Method and system for calculating in-orbit autonomous ground guiding angle of rotary table

Abstract

The invention discloses a method and a system for calculating an on-orbit autonomous ground guide angle of a rotary table, and belongs to the technical field of test and measurement. The calculation method comprises the following steps: acquiring position information of a target, and converting the position information into a target ECI position coordinate; the satellite orbit element at the moment of 0 is obtained, and the satellite ECI position coordinates are calculated based on the satellite orbit element at the moment of 0; acquiring an installation matrix and a rotation matrix of an observation load on a satellite; converting the target ECI position coordinate and the satellite ECI position coordinate into an observation coordinate system on the satellite based on the installation matrix and the rotation matrix, and calculating to obtain an observation vector; and calculating an azimuth angle and a pitch angle of the observation vector, and taking the azimuth angle and the pitch angle as an in-orbit autonomous ground guide angle of the rotary table. According to the method, the calculation and execution period is remarkably shortened, the whole process is compressed to be within 30 minutes, and the real-time performance and the response speed are greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of testing and measurement, and relates to a method and system for calculating the autonomous on-orbit ground guidance angle of a turntable. Background Art

[0002] In the current field of aerospace technology, the turntable is an important observation and communication equipment carrier on the aircraft. Its accurate ground pointing capability is crucial to achieving efficient earth observation, communication and data transmission tasks. However, the traditional turntable on-orbit ground pointing angle calculation method has many shortcomings, which limits its performance in practical applications.

[0003] In the prior art, the calculation of the turntable's on-orbit pointing angle to the ground usually relies on the ground computing center. The ground computing center will calculate the target azimuth and pitch angle that the turntable needs to adjust to based on the information such as the orbital parameters of the aircraft, the target position and the mission requirements, and send these calculation results to the aircraft through the uplink. However, due to the complexity of the calculation process and the need for multiple iterations and verifications, the entire execution cycle often takes more than 2 days. This long delay not only reduces the real-time performance of the system, but also may lead to the inability to respond to emergencies in a timely manner during the execution of the mission, such as sudden changes in the target position or deterioration of weather conditions. In addition, the traditional calculation method also faces the problem of huge data volume. The ground computing center needs to input a large amount of aircraft position information, target position information, installation matrix and other data into the calculation model to obtain an accurate turntable pointing angle. These data will occupy a large amount of satellite communication resources during the uplink transmission process. At the same time, storing and processing these data on the aircraft also requires a large amount of storage space and computing resources. This is undoubtedly a huge burden for aircraft with limited resources. Summary of the invention

[0004] The purpose of the present invention is to solve the technical problems of insufficient real-time performance and large resource occupation in the prior art method for calculating the on-orbit pointing angle of a turntable, and to provide a method and system for calculating the autonomous on-orbit guidance angle of a turntable.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions: In a first aspect, the present invention discloses a method for calculating an autonomous on-orbit ground guidance angle of a turntable, comprising: Obtaining the location information of the target, and converting the location information into the target ECI location coordinates; Obtain the satellite orbit elements at time 0, and calculate the satellite ECI position coordinates based on the satellite orbit elements at time 0; Obtaining the installation matrix and rotation matrix of the observation payload on the satellite; based on the installation matrix and the rotation matrix, transforming the target ECI position coordinates and the satellite ECI position coordinates into the observation coordinate system on the satellite, and calculating the observation vector; The azimuth and pitch angles of the observation vector are calculated, and the azimuth and pitch angles are used as the autonomous on-orbit ground guidance angles of the turntable.

[0006] Further improvements are: The location information of the target is: the latitude and longitude of the target location (L, B, H); The position information is converted into the target ECI position coordinates as follows: First, convert the latitude, longitude and height (L, B, H) of the target location into ECEF coordinates , and then the ECEF coordinates Convert to ECI coordinates ; Wherein, L represents the longitude of the target location; B represents the latitude of the target location; H represents the altitude of the target location; Represents the X-axis coordinate in the ECEF coordinate system; Represents the Y-axis coordinate in the ECEF coordinate system; Represents the Z-axis coordinate in the ECEF coordinate system; Represents the X-axis coordinate in the ECI coordinate system; Represents the Y-axis coordinate in the ECI coordinate system; Represents the Z-axis coordinate in the ECI coordinate system.

[0007] Convert the latitude, longitude and height (L, B, H) of the target location into ECEF coordinates Specifically:

[0008] in, The radius of the Earth , is a constant; L represents the longitude of the target location; B represents the latitude of the target location; H represents the height of the target location; Represents the X-axis coordinate in the ECEF coordinate system; Represents the Y-axis coordinate in the ECEF coordinate system; Represents the Z-axis coordinate in the ECEF coordinate system.

[0009] ECEF coordinates Convert to ECI coordinates Specifically: Calculate the ECI coordinates based on the nutation matrix P, precession matrix N, rotation matrix R and polar motion matrix W:

[0010] The nutation matrix P is calculated by the following formula:

[0011]

[0012]

[0013]

[0014]

[0015]

[0016] in, , , Three rotation parameters representing the precession correction angle; represents the number of Julian centuries between the reference epoch and the observation epoch t; represents the Julian day at the observation time t; represents the reference epoch; Gregorian calendar time The conversion process of year, month, day, hour, minute and second to Julian day is as follows:

[0017] in, Express Rounding; Indicates year; Indicates month; Indicates the day; When indicating; Indicates points; Indicates seconds; The precession matrix N is calculated by the following formula:

[0018]

[0019]

[0020] in, , represents the mean ecliptic longitude of the ascending node of the moon; A and A' represent the nutation coefficient of the ecliptic longitude; B and B' represent the nutation coefficient of the intersection angle, in units of ; represents the precession of the equinoxes; It indicates the movement of the ecliptic meridian; Indicates the nutation angle;

[0021]

[0022]

[0023]

[0024]

[0025]

[0026] in, express ; Indicates the moon's mean anomaly angle; represents the mean anomaly angle of the sun; Represents the lunar latitude parameter; Indicates the mean angular distance between the sun and the moon; The rotation matrix R is calculated by the following formula:

[0027]

[0028]

[0029]

[0030] in, Indicates Greenwich sidereal time; It represents the mean Greenwich sidereal time of the day; ; Superscript The unit is time seconds, according to Perform angle unit conversion; The polar shift matrix W is calculated by the following formula:

[0031] in, Retrieved from the EOP file, the unit is arcsecond; ; The interval between two adjacent rows of EOP data is one day. To calculate the specific time of the day, linear interpolation is required: .

[0032] The method of obtaining the satellite orbit elements at time 0 and calculating the satellite ECI position coordinates based on the satellite orbit elements at time 0 is specifically as follows: calculate Satellite orbit elements at time :

[0033]

[0034]

[0035]

[0036]

[0037]

[0038] in, ; a represents the semi-major axis of the satellite orbit; represents the orbital eccentricity; represents the orbital inclination; represents the right ascension of the ascending node of the satellite orbit at time t; It represents the right ascension of the orbit ascending node at time 0; It represents the rate of change of right ascension of ascending node in time period t; Indicates the time when the turntable task is executed relative to time 0; represents the radius of the Earth; represents the argument of perigee at time t; It represents the argument of perigee at time 0; represents the mean anomaly of the command epoch; Indicates the mean anomaly angle at time 0; represents the rate of change of the mean anomaly; Indicates the number of orbital circles in a day; The eccentric anomaly angle E is solved by the iterative method to obtain the true anomaly angle ;

[0039] in, It represents the eccentric anomaly angle E; Indicates the initial value of E constructed; It represents the value of the anomaly angle E after n iterations; Function constructed for solving E by iterative method; , It represents the first and second order reciprocals of F to E;

[0040] in, represents the true anomaly angle; Based on the satellite orbit elements at time 0 and substituting into the true anomaly Solve the satellite ECI position coordinates: .

[0041] The calculation of the observation vector is specifically as follows:

[0042]

[0043] in, represents the installation matrix of the observation payload on the satellite, The default is the third-order identity matrix; represents the posture matrix; Represents the attitude quaternion; , , Indicates the location information of the target in the ECI coordinate system; , , Indicates the location information in the satellite ECI coordinate system.

[0044] The azimuth and pitch angles of the observation vector are calculated, and the azimuth and pitch angles of the observation vector are used as the on-orbit autonomous ground guidance angles of the turntable:

[0045]

[0046] The turntable will pitch the target angle As the target angle, it can realize the real-time observation of the target on orbit; in, Indicates the turntable azimuth target angle; Indicates the turntable pitch target angle.

[0047] In a second aspect, the present invention discloses a system for calculating an autonomous on-orbit ground guidance angle of a turntable, comprising: A target ECI position coordinate module is used to obtain the position information of the target and convert the position information into the target ECI position coordinates; A satellite ECI position coordinate module is used to obtain the satellite orbit elements at time 0 and calculate the satellite ECI position coordinates based on the satellite orbit elements at time 0; A satellite observation coordinate system module is used to obtain the installation matrix and rotation matrix of the observation payload on the satellite; based on the installation matrix and the rotation matrix, the target ECI position coordinates and the satellite ECI position coordinates are transformed into the observation coordinate system on the satellite to calculate the observation vector; The turntable ground guidance angle module is used to calculate the azimuth and pitch angle of the observation vector, and use the azimuth and pitch angle as the turntable's on-orbit autonomous ground guidance angle.

[0048] In a third aspect, the present invention discloses an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned method for calculating the in-orbit autonomous ground guidance angle of the turntable when executing the computer program.

[0049] In a fourth aspect, the present invention discloses a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the above-mentioned method for calculating the autonomous on-orbit ground guidance angle of the turntable is implemented.

[0050] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses a method for calculating the autonomous ground guidance angle of a turntable on-orbit. Through real-time calculation on-orbit, the position information of the target and the satellite position information are converted into ECI position coordinates, and the ECI position coordinate system is converted into the observation coordinate system on the satellite based on the installation matrix and rotation matrix of the observation payload on the satellite to obtain the observation vector, calculate the azimuth and pitch angle of the observation vector, and use the azimuth and pitch angle of the observation vector as the autonomous ground guidance angle of the turntable on-orbit; this method significantly shortens the calculation and execution cycle, compresses the entire process to less than 30 minutes, and greatly improves the real-time performance and response speed. Since the method of the present invention can calculate the target angle of the turntable in real time, it can adapt to the change of the position of the aircraft more quickly. This is particularly important for tasks that require rapid adjustment of the observation direction, such as tracking fast-moving aircraft or targets. In the prior art, the calculation of the turntable's on-orbit pointing angle to the ground usually relies on calculations on the ground, and then the results are injected into the satellite, and this process often takes more than 2 days. Secondly, the present invention is an autonomous calculation on-orbit, and there is no need to inject a large amount of data to the ground and then return to the satellite, thereby significantly reducing the amount of data transmission. In the prior art, since calculations need to be performed on the ground and the results need to be uploaded to the satellite, a large amount of data needs to be transmitted. This not only occupies valuable communication resources, but may also affect the real-time nature of the task due to data transmission delays. In addition, the method of ground calculations and uploading results often requires the satellite to store and process a large amount of data, which places high demands on the storage and processing capabilities on the satellite. The method of the present invention reduces the occupation of on-board resources by directly calculating on orbit, allowing the satellite to perform other tasks more efficiently. Finally, the method of the present invention enables the turntable to autonomously calculate the target angle of the turntable, thereby improving the flexibility of the system. This means that the turntable can adjust the observation direction at any time according to the mission requirements without relying on ground calculations and instructions. Since the links of ground calculations and data transmission are reduced, the method of the present invention reduces the risk of system failure. By directly calculating on orbit, calculation errors can also be monitored and corrected in real time, further improving the reliability of the system. In summary, the present invention uses the DSP (Digital Signal Processor) software on the turntable subsystem to calculate the position information of the aircraft at the mission time in real time through a recursive algorithm, and uses a satellite pointing algorithm to solve the parameters such as the aircraft position information, target position information and installation matrix into the target azimuth and pitch angle of the turntable. This method not only improves the real-time performance of the system, but also reduces the data transmission volume of the uplink and reduces the resource occupation on the aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0052] Figure 1 It is a flow chart of a method for calculating the autonomous ground guidance angle of a turntable on-orbit in the present invention; Figure 2 is a table of nutation sequences used in the present invention; Figure 3 This is a module diagram of a turntable on-orbit autonomous ground guidance angle calculation system in the present invention. DETAILED DESCRIPTION

[0053] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0054] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0056] Terminology explanation: 1. ECEF coordinate system: It is the abbreviation of Earth-Centered Earth-Fixed coordinate system. In the ECEF coordinate system, the specific meanings of the X, Y, and Z axes are as follows: The origin of the coordinate system is at the center of mass of the Earth.

[0057] X-axis: points to the intersection of the prime meridian and the equator, that is, the longitude 0° point on the equator.

[0058] Z axis: points directly to the North Pole of the Earth and coincides with the Earth's rotation axis.

[0059] Y-axis: It forms a right-hand coordinate system with the X-axis and the Z-axis, ensuring the integrity and consistency of the coordinate system. According to the right-hand rule, you can imagine placing your right hand half-clenched on a plane, with your thumb pointing upward (that is, pointing to the Z-axis), and the other fingers are pointing from the X-axis to the Y-axis. Specifically, the Y-axis is perpendicular to the plane formed by the X-axis and the Z-axis (that is, the xOz plane), which can also be understood as passing through the equator and the 90-degree longitude line.

[0060] 2. ECI coordinate system: Earth-Centered Inertial Frame (ECI) is an important spatial reference frame. In the ECI coordinate system, the specific meanings of the X, Y, and Z axes are as follows: The origin of the coordinate system is at the center of mass of the Earth.

[0061] X-axis: points to the vernal equinox, which is the intersection of the Earth's orbit and the ecliptic plane. This point is also called the intersection of the Earth's orbit and the equatorial plane. It is the point on the Earth where the sun shines directly on the equator at the vernal equinox every year.

[0062] Z axis: perpendicular to the equatorial plane, pointing to the North Pole of the Earth. This axis represents the Earth's rotation axis, which is the axis that remains unchanged when the Earth rotates.

[0063] Y axis: It forms the right-hand screw rule with the X axis and the Z axis to ensure that the three axes of the coordinate system are perpendicular to each other. Specifically, if you hold the Z axis with your right hand and your thumb points to the North Pole, the direction in which the four fingers are bent is the positive direction of the Y axis.

[0064] 3. DSP (Digital Signal Processor): digital signal processor.

[0065] 4. CD-ROM (Compact Disc Read-Only Memory: read-only CD.

[0066] 5. EOP (Earth Orientation Parameters): Earth orientation parameters.

[0067] The present invention is further described in detail below in conjunction with the accompanying drawings: See also Figure 1 The embodiment of the present invention discloses a method for calculating an autonomous ground guidance angle of a turntable on-orbit, comprising: S1, obtaining the location information of the target and converting the location information into the target ECI location coordinates; S2, obtaining the satellite orbit elements at time 0, and calculating the satellite ECI position coordinates based on the satellite orbit elements at time 0; S3, obtaining the installation matrix and rotation matrix of the observation payload on the satellite; based on the installation matrix and the rotation matrix, transforming the target ECI position coordinates and the satellite ECI position coordinates into the observation coordinate system on the satellite, and calculating the observation vector; S4, calculating the azimuth and pitch angle of the observation vector, and using the azimuth and pitch angle of the observation vector as the on-orbit autonomous ground guidance angle of the turntable.

[0068] The present invention discloses a method for calculating the autonomous ground guidance angle of a turntable on orbit. First, the position information of a target (such as a ground station, other satellites, etc.) is obtained by some means (such as ground observation, radar detection, etc.). Then, these position information are converted into coordinates in the ECI coordinate system. This usually involves converting information such as the longitude, latitude and altitude of the target into three-dimensional coordinates relative to the center of mass of the earth. The orbital elements of the satellite at time 0 are obtained. Using these orbital elements and a satellite orbit calculation model (such as the Kepler equation, etc.), the ECI position coordinates of the satellite at any time (including the current time) are calculated. The ECI position coordinates of the target and the satellite are subtracted to obtain an observation vector in the satellite coordinate system, and the observation vector is a vector pointing from the satellite to the target. The installation matrix and rotation matrix of the observation payload on the satellite are obtained. These matrices describe the installation position and attitude of the observation payload relative to the satellite body. Using these matrices, the observation vector in the satellite coordinate system is transformed into the payload observation coordinate system. Then, the payload azimuth and pitch angle corresponding to the observation vector are calculated. The azimuth is the angle between the projection of the observation vector on the horizontal plane and a reference direction (such as the flight direction of the satellite); the pitch angle is the angle between the observation vector and the horizontal plane. Finally, the azimuth and pitch angles of the observation vector are used as the autonomous on-orbit ground guidance angles of the turntable. These angles can be used to guide the turntable (such as the antenna or camera on the satellite) to aim at the target. This method obtains the ECI position coordinates of the target and the satellite, and then uses the observation vector calculation and coordinate transformation to finally obtain the turntable's on-orbit autonomous ground guidance angle. This method has high precision and real-time performance, and is suitable for target positioning and tracking tasks in the fields of satellite navigation, remote sensing, and communications.

[0069] The content of the present invention is described in detail below in conjunction with specific embodiments: Step 1: Obtain the location information of the target and convert the location information into the target ECI location coordinates; ECI coordinates are the Earth's inertial coordinate system, which rotates with the Earth but is fixed to the Earth. Its origin is located at the Earth's center of mass, and its axes point to the stellar reference points. It does not rotate with the Earth and is obtained from the J2000 coordinate system. Satellite latitude and longitude belong to the ECEF coordinate system (Earth-centered Earth-fixed coordinate system), which is fixed to the Earth and rotates with the Earth, and is suitable for describing the position of fixed points on the Earth.

[0070] The location information of the target is the latitude and longitude (L, B, H) obtained by the ECEF coordinate system; The position information is converted into the target ECI position coordinates (J2000 coordinate system) as follows: First convert the latitude and longitude (L, B, H) into ECEF coordinates , and then the ECEF coordinates Convert to ECI coordinates .

[0071] Wherein, L represents the longitude of the target location; B represents the latitude of the target location; H represents the altitude of the target location; Represents the X-axis coordinate in the ECEF coordinate system; Represents the Y-axis coordinate in the ECEF coordinate system; Represents the Z-axis coordinate in the ECEF coordinate system; Represents the X-axis coordinate in the ECI coordinate system; Represents the Y-axis coordinate in the ECI coordinate system; Represents the Z-axis coordinate in the ECI coordinate system.

[0072] Convert the latitude, longitude and height (L, B, H) into ECEF coordinates Specifically:

[0073] The radius of the earth , , The above equation can be solved by iteration method.

[0074] ECEF coordinates Convert to ECI coordinates Specifically: The nutation matrix P is calculated by the following formula:

[0075]

[0076]

[0077]

[0078]

[0079] in, , , Three rotation parameters representing the precession correction angle; represents the number of Julian centuries between the reference epoch and the observation epoch t; represents the Julian day at the observation time t; represents the reference epoch;

[0080] Gregorian calendar time Year Month Day Hour Minute Second ( ) to Julian day as follows:

[0081] in, Express Rounding; Indicates year; Indicates month; Indicates the day; When indicating; Indicates points; Indicates seconds; The precession matrix N is calculated by the following formula:

[0082]

[0083]

[0084]

[0085] in, , Take the first 5 columns in the nutation coefficient table, Indicates the mean ecliptic longitude of the ascending node of the moon; A and A' indicate the nutation coefficients of the ecliptic longitude, and B and B' indicate the nutation coefficients of the intersection angle, corresponding to the nutation sequence table 5-8 columns of data, unit ; represents the precession of the equinoxes; It indicates the movement of the ecliptic meridian; Indicates the nutation angle;

[0086]

[0087]

[0088]

[0089]

[0090]

[0091] Among them, Figure 2 As shown, AA'BB' corresponds to the nutation sequence table 5-8 data, unit ; express ; Indicates the moon's mean anomaly angle; represents the mean anomaly angle of the sun; Represents the lunar latitude parameter; Indicates the mean angular distance between the sun and the moon; The rotation matrix R is calculated by the following formula:

[0092]

[0093]

[0094]

[0095] in, Indicates Greenwich sidereal time; It represents the mean Greenwich sidereal time of the day; Superscript The unit is time seconds (s), according to Perform angle unit conversion; The polar shift matrix W is calculated by the following formula:

[0096] in, Retrieved from the EOP file, the unit is arcsecond; ; Table 3 is the original EOP (Earth Orientation Parameters) file in the present invention, and the format is as follows: The columns are ,UTC1-UTC.

[0097] Table 3

[0098] The interval between two adjacent rows of EOP data is one day. To calculate the specific time of the day, linear interpolation is required: .

[0099] Calculate the ECI coordinates based on the P matrix, N matrix, R matrix and W matrix:

[0100] Step 2: Obtain the satellite orbit elements at time 0 and calculate the satellite ECI position coordinates; calculate Satellite orbit elements at time :

[0101]

[0102]

[0103]

[0104]

[0105]

[0106] in, ; a represents the semi-major axis of the satellite orbit; represents the orbital eccentricity; represents the orbital inclination; represents the right ascension of the ascending node of the satellite orbit at time t; It represents the right ascension of the orbit ascending node at time 0; It represents the rate of change of right ascension of ascending node in time period t; Indicates the time when the turntable task is executed relative to time 0; represents the radius of the Earth; represents the argument of perigee at time t; It represents the argument of perigee at time 0; represents the mean anomaly of the command epoch; Indicates the mean anomaly angle at time 0; represents the rate of change of the mean anomaly; Indicates the number of orbital circles in a day;

[0107] in, It represents the eccentric anomaly angle E; Indicates the initial value of E constructed; It represents the value of the anomaly angle E after n iterations; Function constructed for solving E by iterative method; , It represents the first and second order reciprocals of F to E;

[0108] in, represents the true anomaly angle; The satellite ECI position coordinates are: .

[0109] Step 3, obtaining the installation matrix and rotation matrix of the observation payload on the satellite, transforming the target ECI position coordinates and the satellite ECI position coordinates into the observation coordinate system on the satellite based on the installation matrix and the rotation matrix, and calculating the observation vector based on the target coordinates and the satellite coordinates in the observation coordinate system on the satellite; The calculation of the observation vector is specifically as follows:

[0110]

[0111] in, represents the installation matrix of the observation payload on the satellite, The default is the third-order identity matrix; represents the posture matrix; Represents the attitude quaternion; , , Indicates the location information of the target in the ECI coordinate system; , , Indicates the location information in the satellite ECI coordinate system.

[0112] Step 4: Calculate the azimuth and elevation of the observation vector to obtain the target angle that the turntable is pointing to.

[0113] The azimuth and elevation angles of the observation vector are calculated to obtain the target angle pointed by the turntable:

[0114]

[0115] The turntable uses this angle as the target angle, and can achieve real-time observation of the target on orbit; in, Indicates the turntable azimuth target angle; Indicates the turntable pitch target angle.

[0116] See also Figure 3 The present invention discloses a system for calculating the autonomous on-orbit ground guidance angle of a turntable, comprising: A target ECI position coordinate module is used to obtain the position information of the target and convert the position information into the target ECI position coordinates; A satellite ECI position coordinate module is used to obtain the satellite orbit elements at time 0 and calculate the satellite ECI position coordinates based on the satellite orbit elements at time 0; A satellite observation coordinate system module is used to obtain the installation matrix and rotation matrix of the observation payload on the satellite; based on the installation matrix and the rotation matrix, the target ECI position coordinates and the satellite ECI position coordinates are transformed into the observation coordinate system on the satellite to calculate the observation vector; The turntable ground guidance angle module is used to calculate the azimuth and pitch angle of the observation vector, and use the azimuth and pitch angle as the turntable's on-orbit autonomous ground guidance angle.

[0117] The third object of the present invention is to provide an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method for calculating the in-orbit autonomous ground guidance angle of the turntable when executing the computer program.

[0118] The method for calculating the on-orbit autonomous ground guidance angle of the turntable comprises the following steps: Obtaining the location information of the target, and converting the location information into the target ECI location coordinates; Obtain the satellite orbit elements at time 0, and calculate the satellite ECI position coordinates based on the satellite orbit elements at time 0; Obtaining the installation matrix and rotation matrix of the observation payload on the satellite; based on the installation matrix and the rotation matrix, transforming the target ECI position coordinates and the satellite ECI position coordinates into the observation coordinate system on the satellite, and calculating the observation vector; The azimuth and pitch angles of the observation vector are calculated, and the azimuth and pitch angles are used as the autonomous on-orbit ground guidance angles of the turntable.

[0119] The fourth object of the present invention is to provide a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the steps of the method for calculating the in-orbit autonomous ground guidance angle of the turntable.

[0120] The method for calculating the on-orbit autonomous ground guidance angle of the turntable comprises the following steps: Obtaining the location information of the target, and converting the location information into the target ECI location coordinates; Get the satellite orbit elements at time 0 and calculate the satellite ECI position coordinates; Obtaining the installation matrix and rotation matrix of the observation payload on the satellite; based on the installation matrix and the rotation matrix, transforming the target ECI position coordinates and the satellite ECI position coordinates into the observation coordinate system on the satellite, and calculating the observation vector; The azimuth and pitch angles of the observation vector are calculated, and the azimuth and pitch angles are used as the autonomous on-orbit ground guidance angles of the turntable.

[0121] It should be understood by those skilled in the art that the embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM (Compact Disc Read-Only Memory), optical storage, etc.) containing computer-usable program code.

[0122] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks 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.

[0123] 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.

[0124] 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 A step that specifies a function in one or more boxes.

[0125] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for calculating the autonomous ground guidance angle of a turntable on-orbit, characterized in that: include: Obtaining the location information of the target, and converting the location information into the target ECI location coordinates; Obtain the satellite orbit elements at time 0, and calculate the satellite ECI position coordinates based on the satellite orbit elements at time 0; Obtain the installation matrix and rotation matrix of the observation payload on the satellite; Based on the installation matrix and the rotation matrix, the target ECI position coordinates and the satellite ECI position coordinates are transformed into an observation coordinate system on the satellite to calculate an observation vector; The azimuth and pitch angles of the observation vector are calculated, and the azimuth and pitch angles are used as the autonomous on-orbit ground guidance angles of the turntable.

2. The method for calculating the autonomous ground guidance angle of a turntable on-orbit according to claim 1, characterized in that: The location information of the target is: the latitude and longitude of the target location (L, B, H); The position information is converted into the target ECI position coordinates as follows: First, convert the latitude, longitude and height (L, B, H) of the target location into ECEF coordinates , and then the ECEF coordinates Convert to ECI coordinates ; Wherein, L represents the longitude of the target location; B represents the latitude of the target location; H represents the altitude of the target location; Represents the X-axis coordinate in the ECEF coordinate system; Represents the Y-axis coordinate in the ECEF coordinate system; Represents the Z-axis coordinate in the ECEF coordinate system; Represents the X-axis coordinate in the ECI coordinate system; Represents the Y-axis coordinate in the ECI coordinate system; Represents the Z-axis coordinate in the ECI coordinate system.

3. The method for calculating the autonomous on-orbit ground guidance angle of a turntable according to claim 2, characterized in that: Convert the latitude, longitude and height (L, B, H) of the target location into ECEF coordinates Specifically: in, The radius of the Earth , is a constant; L represents the longitude of the target location; B represents the latitude of the target location; H represents the height of the target location; Represents the X-axis coordinate in the ECEF coordinate system; Represents the Y-axis coordinate in the ECEF coordinate system; Represents the Z-axis coordinate in the ECEF coordinate system.

4. The method for calculating the autonomous on-orbit ground guidance angle of a turntable according to claim 3, characterized in that: ECEF coordinates Convert to ECI coordinates Specifically: Calculate the ECI coordinates based on the nutation matrix P, precession matrix N, rotation matrix R and polar motion matrix W: The nutation matrix P is calculated by the following formula: in, , , Three rotation parameters representing the precession correction angle; represents the number of Julian centuries between the reference epoch and the observation epoch t; represents the Julian day at the observation time t; represents the reference epoch; Gregorian calendar time The conversion process of year, month, day, hour, minute and second to Julian day is as follows: in, Express Rounding; Indicates year; Indicates month; Indicates the day; When indicating; Indicates points; Indicates seconds; The precession matrix N is calculated by the following formula: in, , represents the mean ecliptic longitude of the ascending node of the moon; A and A' represent the nutation coefficient of the ecliptic longitude; B and B' represent the nutation coefficient of the intersection angle, in units of ; represents the precession of the equinoxes; It indicates the movement of the ecliptic meridian; Indicates the nutation angle; in, express ; Indicates the moon's mean anomaly angle; represents the mean anomaly angle of the sun; Represents the lunar latitude parameter; Indicates the mean angular distance between the sun and the moon; The rotation matrix R is calculated by the following formula: in, Indicates Greenwich sidereal time; It represents the mean Greenwich sidereal time of the day; Superscript The unit is time seconds, according to Perform angle unit conversion; The polar shift matrix W is calculated by the following formula: in, Retrieved from the EOP file, the unit is arcsecond; ; The interval between two adjacent rows of EOP data is one day. To calculate the specific time of the day, linear interpolation is required: 。 5. The method for calculating the autonomous on-orbit ground guidance angle of a turntable according to claim 4, characterized in that: The method of obtaining the satellite orbit elements at time 0 and calculating the satellite ECI position coordinates based on the satellite orbit elements at time 0 is specifically as follows: calculate Satellite orbit elements at time : in, ; a represents the semi-major axis of the satellite orbit; represents the orbital eccentricity; represents the orbital inclination; represents the right ascension of the ascending node of the satellite orbit at time t; It represents the right ascension of the orbit ascending node at time 0; It represents the rate of change of right ascension of ascending node in time period t; Indicates the time when the turntable task is executed relative to time 0; represents the radius of the Earth; represents the argument of perigee at time t; It represents the argument of perigee at time 0; represents the mean anomaly of the command epoch; Indicates the mean anomaly angle at time 0; represents the rate of change of the mean anomaly; Indicates the number of orbital circles in a day; The eccentric anomaly angle E is solved by the iterative method to obtain the true anomaly angle ; in, It represents the eccentric anomaly angle E; Indicates the initial value of E constructed; It represents the value of the anomaly angle E after n iterations; Function constructed for solving E by iterative method; , It represents the first and second order reciprocals of F to E; in, represents the true anomaly angle; Based on the satellite orbit elements at time 0 and substituting into the true anomaly Solve the satellite ECI position coordinates: 。 6. The method for calculating the on-orbit autonomous ground guidance angle of a turntable according to claim 5, characterized in that: The calculation of the observation vector is specifically as follows: in, represents the installation matrix of the observation payload on the satellite, The default is the third-order identity matrix; represents the posture matrix; Represents the attitude quaternion; , , Indicates the location information of the target in the ECI coordinate system; , , Indicates the location information in the satellite ECI coordinate system.

7. The method for calculating the autonomous on-orbit ground guidance angle of a turntable according to claim 6, characterized in that: The azimuth and pitch angles of the observation vector are calculated, and the azimuth and pitch angles of the observation vector are used as the on-orbit autonomous ground guidance angles of the turntable: The turntable will pitch the target angle As the target angle, it can realize the real-time observation of the target on orbit; in, Indicates the turntable azimuth target angle; Indicates the turntable pitch target angle.

8. A system for calculating the autonomous ground guidance angle of a turntable on-orbit, characterized in that: include: A target ECI position coordinate module is used to obtain the position information of the target and convert the position information into the target ECI position coordinates; A satellite ECI position coordinate module is used to obtain the satellite orbit elements at time 0 and calculate the satellite ECI position coordinates based on the satellite orbit elements at time 0; Satellite observation coordinate system module, used to obtain the installation matrix and rotation matrix of the observation payload on the satellite; Based on the installation matrix and the rotation matrix, the target ECI position coordinates and the satellite ECI position coordinates are transformed into an observation coordinate system on the satellite to calculate an observation vector; The turntable ground guidance angle module is used to calculate the azimuth and pitch angle of the observation vector, and use the azimuth and pitch angle as the turntable's on-orbit autonomous ground guidance angle.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method for calculating the on-orbit autonomous ground guidance angle of the turntable as described in any one of claims 1-7 is implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method for calculating the autonomous on-orbit ground guidance angle of the turntable as described in any one of claims 1 to 7 is implemented.

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