Satellite searching method, device, terminal equipment and computer-readable storage medium

Abstract

Provided are a method, apparatus, terminal device, non-transitory computer-readable storage medium, computer program product, and chip for searching for satellites. The method for searching for satellites includes: estimating the time when the current satellite reaches a predetermined elevation angle using an ephemeris prediction algorithm; calculating an error metric for each of multiple ephemeris prediction algorithms, wherein the error metric is a function of the time difference between the time when the current satellite reaches the predetermined elevation angle and a reference time of an initial satellite ephemeris, and the multiple ephemeris prediction algorithms have different prediction accuracies; selecting a target ephemeris prediction algorithm from the multiple ephemeris prediction algorithms based on the error metrics of the multiple ephemeris prediction algorithms to calculate the position of the current satellite at the current time, wherein the target ephemeris prediction algorithm is the ephemeris prediction algorithm with the lowest prediction accuracy among the ephemeris prediction algorithms that meet an error threshold among the multiple ephemeris prediction algorithms; and searching for the current satellite based on the position of the current satellite at the current time.

Description

Technical Field

[0001] The present disclosure relates to the field of satellite communications, and in particular to a method, apparatus, terminal equipment, and computer-readable storage medium for searching for satellites. Background Art

[0002] In satellite communication systems, after powering on, a terminal device uses initial ephemeris to predict the satellite's position coordinates for a period of time. The device then searches for satellites by aligning its antenna with the predicted satellite coordinates. The accuracy of this process depends on the complexity of the ephemeris prediction algorithm used. While using a highly complex ephemeris prediction algorithm can meet the required accuracy, it increases the computing power of the terminal device, resulting in a longer satellite search time after powering on. Summary of the Invention

[0003] It would be advantageous to provide a mechanism that alleviates, mitigates, or eliminates at least one of the problems described above.

[0004] In a first aspect, a method for searching for satellites is provided. The method includes the following steps: estimating the time when a current satellite reaches a predetermined elevation angle using an ephemeris prediction algorithm; calculating an error metric for each of a plurality of ephemeris prediction algorithms, wherein the error metric is a function of the time difference between the time when the current satellite reaches the predetermined elevation angle and a reference time of initial satellite ephemeris, and the plurality of ephemeris prediction algorithms have different prediction accuracies; selecting a target ephemeris prediction algorithm from the plurality of ephemeris prediction algorithms based on the respective error metrics of the plurality of ephemeris prediction algorithms to calculate the position of the current satellite at the current time, wherein the target ephemeris prediction algorithm is the ephemeris prediction algorithm with the lowest prediction accuracy among the ephemeris prediction algorithms that meet an error threshold among the plurality of ephemeris prediction algorithms; and searching for the current satellite based on the position of the current satellite at the current time.

[0005] In a second aspect, a device for searching for satellites is provided, which includes means for executing the above-mentioned method for searching for satellites.

[0006] In a third aspect, a terminal device is provided. The terminal device includes: one or more processors; and one or more memories coupled to the one or more processors and storing instructions thereon. When the one or more processors execute the instructions individually or collectively, the terminal device performs the above-described satellite search method.

[0007] In a fourth aspect, a non-transitory computer-readable storage medium storing machine-executable instructions is provided. The machine-executable instructions, when executed by one or more processors of a machine, cause the machine to perform any one of the above methods.

[0008] In a fifth aspect, a computer program product is provided comprising machine-executable instructions, which, when executed by one or more processors of a machine, cause the machine to perform any one of the above methods.

[0009] In a sixth aspect, a chip is provided, comprising a circuit system configured to execute any one of the above methods.

[0010] It should be understood that the invention summary is not intended to identify the key or essential features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The above and other objects, features and advantages of the present disclosure will become more apparent through a more detailed description of some embodiments of the present disclosure in the accompanying drawings, in which:

[0012] Figure 1 A schematic flow chart of a method for searching for satellites according to some embodiments of the present disclosure is shown;

[0013] Figure 2 A diagram showing the relationship between the elevation angle of the current satellite and the distance between the current satellite and the terminal device;

[0014] Figure 3 A schematic diagram of a curve showing the distance error of the predicted distance corresponding to an ephemeris prediction algorithm is shown;

[0015] Figure 4 A schematic diagram of a curve showing the distance error of the predicted distance corresponding to another ephemeris prediction algorithm is shown;

[0016] Figure 5 A schematic diagram of a curve showing the distance error of the predicted distance corresponding to another ephemeris prediction algorithm is shown;

[0017] Figure 6 A flowchart illustrating an exemplary method for adjusting an error threshold according to some embodiments of the present disclosure is shown;

[0018] Figure 7 Shown is a simplified block diagram of a terminal device suitable for implementing the exemplary embodiments of the present disclosure. DETAILED DESCRIPTION

[0019] The principle of the present disclosure will now be described with reference to some embodiments. It should be understood that the description of these embodiments is merely for illustrative purposes and helps those skilled in the art to understand and implement the present disclosure without placing any restriction on the scope of the present disclosure. The disclosure described herein can be implemented in a manner different from that described below.

[0020] In the following description, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0021] References in this disclosure to "one embodiment," "an embodiment," "an exemplary embodiment," etc., indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment necessarily includes the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. In addition, when a particular feature, structure, or characteristic is described in conjunction with an exemplary embodiment, whether or not explicitly described, those skilled in the art will recognize that such feature, structure, or characteristic may be combined with other embodiments.

[0022] It should be understood that although the terms "first" and "second" and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are merely used to distinguish one element from another. For example, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element without departing from the scope of the exemplary embodiments. The term "and / or" as used herein includes any and all combinations of one or more of the listed terms.

[0023] The terms used herein are intended only to describe specific embodiments and are not intended to limit exemplary embodiments. As used herein, the singular forms "a," "an," and "the" also include the plural forms, unless the context clearly indicates otherwise. As used herein, "a group of elements" or "a set of elements" is intended to include one or more elements. It should also be understood that the terms "comprise," "include," "have," "have," "include," and / or "comprising," when used herein, specify the presence of the features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0024] As used in this application, the term "circuitry" may refer to one or more or all of the following:

[0025] (a) Hardware circuit implementation only (e.g., implementation only in analog and / or digital circuits)

[0026] (b) a combination of hardware circuitry and software, such as (where applicable):

[0027] (i) a combination of analog and / or digital hardware circuitry and software / firmware; and

[0028] (ii) any portion of a hardware processor (including a digital signal processor) with software, software, and memory that work together to enable a device such as a mobile phone or server to perform various functions, and

[0029] (c) Hardware circuits and / or processors, such as a microprocessor or portion of a microprocessor, that require software (eg, firmware) to operate, but where software is not required for operation, the software may not be present.

[0030] This definition of circuitry applies to all uses of the term in this application. As another example, as used in this application, the term circuitry also includes an implementation of merely a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also includes, for example, if applicable to the particular component, a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network device, or other computing network device.

[0031] As used herein, the term "satellite communication system" refers to a technical system that uses satellites as relay stations for terminal devices to access a network and receive services through the satellite, including low-orbit satellite communication systems and high-orbit satellite communication systems. The term "satellite" refers to, for example, a low-orbit satellite (LEO) or a high-orbit satellite (GEO). The term "terminal device" refers to any terminal device capable of wireless communication. By way of example and not limitation, a terminal device may also be referred to as a communication device, user equipment (UE), subscriber station (SS), portable subscriber station, mobile station (MS), or access terminal (AT). The terminal device may include, but is not limited to, a mobile phone, a cellular phone, a smartphone, a voice over IP (VoIP) phone, a wireless local loop phone, a tablet computer, a wearable terminal device, a personal digital assistant (PDA), a portable computer, a desktop computer, an image capture terminal device such as a digital camera, a gaming terminal device, a music storage and playback device, an in-vehicle wireless terminal device, a wireless endpoint, a mobile station, a notebook embedded device (LEE), a laptop mounted device (LME), a USB dongle, a smart device, a wireless customer equipment (CPE), an Internet of Things (IoT) device, a watch or other wearable device, a head-mounted display (HMD), a vehicle, a drone, medical equipment and applications (e.g., remote surgery), industrial equipment and applications (e.g., robots and / or other wireless devices operating in the context of industrial and / or automated process chains), consumer electronic devices, relay nodes, devices operating on commercial and / or industrial wireless networks, etc. The mobile terminal (MT) portion of the IAB node may perform the functions of a "terminal device" and, therefore, may operate as a terminal device. In the following description, the terms "terminal device," "communication device," "terminal," "user equipment," and "UE" may be used interchangeably.

[0032] In addition, communications between terminal devices and satellites in a satellite communication network may be performed according to any appropriate generation of communication protocols, including but not limited to first generation (1G), second generation (2G), 2.5G, 2.75G, third generation (3G), fourth generation (4G), 4.5G, fifth generation (5G), future sixth generation (6G) communication protocols, and / or any other protocols currently known or to be developed in the future.

[0033] In existing satellite communication systems, after powering on, a terminal device uses initial ephemeris to predict the satellite's position coordinates for a period of time. The device then searches for satellites by aligning its antenna with the predicted satellite coordinates. The accuracy of this process is related to the complexity of the ephemeris prediction algorithm used. While using a highly complex ephemeris prediction algorithm can meet the required accuracy, it increases the computational burden on the terminal device's processor, resulting in a longer satellite search time after powering on.

[0034] The embodiments of the present disclosure propose a solution for a method of searching for satellites, so that a terminal device can accurately search for satellites while saving computing power for searching for satellites. In this solution, the terminal device calculates the error metrics of multiple ephemeris prediction algorithms based on the moment when the current satellite reaches a predetermined elevation angle, and selects a target ephemeris prediction algorithm from the multiple ephemeris prediction algorithms. Since the target ephemeris prediction algorithm is the ephemeris prediction algorithm with the lowest prediction accuracy among the multiple ephemeris prediction algorithms that meet the error threshold, the target ephemeris prediction algorithm is used to calculate the position of the current satellite at the current moment, which can ensure that the calculated position meets the error requirement. At the same time, it reduces the computing power burden of the terminal device for searching for satellites, thereby shortening the time it takes to search for satellites after the terminal device is turned on.

[0035] In an exemplary embodiment, the terminal device is able to dynamically adjust the error threshold corresponding to the target ephemeris prediction algorithm applicable to the next satellite by determining whether the current satellite has passed by and comparing the quality metric of data received from the current satellite during the current satellite's pass with the quality threshold.

[0036] The principles and implementations of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0037] Figure 1 FIG. 1 is a flow chart showing a method 100 for searching for satellites according to some embodiments of the present disclosure, with reference to FIG. Figure 1 , the method for searching for satellites comprises the following steps:

[0038] S101, using an ephemeris prediction algorithm to estimate the moment when the current satellite reaches a predetermined elevation angle.

[0039] In some embodiments, estimating the moment when the current satellite reaches a predetermined elevation angle using an ephemeris prediction algorithm includes: selecting an ephemeris prediction algorithm with the lowest prediction accuracy from multiple ephemeris prediction algorithms to estimate the moment when the current satellite reaches the predetermined elevation angle.

[0040] In other words, after the terminal device is turned on, the ephemeris prediction algorithm with the lowest prediction accuracy is first used to estimate the moment when the current satellite reaches the predetermined elevation angle, thereby reducing the computing power consumption of the elevation angle calculation.

[0041] In some embodiments, multiple ephemeris prediction algorithms are based on the Earth's gravitational field potential function that takes into account the Earth's non-spherical gravitational term, and the Earth's gravitational field potential functions corresponding to different ephemeris prediction algorithms have different orders and degrees.

[0042] The expression of the earth's gravitational field potential function considering the earth's non-spherical gravitational term is as follows (1):

[0043] (1)

[0044] in, is the Earth's equatorial radius, is the product of the gravitational constant and the mass of the Earth. is the gravitational constant, is the mass of the Earth, r is the distance between the satellite and the center of the Earth, 、 are the geocentric latitude and longitude of the satellite in the Earth-fixed coordinate system, and is the normalized gravitational coefficient, is the normalized associated Legendre polynomial, and n and m are the order and degree of the spherical harmonic expansion respectively.

[0045] In other words, the complexity of the ephemeris prediction algorithm is related to the order and degree of the corresponding Earth gravitational field potential function. The higher the complexity of the ephemeris prediction algorithm, the higher the order and degree of the corresponding Earth gravitational field potential function, and thus the higher the prediction accuracy.

[0046] Thus, among the multiple ephemeris prediction algorithms, the ephemeris prediction algorithm with the lowest prediction accuracy is the ephemeris prediction algorithm corresponding to the earth gravitational field potential function of the lowest order and degree.

[0047] In some embodiments, the predetermined elevation angle is selected based on the current distance between the satellite and the terminal device.

[0048] Figure 2 The relationship between the current satellite elevation angle and the distance between the current satellite and the terminal device is shown in the figure. Figure 2Assuming that the current satellite is at actual satellite position 1 at the first moment, the antenna axis 1 corresponding to the current satellite forms an elevation angle 1 with the horizontal plane where the terminal device on Earth is located. Based on the distance r1 between the actual satellite position 1 and the terminal device, and the position error e1 between the satellite position calculated by the antenna axis 1 at this moment and the actual satellite position 1, the axis angle α between the antenna axis 1 and the actual satellite position 1 can be calculated. Similarly, assuming that the current satellite is at actual satellite position 2 at the second moment, the antenna axis 2 corresponding to the current satellite forms an elevation angle 2 with the horizontal plane where the same terminal device on Earth is located. Based on the distance r2 between the actual satellite position 2 and the terminal device, and the position error e2 between the satellite position calculated by the antenna axis 1 at this moment and the actual satellite position 2, the axis angle β between the antenna axis 2 and the actual satellite position 2 can be calculated.

[0049] As can be seen, as the current satellite moves from actual satellite position 1 to actual satellite position 2, the distance between the current satellite and the terminal device changes from r1 to r2, and the elevation angle changes from elevation 1 to elevation 2. In other words, the greater the distance between the current satellite and the terminal device, the smaller the elevation angle formed between the current satellite's antenna axis and the horizontal plane where the terminal device is located on Earth. Furthermore, since the position error e1 and the position error e2 are essentially equivalent, and the axis angle changes from α to β, similarly decreasing as the distance between the current satellite and the terminal device increases, a greater distance between the current satellite and the terminal device also results in a smaller axis angle, meaning a smaller maximum angular deviation caused by the position error.

[0050] Table 1 shows the distance between the current satellite and the terminal device at different elevation angles. The data in Table 1 is derived from a low-orbit satellite at an altitude of about 1000 kilometers in actual conditions.

[0051] Table 1

[0052] Satellite altitude (km) Elevation angle (degrees) Distance (km) 1000 3.000000: 3388.553269 1000 10.000000: 2762.269556 1000 20.000000: 2120.999671 1000 30.000000: 1702.179434 1000 40.000000: 1428.626883 1000 50.000000: 1248.232110 1000 60.000000: 1129.674142 1000 70.000000: 1054.777442 1000 80.000000: 1013.293738 1000 90.000000: 1000.000000

[0053] As shown in Table 1, for the low-orbit satellite, the elevation angle decreases as the distance between the current satellite and the terminal device increases. When the elevation angle is lower than 50 degrees, a change in unit elevation angle will bring about a more obvious distance change.

[0054] S102, calculating an error metric for each of a plurality of ephemeris prediction algorithms.

[0055] The error metric is a function of the time difference between the moment when the current satellite reaches the predetermined elevation angle and the reference moment of the initial satellite ephemeris, and multiple ephemeris prediction algorithms have different prediction accuracies.

[0056] In some embodiments, for any of the multiple ephemeris prediction algorithms, the error metric satisfies the following formula (2):

[0057] (2)

[0058] in, represents the error metric, Indicates the time difference between the moment when the current satellite reaches the predetermined elevation angle and the reference time of the initial satellite ephemeris. Indicates the scheduled duration. Indicates the distance between the current satellite and the terminal device at the predetermined elevation angle. It represents the distance error of the predicted distance between the satellite and the terminal device after a predetermined period of time corresponding to the ephemeris prediction algorithm.

[0059] Taking the ephemeris prediction algorithm with the lowest prediction accuracy as an example, assuming that the predetermined time is 24 hours, the distance error of the predicted distance between the satellite and the terminal device after 24 hours according to the ephemeris prediction algorithm is 10 kilometers. According to the ephemeris prediction algorithm, the distance between the current satellite and the terminal device at the time of the predetermined elevation angle is 3388 kilometers, and the time difference between the time when the current satellite reaches the predetermined elevation angle and the reference time of the initial satellite ephemeris is 1 hour. Substitute it into formula (2) to obtain the error metric of the ephemeris prediction algorithm with the lowest prediction accuracy.

[0060] Taking three different ephemeris prediction algorithms based on the Earth's gravitational field potential function taking into account the Earth's non-spherical gravitational term as an example, for ease of understanding, they are respectively called J22 algorithm, J33 algorithm and J44 algorithm. Among them, the order n<=2 and the degree m<=2 of the Earth's gravitational field potential function corresponding to the J22 algorithm, the order n<=3 and the degree m<=3 of the Earth's gravitational field potential function corresponding to the J33 algorithm, and the order n<=4 and the degree m<=4 of the Earth's gravitational field potential function corresponding to the J44 algorithm.

[0061] Table 2 presents the prediction accuracy of each of the three ephemeris prediction algorithms and compares it with the prediction accuracy of other prediction algorithms that consider the two-body model. Prediction accuracy is reflected in the distance error between the predicted distance between the satellite and the terminal device after 24 hours, corresponding to the ephemeris prediction algorithm. In addition, Table 2 also presents the processor computing time consumed in seconds for each of the three ephemeris prediction algorithms for 24 hours and its equivalent computational effort (in units of the equivalent computational effort of other prediction algorithms that consider the two-body model). The data in Table 2 is derived from a low-orbit satellite at an altitude of approximately 1000 kilometers under actual conditions, as shown below:

[0062] Table 2

[0063] Consider the order and degree of the potential function of the Earth's gravitational field Prediction accuracy Processor computing time consumed in seconds over 24 hours Equivalent computational effort Other prediction algorithms considering the two-body model The potential function of the Earth's gravitational field considering the Earth's non-spherical gravitational term >100 km 0.132765 seconds 1 J22 algorithm n<=2,m<=2 10 kilometers 0.572753 seconds 4 J33 algorithm n<=3,m<=3 5 km 1.471695 seconds 11 J44 algorithm n<=4,m<=4 2 km 2.934477 seconds 22

[0064] As shown in Table 2, among the different ephemeris prediction algorithms based on the consideration of the Earth's gravitational field potential function, the higher the order and degree of the Earth's gravitational field potential function, the higher the prediction accuracy, and the greater the equivalent calculation amount.

[0065] Figure 3 The figure shows a curve diagram of the distance error of the predicted distance corresponding to an ephemeris prediction algorithm. The ephemeris prediction algorithm is the J22 algorithm. From top to bottom along the vertical axis, Figure 3 The total distance error curve 301 of the J22 algorithm, the satellite z-axis error curve 302, the satellite y-axis error curve 303 and the satellite x-axis error curve 304 are included in sequence. Figure 3 The horizontal axis is in minutes, and the vertical axis is in meters. It can be seen that after approximately 24 hours, the total distance error corresponding to the J22 algorithm is approximately 10 kilometers. After approximately 12 hours, the total distance error corresponding to the J22 algorithm is approximately 5 kilometers. Overall, the distance error corresponding to the J22 algorithm increases linearly with the current time delay.

[0066] Figure 4 The figure shows a curve diagram of the distance error of the predicted distance corresponding to another ephemeris prediction algorithm. The ephemeris prediction algorithm is the J33 algorithm. From top to bottom along the vertical axis, Figure 4 The total distance error curve 401 of the J33 algorithm, the satellite z-axis error curve 402, the satellite y-axis error curve 403 and the satellite x-axis error curve 404 are included in sequence. Figure 4 The horizontal axis is in minutes, and the vertical axis is in meters. It can be seen that after approximately 24 hours, the total distance error corresponding to the J33 algorithm is approximately 5 kilometers. After approximately 12 hours, the total distance error corresponding to the J33 algorithm is approximately 2.5 kilometers. Overall, the distance error corresponding to the J33 algorithm increases linearly with the current time delay.

[0067] Figure 5 The figure shows a curve diagram of the distance error of the predicted distance corresponding to another ephemeris prediction algorithm. The ephemeris prediction algorithm is the J44 algorithm. From top to bottom along the vertical axis, Figure 5 The total distance error curve 501, the z-axis error curve 502, the y-axis error curve 503 and the x-axis error curve 504 of the J44 algorithm are included in sequence. Figure 5 The horizontal axis is in minutes, and the vertical axis is in meters. It can be seen that after approximately 24 hours, the total distance error corresponding to the J44 algorithm is approximately 2 kilometers. After approximately 12 hours, the total distance error corresponding to the J44 algorithm is approximately 1 kilometer. Overall, the distance error corresponding to the J44 algorithm increases linearly with the current time delay.

[0068] Therefore, comprehensive Figure 3-Figure 5, we can see that the distance errors corresponding to the three ephemeris prediction algorithms are basically linearly increasing with the current time delay. Figure 3-Figure 5 In the figure, the total distance error corresponding to the three ephemeris prediction algorithms after the same amount of time has passed. It can also be seen that as the order and degree of the Earth's gravitational field potential function considered by the ephemeris prediction algorithm are higher, the corresponding distance error of the predicted distance is smaller.

[0069] S103 , based on the respective error metrics of the multiple ephemeris prediction algorithms, selecting a target ephemeris prediction algorithm from the multiple ephemeris prediction algorithms to calculate the position of the current satellite at the current moment.

[0070] The target ephemeris prediction algorithm is an ephemeris prediction algorithm with the lowest prediction accuracy among the ephemeris prediction algorithms that meet the error threshold among the multiple ephemeris prediction algorithms.

[0071] In some embodiments, a target ephemeris prediction algorithm is selected from a plurality of ephemeris prediction algorithms to calculate the position of the current satellite at the current moment, including: comparing the error metrics of the plurality of ephemeris prediction algorithms with an error threshold in order of prediction accuracy from low to high; and in response to an ephemeris prediction algorithm from the plurality of ephemeris prediction algorithms having an error metric less than the error threshold, selecting the ephemeris prediction algorithm as the target ephemeris prediction algorithm to calculate the position of the current satellite at the current moment.

[0072] In other words, each of the multiple ephemeris prediction algorithms is compared against the error threshold in ascending order of prediction accuracy. If the error metric of a compared ephemeris prediction algorithm is less than the error threshold, that ephemeris prediction algorithm is identified as the target ephemeris prediction algorithm, and subsequent ephemeris prediction algorithms are no longer compared against the error threshold. Furthermore, the terminal device uses the target ephemeris prediction algorithm to calculate the current satellite position at the current moment.

[0073] It should be noted that if the terminal device cannot find the target ephemeris prediction algorithm among multiple ephemeris prediction algorithms, it means that the terminal device cannot search for the current satellite, then the terminal device can select the next satellite as the current satellite to repeat steps S101-S103.

[0074] S104: Search for the current satellite based on the current satellite's position at the current moment.

[0075] In some embodiments, searching for the current satellite based on the position of the current satellite at the current moment includes: in response to determining that the current satellite is within the visual range of the terminal device, aligning the antenna of the terminal device with the position of the current satellite at the current moment to search for the current satellite.

[0076] The visual range of a terminal device refers to the spatial coverage conditions and physical environment constraints that the terminal device needs to meet to establish and maintain an effective communication link with the satellite.

[0077] In some embodiments, the method for searching for satellites further includes: in response to determining that the current satellite has passed and a quality metric of data received by the terminal device from the current satellite during the passage of the current satellite is less than or equal to a quality threshold, selecting the next satellite as the current satellite to repeat all steps in the method for searching for satellites.

[0078] It should be understood that if the terminal device determines that the current satellite has not passed by, then the target ephemeris prediction algorithm is used to continue calculating the position of the current satellite at the next moment, thereby continuing to search for the current satellite.

[0079] In some embodiments, the method for searching for satellites further includes: reducing the error threshold in response to determining that the current satellite has passed and a quality metric of data received by the terminal device from the current satellite during the passage of the current satellite is greater than a quality threshold; and selecting the next satellite as the current satellite to repeat all steps in the method for searching for satellites.

[0080] In other words, when it is determined that the current satellite has passed by, the terminal device further determines whether it is necessary to adjust the error thresholds for multiple ephemeris prediction algorithms by comparing the quality metric of the data received from the current satellite during the current satellite's pass with the quality threshold.

[0081] In some embodiments, the quality metric comprises a block error rate of data received from the current satellite.

[0082] Figure 6 FIG2 is a flow chart illustrating an exemplary method 200 for adjusting an error threshold according to some embodiments of the present disclosure. Figure 6 , the terminal device performs the following steps after searching for the current satellite:

[0083] S601, the terminal device determines whether the current satellite has passed, if so, execute S602, otherwise execute S605;

[0084] S602, the terminal device determines whether the quality metric of data received from the current satellite during the current satellite transit is less than or equal to the quality threshold. If so, execute S604; otherwise, execute S603;

[0085] S603, the terminal device reduces the error threshold, and then executes step S604;

[0086] S604, the terminal device selects the next satellite as the current satellite to repeat all steps of the satellite search method;

[0087] S602: The terminal device uses the target ephemeris prediction algorithm to continue calculating the position of the current satellite at the next moment, and returns to step S601.

[0088] Based on the above method, the terminal device continuously searches for satellites and can adjust the error threshold corresponding to the target ephemeris prediction algorithm applicable to the next satellite based on the current satellite, thereby ultimately improving the overall performance of the terminal device.

[0089] For example:

[0090] Assume that satellites are searched at preset elevation angles of 20 degrees, 40 degrees, 60 degrees, and 80 degrees, the initial error threshold is set to E_THR = 0.001, and the single adjustment unit of the error threshold E_STEP is set to 0.0001. For example, when the quality metric of the data received from the current satellite exceeds the quality threshold for the first time during the current satellite's transit, the error threshold is reduced to 0.0009, where the quality threshold BLER is set to B_THR=10 -4 .

[0091] Table 3 shows the ephemeris prediction algorithms selected for different preset elevation angles. The data in Table 3 is derived from a low-orbit satellite at an altitude of about 1000 kilometers in actual conditions. M22 represents the error metric of the J22 algorithm * 1000, M33 represents the error metric of the J33 algorithm * 1000, and M44 represents the error metric of the J44 algorithm * 1000, as shown in Table 3:

[0092] Table 3

[0093]

[0094] According to the above example of selecting the target ephemeris prediction algorithm from the J22 algorithm, the J33 algorithm, and the J44 algorithm, it can be seen that in many cases, the J22 algorithm or the J33 algorithm can be used as the target ephemeris prediction algorithm to meet the requirements. The J44 algorithm is only needed when the preset elevation angle is relatively high and the time from the initial ephemeris is relatively long (corresponding to the last row in Table 3). Therefore, most of the time, the satellite search method can effectively reduce the amount of calculation required by the terminal device to search for satellites, thereby reducing the computing power burden of the terminal device.

[0095] Figure 7 7 is a simplified block diagram of a terminal device 700 suitable for implementing an embodiment of the present disclosure. Figure 7 As shown, the terminal device 700 includes one or more processors 710 , one or more memories 720 coupled to the processor 710 , and one or more communication modules 740 coupled to the processor 710 .

[0096] The communication module 740 is used for two-way communication. The communication module 740 has at least one antenna to facilitate communication. The communication interface can represent any interface necessary for communicating with other network elements.

[0097] Processor 710 may be of any type suitable for the local technology network and may include, by way of non-limiting example, one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. Terminal device 700 may have multiple processors, such as application-specific integrated circuit chips, which are driven in time to a clock that synchronizes the master processor.

[0098] Memory 720 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM) 724, electrically programmable read-only memory (EPROM), flash memory, hard disks, compact disks (CDs), digital video disks (DVDs), and other magnetic and / or optical memories. Examples of volatile memories include, but are not limited to, random access memory (RAM) 722 and other volatile memories that do not persist during a power outage.

[0099] Computer program 730 includes computer executable instructions that are executed by associated processor 710. Program 730 may be stored in ROM 724. Processor 710 may perform any appropriate actions and processes by loading program 730 into RAM 722.

[0100] The embodiment of the present disclosure can be implemented by the program 730, so that the terminal device 700 can execute the reference Figure 1 Any process of the disclosure discussed. The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0101] In some embodiments, program 730 may be tangibly embodied in a computer-readable medium, which may be contained in terminal device 700 (e.g., memory 720) or other storage device accessible to device 700. Terminal device 700 may load program 730 from the computer-readable medium into RAM 722 for execution. Computer-readable media may include any type of tangible non-volatile memory, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc. Program 730 is stored on the computer-readable medium.

[0102] In general, various embodiments of the present disclosure may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. Certain aspects may be implemented in hardware, while other aspects may be implemented in firmware or software, which may be executed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of the present disclosure are shown and described as block diagrams, flow charts, or using some other graphical representation, it should be understood that, as non-limiting examples, the blocks, devices, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuits or logic, general-purpose hardware or a controller or other computing device, or some combination thereof.

[0103] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer executable instructions, such as instructions included in program modules, which are executed in a device on a target real or virtual processor to perform the above-mentioned reference Figure 1 Method 100 is described. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform specific tasks or implement specific abstract data types. In various embodiments, the functionality of program modules can be combined or separated between program modules as needed. Machine-executable instructions for program modules can be executed on local or distributed devices. In distributed devices, program modules can be located in local and remote storage media.

[0104] The program code for carrying out the disclosed method can be written with any combination of one or more programming languages. These program codes can be provided to the processor or controller of a general-purpose computer, a special-purpose computer or other programmable data processing equipment so that when the program code is executed by the processor or controller, the function / operation specified in the flow chart and / or the block diagram is realized. The program code can be executed fully on the machine as an independent software package, partly on the machine, partly on the machine, partly on a remote machine, partly on a remote machine, or all on a remote machine or server.

[0105] In the context of the present disclosure, computer program codes or related data may be carried by any suitable carrier to enable a device, apparatus or processor to perform various processes and operations as described above. Examples of carriers include signals, computer-readable media, etc.

[0106] A computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. Computer-readable media may include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or apparatuses, or any suitable combination of the foregoing. More specific examples of computer-readable storage media include an electrical connection having one or more wires, a portable computer floppy disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0107] In addition, although operations are described in a specific order, this should not be understood as requiring that these operations be performed in the specific order or sequence shown, or that all operations shown be performed to obtain the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the above discussion, these details should not be interpreted as limiting the scope of this disclosure, but rather as describing features specific to a particular embodiment. Some features described in the context of a separate embodiment may also be combined in a single embodiment. On the contrary, the various features described in the context of a single embodiment may also be implemented individually or in any suitable subcombination in multiple embodiments.

[0108] It should be understood that the use of personally identifiable information should be subject to privacy policies and practices generally recognized as meeting or exceeding industry or government requirements for maintaining user privacy. In particular, personally identifiable information data should be managed and processed to minimize the risk of inadvertent or unauthorized access or use, and the nature of authorized use should be clearly indicated to users.

Claims

1. A method for searching for satellites, characterized in that: The following steps are involved: Use the ephemeris prediction algorithm to estimate the time when the current satellite reaches the predetermined elevation angle; calculating an error metric for each of a plurality of ephemeris prediction algorithms, wherein the error metric is a function of a time difference between a time when the current satellite reaches the predetermined elevation angle and a reference time of initial satellite ephemeris, and the plurality of ephemeris prediction algorithms have different prediction accuracies from one another; selecting a target ephemeris prediction algorithm from the multiple ephemeris prediction algorithms based on respective error metrics of the multiple ephemeris prediction algorithms to calculate the position of the current satellite at a current moment, wherein the target ephemeris prediction algorithm is an ephemeris prediction algorithm having the lowest prediction accuracy among the ephemeris prediction algorithms that meet an error threshold among the multiple ephemeris prediction algorithms; and The current satellite is searched for based on the position of the current satellite at the current moment.

2. The method according to claim 1, wherein The selecting a target ephemeris prediction algorithm from the multiple ephemeris prediction algorithms to calculate the position of the current satellite at the current moment includes: Comparing the error metrics of the plurality of ephemeris prediction algorithms with the error threshold in order of prediction accuracy from low to high; and In response to an error metric of an ephemeris prediction algorithm among the multiple ephemeris prediction algorithms being smaller than the error threshold, the ephemeris prediction algorithm is selected as the target ephemeris prediction algorithm to calculate the position of the current satellite at the current moment.

3. The method according to claim 1, wherein The searching for the current satellite based on the position of the current satellite at the current moment includes: In response to determining that the current satellite is within the visual range of the terminal device, the antenna of the terminal device is aligned with the position of the current satellite at the current moment to search for the current satellite.

4. The method according to claim 1, wherein Also includes: In response to determining that the current satellite has passed by and a quality metric of data received by the terminal device from the current satellite during the passing by of the current satellite is less than or equal to a quality threshold, a next satellite is selected as the current satellite to repeat the steps.

5. The method according to claim 1, wherein Also includes: In response to determining that the current satellite has passed over and a quality metric of data received by a terminal device from the current satellite during the passage of the current satellite is greater than a quality threshold, reducing the error threshold; as well as The next satellite is selected as the current satellite and the steps are repeated.

6. The method according to any one of claims 1 to 5, characterized in that: For any of the multiple ephemeris prediction algorithms, the error metric satisfies: Wherein, M represents the error metric, ΔT represents the time difference between the moment when the current satellite reaches the predetermined elevation angle and the reference moment of the initial satellite ephemeris, t represents the predetermined duration, D represents the distance between the current satellite and the terminal device at the moment of the predetermined elevation angle, and E represents the distance error of the predicted distance between the satellite and the terminal device after the predetermined duration corresponding to the ephemeris prediction algorithm.

7. The method according to any one of claims 1 to 5, characterized in that The estimating the moment when the current satellite reaches a predetermined elevation angle by using an ephemeris prediction algorithm includes: An ephemeris prediction algorithm with the lowest prediction accuracy is selected from the plurality of ephemeris prediction algorithms to estimate the time when the current satellite reaches a predetermined elevation angle.

8. The method according to any one of claims 1 to 5, characterized in that: The multiple ephemeris prediction algorithms are based on the earth's gravitational field potential function taking into account the earth's non-spherical gravitational term, and the earth's gravitational field potential functions corresponding to different ephemeris prediction algorithms have different orders and degrees.

9. The method according to claim 4 or 5, characterized in that The quality metric comprises a block error rate of data received from the current satellite.

10. A device for searching for satellites, characterized in that: include: Apparatus for performing the method according to any one of claims 1 to 9.

11. A terminal device, characterized in that: include: one or more processors; as well as One or more memories coupled to the one or more processors and storing instructions thereon, which, when the instructions are executed individually or collectively by the one or more processors, cause the terminal device to execute the method according to any one of claims 1 to 9.

12. A non-transitory computer-readable storage medium storing machine-executable instructions, characterized in that: When the machine-executable instructions are executed by one or more processors of a machine, the machine is caused to perform the method of any one of claims 1-9.

13. A computer program product comprising machine-executable instructions, characterized in that When the machine-executable instructions are executed by one or more processors of a machine, the machine is caused to perform the method of any one of claims 1-9.

14. A chip, characterized in that: The method comprises a circuit system configured to perform the method of any one of claims 1-9.

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