Ground-based curved surface synthetic aperture radar system

Abstract

The invention discloses a ground-based curved surface synthetic aperture radar system, which comprises a rotating unit, a conversion control unit, a radar acquisition unit and a processing control unit, wherein the rotating unit is used for carrying out composite rotation according to a rotation control instruction so as to generate a rotation angle signal; the radar acquisition unit is driven to perform composite rotation; the conversion control unit is used for generating first data information and collecting a control instruction according to the rotation angle signal; the radar acquisition unit is used for being driven by the rotating unit to perform composite rotation; performing equal-interval sampling according to the acquisition control instruction to obtain second data information; the processing control unit is used for sending a rotation control instruction to the rotation unit so as to control the rotation unit to perform composite rotation; and radar imaging is carried out according to the first data information and the second data information, and the effects of high-precision three-dimensional imaging and low-error three-dimensional deformation information acquisition can be achieved.

Description

Technical Field

[0001] The present application relates to the field of radar imaging technology, and in particular to a ground-based curved surface synthetic aperture radar system. Background Art

[0002] As we all know, SAR (Synthetic Aperture Radar) is a high-resolution radar device and an active ground observation system using microwave imaging technology. It measures the distance by emitting electromagnetic pulses and receiving target echoes, and then generates high-resolution radar images to achieve target observation. It uses the radar antenna on the flight platform to transmit microwave signals to the ground and receive signals reflected from the ground. By recording the echo signals received at multiple different locations and combining them using signal processing technology, an equivalent large-aperture radar signal is formed, thereby achieving high-resolution imaging.

[0003] At present, the spiral arm synthetic aperture radar has important applications in the field of ground monitoring. It is set on the antenna at the end of the spiral arm far away from the rotation center. It generates images after rotation to ensure that a wide range of scenes can be covered in one observation, thereby effectively improving the ground monitoring efficiency of the system. The spiral arm synthetic aperture radar has the advantages of all-day, all-weather, portability and 360-degree all-round observation. It can be widely used in high-resolution imaging and deformation measurement of mines and infrastructure buildings.

[0004] However, there are two problems with the actual use of spiral SAR. On the one hand, in the early stage of design, it was assumed that the spiral arm rotates at a uniform speed and the radar is designed to achieve equally spaced data sampling. However, in the actual process, the motor has non-uniform motion and the above assumptions cannot be met, which ultimately causes imaging defocus and the introduction of interference phase errors. On the other hand, the spiral SAR can only rotate in the horizontal plane, and thus can only achieve two-dimensional high-resolution imaging. If the target object of the actual observation scene is a complex three-dimensional shape, such as mine slopes and infrastructure buildings, the imaging of the spiral SAR will be limited. Summary of the invention

[0005] Based on this, the present application provides a ground-based curved synthetic aperture radar system to solve the problems in related technologies such as the non-uniform motion of the motor and the fact that the radar can only rotate in the horizontal plane, resulting in radar imaging defocusing, introduction of interference phase errors, and only achieving two-dimensional high-resolution imaging.

[0006] In order to solve the above problems, a ground-based curved surface synthetic aperture radar system is provided, comprising a rotation unit, a conversion control unit, a radar acquisition unit and a processing control unit; wherein,

[0007] The rotation unit is used to perform compound rotation according to the rotation control instruction to generate a rotation angle signal, and send the rotation angle signal to the conversion control unit; and drive the radar acquisition unit to perform compound rotation;

[0008] A conversion control unit, used to generate first data information and an acquisition control instruction according to the rotation angle signal, and send the first data information to the processing control unit, and send the acquisition control instruction to the radar acquisition unit;

[0009] The radar acquisition unit is used to be driven by the rotating unit to perform compound rotation; and to perform equal-interval sampling according to the acquisition control instruction to obtain second data information, and send the second data information to the processing control unit;

[0010] The processing control unit is used to send a rotation control instruction to the rotation unit to control the rotation unit to perform compound rotation; and perform radar imaging according to the first data information and the second data information.

[0011] Preferably, the rotating unit comprises a rotating platform and an angle encoding unit; wherein,

[0012] A rotating platform, used for performing compound rotation according to a rotation control instruction;

[0013] The angle encoding unit is used to sample the composite rotation angle of the rotating platform to obtain a rotation angle signal, and send the rotation angle signal to the conversion control unit.

[0014] Preferably, the rotating unit further comprises a rotating arm;

[0015] The rotary arm is arranged on the upper end surface of the rotary platform, and the radar collection unit is arranged at the end of the rotary arm;

[0016] The rotary arm is used to be driven by the rotating platform to perform compound rotation, and to drive the radar acquisition unit to perform compound rotation.

[0017] Preferably, the rotation control instruction includes a horizontal rotation control instruction, the rotating platform is a two-dimensional turntable, and a first driving motor is arranged inside the rotating platform;

[0018] The first driving motor is used for performing horizontal rotation according to a horizontal rotation control instruction.

[0019] Preferably, the rotation control instruction also includes a pitch rotation control instruction, and a second drive motor is also provided inside the rotating platform;

[0020] The second driving motor is used for rotating in the pitch direction according to the pitch rotation control instruction.

[0021] Preferably, the angle encoding unit comprises a horizontal angle encoder;

[0022] The horizontal angle encoder is arranged on the output shaft of the first driving motor, and is used to generate a horizontal rotation angle signal according to the angle of rotation of the two-dimensional turntable in the horizontal direction, and send the horizontal rotation angle signal to the conversion control unit.

[0023] Preferably, the angle encoding unit further comprises a pitch angle encoder;

[0024] The pitch angle encoder is arranged on the output shaft of the second driving motor, and is used to generate a pitch rotation angle signal according to the rotation angle of the two-dimensional turntable in the pitch direction, and send the pitch rotation angle signal to the conversion control unit.

[0025] Preferably, both the horizontal angle encoder and the pitch angle encoder are photoelectric encoders, and the photoelectric encoder is provided with annular clear and dark scale lines, and generates a rotation angle signal according to the scale lines.

[0026] Preferably, the conversion control unit includes a conversion unit;

[0027] The conversion unit is used for converting the horizontal rotation angle signal into a horizontal single-ended signal, and converting the pitch rotation angle signal into a pitch single-ended signal.

[0028] Preferably, the conversion control unit further comprises a control unit;

[0029] The control unit is used to count the horizontal single-ended signals, generate an acquisition control instruction based on a preset horizontal angle trigger interval, and send the acquisition control instruction to the radar acquisition unit; and count the pitch single-ended signals, generate first data information based on a preset pitch angle rising interval, and send the first data information to the processing control unit.

[0030] The embodiments of the present disclosure have at least the following advantages: through the configuration of the rotation unit, the conversion control unit, the radar acquisition unit and the processing control unit, the radar acquisition unit and the rotation unit can work together, and the radar acquisition unit collects radar data at equal intervals and evenly during the compound rotation process of the rotation unit to achieve good quality SAR imaging, thereby achieving the effect of reducing the problems of imaging defocus and introducing interference phase errors and improving the accuracy of three-dimensional imaging of radar data and three-dimensional deformation information. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the conventional technology, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 It is a schematic diagram of the overall structure of a ground-based curved surface synthetic aperture radar system in an embodiment of the present application;

[0033] Figure 2 It is a structural block diagram of a ground-based curved surface synthetic aperture radar system in an embodiment of the present application.

[0034] Figure 3 It is a schematic diagram of the rotation angle of a ground-based curved surface synthetic aperture radar system in an embodiment of the present application. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0036] It should be noted that the illustrations provided in this embodiment only illustrate the basic concept of the present application in a schematic manner, and therefore the drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0037] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which this application can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by this application, should still fall within the scope of the technical contents disclosed in this application.

[0038] The directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "middle", "longitudinal", "lateral", "horizontal", "inner", "outer", "radial", "circumferential" and the like in this specification are based on the directions or positional relationships shown in the drawings and are only for the convenience of simplifying the description. They do not indicate or imply that the devices or elements referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0039] In the prior art, there are two problems in the actual use of the spiral arm synthetic aperture radar; on the one hand, in the early stage of the design of the spiral arm synthetic aperture radar, it is assumed that the spiral arm rotates at a uniform speed and the radar realizes equal-interval data sampling for design, but in the actual process, the motor has non-uniform motion, which cannot meet the above assumptions, and ultimately causes imaging defocus and introduces errors in interference phase; on the other hand, the spiral arm synthetic aperture radar can only rotate in the horizontal plane, and thus can only achieve two-dimensional high-resolution imaging; and if the target object of the actual observation scene is a complex three-dimensional shape, such as a mine slope and infrastructure buildings, the imaging of the spiral arm synthetic aperture radar will be limited. Therefore, the embodiment of the present application provides a ground-based curved surface synthetic aperture radar system, which can achieve the effect of driving the radar acquisition unit to perform compound rotation and realize equal-interval uniform sampling while setting up a rotation unit, a conversion control unit, a radar acquisition unit, and a processing control unit, thereby achieving the effect of improving imaging accuracy and improving deformation inversion accuracy.

[0040] The following is a detailed description of a ground-based curved surface synthetic aperture radar system provided by this embodiment in conjunction with the accompanying drawings. Figure 1 As shown, it includes a rotation unit, a conversion control unit, a radar acquisition unit and a processing control unit; wherein the rotation unit is used to perform compound rotation according to the rotation control instruction to generate a rotation angle signal, and send the rotation angle signal to the conversion control unit; and drive the radar acquisition unit to perform compound rotation; the conversion control unit is used to generate first data information and an acquisition control instruction according to the rotation angle signal, and send the first data information to the processing control unit, and send the acquisition control instruction to the radar acquisition unit; the radar acquisition unit is used to be driven by the rotation unit to perform compound rotation; and perform equal-interval sampling according to the acquisition control instruction to obtain second data information, and send the second data information to the processing control unit; the processing control unit is used to send a rotation control instruction to the rotation unit to control the rotation unit to perform compound rotation; and perform radar imaging according to the first data information and the second data information.

[0041] The first data information includes but is not limited to pitch angle position information; the second data information includes but is not limited to radar echo information.

[0042] Here, since signal transmission is required between the rotation unit, the conversion control unit, the radar acquisition unit and the processing control unit, the rotation unit is electrically connected to the conversion control unit, the conversion control unit is electrically connected to the radar acquisition unit, and the processing control unit is electrically connected to the rotation unit, the conversion control unit and the radar acquisition unit respectively, thereby realizing signal transmission of the overall system.

[0043] Specifically, the rotating unit may be a rotating platform, which may perform compound rotation according to the rotation control instruction, including but not limited to rotation in the horizontal direction and the pitch direction. A rotation angle signal may be generated based on the rotation angle, and the rotation angle signal may be sent to the conversion control unit; at the same time, the radar acquisition unit is arranged at the upper end of the rotating unit, so that the rotating unit may drive the radar acquisition unit to perform compound rotation while rotating.

[0044] The conversion control unit can be any one of MCU (Microcontroller Unit), FPGA (Field-Programmable Gate Array), PLC (Programmable Logic Controller) and ARM (Advanced RISC Machine), which can receive the rotation angle signal sent by the rotation unit, generate first data information according to the rotation angle signal, and send the first data information to the processing control unit so that the processing control unit can perform radar imaging in combination with the information; at the same time, it can also generate an acquisition control instruction and send the acquisition control instruction to the radar acquisition unit so as to control the radar acquisition unit to collect radar data.

[0045] The radar acquisition unit can be a radar acquisition sensor. Since it is arranged at the upper end of the rotating unit, it can be driven by the rotating unit to perform compound rotation; at the same time, it can also receive the acquisition control instructions sent by the conversion control unit, perform equal-interval sampling according to the acquisition control instructions to obtain second data information, and send the second data information to the processing control unit so that the processing control unit can combine the information for radar imaging.

[0046] The processing control unit may be a PC, which may send a rotation control instruction to the rotating unit to control the rotating unit to perform a compound rotation; at the same time, radar imaging may be performed according to the first data information and the second data information to realize three-dimensional imaging of the curved surface synthetic aperture data.

[0047] The above operation, through the setting of the rotation unit, the conversion control unit, the radar acquisition unit and the processing control unit, can drive the radar acquisition unit to perform compound rotation while achieving uniform sampling at equal intervals, thereby achieving the effect of improving imaging accuracy and deformation inversion accuracy; at the same time, the system also has the advantages of high monitoring efficiency, large field of view, small size and light weight.

[0048] In one embodiment, referring to Figure 1 , Figure 2As shown, the rotation unit includes a rotation platform and an angle encoding unit; wherein the rotation platform is used to perform compound rotation according to the rotation control instruction; the angle encoding unit is used to sample the compound rotation angle of the rotation platform to obtain a rotation angle signal, and send the rotation angle signal to the conversion control unit.

[0049] Specifically, since the processing control unit can control the rotating platform to rotate forward, reverse, stop, and cycle, etc., the rotating platform can receive the rotation control instruction sent by the processing control unit and perform compound rotation according to the rotation control instruction. The angle encoding unit is arranged on the rotating platform, and can sample the compound rotation angle of the rotating platform to obtain a rotation angle signal, and send the rotation angle signal to the conversion control unit.

[0050] In one feasible manner, the rotating unit also includes a rotary arm; the rotary arm is arranged on the upper end surface of the rotating platform, and the radar collecting unit is arranged at the end of the rotary arm; the rotary arm is used to be driven by the rotating platform to perform a compound rotation, and to drive the radar collecting unit to perform a compound rotation.

[0051] Specifically, one end of the arm is fixed to the upper end surface of the rotating platform through a connector, and the other end extends to the outside, and can be driven by the rotating platform to perform compound rotation; the radar acquisition unit is set at the end of the arm through a connector, and can be driven by the arm to perform compound rotation, so that the radar acquisition unit can achieve radar data sampling. It should be noted that there is no specific restriction on the connector here, and any connector that can achieve fixed connection can be used in this application document.

[0052] The above operation, through the cooperation of the rotating platform, the angle encoding unit and the rotary arm, enables the radar acquisition unit to achieve equal-interval sampling during the compound rotation process, thereby obtaining three-dimensional deformation information and realizing three-dimensional imaging.

[0053] In one embodiment, continue to refer to Figure 1 , Figure 2 As shown, the rotation control instruction includes a horizontal rotation control instruction, the rotating platform is a two-dimensional turntable, and a first drive motor is arranged inside the rotating platform; the first drive motor is used to rotate in the horizontal direction according to the horizontal rotation control instruction.

[0054] Specifically, the rotating platform is a two-dimensional turntable, and a first drive motor is arranged inside the rotating platform. Here, after power-on, the processing control unit can send a horizontal rotation control instruction to the first drive motor, and after the first drive motor receives the horizontal rotation control instruction, it can rotate 360 ​​degrees in the horizontal direction according to the horizontal rotation control instruction, thereby driving the two-dimensional turntable to rotate 360 ​​degrees in the horizontal direction.

[0055] In one achievable manner, the rotation control instruction also includes a pitch rotation control instruction, and a second drive motor is further provided inside the rotating platform; the second drive motor is used to rotate in the pitch direction according to the pitch rotation control instruction.

[0056] Specifically, a second drive motor is provided inside the rotating platform. Here, the processing control unit can send a pitch rotation control instruction to the second drive motor, and after receiving the pitch rotation control instruction, the second drive motor can rotate in the pitch direction according to the pitch rotation control instruction, thereby driving the two-dimensional turntable to rotate in the pitch direction.

[0057] The above operation, by arranging the first drive motor and the second drive motor inside the two-dimensional turntable, enables the two-dimensional turntable to have the ability of horizontal and pitch rotation, so as to realize the compound rotation of the rotating platform, and then drive the rotary arm to rotate in the horizontal and pitch dimensions. The rotary arm drives the radar acquisition unit to realize 360-degree radar data sampling in the horizontal direction at different pitch angles.

[0058] In one embodiment, referring to Figure 2 , Figure 3 As shown, the angle encoding unit includes a horizontal angle encoder; the horizontal angle encoder is arranged on the output shaft of the first driving motor, and is used to generate a horizontal rotation angle signal according to the angle of rotation of the two-dimensional turntable in the horizontal direction, and send the horizontal rotation angle signal to the conversion control unit.

[0059] Specifically, the horizontal angle encoder is arranged on the output shaft of the first driving motor to realize the coaxial rotation of the horizontal angle encoder and the first driving motor. When the first driving motor drives the two-dimensional turntable to rotate, the horizontal angle encoder can generate a horizontal rotation angle signal according to the angle of rotation of the two-dimensional turntable in the horizontal direction, and can send the horizontal rotation angle signal to the conversion imaging unit. Figure 3 The angle a indicated in the figure is the horizontal rotation angle. The horizontal rotation angle a changes with the horizontal rotation of the two-dimensional turntable. The horizontal angle encoder can generate a horizontal rotation angle signal based on the angle a.

[0060] In one feasible manner, the angle encoding unit also includes a pitch angle encoder; the pitch angle encoder is arranged on the output shaft of the second drive motor, and is used to generate a pitch rotation angle signal according to the angle of rotation of the two-dimensional turntable in the pitch direction, and send the pitch rotation angle signal to the conversion control unit.

[0061] Specifically, the pitch angle encoder is arranged on the output shaft of the second drive motor to realize the coaxial rotation of the pitch angle encoder and the second drive motor. When the second drive motor drives the two-dimensional turntable to rotate, the pitch angle encoder can generate a pitch rotation angle signal according to the rotation angle of the two-dimensional turntable in the pitch direction, and send the pitch rotation angle signal to the conversion control unit. Figure 3 The angle b shown in the figure is the pitch rotation angle. The bottom circle is the rotation trajectory of the two-dimensional turntable when the pitch angle b = 0°. By changing the angle b, the radar data in the horizontal direction can be collected at different pitch angles. Figure 2 As shown by the black dot position, the pitch angle encoder can generate a pitch rotation angle signal based on the angle b.

[0062] The above operation, by setting a horizontal angle encoder and a pitch angle encoder, can make the rotation of the first drive motor and the second drive motor not affected by the movement speed, and realize the collection of the horizontal rotation angle and the pitch rotation angle, forming a horizontal rotation angle signal and a pitch rotation angle signal, so that the subsequent radar acquisition unit can realize the equally spaced and uniform sampling of the angle domain data in the horizontal direction at different pitch angles, that is, at each pitch angle height position, the same angle range of the radar data is sampled in a horizontal rotation of 360°, thereby forming a one-dimensional synthetic aperture at different pitch angles. The one-dimensional synthetic apertures at different pitch angles are combined to obtain a two-dimensional synthetic aperture, thereby obtaining three-dimensional deformation information and realizing three-dimensional imaging.

[0063] In one embodiment, the angle encoding unit includes a photoelectric encoder, which is provided with circular bright and dark scale lines, and generates a rotation angle signal according to the scale lines.

[0064] The angle encoding unit includes but is not limited to a photoelectric encoder, a magnetic encoder, and an electric encoder.

[0065] Specifically, the angle encoder is mainly used to generate a rotation angle signal, i.e., a pulse signal. The angle encoder is set up so that uniform sampling can be achieved at equal intervals later. Here, taking the photoelectric encoder as an example, it is a photoelectric code disk with an axis in the center, on which a circular open and dark scale line is set. After being read by a photoelectric transmitting device or a receiving device, four groups of square wave signals are obtained, which are then combined into four sine waves of A+, A-, B+, and B-. Each sine wave differs by 90 degrees in phase difference, that is, one cycle is 360 degrees. The number of open or dark scale lines provided by the angle encoder per rotation can be called resolution, also known as the number of lines. If an angle encoder has n lines, it means that the signal line corresponding to one rotation of the angle encoder will output n pulses, then the angle corresponding to one pulse is: 360 / number of angle encoder lines, and then the rotation angle is: total number of output pulses / number of angle encoder lines*360, to obtain the rotation angle signal.

[0066] The setting of the above-mentioned photoelectric encoder can achieve the effects of high precision, good anti-magnetic interference performance, no fear of harsh surrounding magnetic field environment, fast response speed, convenient confirmation of turntable position and easy identification of turntable rotation direction.

[0067] In one embodiment, continue to refer to Figure 1 , Figure 2 As shown, the conversion control unit includes a conversion part; the conversion part is used to convert the horizontal rotation angle signal into a horizontal single-ended signal, and convert the pitch rotation angle signal into a pitch single-ended signal.

[0068] Specifically, the conversion unit can be an RS485 signal conversion method or a pulse signal conversion method. That is, it can receive the horizontal rotation angle signal sent by the horizontal angle encoder, convert the horizontal rotation angle signal into a horizontal single-ended signal, and receive the pitch rotation angle signal sent by the pitch angle encoder, and convert the pitch rotation angle signal into a pitch single-ended signal. The specific process is: since the angle encoder can output four sinusoidal wave signals of A+, A-, B+, and B-, the conversion unit can reverse the A- and B- signals and superimpose them on the A+ and B+ phases to achieve the effect of enhancing signal stability. At the same time, the output single-ended signals A and B are used to connect to the pins of the control unit to achieve later pulse counting.

[0069] In one achievable embodiment, the conversion control unit also includes a control unit; the control unit is used to count the horizontal single-ended signal, generate an acquisition control instruction based on a preset horizontal angle trigger interval, and send the acquisition control instruction to the radar acquisition unit; and count the pitch single-ended signal, generate first data information based on a preset pitch angle rising interval, and send the first data information to the processing control unit.

[0070] Specifically, the control unit can count the horizontal single-ended signal, that is, it has the ability to solve the single-ended signal. Since the horizontal angle trigger interval and the pitch angle rise interval are preset in advance inside the processing control unit, and the processing control unit and the conversion control unit are electrically connected, the conversion control unit can also perform specific control based on the preset horizontal angle trigger interval and the pitch angle rise interval. When the processing control unit controls the first drive motor to rotate in the horizontal direction, the horizontal angle encoder can generate a horizontal angle rotation signal, and the conversion unit can convert the horizontal rotation angle signal into a horizontal single-ended signal. The control unit counts the horizontal single-ended signal horizontally to determine whether the preset horizontal trigger interval is reached. If the preset horizontal trigger interval is not reached, the horizontal counting operation continues; if the preset horizontal trigger interval is reached, an acquisition control instruction is generated, that is, a high level is output, and the acquisition control instruction is sent to the radar acquisition unit. After receiving the acquisition control instruction, the radar acquisition unit can perform data acquisition to generate the second data information. This cycle is repeated, and uniform sampling at equal intervals in the horizontal direction can be achieved. It should also be noted that a timer can also be set inside the control unit to achieve the effect of equal interval sampling. At the same time, because the phases A and B differ by 90 degrees, the forward and reverse rotation of the angle encoder, that is, whether the horizontal angle encoder rotates clockwise, can be determined by comparing whether the A phase is in front or the B phase is in front. The specific judgment process is: since the first drive motor rotates one circle, the angle signal output by the angle encoder, that is, the number of pulses is n, then the angle corresponding to one pulse is: 360 / n. Then the angle rotated by the first drive motor is: (360 / n)*the number of pulses rotated; at the same time, the order of the B phase and the A phase is determined. When the B phase and the A phase are both high level first; then B is high level and A is low level, the current first drive motor rotates clockwise; when the B phase and the A phase are both low level first, then B is high level and A is low level, the current first drive motor rotates counterclockwise. Only when the first drive motor rotates clockwise can the acquisition control instruction be generated.

[0071] Here, since the processing and control unit can send a pitch rotation control instruction to the second drive motor only after controlling the first drive motor to rotate one circle, the rotation angle of the second drive motor is determined based on the pitch angle rising interval, and the pitch angle encoder can generate a pitch angle rotation signal; the conversion unit can convert the pitch angle rotation signal into a pitch single-ended signal, the controller performs a pitch count on the pitch single-ended signal, generates first data information based on a preset pitch angle rising interval, and sends the first data information to the processing and control unit, so that the processing and control unit can obtain low-error three-dimensional deformation information and image radar data based on the first data information and the second data information.

[0072] It should be noted that the pitch angle encoder is set here to count the pitch angles. Although the pitch angle increase interval is preset inside the processing control unit, there may be errors in the specific increase process. Therefore, the setting of the pitch angle encoder can improve the accuracy of the first data information, thereby achieving the effect of improving the image quality of radar data imaging.

[0073] The overall implementation principle of this embodiment is as follows: first, after power-on, initialization is performed and the two-dimensional turntable is reset, that is, the horizontal and pitch angles return to the starting angles; then, the processing control unit sends a horizontal rotation control instruction, the first drive motor rotates in the horizontal direction, and the horizontal angle encoder generates a horizontal rotation angle signal while the first drive motor rotates, and sends the horizontal rotation angle signal to the conversion unit, the conversion unit converts the horizontal rotation angle signal into a horizontal single-ended signal, the control unit performs horizontal counting on the horizontal single-ended signal to determine whether the preset horizontal trigger interval is reached, if the preset horizontal trigger interval is not reached, the horizontal counting operation is continued; if the preset horizontal trigger interval is reached, an acquisition control instruction is generated, and the acquisition control instruction is sent to the radar acquisition Unit, after receiving the acquisition control instruction, the radar acquisition unit can perform radar data acquisition to generate the second data information, and so on and so forth, it can realize uniform sampling at equal intervals in the horizontal direction; finally, after the processing control unit determines that the first drive motor rotates to the end position, that is, after completing one circle, it sends a pitch rotation control instruction to the second drive motor, and the second drive motor rotates in the pitch direction, and the pitch angle encoder can generate a pitch angle rotation signal while the second drive motor rotates, and the conversion unit can convert the pitch angle rotation signal into a pitch single-ended signal, and the control unit pitch counts the pitch single-ended signal to generate the first data information, and the processing control unit performs radar data imaging based on the first data information and the second data information. And after the processing control unit determines that the second drive motor rotates to the end position, it controls the first drive motor to reverse and return to the initial position, at which time, the radar acquisition unit does not work. After the first drive motor returns to the horizontal origin, the processing control unit sends a horizontal rotation control instruction again and enters the next cycle, and so on and so forth, it can realize uniform sampling at equal intervals in the horizontal direction of the radar acquisition unit at different pitch angles, thereby realizing the SAR precise three-dimensional imaging of high-precision radar data and the acquisition of low-error three-dimensional deformation information.

[0074] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0075] The above embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A ground-based curved surface synthetic aperture radar system, characterized in that: It includes a rotation unit, a conversion control unit, a radar acquisition unit and a processing control unit; wherein, The rotation unit is used to perform compound rotation according to the rotation control instruction to generate the rotation angle signal, and send the rotation angle signal to the conversion control unit; and drive the radar acquisition unit to perform compound rotation; The conversion control unit is used to generate first data information and an acquisition control instruction according to the rotation angle signal, and send the first data information to the processing control unit, and send the acquisition control instruction to the radar acquisition unit; The radar acquisition unit is used to be driven by the rotating unit to perform compound rotation; and to perform equal-interval sampling according to the acquisition control instruction to obtain second data information, and send the second data information to the processing control unit; The processing control unit is used to send a rotation control instruction to the rotation unit to control the rotation unit to perform compound rotation; and perform radar imaging according to the first data information and the second data information.

2. The ground-based curved surface synthetic aperture radar system according to claim 1, characterized in that: The rotating unit includes a rotating platform and an angle encoding unit; wherein, The rotating platform is used to perform compound rotation according to the rotation control instruction; The angle encoding unit is used to sample the composite rotation angle of the rotating platform to obtain a rotation angle signal, and send the rotation angle signal to the conversion control unit.

3. The ground-based curved surface synthetic aperture radar system according to claim 2, characterized in that: The rotating unit also includes a rotating arm; The rotary arm is arranged on the upper end surface of the rotating platform, and the radar collection unit is arranged at the end of the rotary arm; The rotary arm is used to be driven by the rotating platform to perform compound rotation, and to drive the radar acquisition unit to perform compound rotation.

4. The ground-based curved surface synthetic aperture radar system according to claim 2, characterized in that: The rotation control instruction includes a horizontal rotation control instruction, the rotation platform is a two-dimensional turntable, and a first driving motor is arranged inside the rotation platform; The first driving motor is used to rotate in the horizontal direction according to the horizontal rotation control instruction.

5. The ground-based curved surface synthetic aperture radar system according to claim 4, characterized in that: The rotation control instructions also include pitch rotation control instructions, and a second drive motor is also provided inside the rotating platform; The second driving motor is used to rotate in the pitch direction according to the pitch rotation control instruction.

6. The ground-based curved surface synthetic aperture radar system according to claim 5, characterized in that: The angle encoding unit includes a horizontal angle encoder; The horizontal angle encoder is arranged on the output shaft of the first driving motor, and is used to generate a horizontal rotation angle signal according to the angle of rotation of the two-dimensional turntable in the horizontal direction, and send the horizontal rotation angle signal to the conversion control unit.

7. The ground-based curved surface synthetic aperture radar system according to claim 6, characterized in that: The angle encoding unit also includes a pitch angle encoder; The pitch angle encoder is arranged on the output shaft of the second driving motor, and is used to generate a pitch rotation angle signal according to the rotation angle of the two-dimensional turntable in the pitch direction, and send the pitch rotation angle signal to the conversion control unit.

8. The ground-based curved surface synthetic aperture radar system according to any one of claims 2 to 7, characterized in that: The angle encoding unit comprises a photoelectric encoder, which is provided with circular bright and dark scale lines, and generates a rotation angle signal according to the scale lines.

9. The ground-based curved surface synthetic aperture radar system according to claim 7, characterized in that: The conversion control unit includes a conversion unit; The conversion unit is used to convert the horizontal rotation angle signal into a horizontal single-ended signal, and to convert the pitch rotation angle signal into a pitch single-ended signal.

10. The ground-based curved surface synthetic aperture radar system according to claim 9, characterized in that: The conversion control unit also includes a control unit; The control unit is used to count the horizontal single-ended signals, generate an acquisition control instruction based on a preset horizontal angle trigger interval, and send the acquisition control instruction to the radar acquisition unit; And, the pitch single-ended signal is counted, first data information is generated based on a preset pitch angle rising interval, and the first data information is sent to the processing control unit.

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