A method for enhancing three-dimensional grid signal in spatial ultra-sparse array

Abstract

The present invention discloses a method for enhancing a three-dimensional grid signal of a space ultra-sparse array, the method comprising: constructing a distributed star cluster; the distributed star cluster is used as a subarray, each satellite in the star cluster is used as an independent satellite array element, each satellite array element channel uses a far-field beamforming method to synthesize an independent beam to point to the location of a ground target; obtaining parameter information of each satellite in the distributed star cluster; processing the parameter information of each satellite in the distributed star cluster to obtain a near-field beam synthesis direction of the space ultra-sparse array; processing the near-field beam synthesis direction of the space ultra-sparse array to obtain a phase shift value of each satellite array element; using a near-field three-dimensional matching method to process the phase shift value of each satellite array element to obtain a space ultra-sparse array three-dimensional grid enhanced signal. The method of the present invention can effectively enhance the energy of the distributed satellite cluster signal received by the ground receiver.

Description

Technical Field

[0001] The present invention relates to the field of satellite communication technology, and in particular to a method for enhancing three-dimensional grid signals of a spatial ultra-sparse array. Background Art

[0002] With the development of future demand, the demand for high-throughput satellites (large communication capacity, high-speed information transmission) will become more urgent, so the payload has put forward higher gain requirements for antennas. According to antenna theory, in order to increase antenna gain, it is necessary to increase the antenna aperture, and there are three main technical ways to increase the antenna aperture: large reflector antenna, centralized array antenna and distributed array antenna. For satellite-borne applications, due to the limitations of carrying capacity, platform capacity and space environment, more stringent requirements are put forward for antenna design. Satellite-borne centralized array antennas are mainly realized by spatial expansion and splicing. However, in order to reduce gain loss, the surface accuracy of the antenna generally needs to be less than 1 / 20 wavelength. Therefore, with the increase of frequency, the surface accuracy requirements continue to increase, thereby limiting the aperture of the antenna. It can be seen that for satellite-borne applications, the large-aperture reflector and centralized array antenna solutions are adopted. Due to the limitations of carrying capacity, platform capacity and surface accuracy, there is an upper limit to increasing the antenna gain by increasing the absolute aperture. The principle of a distributed antenna array is to install multiple sub-array units with smaller apertures at multiple locations or platforms, achieve signal coherence and utilize the irrelevance of noise to weightedly synthesize the signals of each antenna, thereby increasing the actual aperture and improving the antenna gain.

[0003] In the distributed satellite cluster scenario, when the ground receiver receives satellite signals, the signal received by the receiver is very weak because the satellite is far away from the target radiation source or the radiation source has low transmission power. In order to solve the problem of receiving weak signals, signal enhancement is required. Summary of the invention

[0004] The technical problem to be solved by the present invention is that, in the distributed satellite cluster scenario, when a ground receiver is receiving satellite signals, the energy of the distributed satellite cluster signal received by the ground receiver can be effectively enhanced due to the problem that the satellite is far away from the target radiation source or the radiation source has low transmission power.

[0005] The method of the present invention takes a satellite cluster as a subarray, and adopts far-field beam synthesis to enhance the signal for the array elements in a single satellite; according to the target position of the ground receiver, combined with the position, azimuth, pitch and other information of each satellite in the satellite cluster, the near-field beam synthesis direction of the spatial ultra-sparse array is calculated; the corresponding phase shift value of each array element is calculated according to the beam direction and distance from the target to each satellite antenna array; finally, the inter-satellite beam domain coherent synthesis is performed using the near-field three-dimensional matching principle to obtain an enhanced signal.

[0006] In order to solve the above technical problems, the first aspect of the embodiment of the present invention discloses a method for enhancing a three-dimensional grid signal of a spatial ultra-sparse array, the method comprising:

[0007] S1, constructing a distributed star constellation; the distributed star constellation includes n satellites;

[0008] The distributed star cluster is used as a sub-array, each satellite in the distributed star cluster is used as an independent satellite array element, each satellite array element channel synthesizes an independent beam using a far-field beamforming method, and the independent beams are respectively directed to the locations of ground targets;

[0009] S2, obtaining parameter information of each satellite in the distributed constellation;

[0010] The parameter information is the coordinate information of the satellite in the WGS-84 coordinate system;

[0011] S3, processing parameter information of each satellite in the distributed constellation to obtain a near-field beamforming direction of a spatial ultra-sparse array;

[0012] S4, processing the near-field beamforming direction of the spatial ultra-sparse array to obtain a phase shift value of each satellite array element;

[0013] S5, using a near-field three-dimensional matching method, processing the phase shift value of each satellite array element to obtain a spatial ultra-sparse array three-dimensional grid enhanced signal.

[0014] As an optional implementation manner, in the first aspect of the embodiment of the present invention, the processing of parameter information of each satellite in the distributed constellation to obtain a near-field beamforming direction of a spatial ultra-sparse array includes:

[0015] S31, obtaining target position information of the ground receiver and coordinate information of the satellite WGS-84 in the geodetic coordinate system;

[0016] S32, converting the target position information of the ground receiver into a WGS-84 coordinate system to obtain converted coordinate information;

[0017] S33, processing the converted coordinate information and the coordinate information of the satellite WGS-84 to obtain a unit vector of each satellite in the distributed constellation pointing to a ground receiver target;

[0018] S34, processing the unit vector of each satellite in the distributed constellation pointing to the ground receiver target to obtain the near-field beamforming direction of the spatial ultra-sparse array.

[0019] As an optional implementation manner, in the first aspect of the embodiment of the present invention, converting the target position information of the ground receiver into the WGS-84 coordinate system to obtain the converted coordinate information includes:

[0020] Using a coordinate conversion model, the target position information of the ground receiver is converted into a WGS-84 coordinate system to obtain conversion coordinate information;

[0021] The coordinate transformation model is:

[0022]

[0023] Among them, the target position of the ground receiver in the geodetic coordinate system is (L, B), and the converted coordinate information is (x E ,y E ,z E ), h is the orbital height of the distributed constellation, a is the semi-major axis of the Earth ellipsoid, and e is the first eccentricity of the Earth ellipsoid.

[0024] As an optional implementation manner, in the first aspect of the embodiment of the present invention, the processing of the converted coordinate information and the coordinate information of the satellite WGS-84 to obtain a unit vector of each satellite in the distributed constellation pointing to a ground receiver target includes:

[0025] Using a ground receiver target unit vector calculation model, the conversion coordinate information and the coordinate information of the satellite WGS-84 are processed to obtain a unit vector of each satellite in the distributed constellation pointing to a ground receiver target;

[0026] The ground receiver target unit vector calculation model is:

[0027]

[0028] in, |r xl ,r yl ,r zl | represents the vector [r xl ,r yl ,r zl ] modulo, the total number of satellites in the distributed constellation is n, and the satellite WGS-84 coordinates are (x l ,y l ,z l ), l represents the satellite number in the distributed constellation and l is an integer ranging from 1 to n. The WGS-84 coordinates of the ground receiver target are (x E ,y E ,z E ), r E1 、r E2,…,r En is the unit vector pointing from each satellite in the distributed constellation to the ground receiver target.

[0029] As an optional implementation manner, in the first aspect of the embodiment of the present invention, the near-field beamforming direction of the spatial ultra-sparse array is:

[0030] r=r E1 +r E2 +…+r En

[0031] Among them, r E1 、r E2 ,…,r En is the unit vector of each satellite in the distributed constellation pointing to the ground receiver target, and r is the near-field beamforming direction of the spatial ultra-sparse array.

[0032] As an optional implementation manner, in the first aspect of the embodiment of the present invention, the near-field beamforming direction of the spatial ultra-sparse array is processed to obtain a phase shift value of each satellite array element;

[0033] S41, determining the phase center of the space ultra-sparse array, so that the direction vector from the phase center of the space ultra-sparse array to the ground receiver target is the near-field beamforming direction r of the space ultra-sparse array, and the distance from the phase center of the space ultra-sparse array to the ground receiver target is the orbit height h of the distributed constellation;

[0034] S42, obtaining the distance d from the target to each satellite antenna array in the distributed constellation l =|r xl ,r yl ,r zl |;

[0035] S43, calculating the unit vector r of each satellite in the distributed constellation pointing to the ground receiver target E1 、r E2 ,…,r En and the distance d from the target to each satellite antenna array in the distributed constellation l =|r xl ,r yl ,r zl | process to obtain the direction and distance pair (r El ,d l ), l = 1, 2, L, n;

[0036] S44, for each satellite antenna array direction and distance pair (r El ,d l) and the direction and distance pair (r, h) of the phase center of the preset spatial ultra-sparse array are processed to obtain the phase shift value of each satellite array element.

[0037] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0038] (1) The present invention uses far-field and near-field two-stage beamforming to enhance the signal, and can fully utilize the different beam characteristics of the far-field and near-field of the distributed constellation space ultra-sparse array for beamforming;

[0039] (2) The present invention utilizes the near-field three-dimensional matching principle to perform inter-satellite beam domain coherent synthesis, which can fully utilize the spatial three-dimensional information of the distributed satellite cluster space ultra-sparse array;

[0040] (3) The present invention can effectively enhance the energy of distributed satellite group signals received by ground receivers. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0042] Figure 1 It is a schematic flow chart of a method for enhancing three-dimensional grid signals in a spatial ultra-sparse array disclosed in an embodiment of the present invention;

[0043] Figure 2 It is a flow chart of another method for enhancing three-dimensional grid signals in a spatial ultra-sparse array disclosed in an embodiment of the present invention;

[0044] Figure 3 It is a schematic diagram of three-dimensional grid compensation coherent synthesis disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0045] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme 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 only part of the embodiments of the present invention, not all of the embodiments. 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.

[0046] The terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, device, product or equipment that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods, products or equipment.

[0047] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0048] The present invention discloses a method for enhancing a three-dimensional grid signal of a space ultra-sparse array, the method comprising: constructing a distributed star cluster; the distributed star cluster is used as a subarray, each satellite in the star cluster is used as an independent satellite array element, and each satellite array element channel uses a far-field beamforming method to synthesize an independent beam pointing to the location of a ground target; obtaining parameter information of each satellite in the distributed star cluster; the parameter information includes satellite position information, azimuth information and pitch information; processing the parameter information of each satellite in the distributed star cluster to obtain a near-field beam synthesis direction of the space ultra-sparse array; processing the near-field beam synthesis direction of the space ultra-sparse array to obtain a phase shift value of each satellite array element; using a near-field three-dimensional matching method to process the phase shift value of each satellite array element to obtain a three-dimensional grid enhanced signal of a space ultra-sparse array. The method of the present invention can effectively enhance the energy of a distributed satellite cluster signal received by a ground receiver. The following are detailed descriptions.

[0049] Embodiment 1

[0050] See also Figure 1 , Figure 1 1 is a flow chart of a method for enhancing a three-dimensional grid signal in a spatial ultra-sparse array disclosed in an embodiment of the present invention. Figure 1 The described spatial ultra-sparse array three-dimensional grid signal enhancement method is applied to the field of satellite communication technology. For the distributed satellite cluster scenario, when the ground receiver receives satellite signals, the signal enhancement is performed because the satellite is far away from the target radiation source or the radiation source has low transmission power. The embodiment of the present invention does not limit this. Figure 1 As shown, the spatial ultra-sparse array three-dimensional grid signal enhancement method may include the following operations:

[0051] S1, constructing a distributed star constellation; the distributed star constellation includes n satellites;

[0052] The distributed star cluster is used as a sub-array, each satellite in the distributed star cluster is used as an independent satellite array element, each satellite array element channel synthesizes an independent beam using a far-field beamforming method, and the independent beams are respectively directed to the locations of ground targets;

[0053] S2, obtaining parameter information of each satellite in the distributed constellation;

[0054] The parameter information is the coordinate information of the satellite in the WGS-84 coordinate system;

[0055] S3, processing parameter information of each satellite in the distributed constellation to obtain a near-field beamforming direction of a spatial ultra-sparse array;

[0056] S4, processing the near-field beamforming direction of the spatial ultra-sparse array to obtain a phase shift value of each satellite array element;

[0057] S5, using a near-field three-dimensional matching method, processing the phase shift value of each satellite array element to obtain a spatial ultra-sparse array three-dimensional grid enhanced signal.

[0058] The implementation method of S5 is as follows: at the ground receiver, the signals received from satellites in different directions are phase-shifted by the phase shift value of the corresponding satellite array element, and then all the phase-shifted signals are combined to complete the coherent synthesis of the signals and obtain the spatial ultra-sparse array three-dimensional grid enhanced signal.

[0059] Optionally, the processing of parameter information of each satellite in the distributed constellation to obtain a near-field beamforming direction of a spatial ultra-sparse array includes:

[0060] S31, obtaining target position information of the ground receiver and coordinate information of the satellite WGS-84 in the geodetic coordinate system;

[0061] S32, converting the target position information of the ground receiver into a WGS-84 coordinate system to obtain converted coordinate information;

[0062] S33, processing the converted coordinate information and the coordinate information of the satellite WGS-84 to obtain a unit vector of each satellite in the distributed constellation pointing to a ground receiver target;

[0063] S34, processing the unit vector of each satellite in the distributed constellation pointing to the ground receiver target to obtain the near-field beamforming direction of the spatial ultra-sparse array.

[0064] Optionally, converting the target position information of the ground receiver into a WGS-84 coordinate system to obtain converted coordinate information includes:

[0065] Using a coordinate conversion model, the target position information of the ground receiver is converted into a WGS-84 coordinate system to obtain conversion coordinate information;

[0066] The coordinate transformation model is:

[0067]

[0068] Among them, the target position of the ground receiver in the geodetic coordinate system is (L, B), and the converted coordinate information is (x E ,y E ,z E ), h is the orbital height of the distributed constellation, a is the semi-major axis of the Earth ellipsoid, and e is the first eccentricity of the Earth ellipsoid.

[0069] Optionally, the processing of the converted coordinate information and the coordinate information of the satellite WGS-84 to obtain a unit vector of each satellite in the distributed constellation pointing to a ground receiver target includes:

[0070] Using a ground receiver target unit vector calculation model, the conversion coordinate information and the coordinate information of the satellite WGS-84 are processed to obtain a unit vector of each satellite in the distributed constellation pointing to a ground receiver target;

[0071] The ground receiver target unit vector calculation model is:

[0072]

[0073] in, |r xl ,r yl ,r zl | represents the vector [r xl ,r yl ,r zl ] modulo, the total number of satellites in the distributed constellation is n, and the satellite WGS-84 coordinates are (x l ,y l ,z l ), l represents the satellite number in the distributed constellation and l is an integer ranging from 1 to n. The WGS-84 coordinates of the ground receiver target are (x E ,y E ,z E ), r E1 、r E2 ,…,r Enis the unit vector pointing from each satellite in the distributed constellation to the ground receiver target.

[0074] Optionally, the near-field beamforming direction of the spatial ultra-sparse array is:

[0075] r=r E1 +r E2 +…+r En

[0076] Among them, r E1 、r E2 ,…,r En is the unit vector of each satellite in the distributed constellation pointing to the ground receiver target, and r is the near-field beamforming direction of the spatial ultra-sparse array.

[0077] Optionally, the near-field beamforming direction of the spatial ultra-sparse array is processed to obtain a phase shift value of each satellite array element;

[0078] S41, determining the phase center of the space ultra-sparse array, so that the direction vector from the phase center of the space ultra-sparse array to the ground receiver target is the near-field beamforming direction r of the space ultra-sparse array, and the distance from the phase center of the space ultra-sparse array to the ground receiver target is the orbit height h of the distributed constellation;

[0079] S42, obtaining the distance d from the target to each satellite antenna array in the distributed constellation l =|r xl ,r yl ,r zl |;

[0080] S43, calculating the unit vector r of each satellite in the distributed constellation pointing to the ground receiver target E1 、r E2 ,…,r En and the distance d from the target to each satellite antenna array in the distributed constellation l =|r xl ,r yl ,r zl | process to obtain the direction and distance pair (r El ,d l ), l = 1, 2, L, n;

[0081] S44, for each satellite antenna array direction and distance pair (r El ,d l ) and the direction and distance pair (r, h) of the phase center of the preset spatial ultra-sparse array are processed to obtain the phase shift value of each satellite array element.

[0082] The method for obtaining the phase shift value of each satellite array element is a prior art in the art and is not limited in the present invention.

[0083] It can be seen that the present invention utilizes far-field and near-field two-stage beam synthesis to enhance the signal, and can fully utilize the different beam characteristics of the far field and near field of the distributed star cluster space ultra-sparse array for beam synthesis; the present invention utilizes the near-field three-dimensional matching principle to perform inter-satellite beam domain coherent synthesis, and can fully utilize the spatial three-dimensional information of the distributed star cluster space ultra-sparse array; the present invention can effectively enhance the distributed satellite group signal energy received by the ground receiver.

[0084] Embodiment 2

[0085] See also Figure 2 , Figure 2 1 is a flow chart of another method for enhancing a three-dimensional grid signal in a spatial ultra-sparse array disclosed in an embodiment of the present invention. Figure 2 The described spatial ultra-sparse array three-dimensional grid signal enhancement method is applied to the field of satellite communication technology. For the distributed satellite cluster scenario, when the ground receiver receives satellite signals, the signal enhancement is performed because the satellite is far away from the target radiation source or the radiation source has low transmission power. The embodiment of the present invention does not limit this. Figure 2 As shown, the spatial ultra-sparse array three-dimensional grid signal enhancement method may include the following operations:

[0086] Step 1: Take the satellite cluster as a sub-array and use far-field beamforming to enhance the signal for the array elements in a single satellite. This means that the entire distributed constellation is regarded as a large sub-array, and each satellite in the distributed constellation is regarded as an independent array element. Each satellite array element channel is synthesized into an independent beam through far-field beamforming, which points to the location of the ground target respectively.

[0087] Step 2: According to the target position of the ground receiver, combined with the position, azimuth, pitch and other information of each satellite in the satellite group, the near-field beamforming direction of the spatial ultra-sparse array is calculated, which is specifically:

[0088] Step 2-1: Convert the target position (L, B) of the ground receiver in the geodetic coordinate system to the WGS-84 coordinate system (x E ,y E ,z E ), and its conversion formula is

[0089]

[0090] Where h is the orbital height of the distributed constellation,

[0091]

[0092] Where, e is the first eccentricity of the earth ellipsoid;

[0093] Step 2-2, the total number of satellites in the distributed constellation is n, and the satellite WGS-84 coordinates are (x l ,y l ,z l ), l represents the satellite number in the distributed constellation and l is an integer ranging from 1 to n. The WGS-84 coordinates of the ground receiver target are (x E ,y E ,z E ), calculate the unit vector r pointing from each satellite in the distributed constellation to the ground receiver target E1 、r E2 ,…,r En , and their calculation formulas are:

[0094]

[0095] in, |r xl ,r yl ,r zl | represents the vector [r xl ,r yl ,r zl ]Modulus;

[0096] The above process calculates the direction vector of the target position relative to each satellite;

[0097] Step 2-3, calculate the near-field beamforming direction r, r = r E1 +r E2 +…+r En ;

[0098] Step 3, calculating the corresponding phase shift value of each array element according to the target to each satellite antenna array beam direction and distance, the specific steps include:

[0099] Step 3-1, determine the phase center of the space ultra-sparse array, so that the direction vector from the phase center of the space ultra-sparse array to the ground receiver target is r, and the distance from the phase center of the space ultra-sparse array to the ground receiver target is the distributed constellation orbit height h;

[0100] Step 3-2, the target to each satellite antenna array beam direction is Distance d l =|r xl ,r yl ,r zl |;

[0101] Step 3-3, according to the direction and distance of each satellite antenna array (r El ,d l) are compared with the direction and distance pair (r, h) of the phase center of the spatial ultra-sparse array, and the phase shift value required for each satellite antenna array element is calculated respectively.

[0102] Step 4: Use the near-field three-dimensional matching principle to perform inter-satellite beam domain coherent synthesis to obtain an enhanced signal. Figure 3 It is a schematic diagram of three-dimensional grid compensation coherent synthesis disclosed in an embodiment of the present invention, that is, a schematic diagram of spatial ultra-sparse array three-dimensional grid signal enhancement beam synthesis.

[0103] It can be seen that the present invention utilizes far-field and near-field two-stage beam synthesis to enhance the signal, and can fully utilize the different beam characteristics of the far field and near field of the distributed star cluster space ultra-sparse array for beam synthesis; the present invention utilizes the near-field three-dimensional matching principle to perform inter-satellite beam domain coherent synthesis, and can fully utilize the spatial three-dimensional information of the distributed star cluster space ultra-sparse array; the present invention can effectively enhance the distributed satellite group signal energy received by the ground receiver.

[0104] Through the specific description of the above embodiments, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, it can also be implemented by hardware. Based on such an understanding, the above technical solution can be essentially or partly contributed to the prior art in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, and the storage medium includes a read-only memory (ROM), a random access memory (RAM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), a one-time programmable read-only memory (OTPROM), an electronically erasable rewritable read-only memory (EEPROM), a compact disc (CD-ROM) or other optical disc storage, magnetic disk storage, magnetic tape storage, or any other computer-readable medium that can be used to carry or store data.

[0105] Finally, it should be noted that the method for enhancing three-dimensional grid signals in a spatial ultra-sparse array disclosed in the embodiment of the present invention is only a preferred embodiment of the present invention, and is only used to illustrate the technical solution of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A spatial ultra-sparse array three-dimensional grid signal enhancement method, characterized in that: The method comprises: S1, constructing a distributed star constellation; the distributed star constellation includes n satellites; The distributed star cluster is used as a sub-array, each satellite in the distributed star cluster is used as an independent satellite array element, each satellite array element channel synthesizes an independent beam using a far-field beamforming method, and the independent beams are respectively directed to the locations of ground targets; S2, obtaining parameter information of each satellite in the distributed constellation; The parameter information is the coordinate information of the satellite in the WGS-84 coordinate system; S3, processing parameter information of each satellite in the distributed constellation to obtain a near-field beamforming direction of a spatial ultra-sparse array, including: S31, obtaining target position information of the ground receiver and coordinate information of the satellite WGS-84 in the geodetic coordinate system; S32, converting the target position information of the ground receiver into the WGS-84 coordinate system to obtain converted coordinate information, including: Using a coordinate conversion model, the target position information of the ground receiver is converted into a WGS-84 coordinate system to obtain conversion coordinate information; The coordinate transformation model is: Among them, the target position of the ground receiver in the geodetic coordinate system is (L, B), and the converted coordinate information is (x E ,y E ,z E ), h is the orbital height of the distributed constellation, a is the semi-major axis of the earth ellipsoid, and e is the first eccentricity of the earth ellipsoid; S33, processing the converted coordinate information and the coordinate information of the satellite WGS-84 to obtain a unit vector of each satellite in the distributed constellation pointing to a ground receiver target, including: Using a ground receiver target unit vector calculation model, the conversion coordinate information and the coordinate information of the satellite WGS-84 are processed to obtain a unit vector of each satellite in the distributed constellation pointing to a ground receiver target; The ground receiver target unit vector calculation model is: in, |r xl ,r yl ,r zl | represents the vector [r xl ,r yl ,r zl ] modulo, the total number of satellites in the distributed constellation is n, and the satellite WGS-84 coordinates are (x l ,y l ,z l ), l represents the satellite number in the distributed constellation and l is an integer ranging from 1 to n. The WGS-84 coordinates of the ground receiver target are (x E ,y E ,z E ), r E1 、r E2 ,…,r En is the unit vector pointing from each satellite in the distributed constellation to the ground receiver target; S34, processing the unit vector of each satellite in the distributed constellation pointing to the ground receiver target to obtain a near-field beamforming direction of the spatial ultra-sparse array; The near-field beamforming direction of the spatial ultra-sparse array is: r＝r E1 +r E2 +…+r En Among them, r E1 、r E2 ,…,r En is the unit vector of each satellite in the distributed constellation pointing to the ground receiver target, r is the near-field beamforming direction of the spatial ultra-sparse array; S4, processing the near-field beamforming direction of the spatial ultra-sparse array to obtain a phase shift value of each satellite array element, including: S41, determining the phase center of the space ultra-sparse array, so that the direction vector from the phase center of the space ultra-sparse array to the ground receiver target is the near-field beamforming direction r of the space ultra-sparse array, and the distance from the phase center of the space ultra-sparse array to the ground receiver target is the orbit height h of the distributed constellation; S42, obtaining the distance d from the target to each satellite antenna array in the distributed constellation l =|r xl ,r yl ,r zl |; S43, calculating the unit vector r of each satellite in the distributed constellation pointing to the ground receiver target E1 、r E2 ,…,r En and the distance d from the target to each satellite antenna array in the distributed constellation l =|r xl ,r yl ,r zl | process to obtain the direction and distance pair (r El ,d l ), l=1,2,…,n; S44, for each satellite antenna array direction and distance pair (r El ,d l ) and the direction and distance pair (r, h) of the phase center of the preset spatial ultra-sparse array to obtain the phase shift value of each satellite array element; S5, using a near-field three-dimensional matching method, processing the phase shift value of each satellite array element to obtain a spatial ultra-sparse array three-dimensional grid enhanced signal, including: At the ground receiver, the signals received from satellites in different directions are phase-shifted by the corresponding satellite's array element phase shift value, and then all the phase-shifted signals are combined to complete the coherent synthesis of the signals and obtain the spatial ultra-sparse array three-dimensional grid enhanced signal.

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