A low-orbit SAR satellite data real-time return system and its use method

Abstract

The present invention provides a low-orbit SAR satellite data real-time return system and a method of using the system, comprising a SAR satellite body, a payload phased array antenna assembly connected to the SAR satellite body +Z mounting surface, and a digital transmission phased array antenna assembly connected to the SAR satellite body ‑Y mounting surface, the payload phased array antenna assembly and the digital transmission phased array antenna assembly are both grounded and establish a communication link with the ground, the payload phased array antenna assembly is a flat antenna, the payload phased array antenna assembly is deployed along the X direction, and an inclination angle is set between the digital transmission phased array antenna assembly and the SAR satellite body ‑Y mounting surface. The present invention adopts a digital transmission phased array antenna, and at the same time sets the digital transmission phased array antenna and the payload phased array antenna offset angle θ, and the digital transmission phased array antenna and the payload phased array antenna are not in the same horizontal plane, so as to achieve the purpose of both imaging and establishing satellite-to-ground link data transmission without mutual interference.

Description

Technical Field

[0001] The present invention relates to the field of transmission technology, and in particular to a low-orbit SAR satellite data real-time return system and a use method thereof. Background Art

[0002] Spaceborne synthetic aperture radar (hereinafter referred to as "SAR") uses satellites and other spacecraft as a mobile platform, has all-day, all-weather, and global observation capabilities, and has become an indispensable means of earth observation. In recent years, well-known aerospace agencies at home and abroad have competed to develop SAR satellite programs for global environmental observation to achieve wide-area and high-efficiency earth monitoring.

[0003] SAR satellites have made outstanding contributions to natural resource monitoring, disaster emergency management, earth science research and other fields. They can achieve weekly / monthly / annual updates of global status, monitor the dynamic changes of the earth, understand the laws of surface changes, and explore changes in the human environment.

[0004] During the X-band SAR satellite imaging process, the satellite attitude needs to maintain a certain sideways angle, the imaging frequency is close to the general X-band remote sensing data transmission frequency, and the imaging data volume is large. After imaging, a link needs to be established with the ground station to play back the data, and the imaging data cannot be transmitted to the ground in time to provide services to customers. Therefore, a convenient and practical satellite-to-ground transmission solution is invented, which can transmit the imaging data to the ground in real time during the imaging process to provide customers with timely image services, which has great use value.

[0005] In order to facilitate imaging and data transmission, the general low-orbit X-band SAR satellites, the payload phased array antenna and data transmission antenna must be installed facing the ground. When imaging, the satellite swings 20 to 40 degrees to image; when transmitting data, the satellite stares at the ground station and establishes a satellite-to-ground link for data playback. Therefore, imaging and data transmission cannot work at the same time, which also brings about the problem that remote sensing images cannot be transmitted in real time.

[0006] Therefore, there is an urgent need for a system that can not only image when the satellite is tilted 20 to 40 degrees, but also transmit data under this condition. Summary of the invention

[0007] The present invention aims to solve the problem that SAR satellite imaging and data transmission cannot be performed simultaneously, and provides a low-orbit SAR satellite data real-time return system and a method for using the system. The system adopts a data transmission phased array antenna, and sets an offset angle θ between the data transmission phased array antenna and the payload phased array antenna. The data transmission phased array antenna and the payload phased array antenna are not in the same horizontal plane, so as to achieve the purpose of both imaging and establishing satellite-to-ground link data transmission without mutual interference.

[0008] The present invention provides a low-orbit SAR satellite data real-time return system, comprising a SAR satellite body, a payload phased array antenna assembly connected to the SAR satellite body +Z mounting surface, and a data transmission phased array antenna assembly connected to the SAR satellite body -Y mounting surface;

[0009] The payload phased array antenna assembly and the data transmission phased array antenna assembly are both grounded and establish a communication link with the ground. The payload phased array antenna assembly is a flat antenna. The payload phased array antenna assembly is deployed along the X direction. An inclination angle is set between the data transmission phased array antenna assembly and the SAR satellite body-Y mounting surface.

[0010] The SAR satellite body swings sideways when performing SAR imaging. After the swing, the data transmission phased array antenna assembly can work facing the ground or to the right, and the data transmission beam avoids the payload phased array antenna assembly. SAR imaging payload and ground data transmission are carried out simultaneously.

[0011] The present invention provides a low-orbit SAR satellite data real-time return system. As a preferred embodiment, the SAR satellite body is a box-type satellite body, and the payload phased array antenna assembly is a phased array antenna that is folded on the SAR satellite body +Z mounting surface during the launch phase and unfolded into a plane when in orbit;

[0012] The digital transmission phased array antenna assembly includes a digital transmission phased array antenna mounting bracket and a digital transmission phased array antenna connected to the end of the digital transmission phased array antenna mounting bracket;

[0013] The angle between the working surface of the digital transmission phased array antenna and the -Y mounting surface of the SAR satellite body is θ, and α+θ≥90; θ≤β, where α is the maximum beam scanning angle of the digital transmission phased array antenna, and β is the maximum side swing angle of the payload phased array antenna assembly during imaging.

[0014] The present invention provides a low-orbit SAR satellite data real-time return system, as a preferred embodiment, α=α1+α2, wherein α1 is the half-beam angle of the digital transmission phased array antenna, and α2 is the absolute value of the off-axis angle of the digital transmission phased array antenna.

[0015] The present invention provides a low-orbit SAR satellite data real-time return system. As a preferred embodiment, α1 is 10°, α2 is 60°, the side swing angle of the payload phased array antenna assembly during imaging is 20-40°, and θ is 20°.

[0016] The present invention provides a low-orbit SAR satellite data real-time return system, in which, as a preferred mode, the data transmission phased array antenna beam is not blocked by the SAR satellite body;

[0017] The distance between the end of the working surface of the digital transmission phased array antenna in the +Y direction and the +Z surface of the SAR satellite body is h, and the distance between the end and the -Y surface of the SAR satellite body is d, and tanθ=h / d.

[0018] The present invention provides a low-orbit SAR satellite data real-time return system. As a preferred embodiment, the payload phased array antenna assembly includes a first payload phased array antenna connected to the SAR satellite body +Z mounting surface, a second payload phased array antenna and a third payload phased array antenna respectively connected to both sides of the first payload phased array antenna, and the first payload phased array antenna, the second payload phased array antenna and the third payload phased array antenna are all flat-plate phased array antennas;

[0019] During launch, the second payload phased array antenna and the third payload phased array antenna are respectively folded up and pressed against the +Z plane of the first payload phased array antenna on the same side;

[0020] When in orbit, the second payload phased array antenna and the third payload phased array antenna are respectively deployed along both sides of the first payload phased array antenna to form a coplanar surface and parallel to the Z mounting surface of the SAR satellite body along the X direction, and are located on the side of the digital transmission phased array antenna assembly.

[0021] The present invention provides a low-orbit SAR satellite data real-time return system. As a preferred embodiment, the number of the digital transmission phased array antenna mounting bracket and the digital transmission phased array antenna are both two, which are arranged in parallel.

[0022] The out-of-band suppression of the digital phased array antenna is above 60dB.

[0023] The present invention provides a low-orbit SAR satellite data real-time return system. As a preferred embodiment, a digital transmission phased array antenna mounting bracket includes a first bracket surface connected to the SAR satellite body -Y mounting surface, a second bracket surface connected to the digital transmission phased array antenna, and a third bracket surface connected to both the first bracket surface and the second bracket surface. The second bracket surface, the third bracket surface and the third bracket surface are all planes, and the angle between the first bracket surface and the second bracket surface is 90-θ.

[0024] The present invention provides a method for using a low-orbit SAR satellite data real-time return system, comprising the following steps:

[0025] S1. Assemble the payload phased array antenna assembly and the data transmission phased array antenna assembly with the SAR satellite body;

[0026] S2, when working on-orbit, the payload phased array antenna assembly is unfolded into a flat antenna, and when only data transmission is performed, the process goes to step S3, and when both data transmission and SAR imaging are performed, the process goes to step S4;

[0027] S3, the digital transmission phased array antenna assembly works on the ground and establishes a communication link with the ground station by controlling the direction of the digital transmission beam;

[0028] S4. The SAR satellite body swings sideways by 20 to 40 degrees to perform SAR imaging. At the same time, the digital transmission phased array antenna assembly still transmits imaging data to the ground or to the right, and is not blocked by the SAR satellite body.

[0029] The method for using the low-orbit SAR satellite data real-time return system described in the present invention, as a preferred embodiment, comprises the following steps:

[0030] In steps S3 and S4, the data transmission rate of the payload phased array antenna assembly can reach 2.4 Gbps, realizing real-time return of 2 Gbps data volume for payload imaging;

[0031] In step S3, the phased array antenna assembly of the payload is operated with a left angle of 20° to the ground;

[0032] In step S4, when the SAR satellite body is looking at 20° to the right, the data transmission phased array antenna assembly transmits data directly to the ground; when the SAR satellite body is looking at 40° to the right, the data transmission phased array antenna assembly transmits data to the ground at 20° to the right.

[0033] The present invention has the following advantages:

[0034] The present invention designs the working angles of the data transmission phased array antenna and the SAR payload phased array antenna, which can realize payload imaging and simultaneous data transmission services, and through the spatial layout design and data transmission isolation design, the isolation between the payload and the data transmission antenna meets the simultaneous working requirements. The purpose of real-time return of SAR payload imaging can be achieved, which has great practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram of the structure of a real-time return system for low-orbit SAR satellite data;

[0036] Figure 2 A side view structural diagram of a low-orbit SAR satellite data real-time return system;

[0037] Figure 3 It is a 20° right-view schematic diagram of the structure of a low-orbit SAR satellite data real-time return system;

[0038] Figure 4 It is a schematic diagram of the structure of a low-orbit SAR satellite data real-time return system, viewed from the right at 40°;

[0039] Figure 5 The present invention is a flow chart of a method for using a low-orbit SAR satellite data real-time feedback system.

[0040] Reference numerals:

[0041] 1. SAR satellite body; 2. Payload phased array antenna assembly; 21. First payload phased array antenna; 22. Second payload phased array antenna; 23. Third payload phased array antenna; 3. Digital transmission phased array antenna assembly; 31. Digital transmission phased array antenna mounting bracket; 311. First bracket surface; 312. Second bracket surface; 313. Third bracket surface; 32. Digital transmission phased array antenna. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present invention will be described clearly and completely 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, rather than all the embodiments.

[0043] Example 1

[0044] like Figures 1 to 4 As shown, a low-orbit SAR satellite data real-time return system includes a SAR satellite body 1, a payload phased array antenna assembly 2 connected to the SAR satellite body 1+Z mounting surface, and a data transmission phased array antenna assembly 3 connected to the SAR satellite body 1-Y mounting surface;

[0045] The payload phased array antenna assembly 2 and the data transmission phased array antenna assembly 3 are both grounded and establish a communication link with the ground. The payload phased array antenna assembly 2 is a flat antenna. The payload phased array antenna assembly 2 is deployed along the X direction. An inclination angle is set between the data transmission phased array antenna assembly 3 and the SAR satellite body 1-Y mounting surface;

[0046] The SAR satellite body 1 performs a side swing when performing SAR imaging. After the side swing, the data transmission phased array antenna assembly 3 can work directly facing the ground or right-angled, and the data transmission beam avoids the payload phased array antenna assembly 2. The SAR imaging payload and the ground data transmission are performed simultaneously.

[0047] The SAR satellite body 1 is a box-type satellite body, and the payload phased array antenna assembly 2 is a phased array antenna that is folded on the SAR satellite body 1+Z mounting surface during the launch phase and unfolded into a flat surface when in orbit;

[0048] The payload phased array antenna assembly 2 includes a first payload phased array antenna 21 connected to the SAR satellite body 1+Z mounting surface, a second payload phased array antenna 22 and a third payload phased array antenna 23 respectively connected to both sides of the first payload phased array antenna 21, and the first payload phased array antenna 21, the second payload phased array antenna 22 and the third payload phased array antenna 23 are all flat-plate phased array antennas;

[0049] During transmission, the second payload phased array antenna 22 and the third payload phased array antenna 23 are respectively folded up and pressed against the +Z plane of the first payload phased array antenna 21 on the same side;

[0050] like Figure 1As shown, when in orbit, the second payload phased array antenna 22 and the third payload phased array antenna 23 are respectively deployed along both sides of the first payload phased array antenna 21 to form a coplanar surface and parallel to the Z mounting surface of the SAR satellite body 1 along the X direction, and are located on the side of the data transmission phased array antenna assembly 3;

[0051] like Figure 2 As shown, the digital transmission phased array antenna assembly 3 includes a digital transmission phased array antenna mounting bracket 31 and a digital transmission phased array antenna 32 connected to the end of the digital transmission phased array antenna mounting bracket 31;

[0052] The included angle between the working surface of the digital transmission phased array antenna 32 and the mounting surface of the SAR satellite body 1-Y is θ, and α+θ≥90; θ≤β, where α is the maximum beam scanning angle of the digital transmission phased array antenna 32, and β is the maximum side swing angle of the payload phased array antenna assembly 2 during imaging;

[0053] α=α1+α2, where α1 is the half beam angle of the digital transmission phased array antenna 32, and α2 is the absolute value of the off-axis angle of the digital transmission phased array antenna 32;

[0054] α1 is 10°, α2 is 60°, the side swing angle of the payload phased array antenna assembly 2 during imaging is 20-40°, and θ is 20°;

[0055] The beam of the digital transmission phased array antenna 32 is not blocked by the SAR satellite body 1;

[0056] The distance between the end of the working surface of the digital transmission phased array antenna 32 in the +Y direction and the SAR satellite body 1+Z surface is h, and the distance between the end and the SAR satellite body 1-Y surface is d, and tanθ=h / d;

[0057] There are two digital transmission phased array antenna mounting brackets 31 and two digital transmission phased array antennas 32, which are arranged in parallel.

[0058] The out-of-band suppression of the digital transmission phased array antenna 32 is above 60 dB;

[0059] The digital transmission phased array antenna mounting bracket 31 includes a first bracket surface 311 connected to the SAR satellite body 1-Y mounting surface, a second bracket surface 312 connected to the digital transmission phased array antenna 32, and a third bracket surface 313 connected to both the first bracket surface 311 and the second bracket surface 312. The second bracket surface 312, the second bracket surface 312 and the third bracket surface 313 are all planes, and the angle between the first bracket surface 311 and the second bracket surface 312 is 90-θ.

[0060] like Figure 5 As shown, a method for using a low-orbit SAR satellite data real-time return system includes the following steps:

[0061] S1, assembling the payload phased array antenna assembly 2 and the data transmission phased array antenna assembly 3 with the SAR satellite body 1;

[0062] S2, when working on-orbit, the payload phased array antenna assembly 2 is unfolded into a flat antenna, and when only data transmission is performed, step S3 is entered, and when both data transmission and SAR imaging are performed, step S4 is entered;

[0063] S3, the digital transmission phased array antenna assembly 3 works towards the ground and establishes a communication link with the ground station by controlling the direction of the digital transmission beam;

[0064] The data transmission rate of the payload phased array antenna assembly 2 can reach 2.4Gbps, realizing the real-time return of 2Gbps data volume of payload imaging; the payload phased array antenna assembly 2 is 20° to the left

[0065] Working on the ground;

[0066] S4, the SAR satellite body 1 swings sideways by 20-40 degrees to perform SAR imaging, while the digital transmission phased array antenna assembly 3 still transmits imaging data to the ground or right, and is not blocked by the SAR satellite body 1;

[0067] When the SAR satellite body 1 looks 20° to the right, the digital transmission phased array antenna assembly 3 transmits data directly to the ground; when the SAR satellite body 1 looks 40° to the right, the digital transmission phased array antenna assembly 3 transmits data to the ground by 20° to the right.

[0068] This embodiment uses a data transmission phased array antenna 32. When performing data transmission, there is no need to adjust the attitude of the satellite 1. By controlling the direction of the data transmission beam, a communication link with the ground station is established;

[0069] Two data transmission phased array antennas 32 are used for data transmission, and the data transmission rate can reach 2.4 Gbps, which can realize the real-time return of 2 Gbps data volume of payload imaging;

[0070] The payload phased array antenna 2 is installed on the +Z mounting surface of the satellite 1, and the data transmission phased array antenna 32 is installed on the -Y mounting surface of the satellite 1;

[0071] The half beam angle of the digital transmission phased array antenna 32 is 10°, and the off-axis angle is ±60°; the out-of-band suppression of the digital transmission phased array antenna 32 is above 60 dB;

[0072] During imaging, satellite 1 swings sideways 20 to 40 degrees to form an image;

[0073] Due to the constraints of the beam angle, off-axis angle and lateral swing angle of the digital transmission phased array antenna 32 and the satellite 1, the installation angle of the digital transmission phased array antenna 32 is required as follows: the plane of the digital transmission phased array antenna 32 forms an angle θ with the +Z axis installation surface, which should satisfy the formula 70+θ≥90; θ≤40; select 20°;

[0074] The distance between the installation position of the digital transmission phased array antenna 32 and the +Z plane of the satellite 1 is h, and the distance between the installation position and the -Y plane is d. The calculation relationship between d and h is: tanθ=h / d; if θ is 20° and h is 4cm, then d is 11cm. This ensures that the beam of the digital transmission phased array antenna 32 will not be blocked by the satellite 1.

[0075] In summary, when the satellite 1 is working towards the ground, the phased array antenna 32 can be tilted 20° to the left; when the satellite 1 is looking at 20° to the right, the phased array antenna 32 can work directly towards the ground; when the satellite 1 is looking at 40° to the right, the phased array antenna 32 can be tilted 20° to the right.

[0076] When the SAR payload is working, Figure 3 As shown, the attitude of the star body 1 is 20° to the right, the digital transmission half-beam angle is 10° plus the controllable off-axis angle of ±60°, then the digital transmission 32 beam can scan within a range of ±70°. Because the digital transmission phased array antenna 32 is installed on the -Y plane and the angle with the +Z axis mounting plane is 20°, the phased array antenna 32 can face the ground, and the digital transmission beam can avoid the SAR payload phased array antenna 2 in space, and at the same time establish a communication link with the ground station, so that the payload and the digital transmission can work simultaneously.

[0077] When the SAR payload is working, Figure 4 As shown, the attitude of the star body 1 is 40° to the right, the digital transmission half-beam angle is 10°, plus the controllable off-axis angle of ±60°, the digital transmission beam can scan within a range of ±70°. Because the digital transmission phased array antenna 32 is installed on the -Y plane, and the angle with the +Z axis mounting plane is 20°, the digital transmission phased array antenna 32 turns right 20°, the digital transmission beam can avoid the SAR payload phased array antenna 2 in space, and establish a communication link with the ground station at the same time, so that the payload and the digital transmission can work simultaneously.

[0078] When SAR is not working under load, such as Figure 2 As shown, the satellite 1 is facing the ground, the digital transmission half-beam angle is 10° plus the controllable off-axis angle of ±60°, then the digital transmission beam can scan within a range of ±70°. Since the digital transmission phased array antenna 32 is installed on the -Y plane and the angle with the +Z axis mounting plane is 20°, the digital transmission phased array antenna 32 turns left 20°, and the digital transmission beam can avoid the SAR payload phased array antenna in space and establish a communication link with the ground station at the same time.

[0079] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A low-orbit SAR satellite data real-time return system, characterized by: It comprises a SAR satellite body (1), a payload phased array antenna assembly (2) connected to the +Z mounting surface of the SAR satellite body (1), and a data transmission phased array antenna assembly (3) connected to the -Y mounting surface of the SAR satellite body (1); The payload phased array antenna assembly (2) and the data transmission phased array antenna assembly (3) are both oriented to the ground and establish a communication link with the ground; the payload phased array antenna assembly (2) is a flat-panel antenna; the payload phased array antenna assembly (2) is deployed along the X direction; and an inclination angle is set between the data transmission phased array antenna assembly (3) and the -Y mounting surface of the SAR satellite body (1); The SAR satellite body (1) performs a sideways swing when performing SAR imaging, and after the sideways swing, the data transmission phased array antenna assembly (3) works directly facing the ground or deviating to the right, and the data transmission beam avoids the payload phased array antenna assembly (2), and the SAR imaging payload and the ground data transmission are performed simultaneously; The SAR satellite body (1) is a box-type satellite body, and the payload phased array antenna assembly (2) is a phased array antenna that is folded on the +Z mounting surface of the SAR satellite body (1) during the launch phase and unfolded into a flat surface when in orbit; The digital transmission phased array antenna assembly (3) comprises a digital transmission phased array antenna mounting bracket (31) and a digital transmission phased array antenna (32) connected to the end of the digital transmission phased array antenna mounting bracket (31); The included angle between the working surface of the digital transmission phased array antenna (32) and the -Y mounting surface of the SAR satellite body (1) is θ ,and α + θ ≥90°; θ ≤ β ,in, α is the maximum beam scanning angle of the digital transmission phased array antenna (32), β It is the maximum side swing angle of the payload phased array antenna assembly (2) during imaging.

2. A low-orbit SAR satellite data real-time return system according to claim 1, characterized in that: α = α1 + α2 ,in, α1 is the half beam angle of the digital transmission phased array antenna (32), α2 is the absolute value of the off-axis angle of the digital transmission phased array antenna (32).

3. A low-orbit SAR satellite data real-time return system according to claim 2, characterized in that: α1 is 10°, α 2 The side swing angle of the payload phased array antenna assembly (2) during imaging is 20° to 40°. θ is 20°.

4. The low-orbit SAR satellite data real-time return system according to claim 1, characterized in that: The beam of the digital transmission phased array antenna (32) is not blocked by the SAR satellite body (1); The distance between the end of the working surface of the data transmission phased array antenna (32) in the +Y direction and the +Z surface of the SAR satellite body (1) is: h , and the distance between the SAR satellite body (1) and the -Y plane is d ,and tanθ=h / d .

5. The low-orbit SAR satellite data real-time return system according to claim 1, characterized in that: The payload phased array antenna assembly (2) comprises a first payload phased array antenna (21) connected to the +Z mounting surface of the SAR satellite body (1), a second payload phased array antenna (22) and a third payload phased array antenna (23) respectively connected to both sides of the first payload phased array antenna (21), wherein the first payload phased array antenna (21), the second payload phased array antenna (22) and the third payload phased array antenna (23) are all flat-plate phased array antennas; During transmission, the second payload phased array antenna (22) and the third payload phased array antenna (23) are respectively gathered together at the same side and pressed against the +Z plane of the first payload phased array antenna (21); When in orbit, the second payload phased array antenna (22) and the third payload phased array antenna (23) are respectively deployed along two sides of the first payload phased array antenna (21) to form a coplanar surface and parallel to the Z mounting surface of the SAR satellite body (1) along the X direction, and are located on the side of the data transmission phased array antenna assembly (3).

6. The low-orbit SAR satellite data real-time return system according to claim 1, characterized in that: The number of the digital transmission phased array antenna mounting bracket (31) and the number of the digital transmission phased array antenna (32) are both two, and they are arranged in parallel. The out-of-band suppression of the digital transmission phased array antenna (32) is above 60 dB.

7. The low-orbit SAR satellite data real-time return system according to claim 1, characterized in that: The digital transmission phased array antenna mounting bracket (31) comprises a first bracket surface (311) connected to the -Y mounting surface of the SAR satellite body (1), a second bracket surface (312) connected to the digital transmission phased array antenna (32), and a third bracket surface (313) connected to both the first bracket surface (311) and the second bracket surface (312); the first bracket surface (311), the second bracket surface (312), and the third bracket surface (313) are all planes; and the angle between the first bracket surface (311) and the second bracket surface (312) is 90°-θ.

8. The method for using the low-orbit SAR satellite data real-time return system according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, assembling the payload phased array antenna assembly (2) and the data transmission phased array antenna assembly (3) with the SAR satellite body (1); S2, when working on-orbit, the payload phased array antenna assembly (2) is unfolded into a flat-panel antenna, and when only data transmission is performed, the process proceeds to step S3; when both data transmission and SAR imaging are performed, the process proceeds to step S4; S3, the data transmission phased array antenna assembly (3) works on the ground and establishes a communication link with the ground station by controlling the direction of the data transmission beam; S4, the SAR satellite body (1) is swung sideways by 20° to 40° to perform SAR imaging, while the digital transmission phased array antenna assembly (3) is still transmitting imaging data toward the ground or to the right, and is not blocked by the SAR satellite body (1).

9. The method for using the low-orbit SAR satellite data real-time return system according to claim 8, characterized in that: The following steps are involved: In steps S3 and S4, the data transmission rate of the payload phased array antenna assembly (2) reaches 2.4 Gbps, realizing real-time return of 2 Gbps data volume for payload imaging; In step S3, the payload phased array antenna assembly (2) is operated at a left angle of 20° to the ground; In step S4, when the SAR satellite body (1) is looking at 20° to the right, the data transmission phased array antenna assembly (3) is facing the ground to transmit data; when the SAR satellite body (1) is looking at 40° to the right, the data transmission phased array antenna assembly (3) is tilted 20° to the right to transmit data to the ground.

Images