A satellite system beam position scheduling planning method for a designated area

Abstract

The present invention provides a method for satellite system beam position scheduling planning for a designated area, comprising the following steps: Step 1: inputting information related to the satellite system beam position scheduling plan; Step 2: dividing the area into sub-areas based on the input information; Step 3: calculating the maximum slant range based on the input information; Step 4: performing beam position scheduling planning using the maximum slant range and the divided sub-areas; and Step 5: outputting the optimal beam position scheduling plan. By dividing the designated area into a union of a finite number of non-overlapping sub-areas and measuring the coverage size using the number of beam position coverage sub-areas, the present invention addresses the problem of irregular beam position coverage and difficulty in effective selection. Furthermore, the present invention can solve the beam position scheduling problem for information acquisition and transmission tasks in a designated area, achieving efficient scheduling of satellite antenna beam positions and improving mission performance.

Description

Technical Field

[0001] The present invention relates to the field of satellite equipment system mission planning and resource management, and in particular to a satellite system wave position scheduling planning method for a designated area. Background Art

[0002] Space satellites, with their high speed and wide coverage, are widely used in both military and civilian applications. Due to differences in antenna beamwidths at different operating frequencies and beam orientations, and the Earth's curvature, the coverage of different beam orientations varies from one location to another (this coverage is called the beam position corresponding to the beam orientation). In high-speed, dynamic satellite scenarios, antenna beam position scheduling is a key factor influencing information acquisition and transmission.

[0003] For each operating frequency of a satellite antenna, a corresponding antenna beam table is typically pre-designed. This table contains a finite number of beam positions available for system scheduling. The union of these beam position ranges fully covers the satellite's entire effective field of view. Beam pointing modes are often referred to as "spatial operating modes." Common spatial operating modes include full-field-of-view scanning and designated-area scanning. Full-field-of-view scanning involves sequentially scheduling all beam positions from the preset beam position table based on the operating frequency, achieving time-sharing coverage of the entire field of view. Designated-area scanning, on the other hand, involves selecting a beam position from the corresponding beam position table, one at a time, based on the operating frequency, to scan the designated area as quickly as possible. For a designated area of ​​interest, a convenient and intuitive method is to use longitude and latitude coordinates. However, due to the high speed of satellites, beam position coverage rapidly changes with satellite motion and attitude. The main challenges of designated-area scanning are: first, the intersection of the beam positions formed by the antenna beam on the Earth's surface and the designated area is irregular, making it difficult to measure the effectiveness of the beam position selection; second, the high speed of the satellite and its attitude changes cause the relative position of the satellite antenna beam position and the designated area to vary over time. Therefore, for information acquisition and transmission in a specified area, how to design an efficient wave position scheduling planning strategy is an issue worth considering. Summary of the Invention

[0004] The present invention aims to provide a satellite system beam position scheduling planning method for a specified area. By dividing the specified area into the union of a finite number of non-overlapping sub-areas and measuring the range of the beam position coverage of the specified area by the number of beam position coverage sub-areas, the problem of irregular beam position coverage and difficulty in effective measurement is solved. In addition, based on satellite motion information and designated area information, a beam position scheduling optimization problem is constructed to solve and obtain the optimal beam position scheduling plan, thereby achieving efficient scheduling of satellite-borne antennas and improving work task efficiency.

[0005] The present invention provides a satellite system beam position scheduling planning method for a designated area, comprising the following steps:

[0006] Step 1: Input the satellite system wave position scheduling planning related information;

[0007] Step 2: Divide the sub-regions according to the input information;

[0008] Step 3, calculating the maximum slope distance based on the input information;

[0009] Step 4: Use the maximum slant range and the divided sub-areas to perform wave position scheduling planning;

[0010] Step 5: Output the optimal wave position scheduling plan.

[0011] Furthermore, in step 1, the input satellite system beam position scheduling planning related information includes:

[0012] Specify the longitude and latitude range of the area [L1, L2] × [B1, B2], and the number of longitude divisions n Longi and the number of latitude divisions n Lat ;

[0013] The operating frequency f and the corresponding wave position table used by the satellite equipment. The wave position table of the operating frequency f has a total of n wave positions, among which the beam pointing angle θ corresponding to the i-th wave position is i , azimuth and beamwidth w i , the wave position residence time is ΔT, the wave position scheduling invalid maximum number threshold U max ;

[0014] Satellite orbit height h and effective viewing angle θ sat ;

[0015] Mission start time T1 and the corresponding position of the satellite device at T1 in the WGS84 coordinate system speed and satellite device attitude information; the satellite device attitude information includes yaw angle θ y , pitch angle θ p and the roll angle θ r .

[0016] Furthermore, in step 2, dividing the sub-regions according to the input information includes:

[0017] Divide the number n according to the input longitude Longi and the number of latitude divisions n Lat , calculate the longitude division interval ΔL and latitude division interval ΔB of the area; and divide the designated area evenly into n g =nLongi ×n Lat sub-regions;

[0018] In increasing order of longitude or latitude, they are 1 to n Longi Column or 1 to n Lat row; record the longitude division p∈{1,…,n Longi} column and latitude partition q∈{1,…,n Lat The latitude and longitude coordinates of the four vertices of the sub-region (p,q) of the row are Then, the vertex coordinates of all sub-regions Convert from the latitude and longitude coordinate system to the WGS84 coordinate system, and obtain the corresponding coordinates after conversion:

[0019] Furthermore, in step 3, according to the input effective viewing angle θ sat , calculate the corresponding maximum slope distance D max :

[0020]

[0021] Where R is the semi-major axis of the Earth.

[0022] Furthermore, the time corresponding to the k-th wave position scheduling is T k Initialize k = 1, set M wave scheduling assumptions S m ,m=1,…,M is the empty set and the corresponding score The number of invalid beam scheduling times U=0; in step 4, beam scheduling planning using the maximum slant range and the divided sub-areas includes the following sub-steps:

[0023] Step 4.1: According to the off-axis angle θ of the beam pointing corresponding to the wave position of the current operating frequency f, i and azimuth Calculate the corresponding beam pointing direction vector in the satellite body coordinate system

[0024] Step 4.2: When performing the kth wave position scheduling, based on the position and velocity information of the satellite equipment at time T1, the orbit extrapolation method is used to calculate the k Extrapolated position at time and speed When k=1, the time corresponding to the first wave position scheduling is T1;

[0025] Step 4.3, calculate the satellite equipment at T in the WGS84 coordinate system. k Extrapolated position at time and the four vertices of the subregion (p,q) The corresponding direction vector and distance

[0026] Step 4.4, based on satellite equipment in T k Extrapolated position at time speed And the satellite equipment attitude information, calculate the rotation matrix R from the WGS84 coordinate system to the satellite orbit coordinate system w,o And the rotation matrix R that transforms the satellite orbit coordinate system to the satellite body coordinate system o,b , then the direction vector of the satellite device and the sub-area vertex in the WGS84 coordinate system Convert to the satellite's coordinate system;

[0027] Step 4.5, initialize the n antennas of the satellite equipment to point to the wave position at T k The sub-area number set E covered at the moment i ,i=1,…,n is an empty set, and the sub-area covered by the wave position is searched in the order of i=1,…,n;

[0028] Step 4.6, for the optimal M wave position scheduling assumptions S retained from the initial time to time k-1 m ,m=1,…,M, and calculate T obtained in step 4.5 k The sub-area number set E covered at the moment i ,i=1,…,n and S m Combine to form a task from start to T k The candidate wave position scheduling assumption S at time m,i ,m=1,…,M,i=1,…,n, that is, T k There are a total of Mn candidate wave position scheduling assumptions at the moment;

[0029] Step 4.7, for each candidate wave scheduling hypothesis S m,i , recursively calculate the corresponding wave scheduling hypothesis score G m,i ;

[0030] Step 4.8, schedule the Mn candidate wave positions assuming S m,i ,m=1,…,M,i=1,…,n’s score G m,i Sort and find the first M candidate wave scheduling hypotheses with the largest scores. If the candidate wave scheduling hypothesis with the largest score is greater than T k-1 Assuming that the slot scheduling with the maximum score at the moment does not have any new sub-areas covered, the number of invalid slot scheduling times for the current working frequency is U = U + 1; otherwise, if U is not 0, it is reset to 0;

[0031] Step 4.9, schedule the Mn candidate wave positions and assume S m,i,m=1,…,M,i=1,…,n,the first M largest-scoring candidate wave scheduling hypothesis replaces the updated S m ,G m ,m=1,…,M;

[0032] Step 4.10, judgment condition 1: the optimal M wave position scheduling hypothesis S at the current moment m ,m=1,…,M, there exists a wave position scheduling assumption that has covered all sub-areas; if so, jump to step 5; if not, continue to step 4.11;

[0033] Step 4.11, judgment condition 2: whether the number of invalid wave scheduling times U at the current working frequency is greater than or equal to the threshold U max ; If U≥U max , the current time T k The retained M wave scheduling assumptions and scores are replaced by T k -U max The M wave scheduling hypotheses and scores retained at time ΔT, jump to step 5; if U max , then calculate the next wave position scheduling time T k+1 =T k +ΔT, and update k=k+1, and jump to step 4.2 to continue execution.

[0034] Furthermore, in step 4.4, the rotation matrix R of the WGS84 coordinate system converted to the satellite orbit coordinate system is w,o The specific calculation method is as follows:

[0035] Considering the influence of the Earth's rotation angular velocity, the satellite position and velocity in the WGS-84 coordinate system are converted to the instantaneous inertial coordinate system I;

[0036] Definition of satellite orbit coordinate system: z-axis e z Defined as the unit vector of the line connecting the center of the Earth and the satellite, pointing to the center of the Earth; the x-axis e x Defined as the unit vector of the satellite device velocity direction in the instantaneous inertial coordinate system I; the y-axis e y Defined as a unit vector perpendicular to the x-axis and z-axis and satisfying the right-hand rule;

[0037] Since the WGS84 coordinate system coincides with the instantaneous inertial coordinate system I at the time of establishment, the vector representations in the WGS84 coordinate system and the instantaneous inertial coordinate system I are the same; therefore, according to the definition of the satellite orbit coordinate system, the transformation matrix from the WGS84 coordinate system to the satellite orbit coordinate system is obtained.

[0038] Furthermore, in step 4.4, the rotation matrix R of the satellite orbit coordinate system is converted to the satellite body coordinate system o,b The specific calculation method is as follows:​

[0039] There are 6 possible coordinate axis rotation sequences for converting the satellite orbit coordinate system to the satellite body coordinate system, including: 1-2-3, 1-3-2, 2-1-3, 2-3-1, 3-1-2 and 3-2-1, where 1 represents roll, 2 represents pitch, and 3 represents yaw. One of the rotation sequences is used according to the satellite equipment, and the corresponding rotation matrix R is calculated based on the roll angle, pitch angle and yaw angle to convert the satellite orbit coordinate system to the satellite body coordinate system. o,b .

[0040] Furthermore, in step 4.5, searching for sub-areas covered by the wave position includes:

[0041] Step 4.5.1, according to the sub-area division method of step 2, there are a total of (n Longi +1)(n Lat +1) different sub-region vertices; according to the beam pointing direction vector p i , the direction vectors of satellite equipment and sub-area vertices in the satellite body coordinate system Get the corresponding vector angle:

[0042]

[0043] like If both are true, then the sub-region (p, q) is within the coverage of wave position j; otherwise, the sub-region (p, q) is not within the coverage of wave position j;

[0044] Step 4.5.2, for each subregion (p,q), p∈{1,…,n Longi},q∈{1,…,n Lat}, if the sub-area (p,q) is within the coverage of wave position i, then update the set E i , which will represent the time and sub-area number of the quaternion array (T k ,i,p,q) are added to the set E i ; Otherwise, do not update the set E i .

[0045] Furthermore, in step 4.7, the corresponding wave scheduling hypothesis score G is recursively calculated. m,i as follows:

[0046]

[0047] in, Represents the set E i Does not belong to S m,i The sub-region number set of E i ∩S m,i Represents the set E i Sm,i The sub-area number set; |·| indicates the cardinality of the set; the parameter γ1 is used to measure the score of the currently used wave position covering a new sub-area; the parameter γ2 is used to measure the score of the currently used wave position covering a new sub-area.

[0048] Furthermore, in step 5, the beam scheduling with the highest score is used as the optimal beam scheduling plan when the satellite device uses the working frequency point f, and the optimal beam scheduling plan is output.

[0049] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0050] 1. The present invention solves the problem of irregular wave position coverage and difficulty in effective selection by dividing the designated area into a finite number of non-overlapping sub-areas and measuring the coverage size using the number of wave position coverage sub-areas.

[0051] 2. The present invention can solve the problem of wave position scheduling for information acquisition and transmission tasks in a designated area, realize efficient scheduling of satellite-borne antenna wave positions, and improve mission efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 The flowchart of the satellite system beam position scheduling planning method for a specified area in an embodiment of the present invention is shown.

[0053] Figure 2 Schematic diagram of the definition of the beam pointing off-axis angle and azimuth angle corresponding to the antenna wave position of the satellite device in the satellite body coordinate system in an embodiment of the present invention.

[0054] Figure 3 Schematic diagram of the effective viewing angle of the satellite device in an embodiment of the present invention.

[0055] Figure 4 This is a schematic diagram of evenly dividing a designated latitude and longitude area into sub-areas in an embodiment of the present invention.

[0056] Figure 5 This is an illustration of the ground coverage and wave position coverage under the effective viewing angle of the satellite equipment in the example.

[0057] Figure 6 This is the wave position coverage obtained by applying the wave position scheduling pre-planning method in the example.

[0058] Figure 7 This is the wave position coverage obtained by applying the method of the present invention in the example. DETAILED DESCRIPTION

[0059] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only 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 herein can be arranged and designed in various different configurations.

[0060] 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 as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0061] Example

[0062] like Figure 1 As shown, this embodiment proposes a satellite system beam position scheduling planning method for a specified area, including the following steps:

[0063] Step 1: Input the satellite system wave position scheduling planning related information;

[0064] The input satellite system beam position scheduling planning related information includes:

[0065] (1) Specify the longitude and latitude range of the area [L1, L2] × [B1, B2], and the number of longitude divisions n Longi and the number of latitude divisions n Lat ;

[0066] (2) The operating frequency f and the corresponding wave position table used by the satellite equipment. The wave position table of the operating frequency f has a total of n wave positions, among which the beam pointing angle θ corresponding to the i-th wave position is i , azimuth and beamwidth w i , the wave position residence time is ΔT, the wave position scheduling invalid maximum number threshold U max ;

[0067] (3) Satellite orbit height h and effective viewing angle θ sat ;

[0068] (4) Mission start time T1 and the corresponding position of the satellite equipment at T1 in the WGS84 coordinate system speed Satellite equipment attitude information (yaw angle θ y , pitch angle θ p and the roll angle θ r ).

[0069] Explanation of terms:

[0070] (1) Off-axis angle θ i and azimuth In the satellite coordinate system, the off-axis angle is defined as the angle between the pointing vector and the positive direction of the z-axis, with a valid range of 0° to 90°. The azimuth angle is defined as the angle between the projection vector of the pointing vector on the Oxy plane and the positive direction of the x-axis, with a valid range of 0° to 360°. Figure 2 shown.

[0071] (2) Beam width w i : The beam width of a satellite device antenna refers to the angle between the two directions where the radiation power drops by 3dB on both sides of the maximum radiation direction.

[0072] (3) Wavelength residence time ΔT: The time interval from the start of satellite equipment scheduling a wavelength to the start of the next scheduling.

[0073] (4) Maximum number of invalid wave scheduling thresholds U max : Satellite equipment wave position scheduling planning stop threshold. If two consecutive wave position schedulings do not cover the new area, it is considered that the wave position scheduling has no gain, and the number of invalid wave position scheduling is increased by 1, reaching the maximum number of invalid wave position scheduling threshold U max The current task stops.

[0074] (5) Effective viewing angle θ sat :like Figure 3 As shown, the effective viewing angle is defined as the angle ∠S′SQ between the line SS′ connecting the satellite device and its sub-satellite point and the line SQ connecting the satellite device and the edge of its effective visible range on the earth's surface.

[0075] (6) Yaw angle θ y , pitch angle θ p and the roll angle θ r : Satellite equipment attitude information, the yaw angle, pitch angle and roll angle are defined as the angles of rotation around the y-axis, z-axis and x-axis when converted from the orbital coordinate system to the satellite body coordinate system.

[0076] Step 2: Divide the number n according to the input longitude Longi and the number of latitude divisions n Lat , calculate the longitude division interval ΔL and latitude division interval ΔB of the area; and divide the designated area evenly into n g =n Longi ×n Lat sub-areas, from 1 to n in increasing direction of longitude (or latitude) Longi Column (or 1 to n Lat ), such as Figure 4 As shown. Let the longitude be divided into p∈{1,…,n Longi} column and latitude partition q∈{1,…,n Lat The latitude and longitude coordinates of the four vertices of the sub-region (p,q) of the row are Then, the vertex coordinates of all sub-regions Convert from the latitude and longitude coordinate system to the WGS84 coordinate system, and obtain the corresponding coordinates after conversion:

[0077] Step 3: According to the input effective viewing angle θ sat , calculate the corresponding maximum slope distance D max :

[0078]

[0079] Among them, R = 6378137m is the semi-major axis of the earth.

[0080] Step 4: Let the time corresponding to the k-th wave position scheduling be T k Initialize k = 1, set M wave scheduling assumptions S m ,m=1,…,M is the empty set and the corresponding score The number of invalid wave scheduling times U = 0. Execute the following steps:

[0081] Step 4.1: According to the off-axis angle θ of the beam pointing corresponding to the wave position of the current operating frequency f, i and azimuth Calculate the corresponding beam pointing direction vector in the satellite body coordinate system

[0082] Step 4.2: When performing the kth wave position scheduling (for example, when k=1, the first wave position scheduling corresponds to time T1), based on the position and velocity information of the satellite equipment at time T1, the orbit extrapolation method is used to calculate the time at T k Extrapolated position at time and speed The orbit extrapolation method is a prior art and will not be described in detail here.

[0083] Step 4.3, calculate the satellite equipment at T in the WGS84 coordinate system. k Extrapolated position at time and the four vertices of the subregion (p,q) The corresponding direction vector and distance

[0084] Step 4.4, based on satellite equipment in T k Extrapolated position at time speed And the satellite equipment attitude information (yaw angle, pitch angle and roll angle), calculate the rotation matrix R from the WGS84 coordinate system to the satellite orbit coordinate system w,o And the rotation matrix R that transforms the satellite orbit coordinate system to the satellite body coordinate system o,b , then the direction vector of the satellite device and the sub-area vertex in the WGS84 coordinate system Convert to the satellite coordinate system, that is:

[0085]

[0086] The rotation matrix R of the WGS84 coordinate system converted to the satellite orbit coordinate system w,o The specific calculation method is as follows:

[0087] Considering that the definition of the satellite orbit coordinate system is based on the instantaneous inertial coordinate system I, which coincides with the WGS-84 coordinate system at the instant, but does not have the Earth's rotation speed. First, consider the Earth's rotation angular velocity w e =2π / 86164.1, convert the satellite position and velocity in the WGS-84 coordinate system to the instantaneous inertial coordinate system I, then T k The position and velocity of the satellite equipment at the instantaneous inertial coordinate system I are expressed as:

[0088]

[0089] The satellite orbit coordinate system is defined as follows: the z-axis e z Defined as the unit vector of the line connecting the center of the Earth and the satellite, pointing to the center of the Earth; the x-axis e x Defined as the unit vector of the satellite device velocity direction in the instantaneous inertial coordinate system I; the y-axis e y It is defined as a unit vector perpendicular to the x-axis and z-axis and satisfies the right-hand rule. The specific calculation is as follows:

[0090]

[0091] Since the WGS84 coordinate system coincides with the instantaneous inertial coordinate system I at the time of establishment, the vector representations in the WGS84 coordinate system and the instantaneous inertial coordinate system I are the same. Therefore, the transformation matrix from the WGS84 coordinate system to the satellite orbit coordinate system is:

[0092]

[0093] The rotation matrix R that transforms the satellite orbit coordinate system to the satellite body coordinate system o,b The specific calculation method is as follows:

[0094] Let θ r ,θ p ,θy Represents the roll angle, pitch angle and yaw angle respectively. The three-axis attitude angle given by the attitude is the Euler angle. There are 6 possible coordinate axis rotation orders for converting the satellite orbit coordinate system to the satellite body coordinate system, including: 1-2-3, 1-3-2, 2-1-3, 2-3-1, 3-1-2 and 3-2-1, where 1 represents roll, 2 represents pitch, and 3 represents yaw. In practical applications, it is necessary to calculate the corresponding rotation matrix R for converting the satellite orbit coordinate system to the satellite body coordinate system according to the specific conversion order adopted by the satellite equipment. o,b . Taking the 1-2-3 rotation order as an example, the rotation matrix R o,b The calculation is as follows:

[0095]

[0096] Step 4.5, initialize the n antennas of the satellite equipment to point to the wave position at T k The sub-area number set E covered at the moment i , i=1,…,n is an empty set. Perform the following steps in the order of i=1,…,n to find the sub-area covered by the wave position:

[0097] Step 4.5.1, according to the sub-area division method of step 2, there are a total of (n Longi +1)(n Lat +1) different sub-region vertices. According to the beam pointing direction vector p i , the direction vectors of satellite equipment and sub-area vertices in the satellite body coordinate system Get the corresponding vector angle:

[0098]

[0099] like If both are true, the sub-region (p, q) is within the coverage of wave position j; otherwise, the sub-region (p, q) is not within the coverage of wave position j.

[0100] Step 4.5.2, for each subregion (p,q), p∈{1,…,n Longi},q∈{1,…,n Lat}, if the sub-area (p,q) is within the coverage of wave position i, then update the set E i , which will represent the time and sub-area number of the quaternion array (T k ,i,p,q) are added to the set E i ; Otherwise, do not update the set E i .

[0101] Step 4.6, for the optimal M wave position scheduling assumptions S retained from the initial time to time k-1 m,m=1,…,M, and calculate T obtained in step 4.5 k The sub-area number set E covered at the moment i ,i=1,…,n and S m Combine to form a task from start to T k The candidate wave position scheduling assumption S at time m,i ,m=1,…,M,i=1,…,n, that is, T k There are a total of Mn candidate wave scheduling hypotheses at the moment.

[0102] Step 4.7, for each candidate wave scheduling hypothesis S m,i , the corresponding wave scheduling hypothesis score G can be recursively calculated m,i as follows:

[0103]

[0104] in, Represents the set E i Does not belong to S m,i The sub-area number set (ie relative to the wave scheduling assumption S m,i , T k The number of the sub-area that can be newly covered by the i-th wave position at any moment); E i ∩S m,i Represents the set E i S m,i The sub-area number set (ie relative to the wave scheduling assumption S m,i , T k The number of the sub-area repeatedly covered by the j-th wave position at a given moment); |·| represents the cardinality of the set; the parameter γ1 is used to measure the score of a sub-area newly covered by the currently used wave position; the parameter γ2 is used to measure the score of a sub-area newly covered by the currently used wave position.

[0105] Step 4.8, schedule the Mn candidate wave positions assuming S m,i ,m=1,…,M,i=1,…,n’s score G m,i Sort and find the first M candidate wave scheduling hypotheses with the largest scores. If the candidate wave scheduling hypothesis with the largest score is greater than T k-1 The wave scheduling with the maximum score at the moment assumes that there is no new covered sub-area, then the number of invalid wave scheduling times of the current working frequency point is U=U+1; otherwise, if U is not 0, it is reset to 0.

[0106] Step 4.9, schedule the Mn candidate wave positions and assume S m,i ,m=1,…,M,i=1,…,n,the first M largest-scoring candidate wave scheduling hypothesis replaces the updated S m ,G m,m=1,…,M.

[0107] Step 4.10, judgment condition 1: the optimal M wave position scheduling hypothesis S at the current moment m ,m=1,…,M, there exists a wave position scheduling assumption that has covered all sub-areas; if so, jump to step 5; if not, continue to step 4.11.

[0108] Step 4.11, judgment condition 2: whether the number of invalid wave scheduling times U at the current working frequency is greater than or equal to the threshold U max If U≥U max , the current time T k The retained M wave scheduling assumptions and scores are replaced by T k -U max The M wave scheduling hypotheses and scores retained at time ΔT, jump to step 5; if U max , then calculate the next wave position scheduling time T k+1 =T k +ΔT, and update k=k+1, and jump to step 4.2 to continue execution.

[0109] Step 5: Highest score Wave scheduling assumption As the optimal beam position scheduling plan for the satellite equipment when using the working frequency point f, the optimal beam position scheduling plan is output and the mission is completed.

[0110] An example:

[0111] This example simulates the satellite's position and velocity information per second in the WGS84 coordinate system. The selected orbit data duration is 200 seconds. The specific satellite orbit simulation parameters include: orbit inclination 35°, perigee angle 0°, ascending node right ascension 130°, mean anomaly 20°, perigee and apogee altitudes 700km. Satellite effective viewing angle θ sat The initial orbital position is [-4312745.969m, 5260285.252m, 1956947.794m] and the speed is [-3883.766m / s, -4582.358m / s, 3758.31m / s], and the attitude angle is 0°. The operating frequency of the satellite equipment in this mission is 10000MHz, which corresponds to 49 wave positions. The corresponding beam pointing off-axis angle, azimuth angle and beam width are shown in Table 1, and the wave position coverage formed on the earth's surface is shown in Table 1. Figure 5 ​As shown, the wave position residence time is 20s. In addition, the parameters in the optimization problem are set to γ1 = 3 and γ2 = 0.01. The following comparative analysis shows the coverage effect of the wave position scheduling plan obtained by different methods on the specified area, where the starting longitude and ending longitude of the area are set to 134° and 142° respectively, and the starting latitude and ending latitude are set to 10° and 18° respectively, and the area is divided into n by longitude. Longi = 20 columns and latitude is divided into n Lat =20 lines.

[0112] Table 1, wave position table corresponding to a given operating frequency:

[0113]

[0114] Evaluation Metrics: To assess method performance, this example uses regional coverage as the performance metric. This metric is defined as the sum of the number of subregions covered by the selected wavelet scheduling plan from the start to the end of the task, divided by the total number of subregions. This metric can be used to evaluate the performance of different wavelet scheduling plans when different algorithms are performing the same task. Higher regional coverage indicates better scheduling performance.

[0115] Comparison algorithm: By giving longitude and latitude areas of different sizes, this example compares the task planning efficiency of the wave position scheduling pre-planning method (hereinafter referred to as the comparison method) and the satellite system wave position scheduling planning method proposed in this invention. The wave position scheduling pre-planning method is based on the position and velocity information of the satellite equipment when it starts to perform the task, calculates all possible wave positions that can receive the specified longitude and latitude area in the frame, and schedules them in sequence.

[0116] Effect analysis: Figure 6 、 Figure 7 The coverage results of the wave position scheduling plan for the specified area obtained by using the comparison method and the method of the present invention (retaining 30 optimal scheduling assumptions) are respectively shown. Figure 6 、 Figure 7 As shown, since the comparative method pre-calculates all possible wave positions and schedules them in sequence, it does not consider the changes in the relative position relationship between the satellite movement and the region, and the regional coverage rate is about 50%, with many omissions. The method of the present invention takes into account the real-time changes in the relative position relationship between the satellite movement and the region, and solves the M-best wave position scheduling hypothesis through multi-step dynamic programming. The regional coverage rate is 100%, which effectively improves the regional coverage rate.

[0117] Test conclusion: The satellite system wave position scheduling planning method proposed in this invention can be used for satellite equipment information acquisition and transmission tasks, and can efficiently schedule wave positions for designated areas, which can significantly improve the system's work task efficiency.

[0118] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A satellite system beam position scheduling planning method for a designated area, characterized in that: The steps include: Step 1: Input the satellite system wave position scheduling planning related information; Step 2: Divide the sub-regions according to the input information; Step 3, calculating the maximum slope distance based on the input information; Step 4: Use the maximum slant range and the divided sub-areas to perform wave position scheduling planning; Step 5: Output the optimal wave position scheduling plan; In step 1, the input satellite system beam position scheduling planning related information includes: Specify the longitude and latitude range of the area [L1, L2] × [B1, B2], and the number of longitude divisions n Longi and the number of latitude divisions n Lat ; The operating frequency f and the corresponding wave position table used by the satellite equipment. The wave position table of the operating frequency f has a total of n wave positions, among which the beam pointing angle θ corresponding to the i-th wave position is i , azimuth and beamwidth w i , the wave position residence time is ΔT, the wave position scheduling invalid maximum number threshold U max ; Satellite orbit height h and effective viewing angle θ sat ; Mission start time T1 and the corresponding position of the satellite device at T1 in the WGS84 coordinate system speed and satellite device attitude information; the satellite device attitude information includes yaw angle θ y , pitch angle θ p and the roll angle θ r ; In step 2, the sub-regions are divided according to the input information, including: Divide the number n according to the input longitude Longi and the number of latitude divisions n Lat , calculate the longitude division interval ΔL and latitude division interval ΔB of the area; and divide the designated area evenly into n g =n Longi ×n Lat sub-regions; In increasing order of longitude or latitude, they are 1 to n Longi Column or 1 to n Lat row; record the longitude division p∈{1,…,n Longi } column and latitude partition q∈{1,…,n Lat The latitude and longitude coordinates of the four vertices of the sub-region (p,q) of the row are Then, the vertex coordinates of all sub-regions Convert from the latitude and longitude coordinate system to the WGS84 coordinate system, and obtain the corresponding coordinates after conversion: In step 3, according to the input effective viewing angle θ sat , calculate the corresponding maximum slope distance D max : Where R is the semi-major axis of the Earth; The time corresponding to the kth wave position scheduling is T k Initialize k = 1, set M wave scheduling assumptions S m ,m=1,…,M is the empty set and the corresponding score The number of invalid beam scheduling times U=0; in step 4, beam scheduling planning using the maximum slant range and the divided sub-areas includes the following sub-steps: Step 4.1: According to the off-axis angle θ of the beam pointing corresponding to the wave position of the current operating frequency f, i and azimuth Calculate the corresponding beam pointing direction vector in the satellite body coordinate system Step 4.2: When performing the kth wave position scheduling, based on the position and velocity information of the satellite equipment at time T1, the orbit extrapolation method is used to calculate the k Extrapolated position at time and speed When k=1, the time corresponding to the first wave position scheduling is T1; Step 4.3, calculate the satellite equipment at T in the WGS84 coordinate system. k Extrapolated position at time and the four vertices of the subregion (p,q) The corresponding direction vector and distance Step 4.4, based on satellite equipment in T k Extrapolated position at time speed And the satellite equipment attitude information, calculate the rotation matrix R from the WGS84 coordinate system to the satellite orbit coordinate system w,o And the rotation matrix R that transforms the satellite orbit coordinate system to the satellite body coordinate system o,b , then the direction vector of the satellite device and the sub-area vertex in the WGS84 coordinate system Convert to the satellite's coordinate system; Step 4.5, initialize the n antennas of the satellite equipment to point to the wave position at T k The sub-area number set E covered at the moment i ,i=1,…,n is an empty set, and the sub-area covered by the wave position is searched in the order of i=1,…,n; Step 4.6, for the optimal M wave position scheduling assumptions S retained from the initial time to time k-1 m ,m=1,…,M, and calculate T obtained in step 4.5 k The sub-area number set E covered at the moment i ,i=1,…,n and S m Combine to form a task from start to T k The candidate wave position scheduling assumption S at time m,i ,m=1,…,M,i=1,…,n, that is, T k There are a total of Mn candidate wave position scheduling assumptions at the moment; Step 4.7, for each candidate wave scheduling hypothesis S m,i , recursively calculate the corresponding wave scheduling hypothesis score G m,i ; Step 4.8, schedule the Mn candidate wave positions assuming S m,i ,m=1,…,M,i=1,…,n’s score G m,i Sort and find the first M candidate wave scheduling hypotheses with the largest scores. If the candidate wave scheduling hypothesis with the largest score is greater than T k-1 Assuming that the slot scheduling with the maximum score at the moment does not have any new sub-areas covered, the number of invalid slot scheduling times for the current working frequency is U = U + 1; otherwise, if U is not 0, it is reset to 0; Step 4.9, schedule the Mn candidate wave positions and assume S m,i ,m=1,…,M,i=1,…,n,the first M largest-scoring candidate wave scheduling hypothesis replaces the updated S m ,G m ,m=1,…,M; Step 4.10, judgment condition 1: the optimal M wave position scheduling hypothesis S at the current moment m ,m=1,…,M, there exists a wave position scheduling assumption that has covered all sub-areas; if so, jump to step 5; if not, continue to step 4.11; Step 4.11, judgment condition 2: whether the number of invalid wave scheduling times U at the current working frequency is greater than or equal to the threshold U max ; If U≥U max , the current time T k The retained M wave scheduling assumptions and scores are replaced by T k -U max The M wave scheduling hypotheses and scores retained at time ΔT, jump to step 5; if U max , then calculate the next wave position scheduling time T k+1 =T k +ΔT, and update k=k+1, and jump to step 4.2 to continue execution.​ 2. The satellite system beam position scheduling planning method for a designated area according to claim 1, characterized in that: In step 4.4, the rotation matrix R that converts the WGS84 coordinate system to the satellite orbit coordinate system is w,o The specific calculation method is as follows: Considering the influence of the Earth's rotation angular velocity, the satellite position and velocity in the WGS-84 coordinate system are converted to the instantaneous inertial coordinate system I; Definition of satellite orbit coordinate system: z-axis e z Defined as the unit vector of the line connecting the center of the Earth and the satellite, pointing to the center of the Earth; the x-axis e x Defined as the unit vector of the satellite device velocity direction in the instantaneous inertial coordinate system I; the y-axis e y Defined as a unit vector perpendicular to the x-axis and z-axis and satisfying the right-hand rule; Since the WGS84 coordinate system coincides with the instantaneous inertial coordinate system I at the time of establishment, the vector representations in the WGS84 coordinate system and the instantaneous inertial coordinate system I are the same; therefore, according to the definition of the satellite orbit coordinate system, the transformation matrix from the WGS84 coordinate system to the satellite orbit coordinate system is obtained.

3. The satellite system beam position scheduling planning method for a designated area according to claim 1, characterized in that: In step 4.4, the rotation matrix R of the satellite orbit coordinate system is converted to the satellite body coordinate system o,b The specific calculation method is as follows: There are 6 possible coordinate axis rotation sequences for converting the satellite orbit coordinate system to the satellite body coordinate system, including: 1-2-3, 1-3-2, 2-1-3, 2-3-1, 3-1-2 and 3-2-1, where 1 represents roll, 2 represents pitch, and 3 represents yaw. One of the rotation sequences is used according to the satellite equipment, and the corresponding rotation matrix R is calculated based on the roll angle, pitch angle and yaw angle to convert the satellite orbit coordinate system to the satellite body coordinate system. o,b .

4. The satellite system beam position scheduling planning method for a designated area according to claim 1, characterized in that: In step 4.5, the sub-areas covered by the wave position are found to include: Step 4.5.1, according to the sub-area division method of step 2, there are a total of (n Longi +1)(n Lat +1) different sub-region vertices; according to the beam pointing direction vector p i , the direction vectors of satellite equipment and sub-area vertices in the satellite body coordinate system Get the corresponding vector angle: If θ (l) ≤w i / 2, If both are true, then the sub-region (p, q) is within the coverage of wave position j; otherwise, the sub-region (p, q) is not within the coverage of wave position j; Step 4.5.2, for each subregion (p,q), p∈{1,…,n Longi },q∈{1,…,n Lat }, if the sub-area (p,q) is within the coverage of wave position i, then update the set E i , which will represent the time and sub-area number of the quaternion array (T k ,i,p,q) are added to the set E i ; Otherwise, do not update set E i .

5. The satellite system beam position scheduling planning method for a designated area according to claim 1, characterized in that: In step 4.7, recursively calculate the corresponding wave scheduling hypothesis score G m,i as follows: in, Represents the set E i Does not belong to S m,i The sub-region number set of E i ∩S m,i Represents the set E i S m,i The sub-area number set; |·| indicates the cardinality of the set; the parameter γ1 is used to measure the score of the currently used wave position covering a new sub-area; the parameter γ2 is used to measure the score of the currently used wave position covering a new sub-area.

6. The satellite system beam position scheduling planning method for a designated area according to any one of claims 1 to 5, characterized in that: In step 5, the beam scheduling with the highest score is used as the optimal beam scheduling plan for the satellite device when using the working frequency point f, and the optimal beam scheduling plan is output.

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