Method and device for determining transit time of satellite

Abstract

The embodiment of the invention provides a method and device for determining the transit time of a satellite, which are used for conveniently and quickly predicting the transit time of the satellite. The method is applied to terminal equipment and comprises the steps that two lines of data of a satellite to be monitored during last transit are acquired, and the two lines of data comprise ephemeris time of the satellite to be monitored and orbit parameters of the satellite to be monitored; determining a first position and a first running speed of the to-be-monitored satellite at at least one set moment in the future according to the orbit parameters and ephemeris time of the to-be-monitored satellite; determining position information of the to-be-monitored satellite at at least one set moment in the future according to the first position and the first running speed; and determining whether the to-be-monitored satellite passes through the set ground position at each set moment or not according to a pitch angle determined by each piece of position information and the set ground position.

Description

Technical Field

[0001] The present application relates to the technical field of satellite transit time calculation, and in particular to a method and device for determining satellite transit time. Background Art

[0002] Traditional ephemeris calculation methods usually require real-time acquisition of satellite orbital parameters and other relevant data in order to make accurate orbit predictions. This may involve obtaining the latest orbital data from satellite tracking and control stations or other data sources. If the latest data cannot be obtained in a timely manner, the prediction results may become inaccurate. In addition, the prediction of satellite transit time usually requires the use of specialized astronomical equipment or reliance on online databases, which limits the convenience and flexibility of user use, and the calculation is complex and occupies a high amount of computing resources. Summary of the invention

[0003] The embodiments of the present application provide a method and device for determining a satellite transit time, so as to conveniently and quickly predict a satellite transit time.

[0004] In a first aspect, an embodiment of the present application provides a method for determining a satellite transit time, which is applied to a terminal device, and the method includes:

[0005] Determine two lines of data of the satellite to be monitored, the two lines of data including the ephemeris time of the satellite to be monitored and the orbital parameters of the satellite to be monitored;

[0006] Determine a first position and a first running speed of the satellite to be monitored at at least one set time in the future according to the orbital parameters of the satellite to be monitored and the ephemeris time;

[0007] Determine the position information of the satellite to be monitored at at least one set time in the future according to the first position and the first running speed;

[0008] According to the pitch angle determined by each position information and the set ground position, it is determined whether the satellite to be monitored passes through the set ground position at each set time.

[0009] In a possible implementation, the first position is a coordinate of an earth-centered inertial coordinate system, the position information is a coordinate of an earth-centered earth-fixed coordinate system, and determining the position information of the satellite to be monitored at at least one set time in the future according to the first position and the first running speed includes:

[0010] For each set moment, do the following:

[0011] According to the first conversion relationship between the set time, the geocentric inertial coordinate system and the geocentric earth-fixed coordinate system, the first position and the first running speed are converted to the geocentric earth-fixed coordinate system to obtain the position information of the satellite to be monitored at the set time.

[0012] In a possible implementation, determining the first position and the first running speed of the satellite to be monitored at at least one set time in the future according to the orbital parameters of the satellite to be monitored and the ephemeris time includes:

[0013] According to the second conversion relationship between the Kepler orbit and the geocentric inertial coordinate system, the orbital parameters and the ephemeris time, a first position and a first running speed of the satellite to be monitored in the geocentric inertial coordinate system at at least one set time in the future are determined.

[0014] In a possible implementation, determining, according to the second conversion relationship between the Kepler orbit and the geocentric inertial coordinate system, the orbital parameters, and the ephemeris time, a first position and a first running speed of the satellite to be monitored in the geocentric inertial coordinate system at each future set time, includes:

[0015] Determine the Kepler orbit position and Kepler velocity of the satellite to be monitored at the set time according to the orbital parameters and the ephemeris time;

[0016] Determining a second transformation relationship between the Kepler orbit and the geocentric inertial coordinate system;

[0017] According to the second conversion relationship, the Kepler orbit position and the Kepler velocity, a first position and a first running velocity of the satellite to be monitored in the geocentric inertial coordinate system are determined.

[0018] In a possible implementation, when the terminal device is online, the two lines of data are two lines of data obtained by the terminal device from the server when the satellite to be monitored last passed over the location of the terminal device;

[0019] When the terminal device is offline, the two lines of data of the satellite to be monitored are the two lines of data of the satellite to be monitored acquired from the service end before the terminal device is offline.

[0020] In a possible implementation, the method further includes:

[0021] Determine transit time window information of the satellite to be monitored according to each target set time when the satellite to be monitored passes through the set ground position, wherein the transit time window information includes at least one transit time window;

[0022] Determine a target transit time window closest to the current time, and display a transit countdown reminder on the display interface of the terminal device at a set time before the target transit time window;

[0023] When it is determined according to the transit time window information that the current moment is within a transit time window, the transit time window is displayed on the display interface of the terminal device, and a prompt is given that a satellite is transiting.

[0024] In a possible implementation, the method further includes:

[0025] At set time intervals, deleting the selected transit time window in the transit time window information of the satellite to be monitored for the set ground position from the database of the terminal device;

[0026] The selected transit time window is a transit time window whose end time is earlier than the current time corresponding to the set time interval.

[0027] In a possible implementation, the elevation angle of the satellite to be monitored satisfies the condition described in the following formula:

[0028]

[0029] The Elevation Angle is used to represent the elevation angle between the satellite to be monitored at the set time and the set ground position, and the R e It is used to represent the average radius of the earth, h is used to represent the poster height of the set ground position, and d is used to represent the distance between the set ground position and the satellite to be monitored.

[0030] In a second aspect, an embodiment of the present application provides a device for determining a satellite transit time, comprising:

[0031] An acquisition unit, used for acquiring two lines of data of the satellite to be monitored, wherein the two lines of data include the ephemeris time of the satellite to be monitored and the orbital parameters of the satellite to be monitored;

[0032] A determination unit, configured to determine a first position and a first running speed of the satellite to be monitored at at least one set time in the future according to the orbital parameters of the satellite to be monitored and the ephemeris time number;

[0033] Determine the position information of the satellite to be monitored at at least one set time in the future according to the first position and the first running speed;

[0034] When the pitch angle determined by the position information and the set position meets the set condition, the set time corresponding to the position information is determined, and the satellite to be monitored passes through the set position.

[0035] In a possible implementation, the first position is a coordinate of an earth-centered inertial coordinate system, the position information is a coordinate of an earth-centered earth-fixed coordinate system, and determining the position information of the satellite to be monitored at at least one set time in the future according to the first position and the first running speed includes:

[0036] For each set moment, do the following:

[0037] According to the first conversion relationship between the set time, the geocentric inertial coordinate system and the geocentric earth-fixed coordinate system, the first position and the first running speed are converted to the geocentric earth-fixed coordinate system to obtain the position information of the satellite to be monitored at the set time.

[0038] In a possible implementation, the determining unit, when determining the first position and the first running speed of the satellite to be monitored at at least one set time in the future according to the orbital parameters of the satellite to be monitored and the ephemeris time, is specifically used to:

[0039] According to the second conversion relationship between the Kepler orbit and the geocentric inertial coordinate system, the orbital parameters and the ephemeris time, a first position and a first running speed of the satellite to be monitored in the geocentric inertial coordinate system at at least one set time in the future are determined.

[0040] In a possible implementation, the determining unit, when determining the first position and the first running speed of the satellite to be monitored in the geocentric inertial coordinate system at at least one set time in the future according to the second conversion relationship between the Kepler orbit and the geocentric inertial coordinate system, the orbital parameter, and the ephemeris time, is specifically used to:

[0041] Determine the Kepler orbit position and Kepler velocity of the satellite to be monitored at the set time according to the orbital parameters and the ephemeris time;

[0042] Determining a second transformation relationship between the Kepler orbit and the geocentric inertial coordinate system;

[0043] According to the second conversion relationship, the Kepler orbit position and the Kepler velocity, a first position and a first running velocity of the satellite to be monitored in the geocentric inertial coordinate system are determined.

[0044] In a possible implementation, when the terminal device is online, the two lines of data are two lines of data obtained by the terminal device from the server when the satellite to be monitored last passed over the location of the terminal device;

[0045] When the terminal device is offline, the two lines of data of the satellite to be monitored are the two lines of data of the satellite to be monitored acquired from the service end before the terminal device is offline.

[0046] In a possible implementation manner, the determining unit is further configured to:

[0047] Determine transit time window information of the satellite to be monitored according to each target set time when the satellite to be monitored passes through the set ground position, wherein the transit time window information includes at least one transit time window;

[0048] Determine a target transit time window closest to the current time, and display a transit countdown reminder on the display interface of the terminal device at a set time before the target transit time window;

[0049] When it is determined according to the transit time window information that the current moment is within a transit time window, the transit time window is displayed on the display interface of the terminal device, and a prompt is given that a satellite is transiting.

[0050] In a possible implementation manner, the determining unit is further configured to:

[0051] At set time intervals, deleting the selected transit time window in the transit time window information of the satellite to be monitored for the set ground position from the database of the terminal device;

[0052] The selected transit time window is a transit time window whose end time is earlier than the current time corresponding to the set time interval.

[0053] In a possible implementation, the elevation angle of the satellite to be monitored satisfies the condition described in the following formula:

[0054]

[0055] The Elevation Angle is used to represent the elevation angle between the satellite to be monitored at the set time and the set ground position, and the R e It is used to represent the average radius of the earth, h is used to represent the poster height of the set ground position, and d is used to represent the distance between the set ground position and the satellite to be monitored.

[0056] In a third aspect, an embodiment of the present application provides an execution device, including:

[0057] A memory for storing program instructions;

[0058] The processor is used to obtain the program instructions in the memory and execute the method described in the first aspect and different implementation methods of the first aspect according to the obtained program instructions.

[0059] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium includes computer instructions. When the computer instructions are executed by the computer, the method described in the first aspect and different implementation methods of the first aspect are implemented.

[0060] The beneficial effects of this application are as follows:

[0061] In an embodiment of the present application, the terminal device requests the server to obtain the latest two lines of data each time a satellite passes by, and then saves the two lines of data. When it is necessary to determine the satellite transit time, the satellite transit time can be calculated by obtaining the two lines of data of the satellite saved by the terminal device and setting the position information. The present application does not need to obtain satellite orbit parameters in real time, but only needs to obtain two lines of data when the satellite passed by last, and the satellite transit time can be inferred based on the two lines of data and the position information. The calculation method is simple and easy to implement.

[0062] Other features and advantages of the present application will be described in the subsequent description, and partly become apparent from the description, or be understood by practicing the present application. The purpose and other advantages of the present application can be realized and obtained by the structures specifically pointed out in the written description, claims, and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0064] Figure 1 A schematic diagram of a technical framework provided for an embodiment of the present application;

[0065] Figure 2 A flow chart of a method for determining a satellite transit time provided in an embodiment of the present application;

[0066] Figure 3 A flow chart for determining a transit time window provided in an embodiment of the present application;

[0067] Figure 4 A schematic diagram of a device for determining a satellite transit time provided in an embodiment of the present application;

[0068] Figure 5A structural diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0069] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0070] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0071] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0072] Ephemeris calculation is a key part of satellite orbit prediction and position information calculation. It has important applications in satellite navigation, communication, remote sensing and other fields. Existing ephemeris calculation technologies include the following solutions:

[0073] Two-Line Element Sets (TLE): TLE is a widely used satellite orbit data format. TLE data contains information such as the satellite's orbital parameters, launch date, and the satellite's predicted position and velocity in the future. Traditional TLE ephemeris calculation methods mainly use mathematical models such as SGP4 (Simplified General Perturbations 4) and SDP4 (Simplified Deep-space Perturbations 4) to calculate and predict satellite orbits.

[0074] Numerical integration method: The numerical integration method numerically calculates the differential equation of the satellite orbit to simulate the movement of the satellite under various external disturbances. This method can more accurately describe the changes in satellite orbits, but requires greater computing resources and time, and is suitable for high-precision satellite orbit prediction.

[0075] Dynamic model: The dynamic model is based on Newtonian mechanics and the law of gravity. It takes into account factors such as the earth's gravity, atmospheric disturbances, and the earth's rotation, and solves the satellite's orbital motion through differential equations. This method is suitable for orbit prediction over a long period of time, but there may be certain limitations in real time.

[0076] Kalman filter: Kalman filter is a mathematical method for state estimation, which can be used to estimate the orbit state of a satellite by fusing multiple observation data (such as GPS, star sensors, etc.). It can achieve orbit estimation and prediction with good real-time performance.

[0077] Particle filter: Particle filter is a nonlinear filtering technology based on the Monte Carlo method, which can be used for satellite orbit estimation and prediction. It can handle nonlinear and non-Gaussian systems and is suitable for complex satellite orbit calculation scenarios.

[0078] However, the prediction of satellite transit time based on the above methods usually requires the use of specialized equipment or reliance on online databases, which consumes a lot of computing resources and has the following limitations:

[0079] High computational resource requirements: Some traditional methods (such as numerical integration methods) may require a lot of computing resources and time, especially in real-time environments, which may cause delays and performance issues.

[0080] Requires specialized equipment and is complex to use: Usually, professional astronomical equipment or complex navigation equipment is required to predict satellite transit times, which limits the convenience and flexibility of users. Operating existing equipment or databases requires certain expertise, and ordinary users may find it difficult to easily predict satellite transit times.

[0081] Reliance on real-time data sources: Traditional ephemeris calculation methods usually require real-time acquisition of satellite orbit parameters and other related data in order to make accurate orbit predictions. This may involve obtaining the latest orbit data from satellite tracking and control stations or other data sources. If the latest data cannot be obtained in a timely manner, the prediction results may become inaccurate.

[0082] Based on the above problems, an embodiment of the present application provides a method and device for determining the transit time of a satellite, wherein the terminal device obtains two lines of data from the server when the satellite last transited and saves them. When determining the transit time of a satellite for a set ground position, the transit time can be predicted based on the two lines of saved data and the set ground position. In this application, the satellite transit time can be calculated offline by the terminal device without relying on external services and data sources. Users can use ordinary mobile devices to make predictions at any time without the need for special equipment, which is simple and easy to use.

[0083] In order to better understand the solution proposed in this application, the technical framework of the method for determining the satellite transit time involved in this application is briefly introduced below.

[0084] like Figure 1 As shown, the technical framework of this application is mainly composed of data acquisition and storage, transit time prediction, satellite coverage, resource optimization, user interface and notification, and cache management.

[0085] Data acquisition and storage: This application proposes a method for determining satellite transit time, which can be integrated into a mobile application. The TLE management server sends two lines of data from the satellite to the constellation, obtains two lines of data from the satellite from the constellation, and saves them in the local storage of the mobile application (TLE database) for subsequent satellite transit time prediction calculations. The data acquisition and storage module is responsible for communicating with the server, obtaining two lines of data from the satellite, and then saving the data in the local storage.

[0086] Transit time prediction: Satellite transit time prediction is the core function of this application. When the satellite is offline, the user can predict the transit time by inputting or obtaining the current GPS position and using the two lines of satellite data saved. The transit time prediction module uses mathematical models and algorithms such as SGP4, combined with the satellite's orbital parameters and GPS position, to calculate the satellite's transit time in the area where the GPS position is located.

[0087] Satellite coverage: The coverage judgment module in the system will determine whether the mobile terminal is within the coverage of the satellite based on the satellite's orbital parameters and the current GPS position. If it is not within the coverage, a floating window will be displayed to count down the satellite transit time.

[0088] Resource optimization: In order to improve application performance and user experience, the terminal device uses a resource optimization module to balance the accuracy of calculation results and the consumption of computing resources. The resource optimization module can select appropriate calculation strategies, numerical methods, and calculation accuracy according to application requirements. This ensures that the calculation time and resource overhead are reduced while maintaining the accuracy of the calculation results.

[0089] User Interface and Notification: The user interface module provides an intuitive and user-friendly interface that allows users to manually enter or automatically obtain GPS positions. Users can view the predicted results of satellite transit times and coverage prompts through the interface. The system can also set a system alarm through the notification module to remind users of satellite transit times.

[0090] Cache management: To improve the response speed of the application, the cache management module can save the previous transit time prediction results. When the satellite transit time at the same location is queried again, the cache can be checked first. If there is cached data, it will be provided to the user directly, thus avoiding repeated calculations.

[0091] refer to Figure 2 As shown, Figure 2 The flowchart of a method for determining a satellite transit time provided by the present application is exemplarily shown. The method can be executed by a terminal device, and specifically can be executed by a processor in the terminal device. The method flow is specifically as follows:

[0092] 201, obtain two lines of data of the satellite to be monitored.

[0093] In some embodiments, the two lines of data include the ephemeris time of the satellite to be monitored and the orbital parameters of the satellite to be monitored. When the satellite passes by the location of the terminal device, the terminal device can request the server to obtain the latest two lines of data when the satellite passes by, and save them in the local database.

[0094] In some scenarios, when the terminal device is online, the two lines of data are obtained from the server when the terminal device last passed the location of the monitored satellite. When the terminal device is offline, the two lines of data of the monitored satellite are obtained from the server before the terminal device goes offline.

[0095] 202 , determining a first position and a first running speed of the satellite to be monitored at at least one set time in the future according to the orbital parameters and ephemeris time of the satellite to be monitored.

[0096] In some embodiments, the first position and first running speed of the satellite to be monitored in the geocentric inertial coordinate system at each future set time can be determined based on the second conversion relationship between the Kepler orbit and the geocentric inertial coordinate system, orbital parameters and ephemeris time.

[0097] 203 : Determine position information of the satellite to be monitored at at least one set time in the future according to the first position and the first running speed.

[0098] The position information is the coordinates of the earth-centered earth-fixed coordinate system. When determining the position information of the satellite to be monitored at at least one set time in the future, it can be specifically implemented in the following manner: for each set time, perform the following operations: according to the first conversion relationship between the set time, the earth-centered inertial coordinate system and the earth-centered earth-fixed coordinate system, convert the first position and the first running speed to the earth-centered earth-fixed coordinate system to obtain the position information of the satellite to be monitored at the set time.

[0099] 204 , determining whether the satellite to be monitored passes through the set ground position at each set time according to the pitch angle determined by each position information and the set ground position.

[0100] In some embodiments, for each set time, the elevation angle of the satellite to be monitored satisfies the condition described in the following formula:

[0101]

[0102] Elevation Angle is used to indicate the elevation angle between the satellite to be monitored at the set time and the set ground position. e It is used to represent the average radius of the earth, h is used to represent the poster height of the set ground position, and d is used to represent the distance between the set ground position and the satellite to be monitored.

[0103] As an example, the first position and the first running speed of the satellite to be monitored in the geocentric inertial coordinate system can be determined in the following manner:

[0104] The orbital parameters of the satellite to be monitored include the major semi-axis, eccentricity, inclination, right ascension of the ascending node, argument of perigee, and mean anomaly, which can be represented by a, e, i, ω, Ω, and M, respectively. In the present application, when determining the first position and the first running speed, it can be achieved by an instantaneous root orbit calculation algorithm. Specifically, the Kepler orbital position and Kepler velocity of the satellite to be monitored at a set time are determined according to the orbital parameters and the ephemeris time. Further, the second conversion relationship between the Kepler orbit and the geocentric inertial coordinate system can be determined, and the first position and first running speed of the satellite to be monitored in the geocentric inertial coordinate system can be determined according to the second conversion relationship, the Kepler orbital position and the Kepler velocity. Among them, the geocentric inertial coordinate system can also be referred to as an ECI orbit.

[0105] The specific algorithm is as follows:

[0106] Step 1: Calculate the average angular velocity of the track, which satisfies the following formula:

[0107]

[0108] Here, n is used to represent the average angular velocity of the orbit, and μ is used to represent the Kepler constant.

[0109] Step 2: Calculate the mean anomaly, eccentric anomaly and true anomaly respectively using orbital parameters:

[0110] M = n(t-t0);

[0111] E = M + esin (E);

[0112]

[0113] Among them, M, E, and θ are used to represent the mean anomaly, eccentric anomaly, and true anomaly, respectively; t is used to represent the set time in the future; and t0 is used to represent the ephemeris time.

[0114] Step 3: Calculate the Keplerian orbit position vector using eccentricity, inclination, and true anomaly

[0115]

[0116] Step 4: Determine the Keplerian orbit velocity vector from the eccentricity, inclination, true anomaly, and Kepler constants

[0117]

[0118] Step 5: Determine the rotation matrix from Keplerian orbit to ECI orbit:

[0119]

[0120]

[0121]

[0122] Among them, R3(Ω) is used to represent the rotation matrix of the perigee argument, R1(i) is used to represent the rotation matrix of the orbital inclination, and R3(ω) is used to represent the rotation matrix of the ascending node right ascension.

[0123] Based on the above three rotation parameters, determine the conversion matrix from ECI orbit to Kepler orbit:

[0124]

[0125]

[0126] Furthermore, the Kepler orbit to ECI orbit rotation matrix is:

[0127]

[0128]

[0129] Step 6: According to the Kepler orbit to ECI orbit rotation matrix, rotate the position vector to the ECI orbit to obtain the satellite position under the ECI orbit:

[0130]

[0131] Step 7: According to the Kepler orbit to ECI orbit rotation matrix, the velocity vector is rotated to the ECI orbit to obtain the satellite velocity under the ECI orbit:

[0132]

[0133] In some scenarios, when determining the location information at a set time in the future, it can be implemented through the following algorithm:

[0134] Step 1: Determine the set time, the first position and the first running speed, which can be obtained by t, {r} X and {v} X express.

[0135] Step 2: Generate the rotation matrix around the x, y, and z axes:

[0136]

[0137]

[0138]

[0139] Step 3: Calculate the corrections for precession, nutation, Earth rotation, and polar motion.

[0140] P=R z (-z A )R y (θ A )R z (-ξ A );

[0141] Where P is used to represent the precession correction, z A ,θ A ,ξ A These are all empirical parameters.

[0142] In some embodiments, the nutation correction satisfies the condition shown in the following formula:

[0143] N=R x (-ε-Δε)R z (-Δψ)R x (ε);

[0144] ε=A1”-A2”T-A3”T 2 +A4”T 3 ;

[0145] Among them, T can be determined by the Julian day parameters, T is used to represent the time difference between time t and J2000.0, and A1, A2, A3, and A4 are all set parameters.

[0146]

[0147] Among them, A 0j , A 1j , B 0j , B 1j Used to represent the nutation coefficient in the IAU200B model, which can be obtained empirically.

[0148] In some embodiments, the earth rotation correction satisfies the following formula:

[0149] E=R z (GMST);

[0150] Among them, GMST is used to represent Greenwich mean sidereal time.

[0151] In some embodiments, the polar motion correction satisfies the following formula:

[0152] M=R y (-x p )R x (-y p ).

[0153] Among them, x p ,y p They are used to represent the polar shift parameters, where x p The polar shift parameter used to represent the longitude direction, y p The polar shift parameter used to represent the latitude direction.

[0154] Furthermore, the first transformation relationship between the Earth-centered inertial coordinate system and the Earth-centered Earth-fixed coordinate system can be expressed as MENP. Furthermore, the position information in the Earth-centered Earth-fixed coordinate system is: x =MENP{r} X ; The second running speed in the Earth-centered Earth-fixed coordinate system is: {v} x =MENP{v} X .

[0155] In some embodiments, the transit time window information of the satellite to be monitored can be determined according to each target setting time of the satellite to be monitored in the set ground position transit, wherein the transit time window information includes at least one transit time window. Further, determine the target transit time window closest to the current moment, and perform a transit countdown reminder on the display interface of the terminal device at the setting time before the target transit time window. For example, the current moment is 13:00:00, if the first transit time window is 13:00:51-13:01:00 in the transit time window information, then the window is used as the target window, and the transit countdown reminder is performed on the display interface of the terminal device at the setting time before the target transit time window. As an example, it can be reminded 10 seconds before the start time of the transit time window, that is to say, the countdown reminder starts at 13:00:41, and of course it can also be set to other setting times, and this application is not specifically limited to this. In other scenarios, when it is determined that the current time is within the first transit time window according to the transit time window information, the first transit time window is displayed on the display interface of the terminal device, and a prompt indicating that the satellite is passing. For example, if the current time is 13:00:55 and the first transit time window is 13:00:55-13:01:00, the display interface of the terminal device indicates that the satellite is passing.

[0156] In a possible implementation, the satellite's ephemeris time can be obtained from two lines of satellite data, the two lines of data are put into the SGP4 calculation model, and the time range for calculating the orbit is converted to a time range with the ephemeris time as the coordinate origin. If the whole second output is required, the orbit time to be calculated, except for the first time point, the remaining time points are moved to the whole second time points. If the whole point output is not required, the time point taken each time is the time range within which the satellite orbit position is obtained by moving the point at the whole second interval. For example: if the ephemeris time is 2020-09-12 13:32:43.017, the step size is 10 seconds, and the starting time of the satellite orbit trajectory to be calculated is 2020-09-12 13:32:40.045, if the whole second is output, the time of the first orbit point obtained is 2020-09-12 13:32:40.045, the time of the second orbit point is 2020-09-12 13:32:51.000, the time of the third orbit point is 2020-09-12 13:33:01.000, and so on. If the whole second output is not performed, the time of the first orbital point obtained is 2020-09-12 13:32:40.045, the time of the second orbital point is 2020-09-12 13:32:50.045, the time of the third orbital point is 2020-09-12 13:33:00.045, and so on. After determining the time point of each acquisition of the satellite's trajectory, the offset between the time point and the ephemeris time in the two rows of data can be passed to the SGP4 calculation model, which will automatically calculate the orbital position and velocity of the satellite at that time point. Furthermore, the next set moment in the future can be determined according to the step size, and then the orbital position and velocity of the satellite corresponding to the next set moment can be determined.

[0157] In some embodiments, after determining the first position (track point) of the satellite to be monitored at each preset time in the future, the track points may be traversed to determine the transit time window of the satellite to be monitored.

[0158] As an example, when determining the transit time window, the specific process is as follows: Figure 3 As shown, the details are as follows:

[0159] 301, obtaining the trajectory point of the satellite to be monitored at the current set time.

[0160] 302, determine the location information of the trajectory point at the current moment.

[0161] 303, determining a pitch angle according to the position information and a set ground position.

[0162] 304 , determining whether the pitch angle satisfies the constraint condition.

[0163] For example, if the pitch angle satisfies the constraint condition, execute 305 , otherwise execute 311 .

[0164] 305 , determining whether the current set time satisfies the start condition of the transit time window.

[0165] The starting condition of the transit time window is that the previous moment of the current set moment is not a transit time.

[0166] Exemplarily, if satisfied, execute step 306 , otherwise execute step 307 .

[0167] 306 , using the current set time and pitch angle as the start time and start pitch angle of the transit time window.

[0168] 307, record the pitch angle at the current set time.

[0169] 308, determining whether the transit time window is complete.

[0170] If complete, execute step 309 , otherwise execute step 310 .

[0171] 309, returning the transit time window and the pitch angle corresponding to each set time in the transit time window.

[0172] 310, obtaining the trajectory point at the next set time.

[0173] After obtaining the trajectory point at the next set time, step 302 may be executed.

[0174] 311, determine whether the current set time satisfies the end condition of the transit time window.

[0175] The end condition of the transit time window is that the previous set time before the current set time is the transit time.

[0176] If so, execute step 312 ; otherwise, execute step 308 .

[0177] 312, taking the current set time and pitch angle as the end time and end pitch angle of the transit time window.

[0178] As an example, the pitch angle is taken as the angle between the line connecting the set ground position and position information and the projection of the line on the ground. Assume that the ephemeris time of the last satellite transit is 05:30:01, and the trajectory point of the satellite to be monitored is calculated once every set time interval. The following takes the time interval of 1 second as an example. If the monitoring time window is 13:00:00-14:00:00, the constraint condition is greater than or equal to 45 degrees. For example, the current set time is 13:00:50, obtain the satellite trajectory point of 13:00:50, and calculate the pitch angle. When it is determined that the pitch angle is less than 45 degrees, 13:00:49 is not the transit time and there is no transit time window, obtain the satellite trajectory point of 13:00:51, and calculate the pitch angle. When it is determined that the pitch angle is equal to 45 degrees, since 13:00:50 is not the transit time, it is determined that 13:00:51 is the start time of the transit time window, and the current pitch angle is recorded as the starting pitch angle. Similarly, the next moment is obtained and the above steps are performed. When it is determined that the pitch angle corresponding to the trajectory point at 13:01:00 is greater than 45 degrees, since 13:00:59 is the transit time, 13:01:00 is determined to be the end time of the transit time window, and the current pitch angle is recorded as the end pitch angle. Therefore, within this monitoring time window, 13:00:51-13:01:00 is the satellite's transit time window.

[0179] In some embodiments, if the transit time window is 13:00:51-13:01:00 and the monitoring time window is 12:30:00-13:00:55, then the transit time window in the monitoring time window is 13:00:51-13:00:55. Similarly, if the monitoring time window is 13:00:55-13:30:55, then the transit time window in the monitoring time window is 13:00:55-13:01:00.

[0180] In some embodiments, the monitoring time window may be set to a longer or shorter time, which is not specifically limited in this application.

[0181] In some embodiments, before obtaining two lines of data of the satellite to be monitored, it is determined that there is no transit time window information of the satellite to be monitored for the set ground position in the database of the terminal device. That is to say, in the present application, before obtaining two lines of data of the satellite to be monitored, it is necessary to determine whether there is transit time window information of the satellite to be monitored for the set ground position in the database of the terminal device. If not, then obtain the two lines of data of the satellite to be monitored and calculate. If there is transit time window information of the satellite to be monitored for the set ground position in the database of the terminal device, determine whether there is a target transit time window. At this point, there is no need to obtain the two lines of data of the satellite to be monitored, and the target transit time window is directly determined from the transit time window information, which saves the computing resources of the terminal device. Wherein, the target transit time window is the transit time window at the current moment, or the transit time window after the current moment.

[0182] Specifically, when the terminal device database contains transit time window information of the satellite to be monitored for the set ground position, it can be determined whether there is a target transit time window in the transit time window information according to the current time. Further, when it is determined that there is a target transit time window, the target transit time window is displayed on the display interface of the terminal device.

[0183] As an example, when there is transit time window information for a set ground position in the database of the terminal device, if the current time is 2020-09-12 13:33:00, and the transit time window information includes a transit time window with a transit time of 2020-09-12 13:40:00 to 2020-09-12 13:40:10, the transit time window is displayed on the display interface of the terminal device. In some scenarios, if the current time is 2020-09-12 13:33:00, and the transit time window information includes a transit time window with a transit time of 2020-09-12 13:32:55 to 2020-09-12 13:33:05, it is determined that the current time is within the transit time window, and the transit time window is displayed on the display interface of the terminal device, and a prompt is given that the satellite is transiting.

[0184] In some embodiments, when calculating the transit time window of the satellite to be monitored, the monitoring window duration can be set arbitrarily. For example, the monitoring window duration can be set within the next 10 hours, or it can be set to a monitoring window duration of 1 day, 2 days or 3 days, and the present application does not specifically limit this. After determining the transit time window information, the transit time window information can be stored in a database. In addition, at a set time interval, the selected transit time window in the transit time window information of the satellite to be monitored for the set ground position in the data of the terminal device is deleted. Among them, the selected transit time window is the transit time window whose end time is earlier than the transit time window at the corresponding moment.

[0185] As an example, after the terminal device calculates the transit time window information with a monitoring window duration of two days at 2020-09-12 13:33:00, the transit time window information is saved in the database of the terminal device. Furthermore, taking the setting time interval as 12 hours as an example, the transit time window in the database with an end time earlier than 2020-09-13 01:33:00 is deleted to free up the memory of the terminal device. Of course, the setting time interval can also be set to a shorter or longer duration, and this application does not specifically limit this.

[0186] Based on the same technical concept, such as Figure 4 As shown, the embodiment of the present application provides a device 400 for determining a satellite transit time. The device 400 can perform any step in the above-mentioned method for determining a satellite transit time, and will not be described again to avoid repetition. The device 400 includes an acquisition unit 401 and a determination unit 402.

[0187] An acquisition unit 401 is used to acquire two lines of data of the satellite to be monitored, wherein the two lines of data include the ephemeris time of the satellite to be monitored and the orbital parameters of the satellite to be monitored;

[0188] A determination unit 402 is used to determine a first position and a first running speed of the satellite to be monitored at at least one set time in the future according to the orbital parameters of the satellite to be monitored and the ephemeris time number;

[0189] Determine the position information of the satellite to be monitored at at least one set time in the future according to the first position and the first running speed;

[0190] When the pitch angle determined by the position information and the set position meets the set condition, the set time corresponding to the position information is determined, and the satellite to be monitored passes through the set position.

[0191] In a possible implementation, the first position is a coordinate of an earth-centered inertial coordinate system, the position information is a coordinate of an earth-centered earth-fixed coordinate system, and determining the position information of the satellite to be monitored at at least one set time in the future according to the first position and the first running speed includes:

[0192] For each set moment, do the following:

[0193] According to the first conversion relationship between the set time, the geocentric inertial coordinate system and the geocentric earth-fixed coordinate system, the first position and the first running speed are converted to the geocentric earth-fixed coordinate system to obtain the position information of the satellite to be monitored at the set time.

[0194] In a possible implementation, the determining unit 402, when determining the first position and the first running speed of the satellite to be monitored at at least one set time in the future according to the orbital parameters of the satellite to be monitored and the ephemeris time, is specifically configured to:

[0195] According to the second conversion relationship between the Kepler orbit and the geocentric inertial coordinate system, the orbital parameters and the ephemeris time, a first position and a first running speed of the satellite to be monitored in the geocentric inertial coordinate system at at least one set time in the future are determined.

[0196] In a possible implementation, the determining unit 402, when determining, according to the second conversion relationship between the Kepler orbit and the geocentric inertial coordinate system, the orbital parameter, and the ephemeris time, the first position and the first running speed of the satellite to be monitored in the geocentric inertial coordinate system at at least one set time in the future, is specifically configured to:

[0197] Determine the Kepler orbit position and Kepler velocity of the satellite to be monitored at the set time according to the orbital parameters and the ephemeris time;

[0198] Determining a second transformation relationship between the Kepler orbit and the geocentric inertial coordinate system;

[0199] According to the second conversion relationship, the Kepler orbit position and the Kepler velocity, a first position and a first running velocity of the satellite to be monitored in the geocentric inertial coordinate system are determined.

[0200] In a possible implementation, when the terminal device is online, the two lines of data are two lines of data obtained by the terminal device from the server when the satellite to be monitored last passed over the location of the terminal device;

[0201] When the terminal device is offline, the two lines of data of the satellite to be monitored are the two lines of data of the satellite to be monitored acquired from the service end before the terminal device is offline.

[0202] In a possible implementation manner, the determining unit 402 is further configured to:

[0203] Determine transit time window information of the satellite to be monitored according to each target set time when the satellite to be monitored passes through the set ground position, wherein the transit time window information includes at least one transit time window;

[0204] Determine a target transit time window closest to the current time, and display a transit countdown reminder on the display interface of the terminal device at a set time before the target transit time window;

[0205] When it is determined according to the transit time window information that the current moment is within a transit time window, the transit time window is displayed on the display interface of the terminal device, and a prompt is given that a satellite is transiting.

[0206] In a possible implementation, the determining unit 402 is further configured to: delete, at a set time interval, the selected transit time window in the transit time window information of the satellite to be monitored for the set ground position from a database of the terminal device;

[0207] The selected transit time window is a transit time window whose end time is earlier than the transit time window at the current time corresponding to the set time interval.

[0208] In a possible implementation, the elevation angle of the satellite to be monitored satisfies the condition described in the following formula:

[0209]

[0210] The Elevation Angle is used to represent the elevation angle between the satellite to be monitored at the set time and the set ground position, and the R e It is used to represent the average radius of the earth, h is used to represent the poster height of the set ground position, and d is used to represent the distance between the set ground position and the satellite to be monitored.

[0211] Based on the same technical concept, see Figure 5 As shown, an embodiment of the present application provides an electronic device 500, which can perform any step in the above-mentioned method for determining the satellite transit time. To avoid repetition, it is not repeated here. The device 500 includes a memory 501 and a processor 502.

[0212] The memory 501 is used to store program instructions;

[0213] The processor 502 is used to call the program instructions stored in the memory and execute the various steps of the above-mentioned method for determining the satellite transit time according to the obtained program.

[0214] In the embodiment of the present application, the processor 502 may be a general-purpose processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, or a discrete hardware component, and may implement or execute the methods, steps, and logic block diagrams disclosed in the embodiment of the present application. The general-purpose processor may be a microprocessor or any conventional processor, etc. The steps of the method disclosed in the embodiment of the present application may be directly embodied as being executed by a hardware processor, or may be executed by a combination of hardware and software modules in the processor.

[0215] Memory 501, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer executable programs and modules. Memory 501 may include at least one type of storage medium, such as flash memory, hard disk, multimedia card, card-type memory, random access memory (Random Access Memory, RAM), static random access memory (Static Random Access Memory, SRAM), programmable read-only memory (Programmable Read Only Memory, PROM), read-only memory (Read Only Memory, ROM), electrically erasable programmable read-only memory (Electrically Erasable Programmable Read-Only Memory, EEPROM), magnetic storage, disk, optical disk, etc. Memory 501 is any other medium that can be used to carry or store a desired program code in the form of an instruction or data structure and can be accessed by a computer, but is not limited thereto. The memory 501 in the embodiment of the present application can also be a circuit or any other device that can realize a storage function, for storing program instructions and / or data.

[0216] Based on the same technical concept, an embodiment of the present application provides a computer-readable storage medium, which stores computer instructions. When the computer instructions are executed on a computer, the computer executes each step of the above-mentioned method for determining the satellite transit time.

[0217] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0218] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0219] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0220] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0221] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A method for determining a satellite transit time, characterized in that: Applied to terminal equipment, including: Acquire two lines of data of the satellite to be monitored, the two lines of data including the ephemeris time of the satellite to be monitored and the orbital parameters of the satellite to be monitored; Determine a first position and a first running speed of the satellite to be monitored at at least one set time in the future according to the orbital parameters of the satellite to be monitored and the ephemeris time; Determine the position information of the satellite to be monitored at at least one set time in the future according to the first position and the first running speed; According to the pitch angle determined by each position information and the set ground position, it is determined whether the satellite to be monitored passes through the set ground position at each set time.

2. The method according to claim 1, characterized in that The first position is a coordinate of an earth-centered inertial coordinate system, the position information is a coordinate of an earth-centered earth-fixed coordinate system, and determining the position information of the satellite to be monitored at at least one set time in the future according to the first position and the first running speed includes: For each set moment, do the following: According to the first conversion relationship between the set time, the geocentric inertial coordinate system and the geocentric earth-fixed coordinate system, the first position and the first running speed are converted to the geocentric earth-fixed coordinate system to obtain the position information of the satellite to be monitored at the set time.

3. The method according to claim 1, characterized in that The step of determining a first position and a first running speed of the satellite to be monitored at at least one set time in the future according to the orbital parameters of the satellite to be monitored and the ephemeris time comprises: According to the second conversion relationship between the Kepler orbit and the geocentric inertial coordinate system, the orbital parameters and the ephemeris time, a first position and a first running speed of the satellite to be monitored in the geocentric inertial coordinate system at at least one set time in the future are determined.

4. The method according to claim 3, characterized in that The determining, according to the second conversion relationship between the Kepler orbit and the geocentric inertial coordinate system, the orbital parameters and the ephemeris time, a first position and a first running speed of the satellite to be monitored in the geocentric inertial coordinate system at each future set time, comprises: Determine the Kepler orbit position and Kepler velocity of the satellite to be monitored at the set time according to the orbital parameters and the ephemeris time; Determining a second transformation relationship between the Kepler orbit and the geocentric inertial coordinate system; According to the second conversion relationship, the Kepler orbit position and the Kepler velocity, a first position and a first running velocity of the satellite to be monitored in the geocentric inertial coordinate system are determined.

5. The method according to claim 1, characterized in that When the terminal device is online, the two lines of data are two lines of data obtained by the terminal device from the server when the satellite to be monitored last passed over the location of the terminal device; When the terminal device is offline, the two lines of data of the satellite to be monitored are the two lines of data of the satellite to be monitored acquired from the service end before the terminal device is offline.

6. The method according to claim 1, characterized in that The method further comprises: Determine transit time window information of the satellite to be monitored according to each target set time when the satellite to be monitored passes through the set ground position, wherein the transit time window information includes at least one transit time window; Determine a target transit time window closest to the current time, and display a transit countdown reminder on the display interface of the terminal device at a set time before the target transit time window; When it is determined according to the transit time window information that the current time is within the first transit time window, the first transit time window is displayed on the display interface of the terminal device, and a prompt is given that the satellite is transiting.

7. The method according to claim 6, characterized in that The method further comprises: At set time intervals, deleting the selected transit time window in the transit time window information of the satellite to be monitored for the set ground position from the database of the terminal device; The selected transit time window is a transit time window whose end time is earlier than the current time corresponding to the set time interval.

8. The method according to any one of claims 1 to 7, characterized in that: The satellite pitch angle to be monitored satisfies the following formula: The Elevation Angle is used to represent the elevation angle between the satellite to be monitored at the set time and the set ground position, and the R e It is used to represent the average radius of the earth, h is used to represent the poster height of the set ground position, and d is used to represent the distance between the set ground position and the satellite to be monitored.

9. A device for determining satellite transit time, characterized in that: include: An acquisition unit, used for acquiring two lines of data of the satellite to be monitored, wherein the two lines of data include the ephemeris time of the satellite to be monitored and the orbital parameters of the satellite to be monitored; A determination unit, configured to determine a first position and a first running speed of the satellite to be monitored at at least one set time in the future according to the orbital parameters of the satellite to be monitored and the ephemeris time; Determine the position information of the satellite to be monitored at at least one set time in the future according to the first position and the first running speed; When the pitch angle determined by the position information and the set position meets the set condition, the set time corresponding to the position information is determined, and the satellite to be monitored passes through the set position.

10. An execution device, characterized in that: include: A memory for storing program instructions; A processor is used to obtain program instructions in the memory and execute the method according to any one of claims 1 to 8 according to the obtained program instructions.

11. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes computer instructions, and when the computer instructions are executed by a computer, the method according to any one of claims 1 to 8 is implemented.

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