CN115542353A

CN115542353A - Satellite capturing method, device, electronic equipment and storage medium

Info

Publication number: CN115542353A
Application number: CN202211199569.6A
Authority: CN
Inventors: 朱棣; 钟华; 张博; 宋鹏鹏
Original assignee: China Star Network Innovation Research Institute Co ltd
Current assignee: China Star Network Innovation Research Institute Co ltd
Priority date: 2022-09-29
Filing date: 2022-09-29
Publication date: 2022-12-30

Abstract

The embodiment of the application provides a satellite capturing method, a satellite capturing device, electronic equipment and a storage medium, relates to the technical field of satellite positioning, and can improve the satellite capturing speed. The satellite acquisition method is applied to a receiver and comprises the following steps: capturing a first satellite of each of a plurality of partitions of a low-orbit satellite constellation; when a first satellite in any partition is captured, taking the captured first satellite as a reference satellite, taking the partition to which the reference satellite belongs as a reference partition, taking the reference satellite as an initial position, and sequentially capturing other satellites in the reference partition according to a preset sequence; if the number of the satellites captured in the reference partition reaches n satellites, wherein n is larger than or equal to 4, determining the current position and the current time of the receiver according to the n satellites; acquiring ephemeris information of a current sky satellite according to a current position and current time through a communication system; and capturing a preset number of satellites according to the current position of the receiver, the current time and the ephemeris information of the current sky satellite.

Description

Satellite capturing method and device, electronic equipment and storage medium

Technical Field

The present disclosure relates to the field of satellite positioning technologies, and in particular, to a satellite capturing method, an apparatus, an electronic device, and a storage medium.

Background

The low-orbit giant satellite constellation becomes an advantageous technology in the field of satellite positioning due to the characteristics of the low-orbit giant satellite constellation, for example, due to the advantage of the number of visible stars, the performance of the low-orbit giant satellite constellation is improved for the sheltering environment such as urban canyons, and the robustness of the system is also strong; because the low-orbit satellite has short period and quick change of spatial configuration, the correlation between observation epochs can be reduced, and the convergence speed during high-precision positioning calculation is improved; due to the fact that the track is reduced, stronger ground power can be obtained under the same transmitting power, and the application effect of the positioning system is improved.

However, the receiver in the current positioning device has a slow acquisition speed when acquiring the satellites in the giant constellation.

Disclosure of Invention

The technical scheme of the application provides a satellite capturing method, a satellite capturing device, electronic equipment and a storage medium, and the satellite capturing speed can be improved.

In a first aspect, a satellite acquisition method is provided, which is applied to a receiver, and includes: capturing a first satellite of each of a plurality of partitions of a low orbit satellite constellation; when a first satellite in any partition is captured, taking the captured first satellite as a reference satellite, taking the partition to which the reference satellite belongs as a reference partition, taking the reference satellite as an initial position, and sequentially capturing other satellites in the reference partition according to a preset sequence; if the number of the satellites captured in the reference partition reaches n satellites, and n is larger than or equal to 4, determining the current position and the current time of the receiver according to the n satellites; acquiring ephemeris information of a current sky satellite according to a current position and current time through a communication system; and capturing a preset number of satellites according to the current position, the current time and ephemeris information of the current sky satellite of the receiver.

In one possible embodiment, if the number of satellites acquired in the reference partition does not reach n satellites and the last satellite in the reference partition has been acquired, then the acquisition of the first satellite of each of the plurality of partitions of the low orbit satellite constellation is re-performed.

In one possible embodiment, the process of acquiring a preset number of satellites according to the current position of the receiver, the current time and ephemeris information of the current sky satellite includes: calculating the satellite position according to the ephemeris information of the current sky satellite and the current time; calculating prior Doppler and a predicted code phase according to the satellite position, the current time and the current position of the receiver; and capturing a preset number of satellites according to the satellite positions, the prior Doppler and the predicted code phases.

In one possible embodiment, the predetermined sequence is a sequence that is gradually outward and sequentially adjacent, centered on the reference satellite.

In one possible implementation, the number of satellites in each partition is ≦ m, which is the minimum number of visible satellites within the service area of the low-orbit satellite constellation.

In one possible implementation, the number of satellites in each partition is greater than a partition corresponding number threshold, the number threshold being used to ensure that there are at least n-1 satellites in view in the corresponding partition when the first satellite in the corresponding partition is at the lowest elevation angle of reception.

In one possible embodiment, n =4.

In a second aspect, there is provided a satellite capturing apparatus applied to a receiver, the apparatus including: an acquisition module for acquiring a first satellite of each of a plurality of partitions of a low-orbit satellite constellation; the acquisition module is further used for acquiring a first satellite in any partition, taking the acquired first satellite as a reference satellite, taking the partition to which the reference satellite belongs as a reference partition, taking the reference satellite as an initial position, and sequentially acquiring other satellites in the reference partition according to a preset sequence; the information determining module is used for determining the current position and the current time of the receiver according to the n satellites if the number of the satellites captured in the reference partition reaches n satellites, and n is larger than or equal to 4; the acquisition module is used for acquiring ephemeris information of a current sky satellite according to the current position and the current time of the receiver; the acquisition module is further used for acquiring a preset number of visible satellites according to the current position and the current time of the receiver and ephemeris information of the current sky satellite.

In a third aspect, an electronic device is provided, including: a processor and a memory, the memory for storing at least one instruction, the instruction being loaded and executed by the processor to implement the satellite acquisition method described above.

In a fourth aspect, a computer storage medium is provided that includes computer instructions that, when executed on an electronic device, cause the electronic device to perform the satellite acquisition method described above.

According to the satellite capturing method, the satellite capturing device, the electronic equipment and the storage medium, the satellite is partitioned by utilizing the constellation operation characteristics in advance, the first satellite in any partition is captured, the captured first satellite is used as the reference satellite, other satellites around the reference satellite are captured according to the preset sequence, after n satellites in the reference partition are captured, the current position and the current time can be determined, ephemeris information is obtained through the communication system based on the current position and the current time, then a preset number of satellites are captured according to the ephemeris information, the whole constellation satellite capturing process is achieved, the satellite capturing speed is improved on the premise that the cost of capturing resources does not need to be greatly increased, and no prior information is needed before capturing.

Drawings

Fig. 1 is a schematic flowchart of a satellite acquisition method according to an embodiment of the present application;

FIG. 2 is a schematic flow chart illustrating another method for satellite acquisition according to an embodiment of the present disclosure;

fig. 3 is a block diagram of a satellite capturing device according to an embodiment of the present disclosure;

fig. 4 is a block diagram of an electronic device in an embodiment of the present application.

Detailed Description

The terminology used in the description of the embodiments section of the present application is for the purpose of describing particular embodiments of the present application only and is not intended to be limiting of the present application.

As shown in fig. 1, an embodiment of the present application provides a satellite acquisition method, which may be used in a receiver, and is a cold start process for acquiring a positioning signal or a navigation signal by the receiver, where the method includes:

step 101, capturing a first satellite of each partition of a plurality of partitions of a low-orbit satellite constellation;

the low-orbit satellite constellation can be a Walker constellation or a constellation system with a similar structure, and specifically can be a low-orbit giant satellite constellation, wherein in the motion of the constellation system with the structure, each satellite has a fixed and unique satellite number, in a plurality of adjacent orbital planes, a plurality of satellites in each orbital plane form a partition, the satellites in the partitions do not change, namely in the same partition, after one satellite is determined, the numbers of other satellites can be deduced and determined. For example, N satellites in the low-orbit satellite constellation are divided into a plurality of partitions, and when the number of satellites in each partition is as consistent as possible and cannot be completely consistent, the number of satellites in different partitions may have several differences. The division of the partitions should correspond to the actual position of the satellites in the constellation. And numbering the satellite at the fixed position in each subarea as a first satellite, and sequentially numbering other satellites in the subareas from the first satellite according to a preset sequence. For example, the satellites in each sector are approximately in a circle which is spirally numbered outwards with a first satellite as a center, and outwards from the first satellite, the satellite which is closest to the first satellite and adjacent to the first satellite is the second satellite, the satellite which is closest to the second satellite and adjacent to the second satellite is the third satellite, and so on.

When a first satellite in any partition is captured, taking the captured first satellite as a reference satellite, taking the partition to which the reference satellite belongs as a reference partition, taking the reference satellite as an initial position, sequentially capturing other satellites in the reference partition according to a preset sequence, namely taking the reference satellite as the initial position, executing step 102, and capturing the next satellite in the reference partition according to the preset sequence;

when the first satellite in any subarea is captured, the capture of the first satellite in other subareas is stopped, and the other satellites in the reference subarea are captured by taking the reference satellite as a starting point until all the satellites in the reference subarea are captured. For example, the adjacent satellites are sequentially acquired in an outward order from the reference satellite as a center, that is, the other satellites in the reference partition are acquired in a number order, wherein the process of acquiring the satellite may be regarded as a process of searching for the satellite, which may or may not be acquired.

Step 103, determining whether the number of the satellites captured in the reference partition reaches n satellites, if so, that is, if the number of the satellites captured in the reference partition reaches n satellites and n is greater than or equal to 4, executing step 104, determining the current position and the current time of the receiver according to the n satellites, wherein the current position refers to the current position of the receiver, and since the number of the captured satellites is n and the number is small, the determined current position is the current approximate position of the receiver, the current time is the current approximate time, and the error is large;

105, acquiring ephemeris information of a current sky satellite according to the current position and the current time of the receiver;

specifically, here, ephemeris information of a current sky satellite may be acquired through a communication system according to a current position and a current time of the receiver, and the communication system may be a satellite communication system of the low-orbit satellite constellation or another communication system. The ephemeris information includes the number of the satellite and its corresponding orbit information.

And step 106, capturing a preset number of satellites according to the current position and the current time of the receiver and the ephemeris information of the current sky satellite.

According to the satellite capturing method, the first satellite in any partition is captured by utilizing the operating characteristics of the constellation in advance, the captured first satellite serves as a reference satellite, other satellites around the reference satellite are captured according to the preset sequence, after n satellites in the reference partition are captured, the current position and the current time can be determined, ephemeris information is obtained through the communication system based on the current position and the current time, then a preset number of satellites are captured according to the ephemeris information, the whole constellation satellite capturing process is achieved, the satellite capturing speed is increased on the premise that the cost of capturing resources does not need to be greatly increased, and no prior information is needed before capturing.

In a possible embodiment, in step 103, if no, that is, if the number of satellites captured in the reference partition does not reach n satellites, step 107 is performed to determine whether the last satellite in the reference partition has been captured, if no, step 102 is performed to capture the next satellite in the reference partition according to the preset sequence, and if yes, that is, if the number of satellites captured in the reference partition does not reach n satellites and the last satellite in the reference partition has been captured, step 101 is performed again to capture the first satellite of each partition of the plurality of partitions of the low-orbit satellite constellation.

In a possible implementation, as shown in fig. 2, the step 106 of acquiring a preset number of satellites according to the current position of the receiver, the current time, and ephemeris information of the current sky satellite includes:

step 1061, calculating the satellite position according to the ephemeris information of the current sky satellite and the current time;

step 1062, calculating prior Doppler and predicted code phase according to the satellite position, current time and current position of the receiver;

and step 1063, capturing a preset number of satellites according to the satellite positions, the prior Doppler and the predicted code phases.

After a preset number of satellites are captured, the whole satellite capturing process of the low-orbit satellite constellation is realized, and the accurate position of the receiver can be calculated according to the captured satellites, namely, satellite positioning or satellite navigation is realized.

In a possible embodiment, the preset sequence is a sequence that is gradually outward and adjacent in sequence with the reference satellite as the center, and in fact, the preset sequence may be a sequence of satellite numbers in the partition, and so on from the first satellite, the second satellite, the third satellite, and so on, that is, the preset sequence is a circular sequence that is approximately centered at the first satellite and spirals outward.

In one possible implementation, the number of satellites in each partition is ≦ m, which is the minimum number of visible satellites within the service area of the low-orbit satellite constellation. To ensure that satellites within a partition do not have a large number of invisible satellites that cannot be captured. That is, since there are a large number of invisible satellites in the service area of the satellite constellation, the number of satellites in each partition cannot be too large, and if there are too many satellites in each partition, there is a possibility that a large number of invisible satellites are included, resulting in a low acquisition speed.

Specifically, for any given sector, the threshold number of satellites is set, and it is necessary to ensure that the number of satellites not yet dropped (i.e., visible satellites that can be received) in the sector is not less than n-1 when the first satellite in the sector is at the lowest reception elevation (i.e., if the angle is lower than the angle, the satellite signal cannot be received), so as to increase the probability that n satellites are captured in the sector.

In one possible implementation, n =4,4 satellites are the smallest number, and the number of satellites of the receiver's current approximate position calculation can be implemented to allow for efficiency and accuracy.

The embodiments of the present application are described below by calculation with reference to a specific example.

Assuming a current low-orbit satellite constellation, the orbit height is 500km, and the total number of satellites is 1800, wherein 60 satellites per orbital plane, and 30 orbital planes are total. The overhead time for each satellite is about 10 minutes. The navigation signal adopts 7GHz, the navigation spread spectrum code period is 4096 chips, each main frame of avionics text is 1500 bits, the data code rate is 100bps, and the length of one frame is 15s.

According to the satellite visibility analysis, more than 10 satellites can be generally seen at any point in the coverage range, so that only 180 satellites are required to be selected at equal intervals according to the low-orbit satellite constellation, that is, 1800 satellites are divided into 10 partitions at equal intervals, and each 180 satellites are divided into one partition. Currently, more than 3000 correlators are commonly available in the receiver, and the correlators can realize parallel search of 180 low-orbit satellites.

According to the low-orbit satellite motion speed and signal system, the frequency search range and the code phase search range are +/-160 kHz and 4092 chips respectively, and a frequency search step length of 500Hz and a code phase search step length of 0.5 chips are adopted, so that the total number of the resident units of one satellite is searched for N:

the dwell time of the search in each search unit is 1ms, and the search time of one path of correlator is T ₀ ：

T ₀ ＝5245944*0.001＝5246s

Number of blind capturing satellites is N ₁ =180, terminal correlator number N ₂ =3000, then the average time for any satellite acquired by the terminal is:

according to satellite visibility analysis, the number of visible satellites at 15 ° cut-off elevation is within 42, and if the captured first satellite is at the edge, then the first satellite needs to search for 42 × 4 ≈ 180 satellites around the first satellite in the worst case, and the positioning can be realized by randomly searching 3 satellites in the 180 satellites, so the average acquisition time is:

thus, the total average capture time is:

T _acq ＝T _acq1 +T _acq2 ＝237s

time T required by terminal theory for first positioning _TTFF Consisting of two parts, T ₁ To average capture time, T ₂ Time required for navigation message demodulation:

T _TTFF ＝T ₁ +T ₂ ＝237+15＝252s≈4.25min

therefore, the time required by the satellite capturing method is short, namely the satellite capturing speed is improved.

As shown in fig. 3, an embodiment of the present application further provides a satellite capturing apparatus, which may be used in a receiver, and the apparatus includes: an acquisition module 1 for acquiring a first satellite of each of a plurality of partitions of a low orbit satellite constellation; the acquisition module 1 is further configured to, after acquiring a first satellite in any partition, take the acquired first satellite as a reference satellite, take the partition to which the reference satellite belongs as a reference partition, and sequentially acquire other satellites in the reference partition according to a preset sequence by taking the reference satellite as an initial position; the information determining module 2 is used for determining the current position and the current time of the receiver according to the n satellites if the number of the satellites captured in the reference partition reaches n satellites, and n is larger than or equal to 4; the acquisition module 3 is used for acquiring ephemeris information of a current sky satellite according to the current position and the current time of the receiver; the capturing module 1 is further configured to capture a preset number of visible satellites according to the current position of the receiver, the current time, and ephemeris information of the current sky satellite.

The satellite capturing device may apply the satellite capturing method in any of the above embodiments, and the specific process and principle are the same as those in the above embodiments, and are not described herein again.

It should be understood that the above division of the satellite capturing device is only a logical division, and the actual implementation may be wholly or partially integrated into one physical entity, or may be physically separated. And these modules can be realized in the form of software called by processing element; or may be implemented entirely in hardware; and part of the modules can be realized in the form of calling by the processing element in software, and part of the modules can be realized in the form of hardware. For example, any one of the acquisition module 1, the information determination module 2, and the acquisition module 3 may be a processing element that is separately installed, or may be integrated in the satellite acquisition apparatus, for example, be integrated in a certain chip of the satellite acquisition apparatus, or may be stored in a memory of the satellite acquisition apparatus in the form of a program, and a certain processing element of the satellite acquisition apparatus calls and executes the functions of the above modules. Other modules are implemented similarly. In addition, all or part of the modules can be integrated together or can be independently realized. The processing element described herein may be an integrated circuit having signal processing capabilities. In implementation, each step of the above method or each module above may be implemented by an integrated logic circuit of hardware in a processor element or an instruction in the form of software.

For example, the capturing module 1, the information determining module 2 and the obtaining module 3 may be one or more integrated circuits configured to implement the above methods, such as: one or more Application Specific Integrated Circuits (ASICs), or one or more microprocessors (DSPs), or one or more Field Programmable Gate Arrays (FPGAs), among others. As another example, when one of the above modules is implemented in the form of a Processing element scheduler, the Processing element may be a general purpose processor, such as a Central Processing Unit (CPU) or other processor capable of invoking programs. As another example, these modules may be integrated together, implemented in the form of a system-on-a-chip (SOC).

In one possible embodiment, the acquisition module 1 is further configured to re-acquire the first satellite of each of the plurality of partitions of the low-orbit satellite constellation if the number of satellites acquired in the reference partition does not reach n satellites and the last satellite in the reference partition has been acquired.

In one possible embodiment, the predetermined sequence is a sequence that is gradually outward and sequentially adjacent to the reference satellite as a center.

In one possible embodiment, the number of satellites in each sector is greater than a sector corresponding number threshold, the number threshold being used to ensure that there are at least n-1 satellites in view in the corresponding sector when the first satellite in the corresponding sector is at the lowest reception elevation angle.

In one possible embodiment, n =4.

As shown in fig. 4, an embodiment of the present application further provides an electronic device 10, including: a processor 20 and a memory 30, the memory 30 being configured to store at least one instruction which is loaded and executed by the processor 20 to implement the satellite acquisition method in any of the embodiments described above.

The processor 20 may comprise one or more processing units, wherein the different processing units may be separate devices or may be integrated in one or more processors.

The memory 30 may be used to store computer-executable program code, which includes instructions. The memory may include a program storage area and a data storage area. Further, the memory 30 may include a high-speed random access memory, and may further include a nonvolatile memory, such as at least one magnetic disk storage device, a flash memory device, a universal flash memory (UFS), and the like. The processor 20 executes various functional applications of the electronic device and data processing by executing instructions stored in the memory 30.

The electronic device may be any device or device having a satellite positioning or satellite navigation function, such as a receiver, a chip, a mobile phone, a tablet computer, a Personal Computer (PC), a wearable electronic device, a vehicle-mounted device, and a vehicle.

Embodiments of the present application further provide a computer storage medium, which includes computer instructions, and when the computer instructions are run on an electronic device, the electronic device is caused to execute the satellite acquisition method according to any of the above embodiments.

In the above embodiments, all or part of the implementation may be realized by software, hardware, firmware, or any combination thereof. When implemented in software, it may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the procedures or functions described in accordance with the present application are generated, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wire (e.g., coaxial cable, fiber optic, digital subscriber line) or wirelessly (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid State Disk), among others.

In the embodiments of the present application, "at least one" means one or more, "a plurality" means two or more. "and/or" describes the association relationship of the associated objects, and means that there may be three relationships, for example, a and/or B, and may mean that a exists alone, a and B exist simultaneously, and B exists alone. Wherein A and B can be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. "at least one of the following" and similar expressions refer to any combination of these items, including any combination of singular or plural items. For example, at least one of a, b, and c may represent: a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, c may be single or multiple.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for satellite acquisition, applied to a receiver, the method comprising:

capturing a first satellite of each of a plurality of partitions of a low-orbit satellite constellation;

when a first satellite in any partition is captured, taking the captured first satellite as a reference satellite, taking the partition to which the reference satellite belongs as a reference partition, and sequentially capturing other satellites in the reference partition according to a preset sequence by taking the reference satellite as an initial position;

if the number of the satellites captured in the reference partition reaches n satellites, wherein n is larger than or equal to 4, determining the current position and the current time of the receiver according to the n satellites;

acquiring ephemeris information of a current sky satellite according to the current position and the current time of the receiver;

and capturing a preset number of satellites according to the current position of the receiver, the current time and the ephemeris information of the current sky satellite.

2. The method of claim 1,

re-executing the acquiring the first satellite of each of the plurality of partitions of the low-orbit satellite constellation if the number of satellites acquired in the reference partition does not reach n satellites and the last satellite in the reference partition has been acquired.

3. The method of claim 1,

the process of capturing a preset number of satellites according to the current position of the receiver, the current time, and ephemeris information of the current sky satellite includes:

calculating a satellite position according to ephemeris information of the current sky satellite and the current time;

calculating a priori Doppler and a predicted code phase according to the satellite position, the current time and the current position of the receiver;

and capturing a preset number of satellites according to the satellite positions, the prior Doppler and the predicted code phases.

4. The method of claim 1,

the preset sequence is a sequence which is gradually outward and sequentially adjacent by taking the reference satellite as a center.

5. The method of claim 1,

the number of satellites in each partition is less than or equal to m, and m is the minimum number of visible satellites in a service area of the low-orbit satellite constellation.

6. The method of claim 1,

the number of satellites in each partition is greater than a number threshold corresponding to the partition, and the number threshold is used for ensuring that at least n-1 visible satellites are in the corresponding partition when the first satellite in the corresponding partition is located at the lowest receiving elevation angle.

7. The method of claim 1,

n＝4。

8. a satellite acquisition apparatus, applied to a receiver, the apparatus comprising:

an acquisition module for acquiring a first satellite of each of a plurality of partitions of a low-orbit satellite constellation;

the acquisition module is further used for acquiring a first satellite in any partition, taking the acquired first satellite as a reference satellite, taking the partition to which the reference satellite belongs as a reference partition, and sequentially acquiring other satellites in the reference partition according to a preset sequence by taking the reference satellite as an initial position;

the information determining module is used for determining the current position and the current time of the receiver according to the n satellites if the number of the satellites captured in the reference partition reaches n satellites, and n is larger than or equal to 4;

the acquisition module is used for acquiring ephemeris information of a current sky satellite according to the current position and the current time of the receiver;

the capturing module is further configured to capture a preset number of visible satellites according to the current position of the receiver, the current time, and ephemeris information of the current sky satellite.

9. An electronic device, comprising:

a processor and a memory for storing at least one instruction which is loaded and executed by the processor to implement the satellite acquisition method of any one of claims 1 to 7.

10. A computer storage medium comprising computer instructions which, when run on an electronic device, cause the electronic device to perform the satellite acquisition method of any one of claims 1 to 7.