CN110988851B - Different-orbit single-star time-sharing frequency measurement positioning method based on star optimization - Google Patents
Different-orbit single-star time-sharing frequency measurement positioning method based on star optimization Download PDFInfo
- Publication number
- CN110988851B CN110988851B CN201911314001.2A CN201911314001A CN110988851B CN 110988851 B CN110988851 B CN 110988851B CN 201911314001 A CN201911314001 A CN 201911314001A CN 110988851 B CN110988851 B CN 110988851B
- Authority
- CN
- China
- Prior art keywords
- satellite
- positioning
- observation
- star
- time
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000005259 measurement Methods 0.000 title claims abstract description 83
- 238000000034 method Methods 0.000 title claims abstract description 26
- 238000005457 optimization Methods 0.000 title claims abstract description 14
- 230000005855 radiation Effects 0.000 claims abstract description 59
- 238000010790 dilution Methods 0.000 claims abstract description 12
- 239000012895 dilution Substances 0.000 claims abstract description 12
- 101000606504 Drosophila melanogaster Tyrosine-protein kinase-like otk Proteins 0.000 claims abstract description 11
- 230000000007 visual effect Effects 0.000 claims abstract description 7
- 239000011159 matrix material Substances 0.000 claims description 18
- 238000009795 derivation Methods 0.000 claims description 4
- 230000004069 differentiation Effects 0.000 claims description 3
- 230000008569 process Effects 0.000 claims description 2
- 230000000694 effects Effects 0.000 abstract description 9
- 229910052741 iridium Inorganic materials 0.000 description 17
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 description 17
- 238000010586 diagram Methods 0.000 description 5
- 238000004088 simulation Methods 0.000 description 3
- 101000628562 Homo sapiens Serine/threonine-protein kinase STK11 Proteins 0.000 description 2
- 102100026715 Serine/threonine-protein kinase STK11 Human genes 0.000 description 2
- 230000006978 adaptation Effects 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
Classifications
-
- 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
- G01S11/00—Systems for determining distance or velocity not using reflection or reradiation
- G01S11/02—Systems for determining distance or velocity not using reflection or reradiation using radio waves
- G01S11/10—Systems for determining distance or velocity not using reflection or reradiation using radio waves using Doppler effect
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Remote Sensing (AREA)
- Position Fixing By Use Of Radio Waves (AREA)
- Navigation (AREA)
Abstract
The invention discloses an off-track single-star time-sharing frequency measurement positioning method based on star optimization, which comprises the following steps: measuring the frequency of a signal transmitted by a ground radiation source reaching an observation satellite; establishing a model of different-orbit single-satellite time-sharing frequency measurement positioning, selecting a plurality of satellites with different orbits to respectively measure frequencies at different moments, and establishing a positioning equation set according to the measured plurality of different signal frequencies; deriving geometric dilution precision factors, and analyzing the influence of various factors on positioning precision; and establishing an star optimizing model, and optimizing the selection of the orbit and the satellite observation time to improve the positioning precision. In the limited sight range, the single star flying through different orbits of the positioning visual area at different moments is utilized to independently observe the same interference source for multiple times, and the positioning effect is stable and the precision is higher compared with a single-star time-sharing frequency measurement positioning scheme due to the differences in the aspects of flight direction, observation position distribution and the like, meanwhile, the space between the satellites is larger, and the measurement position selection can be more flexible.
Description
Technical Field
The invention provides an off-track single-satellite time-sharing frequency measurement positioning method based on star optimization.
Background
The passive positioning technology of the radiation target source, in particular to a passive positioning system based on a modern medium-low orbit satellite, has a large positioning area range, can rapidly position the emission signals of sea, land and air targets, and has important functions and wide application prospects in the civil and military fields. The common radiation source positioning system comprises a single-star positioning system and a multi-star positioning system, and compared with the multi-star positioning technology, the radiation source single-star positioning technology has the advantages of high positioning probability, good availability, convenient application and deployment and the like, particularly under the shielding limit conditions of vegetation, landforms, buildings and the like, the satellite opposite visibility angle of a radio target is limited, and under the condition that a plurality of satellites cannot be used for positioning, the single-star positioning has an irreplaceable function.
The conventional single-star positioning system has the advantages of low cost, good flexibility, no special requirements on satellite attitude and the like, and becomes a research hot spot. However, the smaller the adjacent two frequency measurement intervals of the single-satellite frequency measurement positioning technology are, the poorer the positioning effect is and the positioning blind area exists below the satellite running track line. If the visible area of the target source is narrowed due to the shielding object, the measurement travel distance of the visible satellite is reduced, the frequency measurement interval between two adjacent times by using the single-satellite frequency measurement positioning technology is very short, and the positioning error of the target source under the satellite flight track is further increased. The star-based preferred different-orbit single-star time-sharing frequency measurement positioning technology can effectively improve positioning accuracy in a positioning scene with limited sight by optimizing the orbit and satellite observation positions.
Disclosure of Invention
The invention aims at: aiming at the problem of difficult positioning caused by the reduction of the probability of a target source visible satellite in a field-of-view limited positioning scene, the method for positioning the different-orbit single-satellite time-sharing frequency measurement based on star optimization is provided, and the obvious improvement of positioning precision is realized by optimizing the orbit and the satellite observation position.
In order to achieve the above object, the method specifically comprises the following steps:
a star optimization-based off-track single-star time-sharing frequency measurement positioning method comprises the following steps:
s1: measuring the frequency of a signal transmitted by a ground radiation source reaching an observation satellite;
s2: establishing a model of different-orbit single-satellite time-sharing frequency measurement positioning, selecting three satellites with different orbits to respectively measure frequencies at different moments, and establishing a positioning equation set according to the measured three different signal frequencies;
s3: deriving geometric dilution precision factors (GDOP) of the different-orbit single-satellite time-sharing frequency measurement positioning technology, and analyzing the influence of various factors on positioning precision;
s4: and establishing an star optimizing model, and optimizing the selection of the orbit and the satellite observation time to further improve the positioning precision.
Preferably: in the step S1, the frequency of the signal sent by the ground radiation source reaching the observation satellite is measured in the different-orbit single-satellite time-sharing frequency measurement positioning technology.
The different-orbit single-satellite time-sharing frequency measurement positioning technology is a positioning technology which utilizes the corresponding relation between Doppler frequency shift generated by the movement of a satellite relative to a radiation source and the position of the radiation source to calculate the position of a target.
The satellite frequency measurement positioning schematic diagram is shown in fig. 2, for a radiation source which is stationary on the ground or in the air, the carrier frequency reaching the satellite will generate Doppler frequency shift effect due to the movement of the satellite, the frequency difference exists between the frequencies of the measured signals reaching the satellite and the actual signals of the radiation source of the satellites in different orbits at different moments, the equal frequency surface corresponding to the frequencies measured by the satellites is the conical surface of the cone-top at the satellite, the conical surface passes through the conical surface of the radiation source, and the conical angles are mutually unequal due to the movement of the satellite. Thus, the frequency f of the signal transmitted by the radiation source measured by the satellite ij For the actual frequency f of the ground radiation source signal c Adding the Doppler shift f generated by satellite motion d I.e.
Where v is the relative velocity between the source and the satellite, c is the speed of light, f c Is the actual signal frequency of the radiation source, theta is the relative speed of the radiation source and the satellite and the included angle between the radiation source and the satellite connecting line, i is the orbit number of the observation satellite, and j is the observation time t of the observation satellite in the orbit j 。
Preferably: in the step S2, a positioning equation set of the different-track single-satellite time-sharing frequency measurement positioning technology is established.
Assume that the position coordinate of a ground stationary radiation source in a ground fixed rectangular coordinate system is s= [ x y z] T The medium-low orbit satellites in different orbits fly over the upper air in the visual range, and the observation time is t 1 ，t 2 ，t 3 ，…，t M The position coordinates of the corresponding observation satellite are s ij ＝[x ij y ij z ij ] T At a speed ofWhere i=1, 2,..n represents the track number, j=1, 2,..m represents the t on the corresponding track j Satellite number of time.
Assume that the measured Doppler frequency is f ij The source frequency is known as f c Then the measurement equation is available as:
wherein:radial velocity for satellite and target;i=1, 2, …, N, j=1, 2, …, M for the relative position between the satellite and the target; c is the propagation velocity of the electromagnetic wave.
Analyzing according to a plurality of measurements, wherein the satellite observation position is s ij I=1, 2, …, N, j=1, 2, M measured signal frequency f ij The method comprises the following steps:
selecting three measurement frequencies f from the measured signal frequencies mp ，f nq ，f kr Wherein m, N, k=1, 2, …, N; p, q, r=1, 2, …, and M subtracting two from one another gives the following set of frequency difference equations:
using the WGS-84 earth ellipsoid model in the analysis, assuming that the long radius of the WGS-84 earth reference ellipsoid is a and the short radius is b, the first eccentricity may be defined as:
general get e 2 ＝0.00669437999013。
According to the ellipsoidal model, if the radiation source is considered to be on the surface with elevation 0, the radiation source position conforms to the following surface equation:
the earth coordinate s of the radiation source can be obtained by combining the frequency difference equation and the earth surface equation and knowing the positions and speeds corresponding to three satellite observation moments and the measured frequency under the condition of considering the earth surface constraint.
Preferably: in the step S3, formula derivation is carried out on a geometric dilution precision factor (GDOP) of the technology according to a positioning model of the different-track single-satellite time-sharing frequency measurement positioning technology, and positioning precision analysis is carried out.
The following derivation considers that the interference source is on the ground, and the satellite observation position is s ij I=1, 2, …, N, j=1, 2, M at the measured signal frequency f ij Three measurement frequencies f are selected mp ，f nq ，f kr Wherein m, N, k=1, 2, …, N; p, q, r=1, 2, …, M, the equation for off-track single-star time-sharing frequency measurement positioning is written as:
the differentiation of the above is obtained:
let the positioning error covariance matrix be P dX ＝E[dXdX T ]Wherein dx= [ dxdy dz ]] T The method comprises the steps of carrying out a first treatment on the surface of the The covariance matrix of the frequency difference and the elevation error is R fH ＝E[dUdU T ]Wherein dU= [ df mp df nq df kr dH] T The method comprises the steps of carrying out a first treatment on the surface of the The covariance matrix of satellite position error isWherein dX ij ＝[dx ij dy ij dz ij ] T I=m, j=p; i=n, j=q; i=k, j=r; the covariance matrix of the satellite speed error is +.>Wherein-> The positioning error covariance matrix is expressed as:
wherein the method comprises the steps of
The geometric dilution precision factor GDOP for the different-track single-star time-sharing frequency difference positioning is as follows:
GDOP(x,y,z)＝tr(P dX )
tr (·) is the trace of the matrix.
Therefore, the positioning accuracy of the different-orbit single-satellite time-sharing frequency measurement positioning technology is related to the elevation error of the radiation source, the frequency measurement error of the observation satellite, the speed error of the observation satellite and the position error of the observation satellite, and when the errors are larger, the positioning accuracy is worse, and the conclusion that the positioning accuracy can be effectively improved by improving the errors can be obtained.
Preferably: in the step S4, the positioning error of the interference source can be minimized by optimally selecting the positions of the satellites in different orbits and the satellites observed by the satellites, so that the positioning accuracy is further improved. The following optimization objective problem can be established:
wherein J is i Representing different satellite flight orbits, i=1, 2,3,..n represents the orbit number, S ij Is t on the corresponding track j Satellite observation position at time of flight through the view region, j=1, 2,3,..m, GDOP (x, y, z) is at radiation source s= [ x, y, z] T A geometric dilution of precision factor of the positioning at the location. By acquiring the minimum value of the GDOP at the radiation source position, the orbit number and the observation time of the corresponding observation satellite can be acquired, and thus the optimal satellite observation position at which the radiation source can be located can be obtained.
The beneficial effects are that: according to the star-based optimal-selection different-orbit single-star time-sharing frequency measurement positioning technology, single satellites flying through different orbits of a positioning visual area at different moments are utilized to independently observe the same interference source for multiple times in a limited visual line range, and due to the differences in the aspects of flight direction, observation position distribution and the like, compared with a single-orbit single-star time-sharing frequency measurement positioning scheme, the positioning effect is stable, the precision is higher, the star distance is larger, and the measurement position selection can be more flexible.
Drawings
Fig. 1: the flow chart of the invention;
fig. 2: a satellite frequency measurement positioning schematic diagram;
fig. 3: different-orbit single-star time-sharing frequency measurement positioning model;
fig. 4: the moving track of the iridium satellite under the satellite on the global scale is visible;
fig. 5: the method comprises the following steps of viewing a sub-satellite running track of an iridium satellite in a visual range of a target source and a running direction;
fig. 6-8: error curve diagram of different track single star time-sharing frequency measurement positioning.
Detailed Description
The technical scheme of the invention is further described in detail below with reference to the accompanying drawings, the invention is implemented on Matlab R2014b and STK11 experimental platforms, and FIG. 1 is a flow chart of the invention, and mainly comprises the following steps:
1. measuring the frequency of the signal transmitted by the ground radiation source reaching the satellite
The different-orbit single-satellite time-sharing frequency measurement positioning technology is a positioning technology which utilizes the corresponding relation between Doppler frequency shift generated by the movement of a satellite relative to a radiation source and the position of the radiation source to calculate the position of a target.
The satellite frequency measurement positioning schematic diagram is shown in fig. 2, for a radiation source which is stationary on the ground or in the air, the carrier frequency reaching the satellite will generate Doppler frequency shift effect due to the movement of the satellite, the frequency difference exists between the frequencies of the measured signals reaching the satellite and the actual signals of the radiation source of the satellites in different orbits at different moments, the equal frequency surface corresponding to the frequencies measured by the satellites is the conical surface of the cone-top at the satellite, the conical surface passes through the conical surface of the radiation source, and the conical angles are mutually unequal due to the movement of the satellite. Thus, the frequency f of the signal transmitted by the radiation source measured by the satellite ij For the actual frequency f of the ground radiation source signal c Adding the Doppler shift f generated by satellite motion d I.e.
Where v is the relative velocity between the source and the satellite, c is the speed of light, f c Is the actual signal frequency of the radiation source, theta is the relative speed of the radiation source and the satellite and the included angle between the radiation source and the satellite connecting line, i is the orbit number of the observation satellite, and j is the observation time t of the observation satellite in the orbit j 。
2. Positioning equation set for establishing different-track single-star time-sharing frequency measurement positioning technology
1. Different-track single-star time-sharing frequency measurement positioning model
The middle-low orbit satellite is far away from the earth in the process of moving around the earth, the altitude is generally more than 150km, the satellite and the radiation source can be approximately regarded as particle motion analysis, and fig. 3 is an off-orbit single-satellite time-sharing frequency measurement positioning model. Assume that the position coordinate of a ground stationary radiation source in a ground fixed rectangular coordinate system is s= [ x y z] T The medium-low orbit satellites in different orbits fly over the upper air in the visual range, and the observation time is t 1 ，t 2 ，t 3 ，…，t M The position coordinates of the corresponding observation satellite are s ij ＝[x ij y ij z ij ] T At a speed ofWhere i=1, 2,..n represents the track number, j=1, 2,..m represents the t on the corresponding track j Satellite number of time.
Assume that the measured Doppler frequency is f ij The source frequency is known as f c Then the measurement equation is available as:
wherein:radial velocity for satellite and target;i=1, 2, …, N, j=1, 2, …, M for the relative position between the satellite and the target; c is the propagation velocity of the electromagnetic wave.
2. Establishment of a set of positioning equations
Analyzing according to a plurality of measurements, wherein the satellite observation position is s ij I=1, 2, …, N, j=1, 2, M measured signal frequency f ij The method comprises the following steps:
selecting three measurement frequencies f from the measured signal frequencies mp ，f nq ，f kr Wherein m, N, k=1, 2, …, N; p, q, r=1, 2, …, and M subtracting two from one another gives the following set of frequency difference equations:
using the WGS-84 earth ellipsoid model in the analysis, assuming that the long radius of the WGS-84 earth reference ellipsoid is a and the short radius is b, the first eccentricity may be defined as:
general get e 2 ＝0.00669437999013。
According to the ellipsoidal model, if the radiation source is considered to be on the surface with elevation 0, the radiation source position conforms to the following surface equation:
the equations (4) and (6) are combined, and the geodetic coordinates s of the radiation source can be obtained by knowing the positions and velocities corresponding to the three satellite observation times and the measured frequencies in consideration of the earth surface constraints.
2. Positioning accuracy analysis of different-orbit single-star time-sharing frequency measurement positioning technology
The positioning accuracy of the off-track single-satellite time-sharing frequency measurement positioning technology is generally described by a geometric dilution accuracy factor (GDOP), which represents the three-dimensional geometric distribution of positioning errors, and the expression is as follows:
wherein: sigma (sigma) x ,σ y ,σ z Is the standard deviation of positioning in 3 directions.
The following derivation considers that the interference source is on the ground, and the satellite observation position is s ij I=1, 2, …, N, j=1, 2, M at the measured signal frequency f ij Three measurement frequencies f are selected mp ，f nq ，f kr Wherein m, N, k=1, 2, …, N; p, q, r=1, 2, …, M, the equation for off-track single-star time-sharing frequency measurement positioning is written as:
the differentiation of the above is obtained:
let the positioning error covariance matrix be P dX ＝E[dXdX T ]Wherein dx= [ dxdy dz ]] T The method comprises the steps of carrying out a first treatment on the surface of the The covariance matrix of the frequency difference and the elevation error is R fH ＝E[dUdU T ]Wherein dU= [ df mp df nq df kr dH] T The method comprises the steps of carrying out a first treatment on the surface of the The covariance matrix of satellite position error isWherein dX ij ＝[dx ij dy ij dz ij ] T I=m, j=p; i=n, j=q; i=k, j=r; the covariance matrix of the satellite speed error is +.>Wherein-> The positioning error covariance matrix is expressed as:
wherein the method comprises the steps of
The geometric dilution precision factor GDOP for the different-track single-star time-sharing frequency difference positioning is as follows:
GDOP(x,y,z)＝tr(P dX ) (11)
tr (·) is the trace of the matrix.
From the above, it can be seen that the positioning accuracy of the different-orbit single-satellite time-sharing frequency measurement positioning technology is related to the elevation error of the radiation source, the frequency measurement error of the observation satellite, the speed error of the observation satellite and the position error of the observation satellite, and when the errors are larger, the positioning accuracy is worse, and the positioning accuracy can be effectively improved by improving the errors.
4. Establishing an optimized star model
As shown in fig. 3, there are a plurality of orbiting satellites flying through the cone-shaped visible region, and by optimally selecting the positions of different orbiting satellites and their observation satellites, the positioning error of the interference source can be minimized, and the positioning accuracy can be further improved.
The following optimization objective problems are established:
wherein J is i Representing different satellite flight orbits, i=1, 2,3,..n represents the orbit number, S ij Is t on the corresponding track j Satellite observation position at time of flight through the view region, j=1, 2,3,..m, GDOP (x, y, z) is at radiation source s= [ x, y, z] T Positioning of a siteIs a geometric dilution of precision factor of (2). By acquiring the minimum value of the GDOP at the radiation source position, the orbit number and the observation time of the corresponding observation satellite can be acquired, and thus the optimal satellite observation position at which the radiation source can be located can be obtained.
5. Comparison of simulation results
The LEO iridium transparent transponder is adopted to perform ground surface target source positioning, and the positioning effects of single-satellite time-sharing frequency measurement positioning and different-track single-satellite time-sharing frequency measurement positioning are compared through the optimization of the observation positions of single-track satellite time-sharing frequency measurement positioning and the optimization of the frequency measurement positions of satellites in different orbits in a time-sharing flying mode into a visible area.
1. Simulation parameters
23Oct 2018 04:00:00 (UTCG) is selected as an initial time, 23Oct 2018 09:00:00 (UTCG) is selected as an end time, and STK11 simulation software is utilized to obtain ephemeris data of the iridium system. Assuming that the target source point is located in south Beijing (east longitude 119 degrees, north latitude 32 degrees and elevation 0 km), the lowest elevation angle of the user of the target source is 71.57 degrees, three iridium satellites pass through the visible range of the target source in the time period, namely 209 # iridium satellites, 306 # iridium satellites and 404 # iridium satellites, the running track of the three iridium satellites on the world is shown in fig. 5, the running track and running direction of the three iridium satellites in the visible range of the target source are shown in fig. 4, and the orbit parameters and the visible time are shown in tables 1 and 2.
TABLE 1 orbital parameters of Iridium over target source visibility range
TABLE 2 View time of Iridium over target Source visibility range
2. Single-track single-star time-sharing frequency-measuring positioning observation star position optimization
If the single-satellite frequency measurement technology is selected to locate the interference source in the scene, three selection schemes exist, the 209, 306 and 404 iridium satellites can be observed for three times at different moments respectively, and the acquired Doppler frequency shift generated by the motion relative to the radiation source is utilized to locate the target source. Assuming a frequency measurement interval of 2s, the two fixed satellite observation times are the starting time t of the satellite entering the visible area 0 And end time t M The third satellite observation time is t 0 And t M At any time t j J represents the time interval between the starting moment and j=2, 4, …, M-2 (j is an even number), the signal carrier frequency is 1.620GHz, the frequency measurement error is 1Hz, the elevation error, the satellite speed error and the position error are ignored, and the minimum positioning error and the corresponding satellite observation moment of three selection schemes for carrying out single-orbit single-satellite time-sharing frequency measurement positioning by using 209, 306 and 404 iridium satellites are shown in table 3.
Table 3 Single track single star time sharing frequency measurement positioning observation star position selection optimization scheme and minimum positioning error thereof
As can be seen from Table 3, when the single-track single-satellite frequency measurement positioning technology is used for positioning, the closer the third satellite observation time is to the starting time t of the satellite entering the visible area 0 And end time t M Central instant t in between M/2 The better the positioning effect. The target source position is just near the running track line of the No. 209 iridium satellite under the visible range, so that the single-satellite frequency measurement positioning effect is worst by utilizing the No. 209 iridium satellite, and the single-satellite frequency measurement positioning effect by utilizing the No. 306 iridium satellite is best compared, and the minimum positioning error is 6.4259km, so that the positioning precision of single-satellite frequency measurement positioning by utilizing the single-rail is not high under the condition of limited field of view. The following considers the case of locating the third satellite observation position on different orbits, and discusses the different orbit single-satellite time-sharing frequency measurement positioning technology under the sceneInfluence of positioning accuracy.
3. Observation star position optimization of different-track single-star time-sharing frequency measurement positioning
Assuming that two satellite positions are in one orbit and a third satellite position is in the other orbit, there are six alternatives, the minimum positioning error of which and the corresponding satellite observation times are shown in table 4. If the frequency measurement interval is 2s, the two fixed satellite observation moments are the starting moment t of the satellite entering the visible area on the same orbit 0 And end time t M The third satellite observation time is any time t on the other orbit j J represents the time interval between the starting moment, j=0, 2, …, M (j is an even number), the signal carrier frequency is 1.620GHz, the frequency measurement error is 1Hz, the elevation error, the satellite speed error and the position error are ignored, and the positioning error curve diagram compared with the single-orbit single-satellite frequency measurement positioning is shown in fig. 6,7 and 8.
TABLE 4 optimal scheme for selecting and optimizing observation star position for different-track single-star time-sharing frequency measurement positioning and minimum positioning error thereof
As can be seen from table 4, the minimum positioning error of all schemes using the off-track single-satellite time-sharing frequency-measuring positioning technology is obviously reduced compared with that of the single-track single-satellite frequency-measuring positioning scheme, and the positioning accuracy can reach the hundred-meter level; the satellite observation time corresponding to the minimum positioning error is the initial time, the end time or the center time. From fig. 6,7 and 8, it can be seen that under the original single track condition, another track is introduced, and the different track single satellite time-sharing frequency measurement is utilized for positioning, so that the positioning accuracy of the original single track single satellite frequency measurement positioning can be improved, the positioning error change is stable, and the satellite observation time is flexible to select. Simulation results show that the different-orbit single-star time-sharing frequency measurement positioning technology can remarkably improve the positioning precision under the condition of limited view field, and the positioning precision can reach the hundred-meter level by optimizing star selection.
The foregoing is only a preferred embodiment of the invention, it being noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the present invention, and such modifications and adaptations are intended to be comprehended within the scope of the invention.
Claims (4)
1. The star-optimized off-track single-star time-sharing frequency measurement positioning method is characterized by comprising the following steps of:
s1: measuring the frequency of a signal transmitted by a ground radiation source reaching an observation satellite;
s2: establishing a model of different-orbit single-satellite time-sharing frequency measurement positioning, selecting a plurality of satellites with different orbits to respectively measure frequencies at different moments, and establishing a positioning equation set according to the measured plurality of different signal frequencies;
s3: deriving a geometric dilution precision factor, and determining the influence of the factors such as elevation error of a radiation source, frequency measurement error of an observation satellite, speed error of the observation satellite and position error of the observation satellite on positioning precision;
the step of deriving the geometric dilution of precision factor comprises:
the following derivation considers that the interference source is on the ground, and the satellite observation position is s ij I=1, 2, …, N, j=1, 2, M at the measured signal frequency f ij Three measurement frequencies f are selected mp ，f nq ，f kr Wherein m, N, k=1, 2, …, N; p, q, r=1, 2, …, M, the equation for off-track single-star time-sharing frequency measurement positioning is written as:
the differentiation of the above is obtained:
let the positioning error covariance matrix be P dX ＝E[dXdX T ]Wherein dx= [ dxdy dz ]] T The method comprises the steps of carrying out a first treatment on the surface of the The covariance matrix of the frequency difference and the elevation error is R fH ＝E[dUdU T ]Wherein dU= [ df mp df nq df kr dH] T The method comprises the steps of carrying out a first treatment on the surface of the The covariance matrix of satellite position error isWherein dX ij ＝[dx ij dy ij dz ij ] T I=m, j=p; i=n, j=q; i=k, j=r; the covariance matrix of the satellite speed error is +.>Wherein->i=m, j=p; i=n, j=q; i=k, j=r; the positioning error covariance matrix is expressed as:
wherein the method comprises the steps of
The geometric dilution precision factor GDOP for the different-track single-star time-sharing frequency difference positioning is as follows:
GDOP(x,y,z)＝tr(P dX )
tr (·) is the trace of the matrix;
s4: and establishing an star optimizing model, and optimizing the selection of the orbit and the satellite observation time to further improve the positioning precision.
2. The method for satellite-optimized space-time single-satellite time-sharing frequency measurement and positioning according to claim 1, wherein in step S1, the signal frequency f transmitted by the radiation source measured by the satellite ij For the actual frequency f of the ground radiation source signal c Adding the Doppler shift f generated by satellite motion d I.e.
Where v is the relative velocity between the source and the satellite, c is the speed of light, f c Is the actual signal frequency of the radiation source, theta is the relative speed of the radiation source and the satellite and the included angle between the radiation source and the satellite connecting line, i is the orbit number of the observation satellite, and j is the observation time t of the observation satellite in the orbit j 。
3. The star-optimized-based off-track single-star time-sharing frequency measurement positioning method as set forth in claim 1, wherein the step S2 comprises the steps of:
step S2.1: establishing a model of different-track single-star time-sharing frequency measurement positioning;
assume that the position coordinate of a ground stationary radiation source in a ground fixed rectangular coordinate system is s= [ x y z] T The medium-low orbit satellites in different orbits fly over the upper air in the visual range, and the observation time is t 1 ,t 2 ,t 3 ,…,t M The position coordinates of the corresponding observation satellite are s ij ＝[x ij y ij z ij ] T At a speed ofWhere i=1, 2,..n represents the track number, j=1, 2,..m represents the t on the corresponding track j Satellite numbering at the moment;
assume that the measured Doppler frequency is f ij The source frequency is known as f c The measurement equation is:
wherein:radial velocity for satellite and target;is the relative position between the satellite and the target; c is the propagation speed of electromagnetic waves;
step S2.2: selecting a plurality of satellites with different orbits to respectively measure frequencies at different moments, and establishing a positioning equation set according to the measured signal frequencies;
analyzing according to a plurality of measurements, wherein the satellite observation position is s ij I=1, 2, …, N, j=1, 2, M measured signal frequency f ij The method comprises the following steps:
selecting three measurement frequencies f from the measured signal frequencies mp ，f nq ，f kr Wherein m, N, k=1, 2, …, N; p, q, r=1, 2, …, and M subtracting two from one another gives the following set of frequency difference equations:
in the analysis process, a WGS-84 earth ellipsoid model is used, a long radius of a WGS-84 earth reference ellipsoid is set as a, a short radius is set as b, and a first eccentricity is defined as follows:
according to the ellipsoidal model, if the radiation source is considered to be on the surface with elevation 0, the radiation source position conforms to the following surface equation:
the earth coordinate s of the radiation source can be obtained by combining the frequency difference equation and the earth surface equation and knowing the positions and speeds corresponding to three satellite observation moments and the measured frequency under the condition of considering the earth surface constraint.
4. The star-optimized-based off-track single-star time-sharing frequency measurement positioning method is characterized by comprising the following steps of: the step S4 comprises the following steps:
the following optimization objective problems are established:
wherein J is i Representing different satellite flight orbits, i=1, 2,3,..n represents the orbit number, S ij Is t on the corresponding track j Satellite observation position at time of flight through the view region, j=1, 2,3,..m, GDOP (x, y, z) is at radiation source s= [ x, y, z] T A geometric dilution of precision factor of the positioning; by acquiring the minimum value of the GDOP at the radiation source position, the orbit number and the observation time of the corresponding observation satellite can be acquired, and thus the optimal satellite observation position at which the radiation source can be located can be obtained.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911314001.2A CN110988851B (en) | 2019-12-19 | 2019-12-19 | Different-orbit single-star time-sharing frequency measurement positioning method based on star optimization |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911314001.2A CN110988851B (en) | 2019-12-19 | 2019-12-19 | Different-orbit single-star time-sharing frequency measurement positioning method based on star optimization |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110988851A CN110988851A (en) | 2020-04-10 |
| CN110988851B true CN110988851B (en) | 2023-11-21 |
Family
ID=70095777
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911314001.2A Active CN110988851B (en) | 2019-12-19 | 2019-12-19 | Different-orbit single-star time-sharing frequency measurement positioning method based on star optimization |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110988851B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111999696B (en) * | 2020-08-02 | 2023-07-04 | 中国人民解放军海军工程大学 | Multi-platform direction-finding cross positioning optimization method |
| CN112114341B (en) * | 2020-08-13 | 2022-01-25 | 中国人民解放军军事科学院国防科技创新研究院 | Low-earth-orbit satellite cooperative frequency measurement passive positioning method |
| CN112363190A (en) * | 2020-10-30 | 2021-02-12 | 南京邮电大学 | Different-rail time-sharing single-satellite time difference positioning method |
| CN113642154A (en) * | 2021-07-15 | 2021-11-12 | 中国电子科技集团公司第三十六研究所 | BDS-based satellite passive positioning system selection method |
| CN113742803A (en) * | 2021-09-07 | 2021-12-03 | 辽宁工程技术大学 | Simulation analysis method for band-controlled geometric positioning precision of medium and high orbit SAR (synthetic aperture radar) satellite |
| CN114859114B (en) * | 2022-07-06 | 2022-09-09 | 成都戎星科技有限公司 | Signal target association method for monitoring low-orbit space target based on low-orbit monitoring satellite |
| CN116184449B (en) * | 2022-11-09 | 2023-11-10 | 湖南六九零六信息科技股份有限公司 | Time difference positioning method based on single-satellite time sharing |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106842256A (en) * | 2016-12-12 | 2017-06-13 | 西安空间无线电技术研究所 | A kind of navigation locating method of the mono- star signals of utilization GNSS |
| CN109613583A (en) * | 2019-01-02 | 2019-04-12 | 电子科技大学 | The passive object localization method of the time difference is surveyed based on the direction finding of Dan Xingyu earth station and joint |
| CN109633724A (en) * | 2019-01-16 | 2019-04-16 | 电子科技大学 | Passive object localization method based on single star Yu more earth station's combined measurements |
| CN110045327A (en) * | 2019-03-27 | 2019-07-23 | 南京邮电大学 | A kind of single star interference source localization methods being multiplexed wave beam based on multiple same frequencies |
-
2019
- 2019-12-19 CN CN201911314001.2A patent/CN110988851B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106842256A (en) * | 2016-12-12 | 2017-06-13 | 西安空间无线电技术研究所 | A kind of navigation locating method of the mono- star signals of utilization GNSS |
| CN109613583A (en) * | 2019-01-02 | 2019-04-12 | 电子科技大学 | The passive object localization method of the time difference is surveyed based on the direction finding of Dan Xingyu earth station and joint |
| CN109633724A (en) * | 2019-01-16 | 2019-04-16 | 电子科技大学 | Passive object localization method based on single star Yu more earth station's combined measurements |
| CN110045327A (en) * | 2019-03-27 | 2019-07-23 | 南京邮电大学 | A kind of single star interference source localization methods being multiplexed wave beam based on multiple same frequencies |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110988851A (en) | 2020-04-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110988851B (en) | Different-orbit single-star time-sharing frequency measurement positioning method based on star optimization | |
| US4954837A (en) | Terrain aided passive range estimation | |
| US4405986A (en) | GSP/Doppler sensor velocity derived attitude reference system | |
| Gebre-Egziabher | Design and performance analysis of a low-cost aided dead reckoning navigator | |
| US8630804B2 (en) | Method for geolocating an object by multitelemetry | |
| US6281841B1 (en) | Direction determining apparatus | |
| CN113311436B (en) | Method for correcting wind measurement of motion attitude of laser wind measuring radar on mobile platform | |
| JP2010500578A (en) | A method for fusing multiple GPS measurement types into a weighted least squares solution | |
| CN108896957A (en) | The positioning system and method in a kind of unmanned plane control signal source | |
| CN110456350A (en) | A kind of satellite-borne SAR constellation systems | |
| CN107783157A (en) | External sort algorithm intelligence satellite selection method, system and radar platform based on aeronautical satellite | |
| RU2152625C1 (en) | Method determining orientation of objects in space, range to them and bearing, position coordinates and components of velocity vector by navigation radio signals of spacecraft of space radio navigation systems | |
| CN109471102B (en) | Inertial measurement unit error correction method | |
| Kauffman et al. | Simulation study of UWB-OFDM SAR for navigation with INS integration | |
| Burns et al. | IFSAR for the rapid terrain visualization demonstration | |
| US11428802B2 (en) | Localization using particle filtering and image registration of radar against elevation datasets | |
| Runnalls et al. | Terrain-referenced navigation using the IGMAP data fusion algorithm | |
| CN114325666A (en) | Coherent heterodyne wind measuring radar correction method under high-speed motion | |
| Fried | A Comparative Performance Analysis of Modern Ground‐Based, Air‐Based, and Satellite‐Based Radio Navigation Systems | |
| RU2232102C1 (en) | Distributed information control complex of multi-functional flying vehicle group | |
| RU2776077C1 (en) | Method for determining the location and flight velocity of an aircraft | |
| CN110988796B (en) | Positioning method and system based on frequency offset opportunistic signal | |
| CN110082800B (en) | Differential positioning method | |
| Sametoğlu et al. | Accuracy in Determining Aircraft Position by Terrestrial Radio Navigation | |
| Polat | INS Aiding by Tracking An Unknown Ground Object |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB02 | Change of applicant information |
Address after: Room 201, building 2, phase II, No.1 Kechuang Road, Yaohua street, Qixia District, Nanjing City, Jiangsu Province Applicant after: NANJING University OF POSTS AND TELECOMMUNICATIONS Applicant after: Nanjing Microstar Communication Technology Co.,Ltd. Address before: Yuen Road Qixia District of Nanjing City, Jiangsu Province, No. 9 210046 Applicant before: NANJING University OF POSTS AND TELECOMMUNICATIONS Applicant before: Nanjing Microstar Communication Technology Co.,Ltd. |
|
| CB02 | Change of applicant information | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |