nokia Corporation | Method and apparatus for on-device positioning using compressed fingerprint archives |
| WO2012011624A1 (en) * | 2010-07-21 | 2012-01-26 | (주)브이아이소프트 | System and method for indoor navigation based on a wi-fi radio map and utilizing user mobility in location estimation |
| KR101186303B1 (en) * | 2010-11-04 | 2012-09-26 | 신희태 | Indoor positioning system using a satellite signal generator and the method thereof |
| CA2790461C (en) * | 2011-10-06 | 2016-10-25 | The Boeing Company | Precise absolute time transfer from a satellite system |
| WO2013065042A1 (en) * | 2011-11-02 | 2013-05-10 | Ronen Shai | Generating and using a location fingerprinting map |
| CN102679945B (en) * | 2012-06-05 | 2014-03-05 | 哈尔滨工业大学 | Satellite pointing and attitude measuring method and device based on three-point reflecting cooperation |
| WO2014000090A1 (en) * | 2012-06-26 | 2014-01-03 | The Governing Council Of The University Of Toronto | System, method and computer program for dynamic generation of a radio map |
| FR3030057B1 (en) * | 2014-12-12 | 2017-01-27 | Thales Sa | METHOD AND SYSTEM FOR VALIDATION OF SATELLITE GEOLOCATION |
| GB201704216D0 (en) * | 2017-03-16 | 2017-05-03 | Ranplan Wireless Network Design Ltd | WIFI multi-band fingerprint-based indoor positioning |
| DE102018202983A1 (en) * | 2018-02-28 | 2019-08-29 | Robert Bosch Gmbh | Method for determining a data profile for the satellite-based determination of a position of a vehicle |
| WO2019208592A1 (en) * | 2018-04-27 | 2019-10-31 | 国立大学法人静岡大学 | Satellite positioning system |
| CN109581445B (en) * | 2018-11-01 | 2021-03-19 | 北京航空航天大学 | ARAIM subset selection method and system based on Beidou constellation |
| CN110536235B (en) * | 2019-08-30 | 2020-12-22 | 哈尔滨工程大学 | Indoor positioning method based on position fingerprint screening |
-
2020
- 2020-01-07 CN CN202010014588.1A patent/CN111239777B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2685753A1 (en) * | 2012-07-11 | 2014-01-15 | Forsvarets Forskningsinstitutt | Large-scale peer-to-peer discovery mechanism for frequency allocation |
| WO2017021218A1 (en) * | 2015-07-31 | 2017-02-09 | Avanti Communications Group Plc | Satellite operations support system |
| CN109459016A (en) * | 2018-11-15 | 2019-03-12 | 上海航天控制技术研究所 | A kind of micro-nano satellite cluster relative positioning method based on location fingerprint |
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