Satellite system wave position scheduling planning method for designated area

Abstract

The invention provides a satellite system wave position scheduling planning method for a specified area. The method comprises the following steps: step 1, inputting satellite system wave position scheduling planning related information; 2, dividing sub-regions according to input information; 3, calculating the maximum slope distance according to the input information; step 4, utilizing the maximum slope distance and the divided sub-regions to carry out wave position scheduling planning; and step 5, outputting an optimal wave position scheduling plan. According to the method, the designated area is divided into the union set of the limited number of disjoint sub-areas, the coverage range is measured through the number of the beam position coverage sub-areas, and the problems that the beam position coverage range is irregular and is difficult to effectively select are solved. Moreover, the method can solve the problem of wave position scheduling for the designated area information acquisition and transmission task, achieves the efficient scheduling of the satellite-borne antenna wave position, and improves the task efficiency.

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 have the characteristics of high speed and wide coverage, and have a wide range of application needs in the military and civilian fields. Due to the differences in antenna beam width under different operating frequencies and beam pointing conditions, and due to the factor of the earth's curvature, the ground coverage of different beam pointings is irregular and of different sizes (this coverage is called the beam position corresponding to the beam pointing). In the high-speed dynamic scenario of satellites, antenna beam position scheduling planning is a key factor affecting information acquisition and transmission.

[0003] For each working frequency of the satellite device antenna, a corresponding antenna wave position table is usually pre-designed, which contains a limited number of wave positions that can be selected for system scheduling. The union of these wave position ranges can completely cover the entire effective field of view of the satellite device. The working mode of beam pointing is often called "airspace working mode". Common airspace working modes include scanning the entire field of view range and scanning the designated area. Scanning the entire field of view range refers to scheduling all the wave positions in the wave position table preset according to the working frequency in sequence, so as to achieve time-sharing scanning coverage of the entire field of view; while scanning the designated area range refers to selecting a wave position from the corresponding wave position table according to the working frequency in sequence for scanning, so as to complete the designated area scanning task as quickly as possible. For the designated area of ​​interest, a convenient and intuitive setting method is to use longitude and latitude coordinates. However, due to the high-speed movement of the satellite, the wave position coverage changes rapidly with the movement and attitude of the satellite. The difficulties faced by scanning the designated area are mainly: first, the intersection of the wave position formed by the antenna beam pointing on the earth's surface and the designated area is irregular, and it is difficult to measure the effectiveness of the wave position selection; second, the high-speed movement and attitude change of the satellite will cause the relative position relationship between the satellite device antenna wave position and the designated area to change with time. Therefore, for information acquisition and transmission in a specified area, how to design an efficient wave 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 designated area, which solves the problem that the beam position coverage range is irregular and difficult to measure effectively by dividing the designated area into a union of a finite number of non-overlapping sub-areas and using the number of beam position coverage sub-areas to measure the range of the designated area covered by the beam position; and based on the satellite motion information and the designated area information, a beam position scheduling optimization problem is constructed to solve and obtain the optimal beam position scheduling plan, thereby realizing 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 beam position scheduling planning related information;

[0007] Step 2, dividing the sub-areas according to the input information;

[0008] Step 3, calculating the maximum slope distance according to 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 working frequency point f and the corresponding wave position table used by the satellite equipment. The wave position table of the working frequency point f has a total of n wave positions, among which the beam pointing off-axis angle θ corresponding to the i-th wave position i , azimuth and beam width w i , the wave position residence time is ΔT, and the maximum number of invalid wave position scheduling threshold is 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 equipment attitude information; the satellite equipment attitude information includes the yaw angle θ y , pitch angle θ p and the rolling 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 the latitude division interval ΔB of the area; and divide the specified area evenly into n g =nLongi ×n Lat sub-regions;

[0018] In increasing direction of longitude or latitude, from 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 longitude and latitude 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] Further, 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 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 wave position scheduling times U=0; in step 4, the wave position 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 working frequency point 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 the 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 , and then the direction vector of the satellite device and the sub-area vertex in the WGS84 coordinate system Convert to the satellite 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 scheduling assumptions S retained from the initial time to time k-1 m , m=1,…,M, and the T calculated in step 4.5 is k The sub-area number set E covered at the moment i ,i=1,…,n and S m Combine to form a task starting from T k The candidate wave 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 score. If the candidate wave scheduling hypothesis with the largest score is higher 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;

[0031] Step 4.9, schedule the Mn candidate wave positions assuming S m,i,m=1,…,M,i=1,…,n,the first M largest scoring candidate wave scheduling hypothesis replacement update S m ,G m ,m=1,…,M;

[0032] Step 4.10, judgment condition 1: the optimal M wave scheduling assumptions S at the current moment m ,m=1,…,M has a wave 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 of the current working frequency point 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 assumptions 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 converted to the satellite body coordinate system is 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 of the satellite orbit coordinate system to the satellite body coordinate system is calculated based on the roll angle, pitch angle and yaw angle. o,b .

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

[0041] Step 4.5.1, according to the sub-area division method in 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 the satellite equipment and sub-area vertices in the satellite body coordinate system Get the corresponding vector angle:

[0042]

[0043] like If l=1,2,3,4, 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 is a quaternion array (T k ,i,p,q) are added to the set E i ; Otherwise, do not update 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 Not S m,i The sub-area number set of E i ∩S m,i Represents the set E iS m,i The sub-region number set; |·| indicates taking the set cardinality; the parameter γ1 is used to measure the score of a new sub-region covered by the current wave position; the parameter γ2 is used to measure the score of a sub-region covered again by the current wave position.

[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 union of a finite number of non-overlapping sub-areas and measuring the size of the coverage range by 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 specified area, realize efficient scheduling of satellite-borne antenna wave positions, and improve mission efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0053] Figure 2 The figure is a 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 It is a schematic diagram of evenly dividing a designated longitude and latitude area into sub-areas in an embodiment of the present invention.

[0056] Figure 5 This is the satellite latitude and longitude trajectory diagram simulated in the example.

[0057] Figure 6 This is an illustration of the ground coverage and wave position coverage under the effective viewing angle of the satellite equipment in the example.

[0058] Figure 7 This is the wave position coverage obtained by applying the wave position scheduling pre-planning method in the example.

[0059] Figure 8 This is the wave position coverage obtained by applying the method of the present invention in the example. DETAILED DESCRIPTION

[0060] 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.

[0061] 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.

[0062] Example

[0063] like Figure 1 As shown, this embodiment proposes a satellite system beam position scheduling planning method for a specified area, including the following steps:

[0064] Step 1: Input the satellite system wave position scheduling planning related information;

[0065] The input satellite system beam position scheduling planning related information includes:

[0066] (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 ;

[0067] (2) The operating frequency point f and the corresponding wave position table used by the satellite equipment. The wave position table of the operating frequency point f has a total of n wave positions, among which the beam pointing off-axis angle θ corresponding to the i-th wave position i , azimuth and beam width w i , the wave position residence time is ΔT, and the maximum number of invalid wave position scheduling threshold is U max ;

[0068] (3) Satellite orbit height h and effective viewing angle θ sat ;

[0069] (4) Mission start time T1 and the corresponding position of the satellite equipment at time T1 in the WGS84 coordinate system speed Satellite equipment attitude information (yaw angle θ y , pitch angle θ p and the rolling angle θ r ).

[0070] Terminology explanation:

[0071] (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.

[0072] (2) Beam width w i : The beam width of a satellite equipment antenna refers to the angle between the two directions where the radiation power drops by 3dB on both sides of the maximum radiation direction.

[0073] (3) Wavelength residence time ΔT: The time interval from the start of satellite equipment scheduling a certain wavelength to the start of the next scheduling.

[0074] (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 increases by 1, reaching the maximum number of invalid wave position scheduling threshold U max The current task stops.

[0075] (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.

[0076] (6) Yaw angle θ y , pitch angle θ p and the rolling 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 converting from the orbital coordinate system to the satellite body coordinate system.

[0077] 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 the latitude division interval ΔB of the area; and divide the specified 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 longitude and latitude 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:

[0078] Step 3: According to the input effective viewing angle θ sat , calculate the corresponding maximum slope distance D max :

[0079]

[0080] Among them, R=6378137m is the semi-major axis of the earth.

[0081] Step 4: 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 wave scheduling times U = 0. Perform the following steps:

[0082] Step 4.1, according to the off-axis angle θ of the beam pointing corresponding to the wave position of the current working frequency point f i and azimuth Calculate the corresponding beam pointing direction vector in the satellite body coordinate system

[0083] 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.

[0084] 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

[0085] Step 4.4, based on the satellite equipment in T k Extrapolated position at time speed And 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 , and 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:

[0086]

[0087] 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:

[0088] 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 has no earth 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 this moment are expressed in the instantaneous inertial coordinate system I as follows:

[0089]

[0090]

[0091] 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:

[0092]

[0093]

[0094] 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:

[0095]

[0096] The rotation matrix R of the satellite orbit coordinate system converted to the satellite body coordinate system o,bThe specific calculation method is as follows:

[0097] Let θ r ,θ p ,θ y Respectively represent the roll angle, pitch angle and yaw angle. 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 from the satellite orbit coordinate system to the satellite body coordinate system according to the specific conversion order adopted by the satellite equipment o,b . Let's take the 1-2-3 rotation order as an example. The rotation matrix R o,b The calculation is as follows:

[0098]

[0099] 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 following steps are performed in the order of i=1,…,n to find the sub-area covered by the wave position:

[0100] Step 4.5.1, according to the sub-area division method in 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 the satellite equipment and sub-area vertices in the satellite body coordinate system Get the corresponding vector angle:

[0101]

[0102] like If l=1,2,3,4 all hold true, then the sub-area (p,q) is within the coverage of wave position j; otherwise, the sub-area (p,q) is not within the coverage of wave position j.

[0103] 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 is a quaternion array (T k ,i,p,q) are added to the set E i ; Otherwise, do not update set E i .

[0104] Step 4.6, for the optimal M wave scheduling assumptions S retained from the initial time to time k-1 m , m=1,…,M, and the T calculated in step 4.5 is k The sub-area number set E covered at the moment i ,i=1,…,n and S m Combine to form a task starting from T k The candidate wave 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.

[0105] 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:

[0106] G m,i =G m +γ1|C Ei (S m,i )|+γ2|E i ∩S m,i |

[0107] Among them, C Ei (S m,i ) represents the set E i Not S m,i The sub-area number set (i.e., 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 time); E i ∩S m,i Represents the set E i S m,i The sub-area number set (i.e., 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 re-covered by the currently used wave position.

[0108] 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 score. If the candidate wave scheduling hypothesis with the largest score is higher than T k-1The 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, when U is not 0, it is reset to 0.

[0109] Step 4.9, schedule the Mn candidate wave positions assuming S m,i ,m=1,…,M,i=1,…,n,the first M largest scoring candidate wave scheduling hypothesis replacement update S m ,G m ,m=1,…,M.

[0110] Step 4.10, judgment condition 1: the optimal M wave scheduling assumptions S at the current moment m ,m=1,…,M, there exists a wave scheduling assumption that has covered all sub-areas; if so, jump to step 5; if not, continue to step 4.11.

[0111] Step 4.11, judgment condition 2: whether the number of invalid wave scheduling times U of the current working frequency point 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 assumptions 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.

[0112] Step 5: The highest score m * =argmin m∈{1,…,M} G m The 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 task is completed.

[0113] An example:

[0114] This example simulates and generates the satellite 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 altitude 700km, and the generated orbit is as follows: Figure 5 As shown. Satellite effective viewing angle θ sat ​The initial orbit 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 satellite equipment operating frequency in this task is 10000MHz, and there are 49 corresponding 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 as follows Figure 6 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 is a comparative analysis of 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, the starting latitude and ending latitude are set to 10° and 18° respectively, and the longitude is divided into n Longi = 20 columns and latitude divided into n Lat =20 lines.

[0115] Table 1, wave position table corresponding to a given operating frequency:

[0116]

[0117] Evaluation index: To evaluate the performance of the method, this example uses regional coverage as the evaluation index, which is specifically defined as the sum of the number of sub-regions covered by the wave positions selected in the wave position scheduling plan from the start of the task to the end of the task divided by the total number of sub-regions. When different algorithms perform the same task, this index can be used to evaluate the performance of different wave position scheduling plans. The higher the regional coverage, the better the scheduling performance.

[0118] 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 the present invention, wherein the wave position scheduling pre-planning method is based on the position speed information when the satellite equipment starts to execute the task, calculates all possible wave positions that can receive the specified longitude and latitude area in the frame, and schedules them in turn.

[0119] Effect analysis: Figure 7 , Figure 8 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 shown respectively. Figure 7 , Figure 8As shown, since the comparison method pre-calculates all possible wave positions and schedules them in sequence, the change in the relative position relationship between the satellite movement and the region is not considered, and the regional coverage 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 is 100%, which effectively improves the regional coverage.

[0120] 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.

[0121] The above description is only a preferred embodiment of the present invention and is 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 satellite system beam position scheduling planning method for a designated area, characterized in that: The steps include: Step 1: input the satellite system beam position scheduling planning related information; Step 2, dividing the sub-areas according to the input information; Step 3, calculating the maximum slope distance according to 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.

2. The satellite system beam position scheduling planning method for a designated area according to claim 1, characterized in that: 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 working frequency point f and the corresponding wave position table used by the satellite equipment. The wave position table of the working frequency point f has a total of n wave positions, among which the beam pointing off-axis angle θ corresponding to the i-th wave position i , azimuth and beam width w i , the wave position residence time is ΔT, and the maximum number of invalid wave position scheduling threshold is 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 equipment attitude information; the satellite equipment attitude information includes the yaw angle θ y , pitch angle θ p and the rolling angle θ r .

3. The satellite system beam position scheduling planning method for a designated area according to claim 2, characterized in that: In step 2, the sub-areas 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 the latitude division interval ΔB of the area; and divide the specified area evenly into n g =n Longi ×n Lat sub-regions; In increasing direction of longitude or latitude, from 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 longitude and latitude coordinates of the four vertices of the sub-region (p, q) of the row are l=1,2,3,4; then, the vertex coordinates of all sub-areas Convert from the latitude and longitude coordinate system to the WGS84 coordinate system, and obtain the corresponding coordinates after conversion:

4. The satellite system beam position scheduling planning method for a designated area according to claim 3, characterized in that: 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.

5. The satellite system beam position scheduling planning method for a designated area according to claim 4, characterized in that: 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 m=1,…,M, the number of invalid wave position scheduling times U=0; in step 4, the wave position 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 working frequency point 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) Direction vector corresponding to l=1,2,3,4 and distance Step 4.4, based on the 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 , and then the direction vector of the satellite device and the sub-area vertex in the WGS84 coordinate system Convert to the satellite 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 scheduling assumptions S retained from the initial time to time k-1 m , m=1,…,M, and the T calculated in step 4.5 is k The sub-area number set E covered at the moment i ,i=1,…,n and S m Combine to form a task starting from T k The candidate wave 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 score. If the candidate wave scheduling hypothesis with the largest score is higher 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; Step 4.9, schedule the Mn candidate wave positions assuming S m,i ,m=1,…,M,i=1,…,n,the first M largest scoring candidate wave scheduling hypothesis replacement update S m ,G m ,m=1,…,M; Step 4.10, judgment condition 1: the optimal M wave scheduling assumptions S at the current moment m ,m=1,…,M has a wave 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 of the current working frequency point 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.​ 6. The method for satellite system beam position scheduling planning for a designated area according to claim 5, characterized in that: In step 4.4, 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: 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.

7. The satellite system beam position scheduling planning method for a designated area according to claim 5, characterized in that: In step 4.4, the rotation matrix R of the satellite orbit coordinate system converted to the satellite body coordinate system is 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 of the satellite orbit coordinate system to the satellite body coordinate system is calculated based on the roll angle, pitch angle and yaw angle. o,b .

8. The method for satellite system beam position scheduling planning for a designated area according to claim 5, 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 in 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 the satellite equipment and sub-area vertices in the satellite body coordinate system l=1,2,3,4 to obtain the corresponding vector angle: If θ (l) ≤w i / 2, If l=1,2,3,4, 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 is a quaternion array representing time and sub-area number (T k ,i,p,q) are added to the set E i ; Otherwise, do not update set E i .

9. The method for satellite system beam position scheduling planning for a designated area according to claim 5, characterized in that: In step 4.7, the corresponding wave scheduling hypothesis score G is recursively calculated m,i as follows: in, Represents the set E i Not S m,i The sub-area number set of E i ∩S m,i Represents the set E i S m,i The sub-region number set; |·| indicates taking the set cardinality; the parameter γ1 is used to measure the score of a new sub-region covered by the current wave position; the parameter γ2 is used to measure the score of a sub-region covered again by the current wave position.

10. The satellite system beam position scheduling planning method for a designated area according to any one of claims 5 to 9, characterized in that: 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.

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