Positioning methods and devices based on low-Earth orbit satellites

Abstract

This application relates to a positioning method and apparatus based on low-Earth orbit (LEO) satellites, applied in the field of satellite navigation technology. The method includes: acquiring the transmission time of satellite signals, the position information of LEO satellites, and the reception time and direction of arrival of satellite signals; using the difference between the reception time and the transmission time as the original transmission time of the satellite signals; selecting an appropriate environmental error compensation model based on the environment type of the receiver, and correcting each original transmission time to obtain a corrected transmission time; calculating the arrival time difference based on the corrected transmission times of the two satellite signals; constructing a system time difference equation set based on the arrival time difference and the position information of the LEO satellites, and solving the system time difference equation set to obtain the initial position information of the receiver; optimizing the initial position information based on the position information of the LEO satellites at each transmission time and the direction of arrival of each satellite signal to obtain the target position information. This can improve the accuracy of positioning.

Description

Technical Field

[0001] This application relates to the field of satellite navigation technology, and in particular to a positioning method and device based on low-Earth orbit satellites. Background Technology

[0002] Positioning technology is fundamental to various intelligent systems and mobile applications in modern society. Among related technologies, positioning primarily relies on high-orbit satellite systems such as GPS (Global Positioning System), GLONASS (Global Navigation Satellite System), and Galileo. However, GNSS signals are difficult to receive in subways and stairwells, leading to inaccurate positioning. Furthermore, while high-orbit satellites are stable, they lack flexibility, cannot constantly update and adjust their transmission systems, and suffer from long signal propagation distances and significant latency. Summary of the Invention

[0003] To address the aforementioned technical problems, this application provides a positioning method, apparatus, electronic device, storage medium, and computer program product based on low-Earth orbit satellites.

[0004] According to a first aspect of this application, a positioning method based on low-Earth orbit satellites is provided, comprising: For each of the multiple pre-modulated low-Earth orbit satellites, the transmission time of the satellite signal transmitted by the low-Earth orbit satellite, the position information of the low-Earth orbit satellite at each transmission time, and the reception time and direction of arrival of the satellite signal transmitted by the low-Earth orbit satellite received by the receiver are obtained. The difference between the reception time and the transmission time corresponding to each satellite signal is used as the original transmission time of the satellite signal; Based on the environment type of the receiver, an appropriate environmental error compensation model is selected to correct the original transmission time of each satellite signal, thus obtaining the corrected transmission time of each satellite signal; the environmental error compensation model includes a normal distribution model and a terrain occlusion compensation model; For every two satellite signals, the time difference of arrival is calculated based on the corrected transmission time of the two satellite signals; Based on the arrival time difference and the low-orbit satellite position information at the transmission times of the two satellite signals, a system time difference equation set is constructed, and the system time difference equation set is solved to obtain the initial position information of the receiver; Based on the position information of the low-orbit satellites at each transmission time and the direction of arrival of each satellite signal, the initial position information is optimized to obtain the target position information.

[0005] Optionally, the step of selecting an appropriate environmental error compensation model based on the environment type of the receiver, and correcting the original transmission time of each satellite signal to obtain the corrected transmission time of each satellite signal includes: When the receiver is in a mountainous environment, the original transmission time of each satellite signal is corrected using a pre-built terrain occlusion compensation model to obtain the corrected transmission time of each satellite signal.

[0006] Optionally, the step of correcting the original transmission time of each satellite signal using a pre-built terrain occlusion compensation model to obtain the corrected transmission time of each satellite signal includes: The raw transmission time of multiple satellite signals According to the pre-built terrain occlusion compensation model By fitting the data, the corrected transmission time for each satellite signal is obtained; This represents the corrected transmission time of the i-th satellite signal; This represents the propagation path length of the i-th satellite signal; The 'c' represents the additional propagation delay caused by the mountain blocking the light; 'c' represents the speed of light.

[0007] Optionally, after determining the original transmission time of each satellite signal, the method further includes: When the receiver is in a tunnel environment, the location information of the virtual reflection point is determined based on the arrival direction of each satellite signal and the tunnel surface. ; Using a pre-built reflection model Determine the location information of the receiver. ; This represents the position information of the low-Earth orbit satellite when the i-th satellite signal is transmitted. This represents the original transmission time of the i-th satellite signal.

[0008] Optionally, the method further includes: Based on the needs of ground missions, multiple low-orbit satellites are modulated using methods such as orbit scheduling, resource tilting, mission priority switching, or accuracy enhancement.

[0009] Optionally, the step of selecting an appropriate environmental error compensation model based on the environment type of the receiver, and correcting the original transmission time of each satellite signal to obtain the corrected transmission time of each satellite signal includes: When the receiver is in an urban environment, the original transmission time of each satellite signal is corrected using a pre-built normal distribution model to obtain the corrected transmission time of each satellite signal.

[0010] Optionally, the step of correcting the original transmission time of each satellite signal using a pre-built normal distribution model to obtain the corrected transmission time of each satellite signal includes: According to the formula: Determine the corrected transmission time of the i-th satellite signal. ; This represents the original transmission time of the i-th satellite signal. The weight is represented by N, which represents the number of satellite signals received by the receiver.

[0011] According to a second aspect of this application, a positioning device based on low-Earth orbit satellites is provided, comprising: The data acquisition module is used to acquire, for each of the multiple pre-modulated low-Earth orbit satellites, the transmission time of the satellite signal transmitted by the low-Earth orbit satellite, the position information of the low-Earth orbit satellite at each transmission time, and the reception time and direction of arrival of the satellite signal transmitted by the low-Earth orbit satellite received by the receiver. The original transmission time determination module is used to take the difference between the receiving time and the sending time of each satellite signal as the original transmission time of the satellite signal. The corrected transmission time determination module is used to call a preset error correction model that matches the environment in which the receiver is located, and correct the original transmission time of each satellite signal to obtain the corrected transmission time of each satellite signal; the error correction model includes a normal distribution model and a terrain occlusion compensation model. The time difference of arrival determination module is used to calculate the time difference of arrival for every two satellite signals based on the corrected transmission time of the two satellite signals. The initial position information determination module is used to construct a system time difference equation set based on the arrival time difference and the position information of the low-orbit satellite at the transmission time of the two satellite signals, and solve the system time difference equation set to obtain the initial position information of the receiver. The target location information determination module is used to optimize the initial location information based on the location information of the low-orbit satellite at each transmission time and the direction of arrival of each satellite signal to obtain the target location information.

[0012] Optionally, the corrected transmission time determination module includes a first correction unit; The first correction unit is used to correct the original transmission time of each satellite signal by using a pre-built terrain occlusion compensation model when the receiver is in a mountainous environment, so as to obtain the corrected transmission time of each satellite signal.

[0013] Optionally, the first correction unit is specifically used to adjust the original transmission time of multiple satellite signals when the receiver is in a mountainous environment. According to the pre-built terrain occlusion compensation model By fitting the data, the corrected transmission time for each satellite signal is obtained; This represents the corrected transmission time of the i-th satellite signal; This represents the propagation path length of the i-th satellite signal; The 'c' represents the additional propagation delay caused by the mountain blocking the light; 'c' represents the speed of light.

[0014] Optionally, the positioning device based on low-Earth orbit satellites further includes: The virtual reflection point location information determination module is used to determine the location information of the virtual reflection point based on the arrival direction of each satellite signal and the tunnel surface when the receiver is in a tunnel environment. ; Receiver location determination module, used to utilize a pre-built reflection model Determine the location information of the receiver. ; This represents the position information of the low-Earth orbit satellite when the i-th satellite signal is transmitted. This represents the original transmission time of the i-th satellite signal.

[0015] Optionally, the positioning device based on low-Earth orbit satellites further includes: The satellite modulation module is used to modulate multiple low-orbit satellites according to ground mission requirements. Modulation methods include: orbit scheduling, resource tilting, mission priority switching, or accuracy enhancement.

[0016] Optionally, the corrected transmission time determination module includes a second correction unit; The second correction unit is used to correct the original transmission time of each satellite signal using a pre-built normal distribution model when the receiver is in an urban environment, so as to obtain the corrected transmission time of each satellite signal.

[0017] Optionally, the second correction unit is specifically used to, when the receiver is in an urban environment, according to the formula: Determine the corrected transmission time of the i-th satellite signal. ; This represents the original transmission time of the i-th satellite signal. The weight is represented by N, which represents the number of satellite signals received by the receiver.

[0018] According to a third aspect of this application, an electronic device is provided, comprising: a processor configured to execute a computer program stored in a memory, wherein the computer program, when executed by the processor, implements the method described in the first aspect.

[0019] According to a fourth aspect of this application, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the method described in the first aspect.

[0020] According to a fifth aspect of this application, a computer program product is provided that, when the computer program product is run on a computer, causes the computer to perform the method described in the first aspect.

[0021] The technical solution provided in this application has the following advantages compared with the prior art: Positioning is achieved using low-Earth orbit (LEO) satellites, and the original transmission times of different satellite signals are calculated. Different environmental error compensation models are selected to correct the original transmission times when the receiver is in different environments, resulting in corrected transmission times. This improves the accuracy of transmission time determination and thus enhances positioning precision. A system of time difference equations is constructed based on the corrected transmission time differences between different LEO satellites and the distance differences between them. Solving these equations allows for receiver positioning. Furthermore, the positioning accuracy is further improved by incorporating the satellite signal arrival angle. LEO satellites have a relatively large elevation angle, making signal reception easier even in obstructed urban environments, thus reducing signal isolation problems caused by buildings and other obstacles. Therefore, this embodiment can achieve accurate positioning in normal environments or GNSS signal isolation environments. Moreover, the short time delay makes it suitable for positioning needs in fully radio frequency environments. Attached Figure Description

[0022] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0023] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a flowchart of a positioning method based on low-Earth orbit satellites in an embodiment of this application; Figure 2 This is a schematic diagram of a positioning device based on low-Earth orbit satellites in an embodiment of this application; Figure 3 This is a schematic diagram of the structure of an electronic device in an embodiment of this application. Detailed Implementation

[0025] To better understand the above-mentioned objectives, features, and advantages of this application, the solution of this application will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0026] Many specific details are set forth in the following description in order to provide a full understanding of this application, but this application may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of this application, and not all embodiments.

[0027] See Figure 1 , Figure 1 This is a flowchart of a positioning method based on low-Earth orbit satellites in an embodiment of this application, which may include the following steps: Step S102: For each of the pre-modulated low-Earth orbit (LEO) satellites, obtain the transmission time of the LEO satellite signal, the LEO satellite's position information at each transmission time, and the reception time and direction of arrival of the satellite signal transmitted by the LEO satellite received by the receiver.

[0028] Compared to high-orbit satellites, low-orbit satellites offer advantages such as lower latency and higher throughput. Furthermore, high-orbit satellites lack operational flexibility, while low-orbit satellites exhibit more predictable trajectories in both time and space, and can be modulated to meet varying needs. Additionally, they are more easily received even in obstructed urban environments, reducing signal isolation caused by buildings and other obstacles. Therefore, low-orbit satellites can be used for positioning to improve accuracy.

[0029] The pre-modulated low-Earth orbit (LEO) satellites can be satellites in the same orbit or satellites in different orbits. Each LEO satellite can transmit satellite signals to a ground receiver multiple times. For each satellite signal, the transmission time, reception time, and direction of arrival of the satellite signal, as well as the LEO satellite's position information at the time of transmission, can be recorded.

[0030] Step S104: The difference between the receiving time and the sending time of each satellite signal is used as the original transmission time of the satellite signal.

[0031] Assume the location of the receiver to be determined is ( The position information of the i-th low-orbit satellite when transmitting satellite signals is ( The time for transmitting satellite signals is t. i The receiving time is t ri The velocity of the propagating body is c. The position information of the j-th low-orbit satellite when transmitting its signal is (x j ,y j ,z jThe time of transmitting the satellite signal is t. j The receiving time is t rj .

[0032] The original transmission time of the satellite signal transmitted by the i-th low-Earth orbit satellite is t. ri - t i The original transmission time of the satellite signal transmitted by the j-th low-Earth orbit satellite is t. rj - t j The distance between the i-th low-orbit satellite and the receiver is The distance between the j-th low-orbit satellite and the receiver is The distance difference between the i-th and j-th low-Earth orbit satellites and the receiver .

[0033] Based on the above principles, the embodiments of this application do not require receiver clock synchronization, and can achieve three-dimensional positioning of the receiver based on the TDOA (Time Difference of Arrival) and (Direction of Arrival) between different satellite signals.

[0034] Step S106: Based on the environment type of the receiver, select the appropriate environmental error compensation model to correct the original transmission time of each satellite signal, obtaining the corrected transmission time for each satellite signal. The environmental error compensation models include a normal distribution model and a terrain occlusion compensation model.

[0035] It should be noted that since different environments have different effects on satellite signal transmission, experimental data under different environments can be collected. By analyzing the experimental data, a suitable correction algorithm can be selected to correct the original transmission time of each satellite signal, thereby improving the accuracy of the satellite signal arrival time difference and thus improving the positioning accuracy.

[0036] For example, experimental data in urban environments and mountainous environments can be found in Tables 1 and 2, respectively. The trends in positioning error and signal transmission time under each environment help analyze the system's performance in different conditions.

[0037] Table 1 In urban environments, signal transmission time is prone to fluctuations due to building obstruction and multipath effects, leading to increased positioning errors.

[0038] Table 2 In mountainous environments, due to signal attenuation and multipath effects, signal transmission time is longer. DOA is stable but has deviations, which has a significant impact on positioning accuracy.

[0039] Based on the above analysis, corresponding correction algorithms can be constructed to correct the original transmission time. Optionally, it can be assumed that the signal transmission time error in urban environments follows a normal distribution, and a normal distribution model can be constructed to correct the original transmission time. In mountainous environments, signal transmission is affected by terrain obstruction; therefore, a terrain obstruction compensation model can be constructed to correct the original transmission time.

[0040] Specifically, when the receiver is in an urban environment, the transmission time error of each satellite signal has zero mean, and the random variable is a Gaussian distribution with variance of... , is represented as: . The difference between the original transmission time and the corrected transmission time of each satellite signal follows a normal distribution model. This can be determined using the following formula: That is, minimizing the weighted sum of the transmission time residuals to obtain the corrected transmission time of the i-th satellite signal. . This represents the original transmission time of the i-th satellite signal. The weight represents the number of satellite signals received by the receiver. It can be adjusted based on factors such as signal strength, satellite elevation angle, satellite or receiver visibility, and satellite signal propagation path (whether there is significant reflection).

[0041] When the receiver is in a mountainous environment, the original transmission time of each satellite signal is corrected using a pre-built terrain occlusion compensation model to obtain the corrected transmission time for each satellite signal. The pre-built terrain occlusion compensation model can... Signal transmission time includes the time consumed by the satellite signal's propagation path. In addition, there is the additional propagation delay caused by the mountain blocking the path. .

[0042] The original transmission times of multiple satellite signals are fitted according to the terrain occlusion compensation model described above to obtain the corrected transmission time of each satellite signal. This represents the corrected transmission time of the i-th satellite signal; represents the propagation path length of the i-th satellite signal; c represents the speed of light; The additional propagation delay caused by mountain shading can be estimated using a terrain DEM (Digital Elevation Model). Specifically, the impact path of terrain shading can be estimated based on the DEM, and then the propagation delay can be calculated based on the impact path. .

[0043] Optionally, before fitting the original transmission times of multiple satellite signals using a terrain occlusion compensation model, original transmission times that do not conform to spatial geometric consistency can be excluded to improve positioning accuracy. For example, if the original transmission time deviates significantly from the position solution calculated from other sets of measurements, or is seriously inconsistent with the DOA derivation direction, it is considered a "pseudo-original transmission time." Alternatively, original transmission times of weak signal paths can be filtered out based on signal strength (such as signal-to-noise ratio).

[0044] Step S108: For every two satellite signals, calculate the time difference of arrival based on the corrected transmission time of the two satellite signals.

[0045] As mentioned earlier, for any two low-Earth orbit (LEO) satellites (e.g., the i-th LEO satellite and the j-th LEO satellite), the original transmission time of the satellite signal transmitted by the i-th LEO satellite is t. ri - t i The original transmission time of the satellite signal transmitted by the j-th low-Earth orbit satellite is t. rj - t j The time difference between the arrival of the two satellite signals at the receiver is Similarly, assuming the corrected transmission times are respectively and Calculate the arrival time difference according to the corrected transmission time. .and compared to, It is more accurate.

[0046] Step S110: Based on the arrival time difference and the position information of the low-orbit satellite at the transmission time of the two satellite signals, construct a system time difference equation set, solve the system time difference equation set, and obtain the initial position information of the receiver.

[0047] Based on the time difference of arrival and the position information of the low-Earth orbit satellite at the transmission times of the two satellite signals, the time difference equation for a single system is expressed as follows: .

[0048] Multiple system time difference equations can form a system time difference equation system. By solving this system of equations, the initial position information of the receiver can be obtained. For example, the initial position information of the receiver can be obtained using the least squares method.

[0049] Step S112: Optimize the initial position information based on the position information of the low-orbit satellites at each transmission time and the direction of arrival of each satellite signal to obtain the target position information.

[0050] By combining the angle of arrival (OA) of the satellite signal, the relative azimuth between the low-Earth orbit (LEO) satellite and the receiver can be estimated. Combined with the known satellite trajectory, the initial position information can be optimized to further improve positioning accuracy. Optionally, a multi-antenna array can be introduced onto the receiver to enhance the accuracy of the OA, thereby improving positioning accuracy.

[0051] This application utilizes low-Earth orbit (LEO) satellites for positioning. It calculates the original transmission time of different satellite signals and constructs different environmental error compensation models based on the receiver's environment to correct the original transmission time. For example, when the receiver is in an urban or mountainous environment, a pre-constructed normal distribution model or terrain obstruction compensation model is used to correct the original transmission time, obtaining a corrected transmission time to improve the accuracy of transmission time determination and thus improve positioning accuracy. Based on the corrected transmission time difference between different LEO satellites and the distance difference between them, a system time difference equation set is constructed. Solving this equation set allows for receiver positioning. Then, the positioning accuracy is further improved by combining the satellite signal arrival angle. LEO satellites have a large elevation angle, making signal reception easier even in obstructed urban environments, thus reducing signal isolation problems caused by buildings and other obstacles. Therefore, accurate positioning can be achieved in normal environments or GNSS signal isolation environments. Furthermore, the short time delay makes it suitable for positioning needs in fully radio frequency environments.

[0052] In some scenarios, the receiver may be in a tunnel environment. In tunnels, due to the lack of direct signals, signals will be reflected and propagate via multiple paths. Experimental data in tunnel environments can be found in Table 3.

[0053] Table 3 The data in Table 3 reflects the signal characteristics in a tunnel environment, such as a lower DOA. Based on this, a reflection model for a tunnel environment can be pre-constructed: After determining the original transmission time of each satellite signal, if the receiver is in a tunnel environment, the location information of the virtual reflection point is determined based on the arrival direction of each satellite signal and the tunnel surface. Using this reflection model Determine the location information of the receiver. ; This represents the position information of the low-Earth orbit satellite when the i-th satellite signal is transmitted. This represents the original transmission time of the i-th satellite signal. Similarly, a multi-antenna array can be introduced on the receiver to enhance the accuracy of the DOA, thereby improving positioning accuracy.

[0054] Optionally, when using low-Earth orbit (LEO) satellites for positioning, multiple LEO satellites can be modulated according to ground mission requirements. Modulation methods include: orbit scheduling, resource tilting, mission priority switching, or accuracy enhancement. In scenarios involving sudden events in a region (such as disaster relief or temporary traffic control), high-density positioning support is required. LEO satellite coverage strategies can be pre-planned so that multiple satellite orbits converge over the area within a certain period. Controllable orbital inclination / phase difference adjustments can be used to advance / delay the visibility windows of certain satellites to enhance local spatiotemporal density. Assuming an earthquake occurs in a region, the navigation system can be adjusted as follows: By controlling the orbital phase of the four low-Earth orbit satellites in the constellation, a high-frequency convergence is formed near the epicenter. At the same time, the beam direction of these satellites is dynamically switched to the seismic zone through the ground center dispatch system to improve signal quality. High-priority TDOA / DOA data backhaul and processing channels are provided to support receivers that can be quickly deployed on site to complete accurate positioning.

[0055] In urban areas, where users are densely populated, more navigation resources are needed. In rural or maritime scenarios, where users are sparsely populated, fewer navigation resources are required. Low-Earth orbit (LEO) satellites possess electronic or mechanical beamforming capabilities, which can concentrate more beam resources to "illuminate" specific areas. They can also dynamically allocate carrier frequency and power resources (including multi-beam reuse) to improve the navigation / communication quality of a particular area.

[0056] In other scenarios, such as drone swarms, autonomous vehicles, or emergency communication equipment, the system may require higher accuracy / frequency positioning. It can switch to higher frequency positioning (e.g., 1 Hz → 10 Hz) or even activate auxiliary radar / laser ranging modules for short-term enhancement. Resource priority allocation is based on user authentication or task marking to ensure the positioning stability of critical users.

[0057] The positioning method of this application is highly practical and suitable for future application scenarios based on low-Earth orbit satellite systems, such as autonomous driving, pedestrian positioning, and drone route planning.

[0058] It should be noted that although the steps of the method in this disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additional or alternative steps may be omitted, multiple steps may be combined into one step, and / or a step may be broken down into multiple steps.

[0059] This application also provides a positioning device based on low-Earth orbit satellites, see [link to relevant documentation]. Figure 2 The low-Earth orbit satellite-based positioning device 200 includes: The data acquisition module 202 is used to acquire, for each of the multiple low-orbit satellites pre-modulated, the transmission time of the satellite signal transmitted by the low-orbit satellite, the position information of the low-orbit satellite at each transmission time, and the reception time and direction of arrival of the satellite signal transmitted by the low-orbit satellite received by the receiver. The original transmission time determination module 204 is used to take the difference between the receiving time and the sending time of each satellite signal as the original transmission time of the satellite signal. The transmission time correction determination module 206 is used to call a preset error correction model that matches the environment in which the receiver is located, and correct the original transmission time of each satellite signal to obtain the corrected transmission time of each satellite signal; the error correction model includes a normal distribution model and a terrain occlusion compensation model. The arrival time difference determination module 208 is used to calculate the arrival time difference for every two satellite signals based on the corrected transmission time of the two satellite signals. The initial position information determination module 210 is used to construct a system time difference equation set based on the arrival time difference and the position information of the low-orbit satellite at the transmission time of the two satellite signals, and solve the system time difference equation set to obtain the initial position information of the receiver. The target position information determination module 212 is used to optimize the initial position information based on the position information of the low-orbit satellite at each transmission time and the arrival direction of each satellite signal to obtain the target position information.

[0060] Optionally, the corrected transmission time determination module 206 includes a first correction unit, which is used to correct the original transmission time of each satellite signal by using a pre-built terrain occlusion compensation model when the receiver is in a mountainous environment, so as to obtain the corrected transmission time of each satellite signal.

[0061] Optionally, the first correction unit is specifically used to correct the original transmission time of multiple satellite signals when the receiver is in a mountainous environment. According to the pre-built terrain occlusion compensation model By fitting the data, the corrected transmission time for each satellite signal is obtained; This represents the corrected transmission time of the i-th satellite signal; This represents the propagation path length of the i-th satellite signal; The 'c' represents the additional propagation delay caused by the mountain blocking the light; 'c' represents the speed of light.

[0062] Optionally, the low-Earth orbit satellite-based positioning device 200 further includes: The virtual reflection point location information determination module is used to determine the location information of virtual reflection points based on the arrival direction of each satellite signal and the tunnel surface when the receiver is in a tunnel environment. ; Receiver location determination module, used to utilize a pre-built reflection model Determine the location information of the receiver. ; This represents the position information of the low-Earth orbit satellite when the i-th satellite signal is transmitted. This represents the original transmission time of the i-th satellite signal.

[0063] Optionally, the low-Earth orbit satellite-based positioning device 200 further includes: The satellite modulation module is used to modulate multiple low-orbit satellites according to ground mission requirements. Modulation methods include: orbit scheduling, resource tilting, mission priority switching, or accuracy enhancement.

[0064] Optionally, the corrected transmission time determination module 206 includes a second correction unit; The second correction unit is used to correct the original transmission time of each satellite signal using a pre-built normal distribution model when the receiver is in an urban environment, so as to obtain the corrected transmission time of each satellite signal.

[0065] Optionally, the second correction unit is specifically used when the receiver is in an urban environment, according to the formula: Determine the corrected transmission time of the i-th satellite signal. ; This represents the original transmission time of the i-th satellite signal. The weight is represented by N, which represents the number of satellite signals received by the receiver.

[0066] The specific details of each module or unit in the above-mentioned device have been described in detail in the corresponding methods, so they will not be repeated here.

[0067] It should be noted that although several modules or units for the device used to perform actions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to the embodiments of this application, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0068] This application also provides an electronic device, including: a processor; and a memory for storing processor-executable instructions; wherein the processor is configured to execute the low-Earth orbit satellite-based positioning method described in this example embodiment.

[0069] Reference Figure 3 , Figure 3 This is a schematic diagram of the structure of an electronic device in an embodiment of this application. The specific embodiments of this application do not limit the specific implementation of the electronic device.

[0070] like Figure 3 As shown, the electronic device may include: a processor 302, a communication interface 304, a memory 306, and a communication bus 308.

[0071] The processor 302, communication interface 304, and memory 306 communicate with each other via communication bus 308.

[0072] Communication interface 304 is used to communicate with other electronic devices or servers.

[0073] The processor 302 is used to execute program 310, specifically the relevant steps in the above method embodiments.

[0074] Specifically, program 310 may include program code that includes computer operation instructions.

[0075] Processor 302 may be a central processing unit, a specific integrated circuit, or one or more integrated circuits configured to implement the embodiments of this application. The one or more processors included in the smart device may be processors of the same type, such as one or more CPUs; or they may be processors of different types, such as one or more CPUs and one or more ASICs.

[0076] Memory 306 is used to store program 310. Memory 306 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0077] Specifically, program 310 can be used to cause processor 302 to execute the steps in the above-described low-Earth orbit satellite-based positioning method embodiment.

[0078] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the devices and modules described above can be referred to the corresponding process descriptions in the foregoing method embodiments, and will not be repeated here.

[0079] In this embodiment of the application, a computer-readable storage medium is also provided, on which a computer program is stored, which, when executed by a processor, implements the above-described positioning method based on low-Earth orbit satellites.

[0080] It should be noted that the computer-readable storage medium shown in this application can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media may include, but are not limited to: electrical connections having one or more wires, portable computer disks, hard disks, random access memory, read-only memory, erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof. In this application, the computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. The program code contained on the computer-readable storage medium can be transmitted using any suitable medium, including but not limited to: wireless, wire, optical fiber, radio frequency, etc., or any suitable combination thereof.

[0081] In this embodiment of the application, a computer program product is also provided, which, when run on a computer, causes the computer to execute the above-described positioning method based on low-Earth orbit satellites.

[0082] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0083] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A positioning method based on low-Earth orbit satellites, characterized in that, include: For each of the multiple pre-modulated low-Earth orbit satellites, the transmission time of the satellite signal transmitted by the low-Earth orbit satellite, the position information of the low-Earth orbit satellite at each transmission time, and the reception time and direction of arrival of the satellite signal transmitted by the low-Earth orbit satellite received by the receiver are obtained. The difference between the reception time and the transmission time corresponding to each satellite signal is used as the original transmission time of the satellite signal; Based on the type of environment in which the receiver is located, an appropriate environmental error compensation model is selected to correct the original transmission time of each satellite signal, thus obtaining the corrected transmission time of each satellite signal. The environmental error compensation model includes a normal distribution model and a terrain occlusion compensation model; the selection of the appropriate environmental error compensation model based on the environment type of the receiver includes: When the receiver is in a mountainous environment, the original transmission time of each satellite signal is corrected using a pre-built terrain occlusion compensation model to obtain the corrected transmission time of each satellite signal. This correction of the original transmission time of each satellite signal using the pre-built terrain occlusion compensation model includes: [the process of] retrieving the original transmission times of multiple satellite signals... According to the pre-built terrain occlusion compensation model By fitting the data, the corrected transmission time for each satellite signal is obtained; This represents the corrected transmission time of the i-th satellite signal; This represents the propagation path length of the i-th satellite signal; The mountain represents the additional propagation delay caused by obstruction; c represents the speed of light. When the receiver is in an urban environment, the original transmission time of each satellite signal is corrected using the pre-built normal distribution model to obtain the corrected transmission time of each satellite signal. The correction of the original transmission time of each satellite signal using the pre-built normal distribution model to obtain the corrected transmission time of each satellite signal includes: according to the formula: Determine the corrected transmission time of the i-th satellite signal. ;in, This represents the original transmission time of the i-th satellite signal. This represents the weight, and N represents the number of satellite signals received by the receiver; For every two satellite signals, the time difference of arrival is calculated based on the corrected transmission time of the two satellite signals; Based on the arrival time difference and the low-orbit satellite position information at the transmission times of the two satellite signals, a system time difference equation set is constructed, and the system time difference equation set is solved to obtain the initial position information of the receiver; Based on the position information of the low-orbit satellites at each transmission time and the direction of arrival of each satellite signal, the initial position information is optimized to obtain the target position information.

2. The method according to claim 1, characterized in that, After determining the original transmission time of each satellite signal, the method further includes: When the receiver is in a tunnel environment, the location information of the virtual reflection point is determined based on the arrival direction of each satellite signal and the tunnel surface. ; Using a pre-built reflection model Determine the location information of the receiver. ; This represents the position information of the low-Earth orbit satellite when the i-th satellite signal is transmitted. This represents the original transmission time of the i-th satellite signal.

3. The method according to claim 1, characterized in that, The method further includes: Based on the needs of ground missions, multiple low-orbit satellites are modulated using methods such as orbit scheduling, resource tilting, mission priority switching, or accuracy enhancement.

4. A low-Earth orbit satellite-based positioning device based on the method of any one of claims 1-3, characterized in that, The device includes: The data acquisition module is used to acquire, for each of the multiple pre-modulated low-Earth orbit satellites, the transmission time of the satellite signal transmitted by the low-Earth orbit satellite, the position information of the low-Earth orbit satellite at each transmission time, and the reception time and direction of arrival of the satellite signal transmitted by the low-Earth orbit satellite received by the receiver. The original transmission time determination module is used to take the difference between the receiving time and the sending time of each satellite signal as the original transmission time of the satellite signal. The corrected transmission time determination module is used to call a preset error correction model that matches the environment in which the receiver is located, and correct the original transmission time of each satellite signal to obtain the corrected transmission time of each satellite signal; the error correction model includes a normal distribution model and a terrain occlusion compensation model. The time difference of arrival determination module is used to calculate the time difference of arrival for every two satellite signals based on the corrected transmission time of the two satellite signals. The initial position information determination module is used to construct a system time difference equation set based on the arrival time difference and the position information of the low-orbit satellite at the transmission time of the two satellite signals, and solve the system time difference equation set to obtain the initial position information of the receiver. The target location information determination module is used to optimize the initial location information based on the location information of the low-orbit satellite at each transmission time and the direction of arrival of each satellite signal to obtain the target location information.

5. The apparatus according to claim 4, characterized in that, The corrected transmission time determination module includes a first correction unit; The first correction unit is used to correct the original transmission time of each satellite signal by using a pre-built terrain occlusion compensation model when the receiver is in a mountainous environment, so as to obtain the corrected transmission time of each satellite signal.

6. The apparatus according to claim 5, characterized in that, The first correction unit is specifically used to correct the original transmission time of multiple satellite signals when the receiver is in a mountainous environment. According to the pre-built terrain occlusion compensation model By fitting the data, the corrected transmission time for each satellite signal is obtained; This represents the corrected transmission time of the i-th satellite signal; This represents the propagation path length of the i-th satellite signal; The 'c' represents the additional propagation delay caused by the mountain blocking the light; 'c' represents the speed of light.

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