Positioning method and device based on low earth orbit satellite opportunity signal and storage medium

Abstract

The invention discloses a positioning method and device based on low-orbit satellite opportunity signals and a storage medium. Relates to the technical field of satellites. The method comprises the following steps: extracting corresponding signal arrival angle information and Doppler frequency shift information according to an opportunity signal of a low-orbit satellite under a current epoch; determining orbit information of a low-orbit satellite under the current epoch according to a preset satellite two-line orbit data file and a satellite orbit prediction model; under the condition that the number of the low-orbit satellites is not smaller than the preset number of satellites, coarse positioning information of the receiver is generated according to the signal arrival angle information and the orbit information, the coarse positioning information serves as an initial value of iterative solution in the Doppler positioning process for iterative solution, and final positioning information of the receiver is determined; and under the condition that the number of the low-orbit satellites is smaller than the preset number of satellites, calculating final positioning information of the receiver according to the signal arrival angle information, the Doppler frequency shift information and the orbit information.

Description

Technical Field

[0001] The present application relates to the field of satellite technology, and in particular to a positioning method, device and storage medium based on low-orbit satellite opportunity signals. Background Art

[0002] At present, low-orbit satellite positioning technology has been applied in many fields such as backup navigation, military operations, auxiliary agricultural machinery management, and helping to achieve integrated communication, navigation and remote sensing. The opportunity signal positioning method has higher resource utilization and can be applied in a variety of environments because it does not require a pre-set signal system and additional infrastructure construction, and has attracted widespread attention in the field.

[0003] Low-orbit satellite positioning technology has broad application prospects, but it also faces many challenges in the development process. First, the high dynamic and non-cooperative characteristics of low-orbit satellites make it difficult to extract pseudo-range and carrier phase observations. The current low-orbit satellite positioning technology mostly uses the Doppler positioning principle, and the observations are relatively single. When the number of low-orbit satellites used for observation is small, instantaneous positioning cannot be achieved in a single epoch, and the positioning accuracy is also limited. Under normal circumstances, the positioning accuracy can only reach ten meters. Secondly, the iterative solution in the Doppler positioning process is highly dependent on the initial value, which will affect the number of iterative solutions and positioning accuracy.

[0004] The common ideas to solve the problem of limited accuracy are to improve the accuracy of Doppler observations, differential, or carry out combined positioning with multiple sensors. Improving the accuracy of Doppler observations usually requires selecting a specific observation extraction method for the target signal system, such as the frequency domain sliding window estimation method for Starlink beacon signals and the parallel code phase search and capture algorithm for global star signals; differential requires adding a base station with a known position, and eliminating some errors by subtracting the observations of the receiver and the base station at the same epoch to improve positioning accuracy; combined positioning requires additional sensors, such as altimeters and inertial navigation systems. The low-orbit satellite positioning system and other positioning systems work together through the Kalman filter to improve positioning accuracy.

[0005] When using Doppler shift positioning, the positioning result is limited by the number of low-orbit satellites. When the number of observed satellites is less than four, it cannot meet the requirements of instantaneous positioning, and it is necessary to wait for multiple epochs to integrate Doppler. Although low-orbit satellites have a higher movement speed than medium- and high-orbit satellites, it still takes a certain amount of time to accumulate to form sufficient geometric movement, and this process will be affected by the satellite-ground clock difference. In addition, the Doppler positioning solution process cannot avoid dependence on the initial value of the target position. When the initial value is missing, the number of iterative solutions will increase significantly.

[0006] The publication number is CN119001789A, and the name is Doppler frequency shift positioning method, device, equipment and medium based on low-orbit satellites. The method is: receive visible low-orbit satellite ephemeris data; calculate the position of each low-orbit satellite based on the received satellite ephemeris data; calculate the sub-satellite point according to the satellite position, and determine its visible range with the sub-satellite point as the center; take the intersection of the visible ranges of multiple low-orbit satellites, and evenly select points within the intersection range as the initial value points to be selected for positioning; use each initial value point to be selected as the initial value point of the positioning of the Doppler frequency shift observation equation, use the least squares method to calculate the user position, and record the size of the positioning residual; traverse to obtain the minimum positioning residual of all the initial value points to be selected, and judge whether the minimum residual value is less than the residual threshold. If it is less than, it means convergence is successful, and take the user position corresponding to the minimum residual value as the user's positioning result.

[0007] The publication number is CN101855566A, and the name is a system for determining a position via a network. The system includes a base station receiver with a clock and a known position, which determines the distance to the transmitter, obtains a sample sequence of an opportunity signal, and time-marks the sequence with a reception time, based on a calculated distance and a calculated transmission time, or both. The base station receiver sends the time-stamped sequence to a remote receiver and sends the calculated distance as appropriate. Given a sample of the opportunity signal stored and time-stamped by a remote receiver, the time-stamped sequence is associated with the stored sample, and a time offset is calculated as the difference between the reception time at the remote receiver and any one of the following two: the reception time at the base station receiver and the transmission time calculated at the base station receiver. The remote receiver calculates the position based on the time offset and, as appropriate, the distance provided by the base station receiver. The altitude of the remote receiver can be calculated as part of the position calculation, can be determined iteratively based on limiting the Z coordinate to the average altitude, or determined based on the difference in air pressure sensor readings at the base station and the remote receiver.

[0008] There is currently no effective solution to the technical problems in the above-mentioned prior art that the positioning results of Doppler frequency shift positioning are limited by the number of low-orbit satellites, the instantaneous positioning is limited by the number of observed satellites, and the initial value of the Doppler positioning solution process is missing, which leads to an increase in the number of iterative solutions. Summary of the invention

[0009] The embodiments of the present application provide a positioning method, device and storage medium based on low-orbit satellite opportunity signals, so as to at least solve the technical problems existing in the prior art that the positioning results of Doppler frequency shift positioning are limited by the number of low-orbit satellites, the instantaneous positioning is limited by the number of observed stars, and the initial value of the Doppler positioning solution process is missing, resulting in an increase in the number of iterative solutions.

[0010] According to one aspect of an embodiment of the present application, a positioning method based on a low-orbit satellite opportunity signal is provided, including: extracting corresponding signal arrival angle information and Doppler frequency shift information according to the opportunity signal of the low-orbit satellite in the current epoch, wherein the signal arrival angle information is used to indicate the positional relationship between the low-orbit satellite and the receiver, and the Doppler frequency shift information is used to indicate the relative motion information between the low-orbit satellite and the receiver; determining the orbit information of the low-orbit satellite in the current epoch according to a preset satellite two-row orbit data file and a satellite orbit prediction model; when the number of low-orbit satellites is not less than the preset number of satellites, generating coarse positioning information of the receiver according to the signal arrival angle information and the orbit information, and using the coarse positioning information as the initial value of the iterative solution in the Doppler positioning process for iterative solution to determine the final positioning information of the receiver; and when the number of low-orbit satellites is less than the preset number of satellites, calculating the final positioning information of the receiver according to the signal arrival angle information, the Doppler frequency shift information and the orbit information.

[0011] According to another aspect of an embodiment of the present application, a positioning device based on a low-orbit satellite opportunity signal is also provided, including: an information extraction module, used to extract corresponding signal arrival angle information and Doppler frequency shift information according to the opportunity signal of the low-orbit satellite in the current epoch, wherein the signal arrival angle information is used to indicate the positional relationship between the low-orbit satellite and the receiver, and the Doppler frequency shift information is used to indicate the relative motion information between the low-orbit satellite and the receiver; an information determination module, used to determine the orbit information of the low-orbit satellite in the current epoch according to a preset satellite two-row orbit data file and a satellite orbit prediction model; a first positioning information determination module, used to generate coarse positioning information of the receiver according to the signal arrival angle information and the orbit information when the number of low-orbit satellites is not less than the preset number of satellites, and iteratively solve the coarse positioning information as the initial value of the iterative solution in the Doppler positioning process to determine the final positioning information of the receiver; and a second positioning information determination module, used to calculate the final positioning information of the receiver according to the signal arrival angle information, the Doppler frequency shift information and the orbit information when the number of low-orbit satellites is less than the preset number of satellites.

[0012] According to another aspect of an embodiment of the present application, a positioning method based on a low-orbit satellite opportunity signal is also provided, including: a processor; and a memory, connected to the processor, for providing the processor with instructions for processing the following processing steps: extracting corresponding signal arrival angle information and Doppler frequency shift information according to the opportunity signal of the low-orbit satellite at the current epoch, wherein the signal arrival angle information is used to indicate the positional relationship between the low-orbit satellite and the receiver, and the Doppler frequency shift information is used to indicate the relative motion information between the low-orbit satellite and the receiver; determining the orbit information of the low-orbit satellite at the current epoch according to a preset satellite two-row orbit data file and a satellite orbit prediction model; when the number of low-orbit satellites is not less than the preset number of satellites, generating coarse positioning information of the receiver according to the signal arrival angle information and the orbit information, and using the coarse positioning information as the initial value of the iterative solution in the Doppler positioning process for iterative solution to determine the final positioning information of the receiver; and when the number of low-orbit satellites is less than the preset number of satellites, calculating the final positioning information of the receiver according to the signal arrival angle information, the Doppler frequency shift information and the orbit information.

[0013] According to another aspect of the embodiments of the present application, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above method are implemented.

[0014] In the embodiment of the present application, the computing device sets two different positioning methods according to the number of low-orbit satellites, including a serial fusion method and a parallel fusion method, so that the number of low-orbit satellites can be flexibly applied, thereby improving the flexibility and applicability of the system. And when the number of low-orbit satellites is small, the equation for positioning according to the signal arrival angle information and the equation for positioning according to the Doppler frequency shift information are used to simultaneously calculate the final positioning information of the receiver, increase the observation amount, thereby reducing the dependence on the initial value of the target position, reducing the number of iterative solutions, and speeding up the positioning speed. And when the number of low-orbit satellites is large, the technical solution will first calculate the coarse positioning information of the receiver according to the signal arrival angle information as the initial value of the Doppler positioning solution process for calculating the final positioning information of the receiver, thereby limiting the initial value to a reasonable range, reducing the number of iterative solutions, and improving the calculation speed. And then solve the technical problems that the positioning result of Doppler frequency shift positioning in the prior art is limited by the number of low-orbit satellites, the instantaneous positioning is limited by the number of observed stars, and the initial value of the Doppler positioning solution process is missing, resulting in an increase in the number of iterative solutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings: Figure 1is a hardware structure block diagram of a computing device for implementing the method according to Embodiment 1 of the present application; Figure 2 It is a flowchart of a positioning method based on low-orbit satellite opportunity signals according to the first aspect of Example 1 of the present application; Figure 3 is a schematic diagram of a positioning device based on low-orbit satellite opportunity signals according to Embodiment 2 of the present application; and Figure 4 This is a schematic diagram of a positioning device based on low-orbit satellite opportunity signals according to Example 3 of the present application. DETAILED DESCRIPTION

[0016] In order to enable those skilled in the art to better understand the technical solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only embodiments of a part of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work should fall within the scope of protection of the present application.

[0017] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0018] Example 1 According to this embodiment, a method embodiment of a positioning method based on low-orbit satellite opportunity signals is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0019] The method embodiment provided in this embodiment can be executed in a mobile terminal, a computer terminal, a server or a similar computing device. Figure 1 FIG. 1 shows a hardware structure block diagram of a computing device for implementing a positioning method based on low-orbit satellite opportunity signals. Figure 1 As shown, the computing device may include one or more processors (the processor may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA), a memory for storing data, and a transmission device for communication functions. In addition, it may also include: a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of the I / O interface), a network interface, a power supply and / or a camera. It can be understood by those skilled in the art that Figure 1 The structure shown is only for illustration and does not limit the structure of the above electronic device. Figure 1 More or fewer components as shown, or with Figure 1 Different configurations shown.

[0020] It should be noted that the one or more processors and / or other data processing circuits described above may generally be referred to herein as "data processing circuits". The data processing circuits may be embodied in whole or in part as software, hardware, firmware, or any other combination thereof. In addition, the data processing circuit may be a single independent processing module, or may be incorporated in whole or in part into any of the other components in the computing device. As involved in the embodiments of the present application, the data processing circuit acts as a processor control (e.g., selection of a variable resistor terminal path connected to an interface).

[0021] The memory can be used to store software programs and modules of application software, such as the program instructions / data storage device corresponding to the positioning method based on low-orbit satellite opportunity signals in the embodiment of the present application. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory, that is, the positioning method based on low-orbit satellite opportunity signals of the above-mentioned application is realized. The memory may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory may further include a memory remotely arranged relative to the processor, and these remote memories may be connected to the computing device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0022] The transmission device is used to receive or send data via a network. The specific example of the above network may include a wireless network provided by a communication provider of the computing device. In one example, the transmission device includes a network adapter (Network Interface Controller, NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device can be a radio frequency (RF) module, which is used to communicate with the Internet wirelessly.

[0023] The display may be, for example, a touch screen liquid crystal display (LCD) that may enable a user to interact with a user interface of the computing device.

[0024] It should be noted that, in some optional embodiments, the above Figure 1 The computing device shown may include hardware elements (including circuits), software elements (including computer code stored on a computer-readable medium), or a combination of both hardware elements and software elements. Figure 1 This is merely one example of a particular embodiment and is intended to illustrate the types of components that may be present in the computing devices described above.

[0025] In the above operating environment, according to the first aspect of this embodiment, a positioning method based on low-orbit satellite opportunity signals is provided. The method comprises: Figure 1 The computing device implementation shown in . Figure 2 A schematic diagram showing the process of the method is shown in FIG. Figure 2 As shown, the method includes: S202: extracting corresponding signal arrival angle information and Doppler frequency shift information according to the opportunity signal of the low-orbit satellite in the current epoch, wherein the signal arrival angle information is used to indicate the positional relationship between the low-orbit satellite and the receiver, and the Doppler frequency shift information is used to indicate the relative motion information between the low-orbit satellite and the receiver; S204: determining the orbit information of the low-orbit satellite at the current epoch according to the preset two-line satellite orbit data file and the satellite orbit prediction model; S206: when the number of low-orbit satellites is not less than the preset number of satellites, generate coarse positioning information of the receiver according to the signal arrival angle information and the orbit information, and use the coarse positioning information as the initial value of iterative solution in the Doppler positioning process to perform iterative solution to determine the final positioning information of the receiver; and S208: When the number of low-orbit satellites is less than the preset number of satellites, the final positioning information of the receiver is calculated according to the signal arrival angle information, Doppler frequency shift information and orbit information.

[0026] Specifically, the computing device obtains opportunity signals of multiple low-orbit satellites in the current epoch. N All of them are observable stars. The computing device then processes the opportunity signals of multiple low-orbit satellites to extract the signal arrival angle information and Doppler frequency shift information corresponding to each opportunity signal. The signal arrival angle information is used to indicate the positional relationship between the low-orbit satellite and the receiver, and the Doppler frequency shift information is used to indicate the relative motion information between the low-orbit satellite and the receiver.

[0027] Furthermore, the computing device is pre-set with a satellite orbit prediction model for predicting the orbit information of the satellite, and is also pre-set with a satellite two-line orbit data file corresponding to the low-orbit satellite. The satellite orbit prediction model can be, for example, a simplified conventional perturbation model, and the satellite two-line orbit data file is a public file for recording satellite orbit parameters. The computing device then inputs the satellite two-line orbit data file of each low-orbit satellite into the satellite orbit prediction model, and outputs the orbit information corresponding to each low-orbit satellite through the satellite orbit prediction model. The orbit information includes the three-dimensional position coordinates and three-dimensional velocity of the low-orbit satellite.

[0028] Furthermore, the computing device is pre-set with two methods for determining the final position information of the receiver, namely a serial fusion method and a parallel fusion method. The computing device then determines whether the number of low-orbit satellites is less than the preset number of satellites. For example, the preset number of satellites is 4, so that when the number of low-orbit satellites is not less than the preset number of satellites (i.e., 4), the computing device uses the serial fusion method to determine the final positioning information of the receiver. When the number of low-orbit satellites is less than the preset number of satellites (i.e., 4), the computing device uses the parallel fusion method to determine the final positioning information of the receiver.

[0029] More specifically, when the number of low-orbit satellites is not less than the preset number of satellites, for the serial fusion method, the computing device generates coarse positioning information of the receiver based on the signal arrival angle information and the orbit information, and uses the coarse positioning information as the initial value of the iterative solution in the Doppler positioning process to iteratively solve and determine the final positioning information of the receiver.

[0030] When the number of low-orbit satellites is less than the preset number of satellites, for the parallel fusion method, the computing device will fuse the equation for positioning based on the signal arrival angle information and the equation for positioning based on the Doppler frequency shift information, thereby using the equation for positioning based on the signal arrival angle information and the equation for positioning based on the Doppler frequency shift information to perform calculations at the same time to determine the final positioning information of the receiver.

[0031] As described in the background technology, when using Doppler frequency shift positioning, the positioning result is limited by the number of low-orbit satellites. When the number of low-orbit satellites is less than four, it cannot meet the requirements of instantaneous positioning, and it is necessary to wait for multiple epochs to integrate Doppler. Although low-orbit satellites have a higher movement speed than medium- and high-orbit satellites, it still takes a certain amount of time to accumulate to form sufficient geometric movement, and this process will be affected by the satellite-to-ground clock error. In addition, the Doppler positioning solution process cannot avoid dependence on the initial value of the target position. When the initial value is missing, the number of iterative solutions will increase significantly.

[0032] In view of the technical problems described above, through the technical solutions of the embodiments of the present application, the computing device sets two different positioning methods according to the number of low-orbit satellites, including a serial fusion method and a parallel fusion method, so that the number of low-orbit satellites can be flexibly applied, thereby improving the flexibility and applicability of the system. And when the number of low-orbit satellites is small, the equation for positioning according to the signal arrival angle information and the equation for positioning according to the Doppler frequency shift information are used to simultaneously calculate the final positioning information of the receiver, increase the observation amount, thereby reducing the dependence on the initial value of the target position, reducing the number of iterative solutions, and speeding up the positioning speed. And when the number of low-orbit satellites is large, the technical solution will first calculate the coarse positioning information of the receiver according to the signal arrival angle information as the initial value of the Doppler positioning solution process for calculating the final positioning information of the receiver, thereby limiting the initial value to a reasonable range, reducing the number of iterative solutions, and improving the calculation speed. And then solve the technical problems that the positioning result of Doppler frequency shift positioning in the prior art is limited by the number of low-orbit satellites, the instantaneous positioning is limited by the number of observed stars, and the initial value of the Doppler positioning solution process is missing, resulting in an increase in the number of iterative solutions.

[0033] Optionally, the operation of extracting corresponding signal arrival angle information and Doppler frequency shift information based on the opportunity signal of the low-orbit satellite in the current epoch includes: determining the signal arrival angle information based on the opportunity signal and the direction vector of the opportunity signal; and extracting the Doppler frequency shift information based on the opportunity signal using the maximum likelihood estimation method.

[0034] Specifically, the signal arrival angle includes azimuth and elevation, which refers to the propagation direction of the received signal in space and can reflect the positional relationship between the signal source and the receiver. i The azimuth angle of the signal arrival angle corresponding to the low-orbit satellite is marked as , the elevation angle is .

[0035] The receiver uses a phased array antenna to receive opportunity signals. The phased array antenna is a two-dimensional array, and the number of antenna elements can be, for example, or . Thus the direction vector of the opportunity signal is for: , , .

[0036] in Indicates the opportunity signal L The phase difference of the antenna elements is For the i The signal wavelength of the opportunity signal corresponding to the low-orbit satellite, M is the number of antenna elements, L =1~ M , For the i The unit vector of the propagation direction of the opportunity signal of the low-orbit satellite, For the L The position vector of the antenna element, e represents the base of natural logarithms, j Represents an imaginary number.

[0037] Furthermore, the computing device forms a directional beam by adjusting the excitation (phase and amplitude) of the antenna unit, scanning the entire space to find the direction of the maximum response of the signal. The computing device can then use the directional vector to match the received signal: .

[0038] in, w i For the i The beam weights corresponding to the low-orbit satellites are used to calculate the direction vector As beam weight w i , x i For the received i When the beam is aligned with the signal direction of the opportunity signal, the output power Reaching the maximum value, the device then calculates the azimuth of the signal arrival angle information and elevation .

[0039] Furthermore, when the signal subcarrier can be regarded as a sinusoidal signal with stable frequency in a short time, the maximum likelihood estimation method can be used to extract the Doppler frequency shift information of the opportunity signal. The opportunity signal is expressed as follows: .

[0040] in A i , , For the i The amplitude, angular frequency and phase of the sinusoidal signal corresponding to the opportunity signal of the low-orbit satellite. n Used to identify the sampling point number. is zero-mean Gaussian white noise. The optimal estimation function for: .

[0041] in LN i It is with i The processing data length of the opportunity signal of the low-orbit satellite is estimated to be i Angular frequency of the opportunity signal from a low-orbit satellite for: .

[0042] With i The corresponding Doppler frequency shift information of the low-orbit satellite for: .

[0043] Therefore, this technical solution can accurately determine the maximum response direction of the signal by using a phased array antenna to receive the signal and matching it with the directional vector, thereby accurately obtaining the signal arrival angle information (including azimuth and elevation), and enhancing the understanding of the positional relationship between the low-orbit satellite and the receiver.

[0044] Optionally, the operation of generating coarse positioning information of the receiver based on the signal arrival angle information and the orbital information includes: determining the unit vector of the signal propagation direction based on the signal arrival angle information; constructing the spatial straight line equation between the low-orbit satellite and the receiver based on the unit vector and the three-dimensional position coordinates in the orbital information; and calculating the coarse positioning information of the receiver based on the spatial straight line equation.

[0045] Specifically, when the number of low-orbit satellites is not less than the preset number of satellites (i.e., 4), the computing device determines the final positioning information of the receiver using a serial fusion method. The serial fusion method includes two steps: roughly positioning the receiver according to the signal arrival angle information, and then finally positioning the receiver according to the Doppler frequency shift information.

[0046] More specifically, the step of computing the receiver's rough positioning by the computing device includes: First, calculate the device according to the i The azimuth of the signal arrival angle information corresponding to the low-orbit satellite and elevation , the unit vector that determines the direction of signal propagation d i : .

[0047] The computing device then determines the three-dimensional position coordinates of the orbital information of each low-orbit satellite. .in Indicates i The three-dimensional position coordinates of the low-orbit satellite. Then the computing device calculates the unit vector d i And the corresponding three-dimensional position coordinates , construct the i The equation of the straight line in space between a low-orbit satellite and the receiver L i : .

[0048] in t Indicates a parameter.

[0049] For example, construct the equation of the space straight line between the first low-orbit satellite and the receiver L 1: ; Construct the equation of the space line between the second low-orbit satellite and the receiver L 2: ; By analogy, construct the N The equation of the straight line in space between a low-orbit satellite and the receiver L N : .

[0050] Furthermore, the computing device will N The equation of a straight line in space for a low-orbit satellite L 1~ L N Then, the computing device calculates the distance between each spatial straight line and the receiver according to the set of equations, thereby determining the intersection point that minimizes the sum of the distances between each spatial straight line and the receiver as the rough positioning information of the receiver. .

[0051] Therefore, the technical solution reduces the number of iterative solutions and improves the calculation speed by first locating the signal arrival angle to generate an initial value and then locating the Doppler frequency shift.

[0052] Optionally, the operation of calculating the coarse positioning information of the receiver according to the spatial straight line equation includes: calculating the coarse positioning information of the receiver according to the following objective function: , in(x , y , z ) represents the three-dimensional position coordinates of the receiver, L i Indicated by i The space straight line determined by the low-orbit satellite and the receiver, N represents the number of low-orbit satellites, Distance () represents the distance calculation function.

[0053] Specifically, the computing device calculates the mean of the projection points of all low-orbit satellites on the earth's surface based on the three-dimensional position coordinates of the low-orbit satellites. The computing device then uses the mean as an optimization formula for calculating the coarse positioning information of the receiver. In ( x , y , z )’s initial value.

[0054] Further, the computing device determines the optimization formula according to the system of equations consisting of the spatial straight line equations. L i The computing device then uses the least squares method to N The equation of a straight line in space for a low-orbit satellite L 1~ L N The combined equations are solved and the optimization formula is As the solution target, the coarse positioning information of the receiver is calculated . When iteratively calculating the receiver's rough positioning information, if k +1 The result calculated according to the optimization formula is better than the k If the difference is greater than the first k times ( x , y , z ) as coarse positioning information Otherwise, update the positioning result and change L i The value of is used for the next iteration, and the above steps are repeated until the iteration results converge (that is, there is no obvious change in the calculation results of consecutive iterations). k The receiver coordinates calculated by the iteration ( x , y , z ) k +1 iteration for each L i Corresponding parameters , thereby changing L i The value of .

[0055] Therefore, this technical solution uses the objective function in combination with the spatial straight line equation of the low-orbit satellite to calculate the position coordinates of the receiver in three-dimensional space, effectively reducing the positioning error.

[0056] Optionally, the coarse positioning information is used as the initial value of the iterative solution in the Doppler positioning process for iterative solution to determine the final positioning information of the receiver, including: constructing a Doppler frequency shift observation equation based on the Doppler frequency shift information and orbit information; constructing an iterative formula based on the Doppler frequency shift observation equation and the coarse positioning information as the initial value; and iteratively solving the iterative formula to determine the final positioning information of the receiver.

[0057] Specifically, the computing device obtains Doppler frequency shift information and orbit information, and then constructs the Doppler frequency shift observation equation according to the Doppler frequency shift information and orbit information: .

[0058] in is the frequency of satellite signal transmission, is the receiver clock bias, is the frequency receiving error, v i Indicates i The three-dimensional velocity of the low-orbit satellite, represents the three-dimensional position coordinates of the receiver, Indicates i The three-dimensional position coordinates of low-orbit satellites, c represents the wave speed, f (i) ( u ) indicates the i Doppler frequency shift information of low-orbit satellites, .

[0059] Furthermore, the computing device constructs an iterative formula: , .

[0060] in, k is the number of iterations, u k For the k Iterative solution u The estimated value of is the residual vector, For the i The Doppler frequency shift observation equation for a low-orbit satellite is u k The partial derivative at .

[0061] Furthermore, the computing device converts the coarse positioning information of the receiver into As the iterative formula , , The initial value of The initial value of is 0. After that, the computing device iteratively solves the iterative formula and calculates the value obtained by the kth iteration. As the k+1th , , , , thus calculating each round x , y , z , After that, when convergence occurs, we can calculate x , y , z As the final positioning information .

[0062] Therefore, this technical solution uses Doppler frequency shift information and orbit information to construct an accurate Doppler frequency shift observation equation, and combines it with coarse positioning information for iterative solution, which can effectively reduce positioning errors and improve the reliability of positioning results.

[0063] Optionally, the operation of constructing a Doppler frequency shift observation equation according to the Doppler frequency shift information and the orbit information includes: converting the Doppler frequency shift information As initial value f (i) ( u ), and the Doppler frequency shift observation equation is constructed according to the following formula: , in is the frequency of satellite signal transmission, is the receiver clock bias, is the frequency receiving error, v i Indicates i The three-dimensional velocity of the low-orbit satellite, represents the three-dimensional position coordinates of the receiver, Indicates i The three-dimensional position coordinates of low-orbit satellites, c Indicates wave speed.

[0064] Therefore, this technical solution effectively reduces the impact of external interference on positioning results and improves the robustness of the system by comprehensively considering multiple factors such as satellite transmission signal frequency, receiver clock deviation and frequency reception error.

[0065] Optionally, the operation of calculating the final positioning information of the receiver based on the signal arrival angle information, Doppler frequency shift information and orbital information includes: determining the unit vector of the signal propagation direction based on the signal arrival angle information; constructing the spatial straight line equation between the low-orbit satellite and the receiver based on the unit vector and the three-dimensional position coordinates in the orbital information; constructing the Doppler frequency shift equation based on the Doppler frequency shift information and the orbital information; and calculating the final positioning information of the receiver based on the spatial straight line equation and the Doppler frequency shift equation using a preset second optimization formula with the goal of minimizing the signal arrival angle residual and the Doppler frequency shift residual.

[0066] Specifically, when the number of low-orbit satellites is less than a preset number of satellites (ie, 4), the computing device determines the final positioning information of the receiver using a parallel fusion method.

[0067] More specifically, the computing device is configured to i The azimuth of the signal arrival angle information corresponding to the low-orbit satellite and elevation , the unit vector that determines the direction of signal propagation d i : .

[0068] The computing device then determines the three-dimensional position coordinates of the orbital information of each low-orbit satellite. .in Indicates i The three-dimensional position coordinates of the low-orbit satellite. Then the computing device calculates the unit vector d i And the corresponding three-dimensional position coordinates , construct the i The equation of the straight line in space between a low-orbit satellite and the receiver L i : .

[0069] Furthermore, the computing device obtains Doppler frequency shift information and orbit information, and then constructs a Doppler frequency shift observation equation based on the Doppler frequency shift information and orbit information: , in is the frequency of satellite signal transmission, is the receiver clock bias, is the frequency receiving error, v i Indicates i The three-dimensional velocity of the low-orbit satellite, represents the three-dimensional position coordinates of the receiver, Indicatesi The three-dimensional position coordinates of low-orbit satellites, c represents the wave speed, f (i) ( u ) indicates the i Doppler frequency shift information of low-orbit satellites, Represents the unknowns to be determined, including: the three-dimensional position coordinates of the receiver and receiver clock offset .

[0070] Further, the computing device constructs the Doppler frequency shift equation: , .

[0071] in, k is the number of iterations, u k For the k Iterative solution u The estimated value of is the residual vector, For the i The Doppler frequency shift observation equation for a low-orbit satellite is u k The partial derivative at . x 0, y 0, z The initial value of 0 at the first iteration is N The average of the projection points of low-orbit satellites on the earth’s surface, The initial value at the first iteration is 0. f (i) ( u ) indicates the i Doppler frequency shift information of low-orbit satellites, .

[0072] Further, the computing device converts the equation of the line L i And the Doppler frequency shift equation form an equation group. For example, when the number of low-orbit satellites is 3, the equation group is: , , , .

[0073] Further, the computing device calculates ( x , y , z )as well as , and ( x , y , z )as well as Input to the objective function. x , y , z ) is the equation of a straight line in space L 1~ L 3. Thus, the computing device will solve the k-th iteration As the k+1th x 0, y 0, z 0, , using the preset objective function, with the goal of minimizing the signal arrival angle residual and Doppler frequency shift residual, iteratively calculate the final positioning information of the receiver S ( x , y , z ), where the objective function is: , , .

[0074] in For the i The residual error of the signal arrival angle of the low-orbit satellite, For the i The Doppler frequency shift residual of the low-orbit satellite, Indicates i Doppler frequency shift information of low-orbit satellites.

[0075] Therefore, the present technical solution determines the final positioning information of the receiver through a parallel fusion method, so that when the number of low-orbit satellites is small, the straight line equation and the Doppler frequency shift equation can be used to meet the positioning requirements.

[0076] In addition, according to research, multiple observations can be obtained by adding sensors for multi-source fusion positioning, thereby improving positioning accuracy and reducing the number of satellites required for single epoch positioning. Multi-source fusion positioning can, for example, obtain the height information of the receiver or the position and speed information from the inertial navigation system by adding sensors such as altimeters and gyroscopes, and fuse this information with the observation information obtained from the satellite navigation system through a Kalman filter.

[0077] In addition, reference Figure 1 As shown, according to the second aspect of this embodiment, a storage medium is provided, wherein the storage medium includes a stored program, wherein when the program is run, a processor executes any one of the above methods.

[0078] Therefore, according to this embodiment, the computing device sets two different positioning methods according to the number of low-orbit satellites, including a serial fusion method and a parallel fusion method, so that the number of low-orbit satellites can be flexibly applied, thereby improving the flexibility and applicability of the system. And when the number of low-orbit satellites is small, the equation for positioning according to the signal arrival angle information and the equation for positioning according to the Doppler frequency shift information are used to simultaneously calculate the final positioning information of the receiver, increase the observation amount, thereby reducing the dependence on the initial value of the target position, reducing the number of iterative solutions, and speeding up the positioning speed. And when the number of low-orbit satellites is large, the technical solution will first calculate the coarse positioning information of the receiver according to the signal arrival angle information as the initial value of the Doppler positioning solution process for calculating the final positioning information of the receiver, thereby limiting the initial value to a reasonable range, reducing the number of iterative solutions, and improving the calculation speed. And then solve the technical problems existing in the prior art that the positioning result of Doppler frequency shift positioning is limited by the number of low-orbit satellites, the instantaneous positioning is limited by the number of observed stars, and the initial value of the Doppler positioning solution process is missing, resulting in an increase in the number of iterative solutions.

[0079] It should be noted that, for the above-mentioned method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the described action sequence, because according to the present invention, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

[0080] Through the description of the above implementation methods, those skilled in the art can clearly understand that the method according to the above embodiment can be implemented by means of software plus a necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk), and includes a number of instructions for enabling a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods described in each embodiment of the present invention.

[0081] Example 2 Figure 3 The present invention shows a positioning device 300 based on low-orbit satellite opportunity signals according to this embodiment, and the device 300 corresponds to the method according to the first aspect of embodiment 1. Figure 3As shown, the device 300 includes: an information extraction module 310, which is used to extract corresponding signal arrival angle information and Doppler frequency shift information according to the opportunity signal of the low-orbit satellite in the current epoch, wherein the signal arrival angle information is used to indicate the position relationship between the low-orbit satellite and the receiver, and the Doppler frequency shift information is used to indicate the relative motion information between the low-orbit satellite and the receiver; an information determination module 320, which is used to determine the orbit information of the low-orbit satellite in the current epoch according to a preset satellite two-line orbit data file and a satellite orbit prediction model; a first positioning information determination module 330, which is used to generate coarse positioning information of the receiver according to the signal arrival angle information and the orbit information when the number of low-orbit satellites is not less than the preset number of satellites, and iteratively solve the coarse positioning information as the initial value of the iterative solution in the Doppler positioning process to determine the final positioning information of the receiver; and a second positioning information determination module 340, which is used to calculate the final positioning information of the receiver according to the signal arrival angle information, the Doppler frequency shift information and the orbit information when the number of low-orbit satellites is less than the preset number of satellites.

[0082] Optionally, the information extraction module 310 includes: a first determination submodule, used to determine the signal arrival angle information according to the opportunity signal and the direction vector of the opportunity signal; and an information extraction submodule, used to extract Doppler frequency shift information according to the opportunity signal using a maximum likelihood estimation method.

[0083] Optionally, the first positioning information determination module 330 includes: a second determination submodule, used to determine the unit vector of the signal propagation direction based on the signal arrival angle information; a first construction submodule, used to construct the spatial straight line equation between the low-orbit satellite and the receiver based on the unit vector and the three-dimensional position coordinates in the orbital information; and a first calculation submodule, used to calculate the coarse positioning information of the receiver based on the spatial straight line equation.

[0084] Optionally, the first calculation submodule includes: a first calculation unit, configured to calculate the coarse positioning information of the receiver according to the following objective function: , in( x , y , z ) represents the three-dimensional position coordinates of the receiver, L i represents the space straight line determined by the i-th low-orbit satellite and the receiver, N represents the number of low-orbit satellites, Distance () represents the distance calculation function.

[0085] Optionally, the first positioning information determination module 330 includes: a second construction submodule, used to construct a Doppler frequency shift observation equation based on the Doppler frequency shift information and the orbit information; a third construction submodule, used to construct an iterative formula based on the Doppler frequency shift observation equation and the coarse positioning information used as an initial value; and a third determination submodule, used to iteratively solve the iterative formula to determine the final positioning information of the receiver.

[0086] Optionally, the second construction submodule includes: a construction unit, configured to use the Doppler frequency shift information as an initial value f ( u ), and the Doppler frequency shift observation equation is constructed according to the following formula: , in is the frequency of satellite signal transmission, is the receiver clock bias, is the frequency receiving error, v i Indicates i The three-dimensional velocity of the low-orbit satellite, represents the three-dimensional position coordinates of the receiver, Indicates i The three-dimensional position coordinates of low-orbit satellites, c Indicates wave speed.

[0087] Optionally, the second positioning information determination module 340 includes: a fourth determination submodule, used to determine the unit vector of the signal propagation direction according to the signal arrival angle information; a fourth construction submodule, used to construct the spatial straight line equation between the low-orbit satellite and the receiver according to the unit vector and the three-dimensional position coordinates in the orbital information; a fifth construction submodule, used to construct the Doppler frequency shift equation according to the Doppler frequency shift information and the orbital information; and a fifth determination submodule, used to calculate the final positioning information of the receiver according to the spatial straight line equation and the Doppler frequency shift equation with the goal of minimizing the signal arrival angle residual and the Doppler frequency shift residual.

[0088] Therefore, according to this embodiment, the computing device sets two different positioning methods according to the number of low-orbit satellites, including a serial fusion method and a parallel fusion method, so that the number of low-orbit satellites can be flexibly applied, thereby improving the flexibility and applicability of the system. And when the number of low-orbit satellites is small, the equation for positioning according to the signal arrival angle information and the equation for positioning according to the Doppler frequency shift information are used to simultaneously calculate the final positioning information of the receiver, increase the observation amount, thereby reducing the dependence on the initial value of the target position, reducing the number of iterative solutions, and speeding up the positioning speed. And when the number of low-orbit satellites is large, the technical solution will first calculate the coarse positioning information of the receiver according to the signal arrival angle information as the initial value of the Doppler positioning solution process for calculating the final positioning information of the receiver, thereby limiting the initial value to a reasonable range, reducing the number of iterative solutions, and improving the calculation speed. And then solve the technical problems existing in the prior art that the positioning result of Doppler frequency shift positioning is limited by the number of low-orbit satellites, the instantaneous positioning is limited by the number of observed stars, and the initial value of the Doppler positioning solution process is missing, resulting in an increase in the number of iterative solutions.

[0089] Example 3 Figure 4 The present invention shows a positioning device 400 based on low-orbit satellite opportunity signals according to this embodiment, and the device 400 corresponds to the method according to the first aspect of embodiment 1. Figure 4 As shown, the device 400 includes: a processor 410; and a memory 420, which is connected to the processor 410 and is used to provide the processor 410 with instructions for processing the following processing steps: extracting corresponding signal arrival angle information and Doppler frequency shift information according to the opportunity signal of the low-orbit satellite in the current epoch, wherein the signal arrival angle information is used to indicate the position relationship between the low-orbit satellite and the receiver, and the Doppler frequency shift information is used to indicate the relative motion information between the low-orbit satellite and the receiver; determining the orbit information of the low-orbit satellite in the current epoch according to a preset satellite two-line orbit data file and a satellite orbit prediction model; when the number of low-orbit satellites is not less than the preset number of satellites, generating coarse positioning information of the receiver according to the signal arrival angle information and the orbit information, and using the coarse positioning information as the initial value of the iterative solution in the Doppler positioning process for iterative solution to determine the final positioning information of the receiver; and when the number of low-orbit satellites is less than the preset number of satellites, calculating the final positioning information of the receiver according to the signal arrival angle information, the Doppler frequency shift information and the orbit information.

[0090] Optionally, the operation of extracting corresponding signal arrival angle information and Doppler frequency shift information based on the opportunity signal of the low-orbit satellite in the current epoch includes: determining the signal arrival angle information based on the opportunity signal and the direction vector of the opportunity signal; and extracting the Doppler frequency shift information based on the opportunity signal using the maximum likelihood estimation method.

[0091] Optionally, the operation of generating coarse positioning information of the receiver based on the signal arrival angle information and the orbital information includes: determining the unit vector of the signal propagation direction based on the signal arrival angle information; constructing the spatial straight line equation between the low-orbit satellite and the receiver based on the unit vector and the three-dimensional position coordinates in the orbital information; and calculating the coarse positioning information of the receiver based on the spatial straight line equation.

[0092] Optionally, the operation of calculating the coarse positioning information of the receiver according to the spatial straight line equation includes: calculating the coarse positioning information of the receiver according to the following objective function: , in( x , y , z ) represents the three-dimensional position coordinates of the receiver, L i represents the space straight line determined by the i-th low-orbit satellite and the receiver, N represents the number of low-orbit satellites, Distance () represents the distance calculation function.

[0093] Optionally, the coarse positioning information is used as the initial value of the iterative solution in the Doppler positioning process for iterative solution to determine the final positioning information of the receiver, including: constructing a Doppler frequency shift observation equation based on the Doppler frequency shift information and orbit information; constructing an iterative formula based on the Doppler frequency shift observation equation and the coarse positioning information as the initial value; and iteratively solving the iterative formula to determine the final positioning information of the receiver.

[0094] Optionally, the operation of constructing the Doppler frequency shift observation equation according to the Doppler frequency shift information and the orbit information includes: taking the Doppler frequency shift information as the initial value f ( u ), and the Doppler frequency shift observation equation is constructed according to the following formula: , in is the frequency of satellite signal transmission, is the receiver clock bias, is the frequency receiving error, v i Indicates i The three-dimensional velocity of the low-orbit satellite, represents the three-dimensional position coordinates of the receiver, Indicates i The three-dimensional position coordinates of low-orbit satellites, c Indicates wave speed.

[0095] Optionally, the operation of calculating the final positioning information of the receiver based on the signal arrival angle information, Doppler frequency shift information and orbital information includes: determining the unit vector of the signal propagation direction based on the signal arrival angle information; constructing the spatial straight line equation between the low-orbit satellite and the receiver based on the unit vector and the three-dimensional position coordinates in the orbital information; constructing the Doppler frequency shift equation based on the Doppler frequency shift information and the orbital information; and calculating the final positioning information of the receiver based on the spatial straight line equation and the Doppler frequency shift equation with the goal of minimizing the signal arrival angle residual and the Doppler frequency shift residual.

[0096] Therefore, according to this embodiment, the computing device sets two different positioning methods according to the number of low-orbit satellites, including a serial fusion method and a parallel fusion method, so that the number of low-orbit satellites can be flexibly applied, thereby improving the flexibility and applicability of the system. And when the number of low-orbit satellites is small, the equation for positioning according to the signal arrival angle information and the equation for positioning according to the Doppler frequency shift information are used to simultaneously calculate the final positioning information of the receiver, increase the observation amount, thereby reducing the dependence on the initial value of the target position, reducing the number of iterative solutions, and speeding up the positioning speed. And when the number of low-orbit satellites is large, the technical solution will first calculate the coarse positioning information of the receiver according to the signal arrival angle information as the initial value of the Doppler positioning solution process for calculating the final positioning information of the receiver, thereby limiting the initial value to a reasonable range, reducing the number of iterative solutions, and improving the calculation speed. And then solve the technical problems existing in the prior art that the positioning result of Doppler frequency shift positioning is limited by the number of low-orbit satellites, the instantaneous positioning is limited by the number of observed stars, and the initial value of the Doppler positioning solution process is missing, resulting in an increase in the number of iterative solutions.

[0097] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0098] In the above embodiments of the present invention, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0099] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0100] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0101] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0102] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or optical disk, etc. Various media that can store program codes.

[0103] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A positioning method based on low-orbit satellite opportunity signals, characterized in that: include: Extracting corresponding signal arrival angle information and Doppler frequency shift information according to the opportunity signal of the low-orbit satellite in the current epoch, wherein the signal arrival angle information is used to indicate the positional relationship between the low-orbit satellite and the receiver, and the Doppler frequency shift information is used to indicate the relative motion information between the low-orbit satellite and the receiver; Determine the orbit information of the low-orbit satellite at the current epoch according to a preset two-line satellite orbit data file and a satellite orbit prediction model; In a case where the number of the low-orbit satellites is not less than a preset number of satellites, coarse positioning information of the receiver is generated according to the signal arrival angle information and the orbit information, and the coarse positioning information is used as an initial value of iterative solution in a Doppler positioning process for iterative solution to determine final positioning information of the receiver; as well as When the number of the low-orbit satellites is less than the preset number of satellites, the final positioning information of the receiver is calculated according to the signal arrival angle information, the Doppler frequency shift information and the orbit information.

2. The method according to claim 1, characterized in that According to the opportunity signal of the low-orbit satellite in the current epoch, the operation of extracting the corresponding signal arrival angle information and Doppler frequency shift information includes: Determining the signal arrival angle information according to the opportunity signal and the direction vector of the opportunity signal; and The Doppler frequency shift information is extracted according to the opportunity signal using a maximum likelihood estimation method.

3. The method according to claim 1, characterized in that: The operation of generating the coarse positioning information of the receiver according to the signal arrival angle information and the orbit information includes: Determine a unit vector of a signal propagation direction according to the signal arrival angle information; Constructing a spatial straight line equation between the low-orbit satellite and the receiver according to the unit vector and the three-dimensional position coordinates in the orbit information; and The coarse positioning information of the receiver is calculated according to the spatial straight line equation.

4. The method according to claim 3, characterized in that: The operation of calculating the coarse positioning information of the receiver according to the spatial straight line equation includes: The coarse positioning information of the receiver is calculated according to the following objective function: ， in( x , y , z ) represents the three-dimensional position coordinates of the receiver, Indicated by i A space straight line determined by a low-orbit satellite and the receiver, N represents the number of the low-orbit satellites, Distance () represents the distance calculation function.

5. The method according to claim 1, characterized in that The operation of iteratively solving the coarse positioning information as the initial value of iterative solving in the Doppler positioning process to determine the final positioning information of the receiver includes: Constructing a Doppler frequency shift observation equation according to the Doppler frequency shift information and the orbit information; Constructing an iterative formula according to the Doppler frequency shift observation equation and the coarse positioning information as an initial value; and The iterative formula is iteratively solved to determine final positioning information of the receiver.

6. The method according to claim 5, characterized in that The operation of constructing a Doppler frequency shift observation equation according to the Doppler frequency shift information and the orbit information includes: The Doppler frequency shift information is used as the initial value , and construct the Doppler frequency shift observation equation according to the following formula: ， in is the frequency of satellite signal transmission, is the receiver clock bias, is the frequency receiving error, v i Indicates i The three-dimensional velocity of the low-orbit satellite, represents the three-dimensional position coordinates of the receiver, Indicates i The three-dimensional position coordinates of low-orbit satellites, c Indicates wave speed.

7. The method according to claim 1, characterized in that The operation of calculating the final positioning information of the receiver according to the signal arrival angle information, the Doppler frequency shift information and the orbit information includes: Determine a unit vector of a signal propagation direction according to the signal arrival angle information; Constructing a spatial straight line equation between the low-orbit satellite and the receiver according to the unit vector and the three-dimensional position coordinates in the orbit information; Constructing a Doppler frequency shift equation according to the Doppler frequency shift information and the orbit information; With the goal of minimizing the signal arrival angle residual and the Doppler frequency shift residual, the final positioning information of the receiver is calculated according to the spatial straight line equation and the Doppler frequency shift equation.

8. A positioning device based on low-orbit satellite opportunity signals, characterized in that: include: An information extraction module, configured to extract corresponding signal arrival angle information and Doppler frequency shift information according to the opportunity signal of the low-orbit satellite in the current epoch, wherein the signal arrival angle information is used to indicate the positional relationship between the low-orbit satellite and the receiver, and the Doppler frequency shift information is used to indicate the relative motion information between the low-orbit satellite and the receiver; An information determination module, used to determine the orbit information of the low-orbit satellite at the current epoch according to a preset satellite two-line orbit data file and a satellite orbit prediction model; a first positioning information determination module, configured to generate coarse positioning information of the receiver according to the signal arrival angle information and the orbit information when the number of the low-orbit satellites is not less than a preset number of satellites, and to perform iterative solution using the coarse positioning information as an initial value of iterative solution in a Doppler positioning process to determine final positioning information of the receiver; as well as The second positioning information determination module is used to calculate the final positioning information of the receiver according to the signal arrival angle information, the Doppler frequency shift information and the orbit information when the number of the low-orbit satellites is less than the preset number of satellites.

9. A positioning device based on low-orbit satellite opportunity signals, characterized in that: include: processor; as well as A memory, connected to the processor, configured to provide the processor with instructions for processing the following processing steps: Extracting corresponding signal arrival angle information and Doppler frequency shift information according to the opportunity signal of the low-orbit satellite in the current epoch, wherein the signal arrival angle information is used to indicate the positional relationship between the low-orbit satellite and the receiver, and the Doppler frequency shift information is used to indicate the relative motion information between the low-orbit satellite and the receiver; Determine the orbit information of the low-orbit satellite at the current epoch according to a preset two-line satellite orbit data file and a satellite orbit prediction model; In a case where the number of the low-orbit satellites is not less than a preset number of satellites, coarse positioning information of the receiver is generated according to the signal arrival angle information and the orbit information, and the coarse positioning information is used as an initial value of iterative solution in a Doppler positioning process for iterative solution to determine final positioning information of the receiver; as well as When the number of the low-orbit satellites is less than the preset number of satellites, the final positioning information of the receiver is calculated according to the signal arrival angle information, the Doppler frequency shift information and the orbit information.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to claim 1 are implemented.

Images