Terminal positioning method, device, terminal, storage medium and program product

Abstract

The present application provides a terminal positioning method, device, terminal, storage medium and program product. The terminal positioning method is applied to the terminal, and the method includes: determining the target downlink information sent by the network device with a Doppler frequency shift observation value of zero, and determining the target pseudorange observation value between the terminal and the network device, the target downlink information includes the target orbit semi-major axis of the network device; determining a first distance value between the network device and a target projection point of the network device on the ground based on the target orbit semi-major axis, and determining a second distance value between the target projection point and the terminal based on the first distance value and the target pseudorange observation value; determining the target motion parameter of the target projection point based on the target downlink information, and determining the position of the terminal based on the target motion parameter and the second distance value. The present application can efficiently and accurately perform terminal positioning.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a terminal positioning method, device, terminal, storage medium and program product. Background Art

[0002] Terminal positioning technology is widely used in various fields, such as navigation and emergency rescue. Terminal positioning relies on signals from satellite systems, but the communication between satellites and terminals is easily blocked and interfered with, which affects the accuracy of positioning.

[0003] In some methods, the previously calculated terminal position is used as the initial position, and the initial position is used as the starting point of a new round of iteration. The final position of the terminal is obtained within a limited number of iterations through the Newton iteration method. However, this method requires an accurate initial position to achieve accurate positioning of the terminal. In some terminal positioning scenarios, there is often no way to determine the initial position or the initial position needs to be manually entered, resulting in low terminal positioning efficiency. Summary of the Invention

[0004] The present application provides a terminal positioning method, device, terminal, storage medium and program product, which can efficiently perform terminal positioning.

[0005] In a first aspect, a terminal positioning method is proposed, which is applied to a terminal. The method includes:

[0006] Determining target downlink information sent by a network device that shows a Doppler shift observation value of zero, and determining a target pseudorange observation value between the terminal and the network device, the target downlink information including a target orbit semi-major axis of the network device;

[0007] Determine a first distance value between the network device and a target projection point of the network device on the ground based on the target orbit semi-major axis, and determine a second distance value between the target projection point and the terminal based on the first distance value and the target pseudorange observation value;

[0008] A target motion parameter of the target projection point is determined based on the target downlink information, and a position of the terminal is determined based on the target motion parameter and the second distance value.

[0009] In one implementable manner, determining a second distance value between the target projection point and the terminal based on the first distance value and the target pseudorange observation value includes:

[0010] Determine the target pseudorange observation value as the hypotenuse value of a right triangle, and determine the first distance value as the first straight side value of the right triangle;

[0011] In the right triangle, determining a second straight side value based on the hypotenuse value and the first straight side value;

[0012] The second straight edge value is determined as the second distance value.

[0013] In one implementable manner, determining the target motion parameter of the target projection point based on the target downlink information includes:

[0014] Determine, based on the target downlink information, a first target coordinate of the target projection point and a target orientation of the terminal relative to the target projection point, wherein the target orientation is used to indicate a direction in which the target projection point points to the terminal;

[0015] The target orientation and the first target coordinates are determined as the target motion parameters.

[0016] In one implementable manner, the target downlink information further includes a perigee parameter, a true anomaly angle, and a right ascension of the ascending node, and the first target coordinates include a first latitude value and a first longitude value; and determining the first target coordinates of the target projection point and the target orientation of the terminal relative to the target projection point based on the target downlink information includes:

[0017] determining a sum of the value of the perigee parameter and the true anomaly as a latitude parameter;

[0018] determining the first latitude value based on the latitude parameter, and determining the first longitude value based on the latitude parameter and the right ascension of the ascending node;

[0019] Determining a target time corresponding to the target downlink signal, and determining a first time before the target time and a second time after the target time;

[0020] The target direction is determined based on first downlink information corresponding to the first moment and second downlink information corresponding to the second moment.

[0021] In one implementable manner, the target downlink information further includes a latitude argument; and determining the first latitude value based on the latitude parameter includes:

[0022] Determining a first sine value of the latitude parameter and determining a second sine value of the latitude argument;

[0023] An arc sine value corresponding to the product of the first sine value and the second sine value is determined as the first latitude value.

[0024] In one implementable manner, the target downlink information further includes a latitude argument and a target orbit semi-major axis of the network device; and determining the first longitude value based on the latitude parameter and the right ascension of the ascending node includes:

[0025] Determining a first sine value and a first cosine value of the latitude parameter, and determining a second cosine value of the latitude argument;

[0026] determining a first product between the first sine value and the second cosine value, and constructing a four-quadrant inverse tangent function between the first product and the first cosine value to obtain a first value;

[0027] The sum of the first value and the right ascension of the ascending node is determined as the first longitude value.

[0028] In one implementable manner, the first downlink information corresponds to a first pseudorange observation value, and the second downlink information corresponds to a second pseudorange observation value; and determining the target direction based on the first downlink information corresponding to the first moment and the second downlink information corresponding to the second moment includes:

[0029] If the first pseudorange observation value is greater than the second pseudorange observation value, determining that the target direction is a first direction;

[0030] If the first pseudorange observation value is less than the second pseudorange observation value, the target direction is determined to be the second direction.

[0031] In one implementable manner, the target downlink information corresponds to a target velocity vector of the network device, the target motion parameters include a first target coordinate of the target projection point and a target orientation of the terminal relative to the target projection point; and determining the position of the terminal based on the motion parameters and the second distance value includes:

[0032] Performing a vector subtraction calculation on the target velocity vector and a target velocity component in a direction from the center of the earth to the network device to determine a first velocity vector of the target projection point;

[0033] determining a second vector based on the first velocity vector and the target velocity component, wherein the second vector is perpendicular to a plane formed by the first velocity vector and the target velocity vector, and a direction of the second vector corresponds to the target orientation;

[0034] Converting the second vector into a coordinate system corresponding to the first target coordinate to obtain a converted second vector;

[0035] Based on the converted second vector and the second distance value, a second target coordinate of the terminal in a coordinate system corresponding to the first target coordinate is determined, and a position of the terminal is determined based on the second target coordinate.

[0036] In an implementable manner, determining the position of the terminal based on the second target coordinates includes:

[0037] Calculating a first coordinate based on a least squares method and the second target coordinate, and determining a second coordinate using the first coordinate as an input to the least squares method;

[0038] If the error between the first coordinate and the second coordinate is less than a preset error threshold, determining the second coordinate as the location of the terminal;

[0039] If the error value between the first coordinate and the second coordinate is greater than or equal to the preset error threshold, repeat the step of using the output of the least squares method as input to obtain iterative coordinates until the error value between two adjacent iterative coordinates is less than the preset error threshold, and determine the latter iterative coordinate of the two adjacent iterative coordinates as the position of the terminal.

[0040] In a second aspect, a terminal positioning device is provided, which is applied to a terminal, and the device includes:

[0041] an information determination module, configured to determine target downlink information transmitted by a network device, wherein the Doppler shift observation value is zero, and determine a target pseudorange observation value between the terminal and the network device, wherein the target downlink information includes a target orbit semi-major axis of the network device;

[0042] a distance determination module, configured to determine a first distance value between the network device and a target projection point of the network device on the ground based on the target orbit semi-major axis, and determine a second distance value between the target projection point and the terminal based on the first distance value and the target pseudorange observation value;

[0043] A positioning module is used to determine the target motion parameter of the target projection point based on the target downlink information, and determine the position of the terminal based on the target motion parameter and the second distance value.

[0044] In a third aspect, the present application provides a terminal, comprising: a processor, and a memory communicatively connected to the processor;

[0045] The memory stores computer-executable instructions;

[0046] The processor executes the computer-executable instructions stored in the memory to implement the terminal positioning method as described in the first aspect.

[0047] In a fourth aspect, the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, and when the computer-executable instructions are executed by a processor, they are used to implement the terminal positioning method as described in the first aspect.

[0048] In a fifth aspect, the present application provides a computer program product, comprising a computer program, which, when executed by a processor, implements the terminal positioning method as described in the first aspect.

[0049] The terminal positioning method, device, terminal, storage medium and program product provided in the present application obtain target downlink information when the Doppler shift observation value is zero, and determine the first distance value between the target projection point and the network device at the corresponding moment through the target downlink information. In this way, the second distance value between the target projection point and the terminal is determined through the relative position relationship between the target projection point, the terminal and the network device when the Doppler shift observation value is zero, and the second distance value between the target projection point and the terminal is determined through the first distance value. Therefore, the position of the terminal can be accurately and efficiently obtained without the need for an initial position through the second distance value between the target projection point and the terminal and the motion parameters of the target projection point. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0051] Figure 1 is a structural diagram of a communication system shown in an exemplary embodiment;

[0052] Figure 2 This is a flow chart of a terminal positioning method shown in an exemplary embodiment;

[0053] Figure 3 This is a schematic diagram of the relative positions of network devices, target projection points, and terminals shown in an exemplary embodiment;

[0054] Figure 4 is a flow chart of a terminal positioning method shown in another exemplary embodiment;

[0055] Figure 5 is a flow chart of a terminal positioning method shown in another exemplary embodiment;

[0056] Figure 6 is a schematic diagram of pseudorange observation values ​​at different times shown in an exemplary embodiment;

[0057] Figure 7 is a flow chart of a terminal positioning method shown in another exemplary embodiment;

[0058] Figure 8is a schematic diagram of positioning error shown in an exemplary embodiment;

[0059] Figure 9 This is a structural diagram of a terminal positioning device shown in an exemplary embodiment;

[0060] Figure 10 FIG. 1 is a schematic structural diagram of a terminal shown in an exemplary embodiment.

[0061] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0062] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.

[0063] The Global Navigation Satellite System (GNSS) can provide continuous and precise time and positioning services. GNSS mainly uses satellites in Medium Earth Orbit (MEO) to transmit navigation signals. The high orbits of these satellites cause severe signal attenuation in space. The received ground signal power is very low, typically between -160 dBW (decibel relative to one Watt, a unit indicating the relative size of power) and -155 dBW, which is easily blocked and interfered with, affecting positioning accuracy. Secondly, MEO satellites move slowly and their spatial structure changes slowly, resulting in a long time for initialization of Precise Point Positioning (PPP). Once the signal is lost, it needs to be reinitialized, which is not conducive to the real-time PPP requirements in highly dynamic environments.

[0064] LEO satellite positioning systems have attracted attention due to their low orbital altitude, rapid movement, minimal signal loss in space, strong landing power, and excellent anti-interference capabilities. Studies have found that at high elevation angles, the pseudorange and carrier phase observation accuracy of some LEO satellites can reach 0.6 meters and 1.7 millimeters; however, for LEO satellite positioning systems, if the time difference-based GNSS pseudorange positioning method is still used, the system's time synchronization requirements are very high, which will significantly increase the system's construction cost.

[0065] Since most LEO communication satellites are not equipped with high-precision atomic clocks, time synchronization is difficult to achieve. The rapid relative motion of LEO satellites results in large Doppler shifts, making positioning technology based on Doppler characteristics very suitable for LEO satellite positioning systems.

[0066] In the field of navigation, especially in highly dynamic environments, Doppler shift can affect GNSS signals. In some cases, such as when GNSS signals are unavailable due to interference, using Doppler frequency measured by the receiver becomes the only option for positioning.

[0067] Low Earth Orbit (LEO) satellites can be used to supplement GNSS, providing positioning and time information when GNSS signals are unavailable. However, when GNSS signals are unavailable, obtaining a rough current position can become very difficult. Secure positioning and time synchronization rely on the Newton iteration method to solve equations to obtain the terminal's position. The Newton method has high requirements for the accuracy of the terminal's initial position. Simulation and actual data show that the Newton iteration method equations can only converge to obtain the accurate terminal position when the initial position is within 100 kilometers of the terminal's actual position. If the initial coordinate error is too large, the Newton iteration method equations may not converge or be unable to find the correct solution.

[0068] Based on this, the embodiments of the present application propose a terminal positioning method, device, terminal, storage medium and program product, which automatically and accurately determines the terminal positioning based on the target downlink information with zero Doppler frequency shift observation value; at the same time, the positioning can also be used as the initial coordinates of the Newton iteration method, so that the terminal position obtained by subsequent calculation and the Newton iteration method can achieve precise terminal positioning.

[0069] To facilitate understanding of the embodiments of this application, first Figure 1 The communication system applicable to the embodiment of the present application is described in detail. Figure 1 As shown, the communication system 100 may include at least one network device, such as Figure 1 The network device 110 shown; the communication system 100 may also include at least one terminal, such as Figure 1 Terminal 120 is shown. Terminal 120 can be mobile or fixed. Network device 110 is a device that can communicate with terminal 120 via a wireless link, such as a base station or base station controller. Each network device can provide communication coverage for a specific geographic area and can communicate with terminals within that coverage area (cell).

[0070] It should be noted that the technical solutions of the embodiments of the present disclosure can be applied to various communication systems, such as long-term evolution (LTE) systems, fifth-generation (5G) mobile communication systems, 5G new radio (NR) systems, or other future new mobile communication systems.

[0071] In the embodiment of the present application, the network device 110 includes a non-terrestrial network device, such as a satellite. The satellite can be regarded as a mobile network device, and no specific limitation is made here.

[0072] The network device 110 in the embodiment of the present disclosure is an entity on the network side for transmitting or receiving signals, and the network device can be referred to as a network side device. For example, the network device 110 can be an evolved NodeB (eNB), a transmission point (TRP), a next generation NodeB (gNB) in an NR system, a base station in other future mobile communication systems, or an access node in a wireless fidelity (WiFi) system. The embodiments of the present disclosure do not limit the specific technology and specific device form adopted by the network device.

[0073] The network device provided by the embodiment of the present disclosure may be composed of a centralized unit (CU) and a distributed unit (DU), wherein the CU may also be called a control unit. The CU-DU structure may be used to split the protocol layer of a network device, such as a base station, with some functions of the protocol layer being centrally controlled by the CU, and the remaining functions of some or all of the protocol layers being distributed in the DU, which is centrally controlled by the CU.

[0074] The terminal 120 in the embodiment of the present disclosure is an entity on the user side for receiving or transmitting signals, such as a mobile phone. The terminal may also be referred to as a terminal, user equipment (UE), mobile station (MS), mobile terminal (MT), user-side device, etc. The terminal may be a car with communication functions, a smart car, a mobile phone, a wearable device, a tablet computer (Pad), a computer with wireless transceiver functions, a virtual reality (VR) terminal, an augmented reality (AR) terminal, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, etc.

[0075] In some embodiments, the network device 110 sends downlink information, the terminal receives the downlink information, determines the target downlink information that the Doppler frequency shift observation value sent by the network device is zero, and determines the target pseudorange observation value between the terminal and the network device, the target downlink information includes the target orbit semi-major axis of the network device; determines a first distance value between the network device and a target projection point of the network device on the ground based on the target orbit semi-major axis, and determines a second distance value between the target projection point and the terminal based on the first distance value and the target pseudorange observation value; determines the target motion parameters of the target projection point based on the target downlink information, and determines the position of the terminal based on the target motion parameters and the second distance value.

[0076] The embodiments of the present disclosure do not limit the specific technology and specific device form adopted by the terminal.

[0077] It can be understood that the communication system described in the embodiment of the present disclosure is for the purpose of more clearly illustrating the technical solution of the embodiment of the present disclosure, and does not constitute a limitation on the technical solution provided by the embodiment of the present disclosure. Ordinary technicians in this field can know that with the evolution of the system architecture and the emergence of new business scenarios, the technical solution provided by the embodiment of the present disclosure is also applicable to similar technical problems.

[0078] The terminal positioning method and device provided by the present disclosure are described in detail below with reference to the accompanying drawings.

[0079] Figure 2This is a flowchart of a terminal positioning method provided by an embodiment of the present disclosure, which is executed by a terminal. The terminal positioning method in this embodiment can be applied to a terminal, such as a mobile phone or a tablet or smartwatch with mobile communication functions, and the method includes:

[0080] S201. Determine target downlink information that the Doppler shift observation value sent by the network device is zero, and determine a target pseudorange observation value between the terminal and the network device. The target downlink information includes the target orbit semi-major axis of the network device.

[0081] In some embodiments, the network device is a LEO satellite.

[0082] In some embodiments, the orbital altitude of the network equipment is between 500 and 2000 kilometers.

[0083] In some embodiments, the network device may have a corresponding coverage area on the ground. During the operation of the network device, the terminal in the corresponding coverage area may receive downlink information sent by the network device.

[0084] In some embodiments, the coverage area can be determined by measuring the half-angle of visibility of the network device to the center of the Earth, which is visible from the ground station. Assuming the Earth is a uniform sphere, the half-angle of visibility of the network device α can be calculated by the following formula:

[0085]

[0086] Here, R represents the radius of the Earth, which is 6,378 kilometers, and H represents the orbital altitude of the network equipment; is the cut-off altitude angle, The ground coverage area of ​​a network device is affected by its orbital altitude and cutoff angle: as the orbital altitude of the network device increases and the cutoff angle decreases, the visible half-angle α increases, resulting in a corresponding expansion of the ground coverage area.

[0087] For the terminal, when the orbital height and cut-off altitude angle of the network device remain unchanged, the terminal can receive the network device from the beginning, which means that the terminal is located in the coverage area of ​​the current network device. Through the visual half angle, it can be calculated whether the terminal is located in the coverage area of ​​the network device and receives the downlink information sent by the network device.

[0088] For example, in one embodiment, the coverage area of ​​the network device can be calculated using the visual half-angle and the orbital height of the network device, and the duration during which the terminal is within the coverage area of ​​the network device and can receive downlink information sent by the network device can be calculated using the coverage area and the operating speed of the network device.

[0089] In some embodiments, the terminal receives downlink information sent by the network device. During the time when the terminal is located in the coverage area of ​​the network device and can receive the downlink information sent by the network device, the terminal can receive the downlink information sent by the network device, thereby determining the target downlink information with the Doppler frequency shift observation value being zero.

[0090] In some embodiments, the Doppler shift observation value corresponding to each downlink information is the Doppler shift observation value at the moment when the network device sends the corresponding downlink information. When the terminal detects that the Doppler shift observation value corresponding to a downlink information is zero, it can be regarded as the network device passing through the top at this time.

[0091] In some embodiments, the terminal receives downlink information sent by the network device. During the process of receiving the downlink information, on the time axis, the Doppler frequency shift observation value corresponding to each downlink information changes from positive to negative.

[0092] In some embodiments, the downlink information also includes the ephemeris information of the network device when the downlink information is sent, such as the semi-major axis of the orbit of the network device, the speed of the network device, etc., which is not specifically limited here.

[0093] After the downlink information is determined, the pseudorange observation value between the terminal and the network device can be determined through the ephemeris information in the downlink information, such as determining the target pseudorange observation value through the target downlink information.

[0094] In some embodiments, the ephemeris information in the target downlink information can be used to calculate the semi-major axis of the target orbit.

[0095] When determining the target downlink information, the target orbit semi-major axis of the network device corresponding to the target downlink information, the target pseudo-range observation value between the terminal and the network device, and other target ephemeris information can be determined.

[0096] S202. Determine a first distance value between the network device and a target projection point of the network device on the ground based on the semi-major axis of the target orbit, and determine a second distance value between the target projection point and the terminal based on the first distance value and the target pseudorange observation value.

[0097] In some embodiments, starting from the time the terminal receives the downlink information, the projection point of the network device on the earth can be obtained at each moment, so that during the time when the terminal is located in the coverage area of ​​the network device and can receive the downlink information sent by the network device, the projection point of the network device on the earth at each moment can be obtained, so that the projection line of the network device can be obtained during the time when the terminal is located in the coverage area of ​​the network device and can receive the downlink information sent by the network device.

[0098] For the target downlink information, at the time corresponding to the target downlink information, the target projection point of the network device on the ground of the earth can be obtained.

[0099] In some embodiments, the semi-major axis of the target orbit can be regarded as the distance between the center of the earth and the network device at the corresponding time, such as Figure 3 As shown, point A can be regarded as the target projection point of the network device, and the first distance value can be regarded as , is the radius of the Earth, and thus the first distance value can be determined by the semi-major axis of the target orbit:

[0100]

[0101] in, is the first distance value, that is, the distance between the network device and the ground, is the target orbit semi-major axis calculated from the target ephemeris information, is the radius of the Earth.

[0102] In some embodiments, the target pseudorange observation value may be regarded as the distance value between the network device and the terminal at the corresponding moment.

[0103] When the Doppler shift observation value is zero, the network device can be regarded as passing over the top, that is, the connection between the target projection point and the terminal and the line between the network device and the target projection point are regarded as approximately vertical. In this way, the second distance value between the target projection point and the terminal can be determined by the first distance value and the target pseudorange observation value.

[0104] S203: Determine a target motion parameter of the target projection point based on the target downlink information, and determine the location of the terminal based on the target motion parameter and the second distance value.

[0105] In some embodiments, the target motion parameters may include but are not limited to the target orientation of the network device relative to the terminal at the corresponding moment of sending the target downlink information and the first target coordinates of the target projection point.

[0106] In this way, the coordinates of the target projection point at the moment when the Doppler shift observation value is zero, the orientation of the network device relative to the terminal, and the distance between the target projection point and the terminal can be determined, thereby calculating the position of the terminal.

[0107] In an embodiment of the present application, target downlink information is obtained when the Doppler shift observation value is zero, and a first distance value between the target projection point and the network device at the corresponding moment is determined through the target downlink information. In this way, the relative position relationship between the target projection point, the terminal and the network device when the Doppler shift observation value is zero is used, and the second distance value between the target projection point and the terminal is determined through the first distance value. Therefore, the position of the terminal can be accurately and efficiently obtained without the need for an initial position through the second distance value between the target projection point and the terminal and the motion parameters of the target projection point.

[0108] Figure 4is a flowchart of a terminal positioning method shown in another exemplary embodiment, the method being executed by the terminal. Figure 4 propose Figure 2 A method for calculating the second distance value in step S202, Figure 4 The terminal positioning methods in include:

[0109] S401: Determine a target pseudorange observation value as a hypotenuse value of a right triangle, and determine a first distance value as a first straight side value of the right triangle.

[0110] In some embodiments, when the network device passes overhead, the Doppler shift observation value is zero. At this time, the two straight lines between the line between the target projection point and the terminal and the line between the network device and the target projection point are considered to be approximately perpendicular.

[0111] like Figure 3 As shown in the figure, the terminal is identified as B, the network device is identified as C, the line between the target projection point and the terminal is regarded as X, the length is the second distance value, the line between the network device and the target projection point is regarded as h, the length is the first distance value, P is the line between the network device and the terminal, the length is the target pseudorange observation value, and the two straight lines corresponding to X and h are approximately perpendicular.

[0112] In this way, the straight line corresponding to P is regarded as the hypotenuse of the right triangle, that is, the target pseudorange observation value is determined as the hypotenuse value of the right triangle, and the straight line corresponding to h is regarded as a straight side of the right triangle, that is, the first distance value is determined as the first straight side value of the right triangle. Through the hypotenuse and one straight side of the right triangle, the value corresponding to the other straight side, that is, the second straight side, can be calculated.

[0113] S402. In a right triangle, determine a second straight side value based on the hypotenuse value and the first straight side value.

[0114] In some embodiments, the square of the second straight side value is equal to the square of the hypotenuse value minus the square of the first straight side value, thereby obtaining the second straight side value.

[0115] S403: Determine the second straight edge value as the second distance value.

[0116] In some embodiments, the second straight edge value is determined as a second distance value, ie, a distance value between the target projection point and the network device.

[0117] In an embodiment of the present application, at a special moment when the Doppler shift observation value is zero, the line between the target projection point and the terminal, and the line between the network device and the target projection point can be considered to be approximately vertical, so that the second distance value is determined by the target pseudorange observation value and the first distance value, and the position of the terminal can be accurately calculated subsequently by the second distance value.

[0118] Figure 5is a flowchart of a terminal positioning method shown in another exemplary embodiment, the method being executed by the terminal. Figure 5 propose Figure 2 A method for obtaining target motion parameters in step S203, Figure 5 The terminal positioning methods in include:

[0119] S501: Determine first target coordinates of a target projection point and a target orientation of a terminal relative to the target projection point based on target downlink information.

[0120] In some embodiments, the target orientation is used to indicate the direction in which the target projection point points to the terminal.

[0121] In some embodiments, the target motion parameters include a target orientation and a first target coordinate.

[0122] The first target coordinates include a first latitude value and a first longitude value, which can be calculated using the ephemeris information corresponding to the target downlink information.

[0123] In some embodiments, the target downlink information further includes perigee parameters, true anomaly angle, and right ascension of ascending node, and the first target coordinates include a first latitude value and a first longitude value.

[0124] The sum of the value of the perigee parameter and the true anomaly angle is determined as the latitude parameter; a first latitude value is determined based on the latitude parameter, and a first longitude value is determined based on the latitude parameter and the right ascension of the ascending node; a target time corresponding to the target downlink signal is determined, and a first time before the target time and a second time after the target time are determined; and a target orientation is determined based on first downlink information corresponding to the first time and second downlink information corresponding to the second time.

[0125] In some embodiments, the projection point is the position of the network device projected on the earth's surface, which changes as the network device moves on the orbit. The target projection point corresponds to the position of the network device projected on the earth's surface, which is the first target coordinate.

[0126] The calculation of the first target coordinates requires the orbital roots, the latitude parameters of the network equipment and the right ascension of the ascending node. The relevant information can be read from the ephemeris data.

[0127] In some embodiments, the latitude parameter is calculated as follows:

[0128]

[0129] in, represents the latitude parameter, represents the true anomaly angle, is the value of the perigee parameter.

[0130] In some embodiments, a first sine value of the latitude parameter is determined, and a second sine value of the latitude argument is determined; and an arc sine value corresponding to the product of the first sine value and the second sine value is determined as the first latitude value.

[0131] The calculation of the first latitude value can be:

[0132]

[0133] in, is the first dimension value, is the argument of latitude, is the first sine value of the latitude parameter, is the second sine of the latitude argument, and arcsin is the inverse sine function.

[0134] In some embodiments, the target downlink information also includes the latitude argument and the target orbit semi-major axis of the network device.

[0135] Determine a first sine value and a first cosine value of the latitude parameter, and determine a second cosine value of the latitude argument; determine a first product between the first sine value and the second cosine value, construct a four-quadrant inverse tangent function between the first product and the first cosine value, and obtain a first value; determine the sum of the first value and the right ascension of the ascending node as the first longitude value.

[0136] In some embodiments, the calculation of the first longitude value may be:

[0137]

[0138] in, is the first longitude value, is the right ascension of the ascending node, is the second cosine value, is the first cosine value, is the four-quadrant inverse tangent function.

[0139] In some embodiments, the first downlink information corresponds to a first pseudorange observation value, and the second downlink information corresponds to a second pseudorange observation value.

[0140] In some embodiments, the first pseudorange observation value may be calculated based on the ephemeris information in the first downlink information, and the second pseudorange observation value may be calculated based on the ephemeris information in the second downlink information.

[0141] If the first pseudorange observation value is greater than the second pseudorange observation value, the target direction is determined to be the first direction; if the first pseudorange observation value is less than the second pseudorange observation value, the target direction is determined to be the second direction.

[0142] like Figure 6As shown in the figure, assume that a satellite moves from south to north. At different times, the network device is located at different points on L2, and the terminal receives the downlink signal. The Doppler shift observation and pseudorange observation at each time can be obtained. Assume that the network device is a polar orbiting satellite and the terminal is west of the sub-satellite point track. At time t1, the pseudorange observation is R1. Time t1 is regarded as the first time, and R1 is set as the first pseudorange observation value. At t1 + Δt, assume that the network device passes overhead. This time point is the target time, which is the time when the Doppler shift observation changes from positive to negative. At time t1 + 2Δt, the pseudorange observation is R2. Time t1 + 2Δt is regarded as the second time, and R2 is set as the second pseudorange observation value. Due to the influence of the earth's rotation, at different times, the terminal can be regarded as being located at different points relative to L1. R1 > R2, which is the pseudorange measurement characteristic when the terminal is west of the projection point. When R1 < R2, this is the pseudorange measurement characteristic when the terminal is east of the projection point. Based on the measurement characteristics of the pseudorange, the eastward or westward direction of the receiving terminal on the sub-satellite point track can be determined.

[0143] Also assume that the network device is an inclined orbit satellite. Compared with the polar orbiting satellite, the motion of the inclined orbit satellite is more complex. However, in principle, a similar processing method can be adopted. Since the trajectory of the inclined orbit satellite does not intersect the earth's equator or the north and south poles perpendicularly, its ground projection point will present an inclined waveform trajectory. Therefore, at this time, there is no need to focus on the east-west direction of the terminal at the projection point, but on the left-right direction of the terminal at the projection point. By a similar method to that of the polar orbiting satellite, the orientation of the receiver is determined.

[0144] In some embodiments, the eastward direction of the network device being a polar orbiting satellite and the leftward direction of the network device being an inclined orbit satellite are set as the first direction, and the westward direction of the network device being a polar orbiting satellite and the rightward direction of the network device being an inclined orbit satellite are set as the second direction.

[0145] S502. Determine the target azimuth and the first target coordinate as the target motion parameters.

[0146] In some embodiments, the target azimuth is used to indicate the direction from the target projection point to the terminal, and the first target coordinate is the position of the target projection point. Subsequently, the position of the terminal can be calculated through the target motion parameters and the second distance value.

[0147] Figure 7 It is a flowchart of a terminal positioning method shown in another exemplary embodiment. This method is executed by the terminal. Figure 7 Propose Figure 2 A method for obtaining the position of a terminal in step S203 in Figure 7 The terminal positioning method in

[0148] S701 : Perform vector subtraction calculation on a target velocity vector and a target velocity component in a direction from the center of the earth to the network device to determine a first velocity vector of a target projection point.

[0149] In some embodiments, the target downlink information corresponds to the target velocity vector of the network device, and the target velocity vector can be calculated through the ephemeris data in the target downlink information. The target motion parameters include the first target coordinates of the target projection point and the target orientation of the terminal relative to the target projection point.

[0150] In some embodiments, the position of the network device at different times can be regarded as a time-dependent function, represented by r(t). The time derivative of r(t) is the speed of the network device at different times. The speed is a vector, which includes speed components of different axes in the three-dimensional coordinate system.

[0151] For the target projection point, the corresponding velocity component is the target velocity vector of the network device at the corresponding moment. The target velocity component in the direction from the center of the earth to the network device is subtracted to determine the first velocity vector of the target projection point. The first velocity vector is:

[0152]

[0153] in, is the first velocity vector, is the target velocity vector, The target velocity component in the direction from the center of the earth to the network device is considered as a unit vector and is calculated as: .

[0154] S702: Determine a second vector based on the first velocity vector and the target velocity component, where the second vector is perpendicular to a plane formed by the first velocity vector and the target velocity vector.

[0155] A straight line on the surface can be defined by a point and a tangent vector. At the location of the target projection point, a vector can be found that is tangent to v. SDP (t) is perpendicular, and this vector is the second vector.

[0156] Assuming the earth is a sphere, the second vector can be obtained by vector cross product, such as in the following way:

[0157]

[0158] Here, t(t) is the second vector, which can be understood. is a unit vector, obtained by the calculation is also a unit vector.

[0159] It can be understood that the t(t) calculated at this time can have two directions. In the aforementioned embodiment, the target orientation corresponding to the terminal and the target projection point is determined, and the final direction of t(t) can be determined by the target orientation to obtain a second vector. The direction of the second vector corresponds to the target orientation, that is, the angle between the direction of the second vector and the direction corresponding to the target orientation is an acute angle or the same direction.

[0160] S703: Convert the second vector into a coordinate system corresponding to the first target coordinate to obtain a converted second vector.

[0161] In some embodiments, the first target coordinate is the position of the target projection point, and its corresponding coordinate system is a longitude and latitude coordinate system, while the coordinate system formed by the first velocity vector and the second vector is not a longitude and latitude coordinate system. In this embodiment, the first target coordinate is converted to the coordinate system formed by the first velocity vector and the second vector to determine the first coordinate of the target projection point in the coordinate system, and then the first coordinate is converted to the longitude and latitude coordinate system to obtain the second target coordinate.

[0162] In other embodiments, the second vector may also be converted into a vector in the latitude and longitude coordinate system to obtain a converted second vector, where the converted second direction indicates a direction in the latitude and longitude coordinate system.

[0163] S704: Determine the second target coordinates of the terminal in the coordinate system corresponding to the first target coordinates based on the converted second vector and the second distance value, and determine the position of the terminal based on the second target coordinates.

[0164] In some embodiments, the first target coordinates of the target projection point in the latitude and longitude coordinate system are known. Taking the first target coordinates as the starting point, the coordinates of the point whose distance from the target projection point in the corresponding direction of the converted second vector is a second distance value are determined to obtain a second target coordinate, which can be regarded as the roughly obtained position of the terminal.

[0165] In some embodiments, the second target coordinates are used as input to the Newton iteration method to calculate the position of the terminal.

[0166] In one embodiment, the first coordinate is calculated based on the least squares method and the second target coordinate, and the first coordinate is used as the input of the least squares method to determine the second coordinate; if the error value between the first coordinate and the second coordinate is less than a preset error threshold, the second coordinate is determined as the position of the terminal; if the error value between the first coordinate and the second coordinate is greater than or equal to the preset error threshold, the step of using the output of the least squares method as input to obtain the iterative coordinate is repeated until the error value between two adjacent iterative coordinates is less than the preset error threshold, and the latter of the two adjacent iterative coordinates is determined as the position of the terminal.

[0167] In some embodiments, the error value between the first coordinate and the second coordinate is obtained by subtracting the first coordinate from the second coordinate.

[0168] The preset error threshold can be set by an empirical parameter, such as 1. In some embodiments, the error value between the first coordinate and the second coordinate is less than the preset error threshold and is considered to be converged. It can be understood that the second coordinate is used as input and the iterative coordinate is determined by the least squares method. If the error value between the iterative coordinates of two adjacent least squares methods and the second coordinate when the second coordinate is used as input is less than the preset error threshold, it is also considered to be converged.

[0169] In some embodiments, the second coordinate is used as input, the iterative coordinate is determined by the least squares method, and the step of using the previous output of the least squares method as the next input is repeated to obtain the iterative coordinates output by the least squares method each time, until the error value between two adjacent iterative coordinates is less than a preset error threshold, which can be regarded as convergence, and the latter iterative coordinate of the two adjacent iterative coordinates is determined as the position of the terminal.

[0170] In some embodiments, the preset search range may be 50 kilometers. Within an area corresponding to 50 kilometers spread outward from the second target coordinates, the coordinates of each point are searched until the location of the terminal is obtained.

[0171] In some embodiments, a search may be performed within a preset search range using the second target coordinates. After convergence is achieved, the coordinates corresponding to the convergence are the location of the terminal.

[0172] In some embodiments, the calculated terminal position can be used as the initial position of the Newton iteration method, thereby avoiding the problem that the initial position cannot be determined during terminal positioning, and the initial position needs to be manually input, resulting in slow terminal positioning; or the problem that the initial position cannot be determined, resulting in the inability to calculate the correct result.

[0173] In some embodiments, the effectiveness of the above-mentioned terminal positioning method is tested through relevant simulation software, the network device is set to a polar-orbiting satellite, and two rows of roots are set to generate a polar-orbiting satellite orbit, the orbital parameters are set to an orbital semi-major axis of 7076 km, an orbital eccentricity of 0.003123, an orbital inclination of 98.2358 degrees, an ascending node right ascension of 192.8991 degrees, a perigee angular distance of 75.3926 degrees, an initial mean anomaly of 0 degrees, and terminal coordinates of (115.25, 39.26, 0).

[0174] This set of ephemeris is used to simulate and generate pseudorange observations and Doppler frequency shift observations. Using the terminal positioning method shown in the above embodiment, the coordinates of the terminal are calculated to be (115.4572, 39.3847, 0). Using this set of data for positioning solution, the positioning errors in different directions are as follows: Figure 8As shown, Figure 8 The figure in the middle shows the relationship between the terminal's positioning error and positioning epoch in different coordinate axis directions (X-axis, Y-axis, and Z-axis) in the Earth-centered, Earth-fixed (ECEF) coordinate system. The horizontal axis is the positioning epoch, measured in seconds, and the vertical axis is the positioning error, measured in meters. The positioning error in the X-axis corresponds to the X-axis error, the positioning error in the Y-axis corresponds to the Y-axis error, and the positioning error in the Z-axis corresponds to the Z-axis error. It can be seen that as the Doppler shift observations increase, the X-axis error, the Y-axis error, and the Z-axis error converge rapidly at the 13th epoch, about 130 seconds, and eventually converge to an accuracy of 100 meters.

[0175] An embodiment of the present application provides a terminal positioning method. Terminal positioning requires the use of Newton's iteration method to solve the terminal coordinates. The Newton's iteration method is relatively sensitive to the initial position. When the initial coordinates within a certain accuracy range cannot be given, the equations of the Newton's iteration method are very likely to not converge or cannot solve the correct results. The terminal positioning method proposed in this embodiment does not require other configurations and can automatically and accurately calculate the position of the terminal. This position can be used as the initial position of the Newton's iteration method. In this way, the coordinates of the terminal can be accurately calculated through the Newton's iteration method in the future.

[0176] Figure 9 This is a structural diagram of a terminal positioning device according to an exemplary embodiment. The terminal positioning device is applied to a terminal and includes:

[0177] An information determination module 910 is configured to determine target downlink information sent by a network device that indicates a zero Doppler shift observation value, and to determine a target pseudorange observation value between the terminal and the network device. The target downlink information includes a target orbit semi-major axis of the network device.

[0178] a distance determination module 930 configured to determine a first distance between the network device and a target projection point of the network device on the ground based on the semi-major axis of the target orbit, and to determine a second distance between the target projection point and the terminal based on the first distance and the target pseudorange observation value;

[0179] The positioning module 950 is configured to determine a target motion parameter of the target projection point based on the target downlink information, and determine the location of the terminal based on the target motion parameter and the second distance value.

[0180] In one implementation, the distance determination module 930 includes:

[0181] a parameter determination unit, configured to determine the target pseudorange observation value as the hypotenuse value of the right triangle, and determine the first distance value as the first straight side value of the right triangle;

[0182] a straight side calculation unit, configured to determine a second straight side value in a right triangle based on a hypotenuse value and a first straight side value;

[0183] The distance determining unit is configured to determine the second straight edge value as a second distance value.

[0184] In one possible implementation, the positioning module includes:

[0185] a target projection point calculation unit, configured to determine, based on the target downlink information, a first target coordinate of the target projection point and a target orientation of the terminal relative to the target projection point, the target orientation being used to indicate a direction in which the target projection point points to the terminal;

[0186] The operation parameter determination unit is used to determine the target orientation and the first target coordinates as target motion parameters.

[0187] In one implementation, the target downlink information further includes perigee parameters, true anomaly angle, and right ascension of the ascending node; the first target coordinates include a first latitude value and a first longitude value; and the target projection point calculation includes:

[0188] A latitude parameter determination subunit is used to determine the sum of the periapsis parameter value and the true anomaly angle as a latitude parameter;

[0189] a positioning subunit, configured to determine a first latitude value based on the latitude parameter, and determine a first longitude value based on the latitude parameter and the right ascension of the ascending node;

[0190] a time determination subunit, configured to determine a target time corresponding to a target downlink signal, and to determine a first time before the target time and a second time after the target time;

[0191] The target position determining subunit is configured to determine the target position based on the first downlink information corresponding to the first moment and the second downlink information corresponding to the second moment.

[0192] In one implementation, the target downlink information further includes latitude argument; the positioning subunit includes:

[0193] The first parameter determination plate is used to determine the first sine value of the latitude parameter and the second sine value of the latitude argument;

[0194] The latitude determination section is used to determine the arc sine value corresponding to the product of the first sine value and the second sine value as the first latitude value.

[0195] In one implementation, the target downlink information further includes latitude argument; the positioning subunit includes:

[0196] The second parameter determination section is used to determine the first sine value and the first cosine value of the latitude parameter, and to determine the second cosine value of the latitude argument;

[0197] A third parameter determination section is used to determine a first product between the first sine value and the second cosine value, and construct a four-quadrant inverse tangent function between the first product and the first cosine value to obtain a first value;

[0198] A determination block is used to determine the sum of the first value and the right ascension of the ascending node as the first longitude value.

[0199] In one implementation, the first downlink information corresponds to a first pseudorange observation value, and the second downlink information corresponds to a second pseudorange observation value; the target position determination subunit includes:

[0200] A first direction determination block is used to determine the target direction as the first direction if the first pseudorange observation value is greater than the second pseudorange observation value;

[0201] The second direction determination block is used to determine the target direction as the second direction if the first pseudorange observation value is less than the second pseudorange observation value.

[0202] In one implementation, the target downlink information corresponds to a target velocity vector of the network device, and the target motion parameters include a first target coordinate of a target projection point and a target orientation of the terminal relative to the target projection point; the positioning module includes:

[0203] A first vector determining unit is configured to perform a vector subtraction calculation on a target velocity vector and a target velocity component in a direction away from the center of the Earth pointing to the network device, so as to determine a first velocity vector of the target projection point;

[0204] a second vector determining unit, configured to determine a second vector based on the first velocity vector and the target velocity component, wherein the second vector is perpendicular to a plane formed by the first velocity vector and the target velocity vector, and a direction of the second vector corresponds to the target orientation;

[0205] A coordinate conversion unit, configured to convert the second vector into a coordinate system corresponding to the first target coordinate to obtain a converted second vector;

[0206] The positioning unit is configured to determine the second target coordinates of the terminal in a coordinate system corresponding to the first target coordinates based on the converted second vector and the second distance value, and determine the position of the terminal based on the second target coordinates.

[0207] In one possible implementation, the positioning unit includes:

[0208] a first iterative subunit, configured to calculate the first coordinate based on a least square method and the second target coordinate, and determine the second coordinate using the first coordinate as an input of the least square method;

[0209] a positioning subunit, configured to determine the second coordinate as the position of the terminal if an error value between the first coordinate and the second coordinate is less than a preset error threshold;

[0210] The second iterative subunit is used to repeat the step of using the output of the least squares method as input to obtain iterative coordinates if the error value between the first coordinate and the second coordinate is greater than or equal to a preset error threshold, until the error value between two adjacent iterative coordinates is less than the preset error threshold, and determine the latter iterative coordinate of the two adjacent iterative coordinates as the position of the terminal.

[0211] The terminal positioning device provided in this embodiment can be used to execute the above-mentioned terminal positioning method. Its implementation principle and technical effects are similar and will not be described in detail in this embodiment.

[0212] Figure 10 This is a schematic diagram of the structure of a terminal shown in an exemplary embodiment. Figure 10 The terminal 1000 may include: a processor 1001 and a memory 1002, wherein the processor 1001 and the memory 1002 can communicate; illustratively, the processor 1001 and the memory 1002 communicate via a communication bus 1003, the memory 1002 is used to store computer-executable instructions, and the processor 1001 is used to call the computer-executable instructions in the memory to execute the terminal positioning method shown in any of the above method embodiments.

[0213] In some embodiments, the terminal further includes a transceiver for receiving downlink information.

[0214] The processor may be a central processing unit (CPU), or other general-purpose processor, a digital signal processor (DSP), or an application-specific integrated circuit (ASIC). The general-purpose processor may be a microprocessor or any conventional processor. The steps of the method disclosed in this application may be directly implemented as being executed by a hardware processor, or may be implemented by a combination of hardware and software modules in the processor.

[0215] The present application provides a computer-readable storage medium having computer-executable instructions stored thereon; when the computer-executable instructions are executed by a processor, they are used to implement the terminal positioning method as described in any of the above embodiments.

[0216] An embodiment of the present application provides a computer program product, which includes a computer program. When the computer program is executed, it enables a computer to execute the above-mentioned terminal positioning method.

[0217] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of the present application and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0218] It should be understood that the present application is not limited to the exact structure described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A terminal positioning method, characterized in that: Applied to a terminal, the method includes: Determining target downlink information sent by a network device that shows a Doppler shift observation value of zero, and determining a target pseudorange observation value between the terminal and the network device, the target downlink information including a target orbit semi-major axis of the network device; Determine a first distance value between the network device and a target projection point of the network device on the ground based on the target orbit semi-major axis, and determine a second distance value between the target projection point and the terminal based on the first distance value and the target pseudorange observation value; determining target motion parameters of the target projection point based on the target downlink information, and determining a position of the terminal based on the target motion parameters and the second distance value, wherein the target downlink information corresponds to a target velocity vector of the network device, and the target motion parameters include a first target coordinate of the target projection point and a target orientation of the terminal relative to the target projection point; The determining the location of the terminal based on the motion parameter and the second distance value includes: Performing a vector subtraction calculation on the target velocity vector and a target velocity component in a direction from the center of the earth to the network device to determine a first velocity vector of the target projection point; determining a second vector based on the first velocity vector and the target velocity component, wherein the second vector is perpendicular to a plane formed by the first velocity vector and the target velocity vector, and a direction of the second vector corresponds to the target orientation; Converting the second vector into a coordinate system corresponding to the first target coordinate to obtain a converted second vector; Based on the converted second vector and the second distance value, a second target coordinate of the terminal in a coordinate system corresponding to the first target coordinate is determined, and a position of the terminal is determined based on the second target coordinate.

2. The method according to claim 1, characterized in that The determining a second distance value between the target projection point and the terminal based on the first distance value and the target pseudorange observation value includes: Determine the target pseudorange observation value as the hypotenuse value of a right triangle, and determine the first distance value as the first straight side value of the right triangle; In the right triangle, determining a second straight side value based on the hypotenuse value and the first straight side value; The second straight edge value is determined as the second distance value.

3. The method according to claim 1, characterized in that The determining the target motion parameter of the target projection point based on the target downlink information includes: Determine, based on the target downlink information, a first target coordinate of the target projection point and a target orientation of the terminal relative to the target projection point, wherein the target orientation is used to indicate a direction in which the target projection point points to the terminal; The target orientation and the first target coordinates are determined as the target motion parameters.

4. The method according to claim 3, characterized in that The target downlink information further includes a perigee parameter, a true anomaly angle, and a right ascension of the ascending node, and the first target coordinates include a first latitude value and a first longitude value; and determining the first target coordinates of the target projection point and the target orientation of the terminal relative to the target projection point based on the target downlink information includes: determining a sum of the value of the perigee parameter and the true anomaly as a latitude parameter; determining the first latitude value based on the latitude parameter, and determining the first longitude value based on the latitude parameter and the right ascension of the ascending node; Determining a target time corresponding to the target downlink signal, and determining a first time before the target time and a second time after the target time; The target direction is determined based on first downlink information corresponding to the first moment and second downlink information corresponding to the second moment.

5. The method according to claim 4, characterized in that The target downlink information further includes a latitude argument; and determining the first latitude value based on the latitude parameter includes: Determining a first sine value of the latitude parameter and determining a second sine value of the latitude argument; An arc sine value corresponding to the product of the first sine value and the second sine value is determined as the first latitude value.

6. The method according to claim 4, characterized in that The target downlink information further includes a latitude argument; and determining the first longitude value based on the latitude parameter and the right ascension of the ascending node includes: Determining a first sine value and a first cosine value of the latitude parameter, and determining a second cosine value of the latitude argument; determining a first product between the first sine value and the second cosine value, and constructing a four-quadrant inverse tangent function between the first product and the first cosine value to obtain a first value; The sum of the first value and the right ascension of the ascending node is determined as the first longitude value.

7. The method according to claim 4, characterized in that The first downlink information corresponds to a first pseudorange observation value, and the second downlink information corresponds to a second pseudorange observation value; and determining the target direction based on the first downlink information corresponding to the first moment and the second downlink information corresponding to the second moment includes: If the first pseudorange observation value is greater than the second pseudorange observation value, determining that the target direction is a first direction; If the first pseudorange observation value is less than the second pseudorange observation value, the target direction is determined to be the second direction.

8. The method according to claim 1, characterized in that The determining the position of the terminal based on the second target coordinates includes: Calculating a first coordinate based on a least squares method and the second target coordinate, and determining a second coordinate using the first coordinate as an input to the least squares method; If the error between the first coordinate and the second coordinate is less than a preset error threshold, determining the second coordinate as the location of the terminal; If the error value between the first coordinate and the second coordinate is greater than or equal to the preset error threshold, repeat the step of using the output of the least squares method as input to obtain iterative coordinates until the error value between two adjacent iterative coordinates is less than the preset error threshold, and determine the latter iterative coordinate of the two adjacent iterative coordinates as the position of the terminal.

9. A terminal positioning device, characterized in that: Applied to a terminal, the device includes: an information determination module, configured to determine target downlink information transmitted by a network device, wherein the Doppler shift observation value is zero, and determine a target pseudorange observation value between the terminal and the network device, wherein the target downlink information includes a target orbit semi-major axis of the network device; a distance determination module, configured to determine a first distance value between the network device and a target projection point of the network device on the ground based on the target orbit semi-major axis, and determine a second distance value between the target projection point and the terminal based on the first distance value and the target pseudorange observation value; a positioning module, configured to determine target motion parameters of the target projection point based on the target downlink information, and determine the position of the terminal based on the target motion parameters and the second distance value, wherein the target downlink information corresponds to a target velocity vector of the network device, and the target motion parameters include a first target coordinate of the target projection point and a target orientation of the terminal relative to the target projection point; The positioning module includes: a first vector determining unit, configured to perform a vector subtraction calculation on the target velocity vector and a target velocity component in a direction from the center of the earth to the network device, so as to determine a first velocity vector of the target projection point; a second vector determining unit, configured to determine a second vector based on the first velocity vector and the target velocity component, wherein the second vector is perpendicular to a plane formed by the first velocity vector and the target velocity vector, and a direction of the second vector corresponds to the target orientation; a coordinate conversion unit, configured to convert the second vector into a coordinate system corresponding to the first target coordinate to obtain a converted second vector; A positioning unit is used to determine the second target coordinates of the terminal in the coordinate system corresponding to the first target coordinates based on the converted second vector and the second distance value, and determine the position of the terminal based on the second target coordinates.

10. A terminal, characterized in that: include: a processor, and a memory communicatively connected to the processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory to implement the method according to any one of claims 1 to 8.

11. A computer-readable storage medium, characterized in that The computer-readable storage medium stores computer-executable instructions, which are used to implement the method according to any one of claims 1 to 8 when executed by a processor.

12. A computer program product, characterized in that The invention comprises a computer program, which implements the method according to any one of claims 1 to 8 when executed by a processor.

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