Medium-high orbit spaceborne antenna beam position arrangement method

Abstract

The invention relates to the technical field of passive detection, and discloses a medium and high orbit spaceborne antenna beam position arrangement method, which comprehensively considers beam width, beam pointing angle, antenna pointing precision and satellite view field information, and designs antenna beam positions. The problems that in the prior art, it is difficult to achieve satellite view field whole-airspace coverage with few wave potentials, and the utilization rate of the wave potentials is low are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of passive detection, and specifically to a method for arranging wave positions of a spaceborne antenna in medium and high orbits. Background Art

[0002] Due to the characteristics of the orbit of medium and high orbit satellites (orbits of 2000KM - 35000KM), for the detection task of the same area, medium and high orbit satellites have a longer continuous detection duration and a wider coverage field of view than low orbit satellites, and they also require a larger antenna aperture to obtain a larger receiving gain. The intercept probability and detection ability of medium and high orbit satellites for surface targets are closely related to the beam width, the number of instantaneous beams, and the planning of wave position distribution, in addition to being related to sensitivity and instantaneous frequency domain coverage. For an array antenna of a specific frequency band, the beam widths of different frequency points are different. For example, the beam width of a higher frequency point is narrower, and the beam width of a lower frequency point is wider. Therefore, the wave positions of different frequency points need to be designed separately to achieve full scanning of the frequency band and airspace as soon as possible.

[0003] Based on this application background, it is necessary to comprehensively consider information such as beam width, beam pointing angle, antenna pointing accuracy, and satellite field of view, and reasonably design the pointing angle of beam time-sharing scanning (i.e., wave position design), and use as few wave positions as possible to achieve full airspace coverage of the satellite field of view and improve the utilization rate of wave positions. Summary of the Invention

[0004] To overcome the deficiencies of the prior art, the present invention provides a method for arranging wave positions of a spaceborne antenna in medium and high orbits, which solves the problems existing in the prior art such as it being difficult to achieve full airspace coverage of the satellite field of view with fewer wave positions and low utilization rate of wave positions.

[0005] The technical solution adopted by the present invention to solve the above problems is as follows:

[0006] A method for arranging wave positions of a spaceborne antenna in medium and high orbits, which comprehensively considers beam width, beam pointing angle, antenna pointing accuracy, and satellite field of view information to design the antenna wave positions.

[0007] As a preferred technical solution, it includes the following steps:

[0008] S1, set the orbital altitude, field of view, antenna pointing accuracy, and beam width;

[0009] S2, calculate the minimum off-axis angle and the maximum off-axis angle;

[0010] S3, select the nadir point and the beam center pointing with the minimum off-axis angle > 0;

[0011] S4, sequentially select the beam center pointings in the off-axis direction according to the angle coverage rate;

[0012] S5. Calculate the azimuth beam step at different off-axis angles;

[0013] S6. Output the sub-array beam arrangement result;

[0014] S7. Calculate the corresponding main-array beam arrangement result according to the sub-array beam arrangement result;

[0015] S8. Obtain the wave position arrangement results of the main array and the sub-array.

[0016] As a preferred technical solution, in step S1, set the field of view θ u , and divide the field of view θ u with the antenna pointing accuracy Δθ as the step interval to obtain the off-axis angle magnitude θ c of the sub-array beam controllable by the phased array; where θ c = [θ l (1), θ l (2),..., θ l (i),..., θ l (n)] is a 1×n matrix, i represents the beam pointing number, i ∈ [1, n], n represents the total number of beam pointings, n = floor(θ u / Δθ), floor(·) represents rounding down, and θ l (i) is the off-axis angle of the i-th beam pointing that meets the antenna pointing accuracy Δθ.

[0017] As a preferred technical solution, in step S1, interpolate the beam widths of the sub-array phased array antenna at different pointings and a certain frequency band according to the antenna pointing accuracy Δθ, and store the interpolated results in matrix A; where A = [θ f (1), θ f (2),... θ f (i),..., θ f (n)], A is a 1×n matrix, and θ f (i) is the 3dB beam width corresponding to the beam pointing when the off-axis angle magnitude of the sub-array beam is θ l (i).

[0018] As a preferred technical solution, in step S2, the calculation formulas for the minimum off-axis angle and the maximum off-axis angle are:

[0019]

[0020] where θ min (i) represents the minimum off-axis angle of the i-th beam pointing, and θ max (i) represents the maximum off-axis angle of the i-th beam pointing;

[0021] Thus, the θ min(i) The matrix ψ min and the matrix ψ max composed of θ max , use [ψ min , ψ max to represent the field of view range of single-beam formation under different beam pointings; among them, ψ min and ψ max are both 1×n matrices.

[0022] As a preferred technical solution, in step S3, find the subscript k1 corresponding to the first positive number θ min in ψ min (k1) from negative to positive. θ l (k1) is the off-axis angle of the k1-th beam pointing that meets the antenna pointing accuracy Δθ. Let θ r (1) = θ l (k1), and then sequentially execute step S4 in a loop to obtain θ r (M) = θ l (k q ); among them, k1 ∈ [1, n], q ∈ [1, M], θ r (1) represents the off-axis angle selected in the first circle, θ r (M) represents the off-axis angle selected in the M-th circle, and θ l (k q ) represents the off-axis angle of the k q -th beam pointing that meets the antenna pointing accuracy Δθ.

[0023] As a preferred technical solution, in step S4, calculate the off-axis angle θ p of the center of the M-th circle of beam pointings that meets the angle coverage rate η r . The calculation formula is:

[0024]

[0025] Among them, is the difference in the overlapping angle of the off-axis field of view formed by two single-beam pointings, θ f is the beam width corresponding to 3 dB, θ min represents the minimum off-axis angle of the beam pointing, and θ max represents the maximum off-axis angle of the beam pointing;

[0026] Select the off-axis angles of the centers of the beam pointings in the 1st to M-th circles. After selecting up to the M-th circle, obtain the off-axis angle matrix θ r = [θ r (1), θ r (2),..., θ r (i),..., θ r (M)], and then execute step S5; among them, θr is a 1×M matrix.

[0027] As a preferred technical solution, the off-axis angles of the beam pointing centers of the 1st to Mth circles are selected as follows:

[0028] (1) When M = 1, θ r (1) = θ l (k1);

[0029] When M ≥ 2, let θ min = CON(θ min (k1), θ l (k1)), where CON(θ min (k1), θ l (k1)) means finding the θ l (k1) corresponding to the subscript k1; min (k1);

[0030] Let θ max = CON(θ max (k1 + m), θ l (k1 + m)), where CON(θ max (k1 + m), θ l (k1 + m)) means finding the θ l (k1 + m) corresponding to the subscript k1 + m; max (k1 + m);

[0031] Let θ f = CON(θ f (k1 + m), θ l (k1 + m)), where CON(θ f (k1 + m), θ l (k1 + m)) means finding the θ l (k1 + m) corresponding to the subscript k1 + m; f (k1 + m);

[0032] where m represents the subscript offset, m ≥ 1 and m is an integer;

[0033] (2) Substitute θ min , θ max , θ f into formula (2) to calculate η p , and compare it with the set η value. If η p ≥η, then the selected off-axis angle θ r (M) = θ l (k q ) = CON(θ l (k q ), θmax ), and let θ min = CON(θ min (k q ), θ l (k q ))), θ max = CON(θ max (k q + m), θ l (k q + m))), θ f = CON(θ f (k q + m), θ l (k q + m))); Repeat step (2) until θ max > (θ u + θ f (n) / 2);

[0034] where η represents the initial value of the angular coverage rate;

[0035] (3) Obtain the off-axis angles θ r (1), θ r (2),..., θ r (M) corresponding to the first to Mth circles.

[0036] As a preferred technical solution, in step S5, use Δφ M to step in 0 - 360° to select the beam azimuth angle θ q , and the selection method is:

[0037] Introduce the orbital height H and the Earth radius R e , calculate the initial value of the azimuth angle step Δφ M for each circle, where Δφ M represents the azimuth angle step in the off-axis direction θ r (M), and then use Δφ M to step in 0 - 360° to select the beam azimuth angle θ q , including the following steps:

[0038] (1) Calculate the arc length distance d min between θ c1 and the satellite sub-satellite point, and the arc length distance d r (M) between θ c2 and the satellite sub-satellite point. The calculation formula is:

[0039] d c1 = (90 - θ l (k) - cos -1 ((R e + H)·sin(θ l(k)) / R e ))·π·R e / 180 (3)

[0040] d c2 =(90 - θ l (j) - cos -1 ((R e +H)·sin(θ l (j)) / R e ))·π·R e / 180 (4)

[0041] Where j represents the number of the beam pointing;

[0042] (2) According to whether the beam region formed by the sub - array contains the sub - satellite point, the calculation of Δφ M includes the following cases:

[0043] Case 1: When A1 and B are on both sides of the sub - satellite point M, θ min (k)≥0 and θ l (j)≥0;

[0044] Case 2: When A1 and B are on the same side of the sub - satellite point M, θ min (k)<0 and θ l (j)≥0;

[0045] Δφ M is calculated as follows:

[0046]

[0047] Where A1 represents the beam pointing boundary and B represents the beam pointing center;

[0048] (3) According to Δφ M , the azimuth angles φ of each sub - array wave position in the 1st to Mth circles and the required number of sub - array wave positions N q are calculated in sequence. Denote θ q =[φ(1), φ(2),..., φ(N q )]; where φ(1), φ(2),..., φ(N q ) are the azimuth angles of each sub - array wave position in the 1st to Mth circles respectively, θ q is a 1×N q matrix, and θ q is the selected value of the beam azimuth angle.

[0049] As a preferred technical solution, in step S6, the final wave position arrangement information U=|θ r T , θ q T, (θ f / 2) T , N b T |;

[0050] Among them, U is an N q ×4 matrix, N b is the wave position number arranged clockwise, T represents the transpose operation, N b , θ f are both 1×Nq matrices, θ f represents the 3dB beam width selected when the sub-array has different beam pointing directions.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] Compared with the prior art, the present invention provides a method for arranging wave positions of a medium and high orbit spaceborne antenna. The present invention comprehensively considers the influence of factors such as the frequency band required for passive detection, the ground coverage range, the orbital altitude, and the antenna pointing accuracy on the wave position arrangement, reasonably and effectively plans and arranges the sub-array wave positions based on the wave position coverage rate as the evaluation basis, and calculates the associated main array wave positions, which is more in line with the wave position planning and arrangement in engineering applications, reduces the number of invalid wave positions to a certain extent, improves the wave position utilization rate, and saves the passive detection duration. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 is a schematic diagram of the steps of the present invention;

[0054] Figure 2 is a schematic diagram of the single-beam field of view range;

[0055] Figure 3 is a schematic diagram of the angle coverage rate η;

[0056] Figure 4 is a schematic diagram of the wave position relationship between the main array and the sub-array;

[0057] Figure 5 is a schematic diagram of the off-axis and azimuth space of the main array wave positions;

[0058] Figure 6 is a diagram of the wave position arrangement result of the 10GHz sub-array;

[0059] Figure 7 is one of the diagrams of the partial beam arrangement results of the 10GHz main array and sub-array (without considering the pointing accuracy);

[0060] Figure 8 is the second diagram of the partial beam arrangement results of the 10GHz main array and sub-array (considering the pointing accuracy). DETAILED DESCRIPTION OF THE EMBODIMENTS

[0061] The present invention will be further described in detail below in conjunction with embodiments and the accompanying drawings.

[0062] Embodiment 1

[0063] As Figures 1 to 8 shown, the object of the present invention is to provide a method for arranging wave positions of a medium and high orbit spaceborne antenna, especially the influence of factors such as the frequency band required for passive detection, the ground coverage range, the orbital altitude, and the antenna pointing accuracy on the wave position arrangement, and to achieve the full-frequency band, full-region coverage and wave position arrangement tasks of medium and high orbit satellites in the ground coverage field of view. The medium and high orbits involved in the present invention refer to orbits with an orbital altitude range of 2000 KM to 35000 KM.

[0064] A method for arranging wave positions of a medium and high orbit spaceborne antenna, based on the 3dB beam width and beam pointing, considering the constraints of the frequency band required for passive detection, the ground coverage range, the orbital altitude, and the antenna pointing accuracy. First, solve the off-axis angle and azimuth angle of the beam formed by the sub-array antenna, and generate the main array wave position arrangement strategy in sequence according to the sub-array wave position parameters to complete the wave position arrangement task of the medium and high orbit spaceborne antenna. The flow of the entire scheme is as Figure 1 shown, including the following steps:

[0065] Step 1: Set the field of view θ u , and divide the field of view θ u with the antenna pointing accuracy Δθ as the stepping interval to obtain the off-axis angle of the sub-array beam that can be controlled by the phased array and record it as θ c , where θ c =[θ l (1), θ l (2),..., θ l (n)] is a 1×n matrix, and θ l (n) is the off-axis angle of the nth beam pointing that meets the antenna pointing accuracy Δθ, where n = floor(θ u / Δθ); in actual engineering, it is impossible to measure all the antenna beam pointings in the anechoic chamber. Therefore, interpolate the beam widths of the sub-array phased array antenna at different pointings and a certain frequency band according to the antenna pointing accuracy Δθ, and store the results in the matrix A = [θ f (1), θ f (2),..., θ f (n)], where A is a 1×n matrix, and θ f (1) to θ f (n) are the 3dB beam widths under different beam pointings.

[0066] Step 2: Calculate the field of view formed by a single beam at different frequency bands and different beam pointings, which can be defined by the minimum off-axis angle θ min and the maximum off-axis angle θ max in this field of view, θmin and θ max is calculated as follows:

[0067]

[0068] Therefore, the matrix ψ composed of θ minin (i) can be obtained min and the matrix ψ composed of θ max (i), where ψ max , ψ min are both 1×n matrices, and [ψ max , ψ min can represent the field of view range formed by single-beam forming under different beam pointings. As max shown in Figure 2 : M is the sub-satellite point, S represents the satellite, O is the center of the earth, B is the intersection of the beam pointing center and the earth, and A1, A2 are the intersections of the single-beam field of view boundary and the earth; θ min is expressed as ∠A1SM, and θ max is expressed as ∠A2SM; θ l is expressed as ∠MSB, and θ f is expressed as ∠A1SB, ∠A2SB.

[0069] Step 3: To determine the off-axis angle θ r (1) selected in the first circle during the beam arrangement process, it is necessary to find the subscript k1 corresponding to the first positive number θ min in ψ min (k1) from negative to positive. θ l (k1) is the off-axis angle of the beam pointing at this time, and k1 ∈ [1, n]. Let θ r (1) = θ l (k1), and then sequentially execute Step 4 in a loop to obtain θ r (M) = θ l (k q ), q ∈ [1, M]. θ r (M) represents the off-axis angle selected in the Mth circle, and θ l (k q ) represents the off-axis angle of the beam pointing corresponding to the Mth circle.

[0070] Step 4: First, define the angular coverage rate η p , which is defined as the proportion of the overlapping angle of the off-axis fields of view formed by two single-beam pointings. The off-axis angle θ p (M) of the beam pointing center that meets the coverage rate η r can be calculated using the following formula (2). Among them, is the difference in the overlapping angle of the off-axis fields of view formed by two single-beam pointings. As Figure 3 shown. η is defined as the initial value of the angular coverage rate, and the definition is the same as η psame.

[0071]

[0072] Select the off-axis angles of 1 to M circles according to the following algorithm, and execute step 5 after M circles are selected.

[0073]

[0074] Step 5: At this point, the off-axis angle θ is obtained r =[θ r (1), θ r (2), ..., θ r (M)], which is a 1×M matrix; introduce orbital height H, earth radius R e , calculate the initial value of each azimuth step Δφ M , Δφ M Indicates the off-axis direction θ r (M) azimuth angle step, then use Δφ M Step between 0-360° to select the beam azimuth angle θ q .

[0075]

[0076] Step 6: Output the final wave position arrangement information U = [θ r T ,θ q T , (θ f / 2) T , N b T ], U is N q ×4 matrix, N b The wave position number is arranged clockwise, N b ,θ f Both are 1×N q The matrix, θ f Represents the 3dB beam width selected when the secondary array has different beam directions. U=[θ r T ,θ q T , (θ f / 2) T , N b T ] The secondary array angle θ r ,θ q The value is determined according to the antenna pointing accuracy Δθ.

[0077] Step 7: The secondary array is located in the same plane relative to the primary array. Figure 4As shown, the main array wave position close to the sub-satellite point is main wave position 1, and the main wave positions 2, 3, and 4 are arranged in clockwise order.

[0078] According to the secondary array wave position U, the main array wave position azimuth and pitch angle corresponding to each secondary array are calculated in turn. The specific calculation process is as follows, and the spatial diagram is as follows Figure 5 As shown:

[0079] (1) According to the layout method, the main wave position 1 azimuth angle φ′1 (N q )、3 azimuth φ′3(N q ) and the secondary array wave position have the same azimuth information φ(N q ), the main wave positions 1 and 3 are off-axis and point to θ′ r1 (N q ),θ′ r3 (N q ) is calculated as follows:

[0080]

[0081] (2) According to the layout, Δψ is ∠BMP2. The main wave position 2, 4 azimuth φ′2 (N q ),φ′4(N q ) and the off-axis direction points to θ r2 ′(N q ),θ r4 ′(N q ) is calculated as follows:

[0082]

[0083]

[0084] (3) So far, according to 1 to N q The secondary array wave position is used to calculate the main array wave position 1 to 4, and the main array wave position 1 to 4 information is as follows. Among them, P is the main array 1 wave position identifier, which is 1×N q A matrix with all elements being 1:

[0085]

[0086] (4) Angle information θ in U1~U4 r1 ′~θ r4 ′, φ′1~φ′4 are selected according to the antenna pointing accuracy Δθ.

[0087] Step 8: Obtain the main and secondary array wave position information tables U, U1~U4, and the main and secondary array wave position arrangement is completed.

[0088] Example 2

[0089] like Figures 1 to 8As shown, based on Embodiment 1, this embodiment provides a more refined implementation.

[0090] To verify the effectiveness of this method, use this method process, as Figure 1 shown, arrange the main and secondary array wave positions.

[0091] Step 1: Set the field of view θ u = 21°, considering the constraint of the beam pointing by the antenna pointing accuracy Δθ, divide the field of view θ at an interval of Δθ = 0.5° u , obtain the off-axis angle size of the secondary array beam controllable by the phased array and denote it as θ c , where θ c = [0, 0.5, 1.0,..., 20.5, 21] is a 1×43 matrix, n = floor(θ u / Δθ) = 43, θ l (n) is the off-axis angle of the nth beam pointing that meets the antenna pointing accuracy Δθ; in actual engineering, the antenna wave position pointing cannot be measured entirely in the anechoic chamber. Therefore, interpolate the beam widths of the secondary array phased array antenna at different pointings and at a frequency band of 10 GHz according to the antenna pointing accuracy Δθ of the phased array, and store the results in the matrix A = [4.6205, 4.6207,..., 4.9329, 4.9492], where A is a 1×43 matrix, θ f (1) = 4.6205, θ f (n) = 4.9492 are the 3 dB beam widths under different beam pointings.

[0092] Step 2: Calculate the field of view formed by a single beam at different frequency bands and different beam pointings, which can be defined by the minimum off-axis angle θ min and the maximum off-axis angle θ max in this field of view, and the calculation of θ min and θ max is as follows:

[0093]

[0094] Therefore, the matrix ψ min composed of θ min = [-2.3103, -1.8103, -1.3106,..., 18.0335, 18.5254] and the matrix ψ max composed of θ max = [2.3103, 2.8103, 3.3106,..., 22.9665, 23.4746] can be obtained, where ψ min , ψ max are both 1×43 matrices and can represent the field of view range formed by a single beam at different beam pointings. As Figure 2As shown: M is the subsatellite point, S represents the satellite, O is the center of the earth, B is the intersection of the beam pointing center and the earth, A1 and A2 are the intersections of the single beam field of view boundary and the earth; θ min Expressed as ∠A1SM, θ max Expressed as ∠A2SM; θ l Expressed as ∠MSB, θ f Expressed as ∠A1SB, ∠A2SB.

[0095] Step 3: To determine the off-axis angle θ selected for the first pass during beam placement r (1), we need to find ψ min From negative to positive θ min (k1) corresponds to the subscript k1 = 5, θ l (5) = 2 is the off-axis angle of the beam at this time. r (1) = 2, and then repeat step 4 in sequence to obtain θ r (2)~θ r (6),q∈[1,6],θ r (6) represents the off-axis angle selected for the sixth cycle, and 19.5° is the off-axis angle of the beam pointing corresponding to the sixth cycle.

[0096] Step 4: First define the angle coverage η p , defined as the proportion of the off-axis field of view overlap angle formed by two single beam pointing directions, the coverage rate η can be calculated using the following formula (2): p The Mth circle beam points to the center off-axis angle θ r (M). Among them, is the difference in the off-axis field of view overlap angle formed by the two single beam pointing directions, such as Figure 3 As shown. η is defined as the initial value of the angle coverage, set to 0.1, and defined with η p same.

[0097]

[0098] Select the off-axis angles of 1 to M circles according to the following algorithm, and execute step 5 after M circles are selected.

[0099]

[0100] Step 5: At this point, the off-axis angle θ is obtained r =[2, 6, 10, 14, 18, 20.5], which is a 1×6 matrix; introduce orbital height H = 10000km, earth radius R e =6378km, calculate the initial value of the azimuth angle step per circle Δφ M , Δφ M Indicates the off-axis direction θ r (M) azimuth angle step, then use ΔφM Stepwise select the beam azimuth angle θ within 0 - 360° q .

[0101]

[0102]

[0103] Table 1 Sub - array wave position parameter information table

[0104] Number of turns 1 2 3 4 5 6 <![CDATA[Azimuth step Δφ M / degree]]> 72 30 18 12 9 9 Number of azimuthal wave positions / piece 5 12 20 30 40 40

[0105] Step 6: Output the final wave position arrangement information U = [θ r T , θ q T , (θ f / 2) T , N b T , U is a 147×4 matrix, N b is the wave position number arranged clockwise, N b and θ f are both 1×147 matrices, θ f represents the 3dB beam width selected when the sub - array has different beam directions. In U = [θ r T , T , (θ f / 2) T , N b T , the sub - array angles θ r and θ q are selected according to the antenna pointing accuracy Δθ.

[0106] Step 7: The position of the sub - array relative to the main array is in the same plane as shown in Figure 4 . The main array wave position close to the sub - satellite point is the main wave position 1, and the main wave positions 2, 3, and 4 are arranged clockwise in sequence.

[0107] According to the sub - array wave position U, calculate the azimuth and elevation angles of the main array wave position corresponding to each sub - array in sequence. The specific calculation process is as follows, and the space schematic diagram is as shown in Figure 5 :

[0108] (1) According to the layout method, the azimuth angles φ′1(N q ), φ′3(N q ) of the main wave position 1 and 3 have the same azimuth angle information φ(N q ) as the sub - array wave position. The off - axis directions of the main wave positions 1 and 3, θ r1 ′(N q ), θ r3 ′(N q ) are calculated as follows:

[0109]

[0110] (2) According to the layout method, Δψ is ∠BMP2. The azimuth angles φ′2(N q ), φ′4(N q ) and the off-axis direction pointing θ r2 ′(N q ), θ r4 ′(N q ) are calculated as follows:

[0111]

[0112]

[0113] (3) So far, according to groups 1 to N q of the sub-array wave positions, the main-array wave positions 1 to 4 are calculated in sequence, and the information of the main-array wave positions 1 to 4 is as follows. Among them, P is the identifier of the main-array wave position 1, which is a 1×N q matrix with all elements being 1:

[0114]

[0115] (4) The angular information θ r1 ′ to θ r4 ′, φ′1 to φ′4 in U1 to U4 are selected according to the accuracy of the antenna pointing accuracy Δθ.

[0116] Step 8: Obtain the main and sub-array wave position information tables U, U1 to U4. So far, the layout of the main and sub-array wave positions is completed. The layout of the sub-array wave positions at a frequency point of 10 GHz is as Figure 6 shown ( Figure 6 the numbers in it represent the sub-array wave position numbers N b ), 147 sub-array wave positions are arranged, 588 main-array wave positions are arranged, and the main and sub-array wave position results (without restricting the pointing accuracy) are as Figure 7 shown, and the main and sub-array wave position results (restricting the pointing accuracy) are as Figure 8 shown.

[0117] Analysis of simulation results:

[0118] The satellite orbit altitude H = 10000 km, the field of view size θ u = 21°, the maximum field of view θ u between the satellite and the earth is 22.919°, the antenna pointing accuracy Δθ = 0.5. The frequency band of the wave position arrangement is 10 GHz, and the main and sub-array wave positions are arranged according to the scheme proposed in this paper. As Figure 6The shown wave position distribution covers 10 GHz. The initial value of the angular coverage rate is set as η = 0.1, the antenna pointing accuracy is 0.5°. Under the method proposed in this paper, the azimuth accuracy and the off-axis accuracy of the beam meet the selection of the antenna pointing accuracy. The number of wave positions of the sub-array is 147, and the number of wave positions of the main array is 588. Figure 8 It shows the visual arrangement of the beam distributions in the first and second circles. It can be seen from this that the method proposed in this paper solves the problem of the combined arrangement of the wave positions of the main and sub-arrays under the given antenna pointing accuracy. Among them, comparison Figure 7 and Figure 8 respectively show the beam of the main array without taking the accuracy and the wave position arrangement of the main array taking the accuracy. It can be found that when restricted by the antenna pointing accuracy in practical engineering applications, the overlapping area of the originally designed main array beams will increase, which is in line with the beam coverage situation in practical engineering.

[0119] As described above, the present invention can be preferably implemented.

[0120] All the features disclosed in all the embodiments in this specification, or all the steps in any method or process implicitly disclosed, except for the mutually exclusive features and / or steps, can be combined and / or extended and replaced in any way.

[0121] The above description is only a preferred embodiment of the present invention, and does not impose any form of limitation on the present invention. According to the technical essence of the present invention, any simple modification, equivalent replacement, and improvement made to the above embodiments within the spirit and principle of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for arranging the wave positions of medium and high orbit satellite antennas, characterized in that: The antenna position is designed by comprehensively considering the beam width, beam pointing angle, antenna pointing accuracy, and satellite field of view information.

2. The method for arranging the wave positions of medium and high orbit satellite-borne antennas according to claim 1, characterized in that: The following steps are involved: S1, set orbit altitude, field of view, antenna pointing accuracy, and beam width; S2, calculate the minimum off-axis angle and the maximum off-axis angle; S3, select the sub-satellite point and the beam center pointing with the minimum off-axis angle > 0; S4, selecting the off-axis beam center direction in turn according to the angle coverage; S5, calculate the azimuth beam stepping at different off-axis angles; S6, output the secondary array beam arrangement result; S7, calculating the corresponding main array beam arrangement result according to the secondary array beam arrangement result; S8, obtain the wave position arrangement results of the main array and the secondary array.

3. The method for arranging the wave positions of medium and high orbit satellite-borne antennas according to claim 2, characterized in that: In step S1, the field of view θ is set u The field of view is divided into steps θ with the antenna pointing accuracy Δθ as the step interval u , we can get the off-axis angle θ of the phased array controllable secondary array beam c ; where θ c =[θ l (1),θ l (2),...,θ l (i),...,θ l (n)] is a 1×n matrix, i represents the number of the beam pointing, i∈[1,n], n represents the total number of beam pointing, n=floor(θ u / Δθ), floor(·) means rounding down, θ l (i) is the off-axis angle of the i-th beam pointing consistent with the antenna pointing accuracy Δθ.

4. The method for arranging the wave positions of medium and high orbit satellite-borne antennas according to claim 3 is characterized in that: In step S1, the beam width of the sub-array phased array antenna in different directions and a certain frequency band is interpolated according to the antenna pointing accuracy Δθ, and the interpolated result is stored in the matrix A; wherein A=[θ f (1),θ f (2),...θ f (i),...,θ f (n)], A is a 1×n matrix, θ f (i) is the off-axis angle of the secondary array beam, which is θ l (i) corresponds to the 3dB beamwidth of the beam pointing downward.

5. The method for arranging the wave positions of medium and high orbit satellite-borne antennas according to claim 4, characterized in that: In step S2, the calculation formulas for the minimum off-axis angle and the maximum off-axis angle are: Among them, θ min (i) represents the minimum off-axis angle of the i-th beam pointing, θ max (i) represents the maximum off-axis angle of the i-th beam pointing; Thus, we get min (i) The matrix composed of min , by θ max (i) The matrix composed of max , using [ψ min ,ψ max ] represents the field of view of single beam forming under different beam pointing directions; where ψ min , max Both are 1×n matrices.

6. The method for arranging the wave positions of medium and high orbit satellite-borne antennas according to claim 5, characterized in that: In step S3, find ψ min The first positive number θ from negative to positive min (k1) corresponds to the subscript k1, θ l (k1) is the off-axis angle of the k1th beam pointing with the antenna pointing accuracy Δθ, let θ r (1) = θ l (k1), and then execute step S4 in sequence to obtain θ r (M) = θ l (k q ), where k1∈[1,n], q∈[1,M], θ r (1) represents the off-axis angle selected in the first circle, θ r (M) represents the off-axis angle selected for the Mth circle, θ l (k q ) represents the kth q The off-axis angle at which the beam is pointed.

7. The method for arranging the wave positions of medium and high orbit satellite-borne antennas according to claim 6, characterized in that: In step S4, the angle coverage ratio η is calculated. p The Mth circle beam points to the center off-axis angle θ r (M), calculated as: in, is the difference in the off-axis field of view overlap angle formed by the two single beam pointing, θ f is the beam width corresponding to 3dB, θ min represents the minimum off-axis angle of the beam pointing, θ max Indicates the maximum off-axis angle of the beam pointing; Select the off-axis angle of the beam pointing center from the 1st to the Mth circle. When the Mth circle is selected, the off-axis angle matrix θ is obtained. r =[θ r (1),θ r (2),...,θ r (i),...,θ r (M)], and then execute step S5; wherein, θ r is a 1×M matrix.

8. The method for arranging the wave positions of medium and high orbit satellite-borne antennas according to claim 7, characterized in that: Select the off-axis angles of the beam pointing center of the 1st to Mth circles as follows: (1) When M = 1, θ r (1) = θ l (k1); when M ≥2, let θ min =CON(θ min (k1),θ l (k1)), where CON(θ min (k1),θ l (k1)) means to find θ l (k1) corresponds to the θ corresponding to the subscript k1 min (k1); Let θ max =CON(θ max (k1+m),θ l (k1+m)), where CON(θ max (k1+m),θ l (k1+m)) means to find θ l (k1+m) corresponds to the θ corresponding to the subscript k1+m max (k1+m); Let θ f =CON(θ f (k1+m),θ l (k1+m)), where CON(θ f (k1+m),θ l (k1+m)) means to find θ l (k1+m) corresponds to the θ corresponding to the subscript k1+m f (k1+m); Wherein, m represents the subscript offset, m≥1 and m is an integer; (2) Set θ min ,θ max ,θ f Substitute into formula (2) to calculate η p and compared with the set η value. If η p ≥η, then the selected off-axis angle θ is obtained r (M) = θ l (k q )=CON(θ l (k q ),θ max ), and let θ min =CON(θ min (k q ),θ l (k q )),θ max =CON(θ max (k q +m),θ l (k q +m)),θ f =CON(θ f (k q +m),θ l (k q +m)); repeat (2) until θ max >(θ u +θ f (n) / 2); in, η Indicates the initial value of angle coverage; (3) Obtain the off-axis angle θ corresponding to the 1st to Mth circles r (1) θ r (2), ..., θ r (M).

9. A method for arranging the wave positions of medium and high orbit satellite-borne antennas according to claim 7 or 8, characterized in that: In step S5, Δφ is used M Step between 0-360° to select the beam azimuth angle θ q , the selection method is: Introduce orbital height H and earth radius R e , calculate the initial value of each azimuth step Δφ M , Δφ M Indicates the off-axis direction θ r (M) azimuth angle step, then use Δφ M Step between 0-360° to select the beam azimuth angle θ q , including the following steps: (1) Calculate θ min Arc length distance d from the satellite subsatellite point c1 ,θ r (M) Arc length distance d from the satellite subsatellite point c2 , the calculation formula is: d c1 =(90-θ l (k)-cos -1 ((R e +H)·sin(θ l (k)) / R e ))·π·R e / 180 (3) d c2 =(90-θ l (j)-cos -1 ((R e +H)·sin(θ l (j)) / R e ))·π·R e / 180 (4) Wherein, j represents the number of the beam pointing; (2) Depending on whether the beam area formed by the secondary array includes the sub-satellite point, Δφ M The calculation includes the following cases: Case 1: When A1 and B are on both sides of the subsatellite point M, θ min (k)≥0 and θ l (j)≥0; Case 2: When A1 and B are on the same side of the subsatellite point M, θ min (k)<0 and θ l (j)≥0; Δφ M The calculation is as follows: Among them, A1 means the beam points to the boundary, and B means the beam points to the center; (3) According to Δφ M , calculate the azimuth angle φ of each sub-array wave position in the 1st to Mth circles, the required number of sub-array wave positions N q , let θ q =[φ(1),φ(2),...,φ(N q )]; among them, φ(1),φ(2),...,φ(N q ) are the azimuth angles of each sub-array wave position in the 1st to Mth circles, θ q 1×N q The matrix, θ q Select a value for the Beam Azimuth Angle.

10. The method for arranging the wave positions of medium and high orbit satellite antennas according to claim 9, characterized in that: In step S6, the final wave position arrangement information U=[θ r T ,θ q T ,(θ f / 2) T ,N b T ]; Where U is N q ×4 matrix, N b The wave number is arranged clockwise, T represents the transposition operation, N b ,θ f Both are 1×N q The matrix, θ f Represents the 3dB beamwidth selected when the secondary array has different beam pointing directions.

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