Method and system for obtaining radar antenna beam pointing information using laser ranging

Abstract

The application provides a method and system for obtaining radar antenna beam pointing information by laser ranging, comprising: a satellite is equipped with a radar antenna, a star sensor, a measuring antenna and a measuring system; when in orbit, all transmitting channels of the radar antenna transmit microwaves to the measuring antenna one by one and are received by the measuring antenna one by one, at the same time, the measuring antenna is continuously measured by the measuring system, the position of the measuring antenna is transformed into the observation coordinate system of the star sensor according to the fixed position relationship between the laser vibration measuring device and the star sensor in the measuring system and the fixed spatial angle relationship between the laser pointing and the optical axis pointing; during the process of fitting the radar antenna beam pointing by using the measuring antenna to receive the microwaves of all transmitting channels of the radar antenna, the above position change of the measuring antenna is introduced into the fitting process, the fitting deviation of the radar antenna beam pointing caused by the position change of the measuring antenna is equivalently eliminated, and the in-orbit beam pointing information of the radar antenna in the observation coordinate system of the star sensor is obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of spaceborne radar antenna, in particular, to a method and system for obtaining radar antenna beam pointing information by laser ranging, more particularly, to a method and system for obtaining in-orbit radar antenna beam pointing information by laser ranging, the position change amount obtained by continuously measuring the measuring antenna by using a spaceborne measuring system and after conversion is introduced into the radar antenna beam pointing fitting process, the beam pointing fitting deviation caused by the position change of the measuring antenna in the measurement obtaining process is eliminated, and the high-precision obtaining of in-orbit radar antenna beam pointing information is effectively realized. BACKGROUND

[0002] Synthetic aperture radar is an active type of earth observation system, which can be installed on a flight platform such as an airplane or a satellite to implement all-weather and all-day earth observation. Due to its unique advantages in disaster monitoring, environmental monitoring, ocean observation, and resource exploration, it has been increasingly valued by countries around the world. In particular, with the rapid development of space technology in recent years, synthetic aperture radar has been increasingly applied to space-based earth observation, and spaceborne radar antennas of various configurations such as flat phased arrays and reflectors have emerged. Whether it is a flat phased array configuration or a reflector configuration, the basic working principle of a spaceborne radar antenna is to emit directional microwaves to a predetermined target and receive the return wave to achieve imaging of the target. As can be seen from the basic working principle, improving the accuracy of the microwave beam pointing of the spaceborne radar antenna can significantly reduce the deviation angle between the beam pointing and the intended pointing, enhance the radiation intensity of the predetermined target, and thus improve the observation and imaging performance. In practical engineering applications, the microwave beam pointing of the radar antenna in the orbit system in which the satellite is running is usually defined as the in-orbit beam pointing. Currently, satellites usually use star sensors as attitude measurement and control sensors to observe and obtain the attitude of the satellite in orbit. Since the radar antenna is fixed to the satellite, the attitude of the satellite observed by the star sensor is also the attitude of the radar antenna. Therefore, as long as the beam pointing information of the radar antenna in the star observation coordinate system is obtained, the conversion relationship between the star observation coordinate system and the orbit system can be used to obtain the description of the beam pointing of the radar antenna in the orbit system.

[0003] Currently, the satellite-borne radar antenna equipped by radar satellite usually adopts the form of flat phased array or reflector. This kind of antenna is usually deployed by deployment mechanism after the satellite is launched into orbit to splice to form a complete antenna. In this process, the vibration environment of the satellite launch stage, the deployment mechanism and the orbital space environment will affect the beam pointing of the radar antenna, resulting in the deviation between the in-orbit beam pointing of the radar antenna and the beam pointing obtained by ground test, which affects the actual imaging performance of the radar antenna in orbit. For how to obtain the in-orbit beam pointing information of the radar antenna, the main method of existing research and engineering practice is to improve the mechanical performance of the radar antenna, control the shape accuracy of the antenna in orbit, minimize the influence of the aforementioned launch process and in-orbit environment on the mechanical performance of the radar antenna, and usually use the beam pointing information obtained by ground test instead of the in-orbit beam pointing information.

[0004] For example, for the radar antenna in the form of flat phased array, the published patent "Measurement system and measurement method for large plane pointing change" (application number CN201510861101.2) discloses a method of obtaining the position change of each measurement point by linear laser combined with one-dimensional PSD sensing technology, and solving the pointing change of large plane; the published patent "Satellite large array antenna deformation in-orbit measurement system and method based on fiber grating" (application number CN201510864078.2) discloses a method of arranging multiple grating measurement points on the satellite large array antenna surface to form a sensing network; an optical wave demodulator is used to demodulate the collected optical waves to obtain the strain and temperature of each grating measurement point; an information processor is used to calculate the strain and temperature of each grating measurement point and obtain the antenna array surface deformation parameters. The published patent "Satellite-borne antenna mechanical pointing accuracy fast measurement method" (application number CN201710355295.8) discloses a method of using a camera to shoot the antenna array to quickly obtain the coordinates of the reflective marker points, converting to the coordinate system of the theodolite measurement system through the common marker points and fitting the normal line of the antenna array, using the theodolite collimation to measure the satellite reference prism, and obtaining the angle relationship between the theodolites through mutual sighting, and finally calculating the mechanical pointing accuracy of the normal line of the antenna array and the satellite coordinate system to meet the requirements of fast measurement of mechanical pointing accuracy of large-size antenna. The methods disclosed in these patents are only for the array antenna in the form of flat phased array, and the mechanical shape accuracy of the array antenna is measured, and finally only the mechanical pointing information of the antenna is obtained, which is an indirect and approximate equivalent form to obtain the beam pointing information.

[0005] For example, for the radar antenna in the form of a reflecting surface, the disclosed patent "Antenna main beam pointing detection method based on optical imaging and pattern recognition" (application number CN201310221814.3) discloses a method that includes the following steps: step 1: a large field of view visible light camera images the target, captures, identifies and tracks the target; step 2: the large field of view visible light camera guides the small field of view visible light camera to aim at the target for high resolution imaging; step 3: the method of random ellipse detection is used to determine the target antenna area; step 4: the method of spatial circle normal vector determination is used to determine the main beam pointing direction of the target antenna. The invention solves the problem of detecting the main beam pointing direction of a space target antenna, and through the high resolution detection of the target antenna by the small field of view visible light camera, the pattern recognition technology is used to detect the target antenna area and determine the main beam pointing direction of the target antenna. The disclosed patent "Test device and test method for the beam pointing of a reflecting surface antenna" (application number CN201110454082.3) discloses a method that uses an electronic theodolite and an antenna reference mirror, and also includes an optical telescope; the optical telescope is fixed to the antenna support parallel to the mechanical axis of the reflecting surface antenna; a target is placed beside the transmitting antenna; the test device is used to accurately measure the angle between the electrical axis and the mechanical axis of the reflecting surface antenna by combining optical measurement methods with antenna far field pattern testing. This method uses an optical telescope fixed to the antenna support parallel to the mechanical axis of the reflecting surface antenna, and a target is placed beside the transmitting antenna, and finally the angle between the electrical axis and the mechanical axis of the reflecting surface antenna is accurately measured by combining optical measurement methods with antenna far field pattern testing. These patents disclose ground test methods, and are shape measurements of reflecting surface antennas, using the mechanical pointing of the reflecting surface antenna instead of the microwave beam pointing, which also belongs to the form of indirectly and approximately equivalent beam pointing information. The patent "Method for accurately obtaining satellite radar antenna beam pointing" (application number CN201711015900.3) discloses a method that includes the following steps: (1) the radar satellite is equipped with a microwave beam receiving antenna, and the beam receiving antenna and the on-board processing device are used to accurately obtain the radar beam pointing information; (2) the radar satellite is equipped with a laser transmitter, and while the receiving antenna obtains the microwave beam information, the laser transmitter emits a laser beam into the star sensor photosensitive element equipped on the satellite; (3) the inertial pointing of the aforementioned laser beam is obtained through the operation and processing of the star sensor; (4) the relationship between the optical axis pointing of the star sensor and the microwave beam pointing is accurately obtained by fusing the data of the microwave beam pointing information, the laser beam inertial pointing information and the satellite attitude information obtained by the star sensor, and then the microwave beam pointing during the radar imaging process can be accurately corrected. This invention converts the microwave beam pointing information to the satellite attitude coordinate system through the conversion of the on-board optical reference and microwave electrical reference, and accurately obtains the on-orbit pointing information of the beam.The patent discloses a method for obtaining a conversion relationship using a laser and a star sensor. However, as is well known, the starry sky is a relatively dark background space. Using a laser on a star, allowing this intense light source to enter the star sensor and sense it to obtain the beam's direction and position, will inevitably affect the star sensor's ability to observe the starry sky, and thus, the system's measurement accuracy. Furthermore, stray light in space, such as sunlight, moonlight, and atmospheric light, can easily interfere with the laser's light. Therefore, the method disclosed in this patent has significant limitations.

[0006] Patent document CN111398917A (application number: 202010125408.7) discloses an antenna beam pointing test method, including: the radar performs stare detection on the target under a first condition and a second condition, respectively, and obtains the echo amplitude value from the target echo data; the first condition includes the set operating frequency and the pitch beam pointing scanning mode; the second condition includes the preset pitch beam pointing and the agile frequency mode; the echo amplitude value obtained under the first condition and the second condition is compared with the echo amplitude value under the same conditions in the preset standard library when the antenna beam pointing meets the radar usage requirements; if the comparison results under the first condition and the second condition are the same, the antenna beam pointing meets the radar usage requirements.

[0007] Regarding the above-mentioned existing technologies, it is believed that the vibration environment, deployment mechanism and orbital space environment during the satellite launch phase will affect the microwave beam pointing of the radar antenna, resulting in a deviation between the on-orbit beam pointing of the radar antenna and the beam pointing obtained by ground testing, thereby affecting the actual performance of the radar antenna while on orbit. Other indirect approximate equivalent methods are difficult to accurately obtain the on-orbit beam pointing information of the radar antenna and have certain limitations. Summary of the Invention

[0008] In view of the defects in the prior art, the purpose of the present invention is to provide a method and system for obtaining radar antenna beam pointing information using laser ranging.

[0009] According to the present invention, a method for obtaining radar antenna beam pointing information by using laser ranging includes:

[0010] Step S1: equipping the satellite system with a radar antenna, a star sensor, a measurement antenna, and a measurement system;

[0011] Step S2: according to pre-set settings, the laser ranging device in the measurement system is respectively arranged to have a relatively fixed spatial position relationship with the star sensor and the radar antenna, so that the direction of the laser emitted by the laser ranging device in the measurement system and the direction of the optical axis of the star sensor have a relatively fixed spatial angle relationship;

[0012] Step S3: During the on-orbit operation, the radar antenna transmits microwaves to the measuring antenna one by one and the measuring antenna receives the microwaves one by one;

[0013] Step S4: A measuring coordinate system of the laser ranging device is established, the measuring antenna is continuously measured by the laser ranging device, the distance between the measuring antenna and the laser ranging device at the beginning of the measurement is recorded as D 测量天线-测距装置 , and the position change of the measuring antenna in the measuring coordinate system is continuously obtained and recorded as △ 测量天线-测距装置 ;

[0014] Step S5: An observation coordinate system of the star sensor is established, the position change △ 测量天线-测距装置 of the measuring antenna is converted to the observation coordinate system of the star sensor and recorded as △ 测量天线-星敏感器 , the distance D 测量天线-测距装置 between the measuring antenna and the laser ranging device at the beginning of the measurement is converted to the observation coordinate system of the star sensor and recorded as D 测量天线-星敏感器 ;

[0015] Step S6: A measuring antenna coordinate system is established, the radar antenna beam pointing fitting in the measuring antenna coordinate system is performed by using the results obtained in step S3, the beam pointing information is obtained and recorded as r Rad ; in the above fitting process, the position change △ 测量天线-星敏感器 of the measuring antenna is superimposed on the obtained distance D 测量天线-星敏感器 between the measuring antenna and the star sensor to obtain continuous position quantities of the measuring antenna in the observation coordinate system of the star sensor; the position quantities are introduced into the fitting process and are equivalent to be removed, and finally the beam pointing information of the radar antenna in the observation coordinate system of the star sensor is obtained by fitting.

[0016] Preferably, the measuring antenna comprises a satellite-borne beam pointing measuring antenna, and the measuring system comprises a satellite-borne laser ranging device for beam pointing measurement.

[0017] Preferably, there is only a one-way microwave transmission and reception relationship between the radar antenna and the measuring antenna, and the one-way transmission and reception relationship is that the radar antenna transmits and the measuring antenna receives.

[0018] Preferably, the radar antenna transmits microwaves to the measuring antenna, and the measuring system continuously measures the measuring antenna by using the laser ranging method to obtain the position change of the measuring antenna, and the microwave transmission and the laser ranging measurement are started and ended synchronously.

[0019] Preferably, the star sensor observation coordinate system, the measurement coordinate system of the laser ranging device and the measurement antenna coordinate system are established, the relative fixed position relationship between the laser ranging device and the star sensor and the radar antenna, the relative fixed spatial angle relationship between the laser ranging direction of the laser ranging device and the optical axis direction of the star sensor are utilized, and the measurement antenna is continuously measured by the laser ranging device, so that the intermediate quantity is converted, the measurement coordinate system and the measurement antenna coordinate system are converted to be described in the star sensor observation coordinate system, and the reference unification of the conversion process is realized.

[0020] According to the application, a system for obtaining radar antenna beam pointing information by laser ranging is provided, which comprises:

[0021] Module M1: a radar antenna, a star sensor, a measurement antenna and a measurement system are provided in a satellite system;

[0022] Module M2: according to pre-setting, the laser ranging device in the measurement system has a relative fixed spatial position relationship with the star sensor and the radar antenna respectively, and the laser ranging direction of the laser ranging device has a relative fixed spatial angle relationship with the optical axis direction of the star sensor;

[0023] Module M3: during on-orbit operation, all the transmitting channels of the radar antenna transmit microwaves to the measurement antenna one by one and are received by the measurement antenna one by one;

[0024] Module M4: a measurement coordinate system of the laser ranging device is established, the measurement antenna is continuously measured by the laser ranging device, the distance between the measurement antenna and the laser ranging device at the measurement start time is recorded and denoted as D 测量天线-测距装置 , and the position change of the measurement antenna in the measurement coordinate system is continuously obtained and denoted as Δ 测量天线-测距装置 ;

[0025] Module M5: a star sensor observation coordinate system is established, the position change Δ 测量天线-测距装置 of the measurement antenna is converted to be represented in the star sensor observation coordinate system, denoted as Δ 测量天线-星敏感器 , the distance D 测量天线-测距装置 between the measurement antenna and the laser ranging device at the measurement start time is converted to be represented in the star sensor observation coordinate system, denoted as D 测量天线-星敏感器 ;

[0026] Module M6: a measurement antenna coordinate system is established, the radar antenna beam pointing fitting in the measurement antenna coordinate system is performed by using the result obtained by module M3, the beam pointing information is obtained and denoted as r Rad; in the above fitting process, the position change △ 测量天线-星敏感器 superimposed on the obtained distance D between the measuring antenna and the star sensor 测量天线-星敏感器 , to obtain continuous multiple position quantities of the measuring antenna in the star sensor observation coordinate system; the position quantities are introduced into the fitting process and equivalently eliminated, and finally the beam pointing information of the radar antenna in the star sensor observation coordinate system is obtained through fitting.

[0027] Preferably, the measuring antenna comprises a satellite-borne beam pointing measuring antenna, and the measuring system comprises a satellite-borne laser ranging device for beam pointing measurement.

[0028] Preferably, there is only a one-way microwave transmitting and receiving relationship between the radar antenna and the measuring antenna, and the one-way transmitting and receiving relationship is that the radar antenna transmits and the measuring antenna receives.

[0029] Preferably, while the radar antenna transmits microwaves to the measuring antenna, the measuring system continuously measures the measuring antenna by using laser ranging, obtains the position change of the measuring antenna, and the microwave transmission and the laser ranging measurement are started and ended synchronously.

[0030] Preferably, the star sensor observation coordinate system, the measuring coordinate system of the laser ranging device and the measuring antenna coordinate system are established, the relative fixed position relationship between the laser ranging device and the star sensor, the relative fixed spatial angle relationship between the laser pointing direction of the laser ranging device and the optical axis direction of the star sensor, and the continuous measurement of the measuring antenna by the laser ranging device are utilized, the intermediate quantities obtained are converted, the measuring coordinate system and the measuring antenna coordinate system are converted to be described in the star sensor observation coordinate system, and the reference of the overall conversion process is unified.

[0031] Compared with the prior art, the present application has the following beneficial effects:

[0032] 1. In one aspect, the present application ingeniously sets up a relative fixed positional relationship between the space-borne laser ranging device and the star sensor and radar antenna, and makes the laser emitted by the laser ranging device have a relative fixed spatial angle relationship with the optical axis of the star sensor. Through the relative fixed positional relationship and spatial angle relationship, the position of the ranging device and the laser pointing vector can be converted to the observation coordinate system of the star sensor. Then, through the continuous measurement of the measuring antenna by the ranging device, the position change of the measuring antenna is obtained and converted to the observation coordinate system of the star sensor, so that the intermediate quantities obtained are converted to the observation coordinate system of the star sensor, and the reference of the conversion process is unified. On the other hand, on the basis of the unified reference, the position change of the measuring antenna is introduced into the radar antenna beam pointing fitting process and is equivalent to be eliminated, which eliminates the beam pointing fitting deviation caused by the position change of the measuring antenna in the measurement process, and effectively realizes the high-precision acquisition of the radar antenna beam pointing information.

[0033] 2. The present application ingeniously adopts the mode that the microwave emission and the laser ranging start and end synchronously, so that the relative displacement change between the measuring antenna and the radar antenna corresponds directly to the beam pointing measurement process, and there is no time sequence, which can truly reflect the deviation in the beam pointing measurement process and is beneficial to improve the acquisition precision of the radar antenna beam pointing information.

[0034] 3. The present application uses the measuring antenna to measure the radar antenna beam pointing, which belongs to a direct method for acquiring the on-orbit beam pointing information of the radar antenna, and is essentially different from the traditional method for indirectly and approximately equivalent to the beam pointing information by acquiring the mechanical pointing of the radar antenna.

[0035] 4. The present application adopts the mode that all the transmitting channels of the radar antenna transmit microwave one by one, which is not limited by the system and configuration form of the radar antenna, and can be applied to various forms of radar antennas such as flat panel phased array and reflector, and has strong universality. BRIEF DESCRIPTION OF DRAWINGS

[0036] Other characteristics, objects and advantages of the present application will become more apparent through reading the following detailed description of the non-limiting embodiments with reference to the accompanying drawings:

[0037] Figure 1 The flow chart of the method for acquiring the radar antenna beam pointing information by laser ranging.

[0038] Figure 2 The system schematic diagram for acquiring the radar antenna beam pointing information by laser ranging.

[0039] Figure 3 The implementation example schematic diagram for acquiring the radar antenna beam pointing information by laser ranging. DETAILED DESCRIPTION

[0040] The application will be described in greater detail below with reference to specific embodiments. The following examples are helpful for those skilled in the art to further understand the application, but do not limit the application in any form. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the application. These are within the scope of protection of the application.

[0041] Example 1

[0042] The application provides a method for obtaining radar antenna beam pointing information by laser ranging, as shown in Figure 1 , comprising:

[0043] Step S1: In addition to being equipped with a conventional radar antenna and a star sensor, the satellite is also equipped with a measurement antenna (the current measurement antenna is a star-borne beam pointing measurement antenna) and a measurement system (the current measurement system is a star-borne laser measurement system, wherein the star-borne laser measurement system comprises a star-borne laser ranging device and a processing system);

[0044] Step S2: The laser ranging device in the measurement system is arranged in a fixed relative position with the star sensor and the radar antenna, specifically, the laser ranging device in the measurement system has a relative fixed spatial position relationship with the star sensor and the radar antenna, and the laser emitted by the laser ranging device has a relative fixed spatial angle relationship with the optical axis direction of the star sensor;

[0045] Step S3: During on-orbit operation, all the transmitting channels of the radar antenna transmit microwaves to the measurement antenna one by one and are received by the measurement antenna one by one;

[0046] Step S4: A measurement coordinate system (denoted as N system) of the laser ranging device is established, the measurement antenna is continuously measured by the laser ranging device, the distance between the measurement antenna and the laser ranging device at the start time of measurement is recorded, denoted as D 测量天线-测距装置 , and continuous position changes of the measurement antenna in the N system are continuously obtained, denoted as △ 测量天线-测距装置 ;

[0047] Wherein, the measurement coordinate system (N system) of the laser ranging device is a Cartesian coordinate system, which conforms to the right-hand screw rule. The point light source of the laser ranging device is taken as the origin of the coordinate system, the Z-axis direction is consistent with the laser emission direction, and the X-axis and Y-axis can be set according to the geometric shape of the laser ranging device.

[0048] Step S5: Establish a star sensor observation coordinate system (denoted as F system), and according to the relative fixed position relationship between the laser ranging device and the star sensor and the radar antenna and the relative fixed spatial angle relationship between the laser ranging device and the star sensor, the position change △ 测量天线-测距装置 of the measuring antenna in the N system is converted into the star sensor observation coordinate system (F system) and denoted as △ 测量天线-星敏感器 . 测量天线-测距装置 The distance D 测量天线-星敏感器 between the measuring antenna and the laser ranging device at the beginning of the measurement is converted into the star sensor observation coordinate system (F system) and denoted as D Rad .

[0049] The star sensor observation coordinate system (F system) is a Cartesian coordinate system, which conforms to the right-hand screw rule. The Z-axis direction of the star sensor observation coordinate system is the star sensor optical axis direction, and the X-axis is the star sensor transverse axis.

[0050] Step S6: Establish a measuring antenna coordinate system (denoted as p system), and use the result obtained in step S3 to perform radar antenna beam pointing fitting in the measuring antenna coordinate system to obtain beam pointing information (denoted as r Rad , which is referred to as Rad vector). In the above fitting process, the position change △ 测量天线-星敏感器 of the measuring antenna in the star sensor observation coordinate system (F system) is superimposed on the distance D 测量天线-星敏感器 between the measuring antenna and the star sensor to obtain a plurality of continuous position quantities of the measuring antenna coordinate system (p system) in the star sensor observation coordinate system (F system). These continuous position quantities are introduced into the fitting process and are equivalent to being removed, and finally the radar antenna beam pointing Rad vector in the star sensor observation coordinate system (F system) is fitted.

[0051] The measuring antenna coordinate system (p system) is a Cartesian coordinate system, which conforms to the right-hand screw rule, and the Z-axis points to the radar antenna. The origin of the p system is an observation point on the measuring antenna for laser ranging, and the X-axis and Y-axis are set according to the geometric shape of the measuring antenna.

[0052] Specifically, the measuring antenna includes a satellite-borne beam pointing measuring antenna, and the measuring system includes a satellite-borne laser ranging device for beam pointing measurement.

[0053] Specifically, there is only a one-way microwave transmission-reception relationship between the radar antenna and the measuring antenna, that is, all the transmission channels of the radar antenna transmit microwaves to the measuring antenna one by one and are received by the measuring antenna one by one, and the one-way transmission-reception relationship is that the radar antenna transmits and the measuring antenna receives.

[0054] Specifically, the star sensor performs star observation at the same time in step S3 to obtain the satellite on-orbit attitude at the current time, and after the radar antenna beam pointing information in the star sensor observation coordinate system is obtained through the application, the radar antenna beam pointing information in the orbit coordinate system can be obtained through the conversion relationship between the star sensor observation coordinate system and the orbit coordinate system.

[0055] Specifically, the radar antenna transmits microwaves to the measuring antenna, and the measuring system continuously measures the measuring antenna by using the laser ranging method to obtain the position change amount of the measuring antenna, and the microwave transmission and measurement are started and ended synchronously.

[0056] Specifically, the star sensor observation coordinate system, the measuring coordinate system of the laser ranging device and the measuring antenna coordinate system are established, the relative fixed position relationship between the laser ranging device and the star sensor, the laser pointing direction of the laser ranging device and the optical axis direction of the star sensor have a relatively fixed spatial angle relationship, and the measuring antenna is continuously measured by the laser ranging device, the intermediate quantity obtained is converted, the measuring coordinate system and the measuring antenna coordinate system are converted to the star sensor observation coordinate system for description, and the reference of the overall conversion process is unified.

[0057] The application provides a system for obtaining radar antenna beam pointing information by laser ranging, as shown in the figure. Figures 2-3 As shown in the figure, Figure 2 is a schematic diagram of the position relationship and spatial angle relationship between the measuring antenna and the laser ranging device, the one-way microwave transmission-reception relationship between the measuring antenna and the radar antenna, and the continuous measurement relationship of the measuring antenna by the laser ranging device; Figure 3 is a schematic diagram of the relationship between the coordinate systems in the embodiment of the application for obtaining radar antenna beam pointing information by laser ranging;

[0058] Specifically, it comprises:

[0059] Module M1: the satellite is additionally provided with a measuring antenna (the current measuring antenna is a satellite-borne beam pointing measuring antenna) and a measuring system (the current measuring system is a satellite-borne laser measuring system, wherein the satellite-borne laser measuring system comprises a satellite-borne laser ranging device and a processing system) in addition to the conventional radar antenna and the star sensor;

[0060] Module M2: the laser ranging device in the measuring system is arranged in a fixed relative position with the star sensor and the radar antenna, specifically, the laser ranging device in the measuring system has a relatively fixed spatial position relationship with the star sensor and the radar antenna, and the laser pointing direction of the laser ranging device has a relatively fixed spatial angle relationship with the optical axis direction of the star sensor;

[0061] Module M3: During the on-orbit operation, the radar antenna transmits microwaves to the measuring antenna one by one and the measuring antenna receives the microwaves one by one;

[0062] Module M4: A measuring coordinate system (denoted as N system) of the laser ranging device is established, the measuring antenna is continuously measured by the laser ranging device, the distance between the measuring antenna and the laser ranging device at the beginning of the measurement is recorded, denoted as D 测量天线-测距装置 , and continuous multiple position changes of the measuring antenna in the N system are continuously obtained, denoted as △ 测量天线-测距装置 ;

[0063] The measuring coordinate system (N system) of the laser ranging device is a Cartesian coordinate system, which conforms to the right-hand screw rule. The point light source of the laser ranging device is taken as the origin of the coordinate system, the Z-axis direction is consistent with the laser emission direction, and the X-axis and Y-axis can be set according to the geometric shape of the laser ranging device.

[0064] Module M5: An observation coordinate system (denoted as F system) of the star sensor is established, the position change △ 测量天线-测距装置 of the measuring antenna in the N system is converted to the observation coordinate system (F system) of the star sensor and denoted as △ 测量天线-星敏感器 , the distance D 测量天线-测距装置 between the measuring antenna and the laser ranging device at the beginning of the measurement is converted to the observation coordinate system (F system) of the star sensor and denoted as D 测量天线-星敏感器 ;

[0065] The observation coordinate system (F system) of the star sensor is a Cartesian coordinate system, which conforms to the right-hand screw rule. The Z-axis direction of the observation coordinate system of the star sensor is the star sensor optical axis direction, and the X-axis is the star sensor transverse axis.

[0066] Module M6: A measuring antenna coordinate system (denoted as p system) is established, the radar antenna beam pointing fitting in the measuring antenna coordinate system is performed by using the results obtained by module M3 to obtain the beam pointing information (denoted as r Rad , which is referred to as Rad vector); in the above fitting process, the position change △ 测量天线-星敏感器 of the measuring antenna in the observation coordinate system (F system) of the star sensor is superimposed on the distance D 测量天线-星敏感器 between the measuring antenna and the star sensor to obtain continuous multiple position quantities of the measuring antenna coordinate system (p system) in the observation coordinate system (F system) of the star sensor; these continuous multiple position quantities are introduced into the fitting process and are equivalent to be removed, and finally the radar antenna beam pointing Rad vector in the observation coordinate system (F system) of the star sensor is fitted.

[0067] Wherein, the measurement antenna coordinate system (p system) is a Cartesian coordinate system, in line with the right-hand screw rule, the Z axis points to the radar antenna, the origin of the p system is an observation point on the measurement antenna for laser ranging, and the X axis and the Y axis are set according to the geometric shape of the measurement antenna.

[0068] Specifically, the measurement antenna includes a satellite-borne beam pointing measurement antenna, and the measurement system includes a satellite-borne laser ranging device for beam pointing measurement.

[0069] Specifically, there is only a one-way microwave transmission-reception relationship between the radar antenna and the measurement antenna, that is, all the transmission channels of the radar antenna transmit microwaves to the measurement antenna one by one and are received by the measurement antenna one by one, and the one-way transmission-reception relationship is radar antenna transmission and measurement antenna reception.

[0070] Specifically, the star sensor performs star observation at the same time as module M3 to obtain the satellite on-orbit attitude at the current time, and after obtaining the radar antenna beam pointing information in the star sensor observation coordinate system through the present application, the radar antenna beam pointing information in the orbit system can be obtained through the conversion relationship between the star sensor observation coordinate system and the orbit system.

[0071] Specifically, while the radar antenna transmits microwaves to the measurement antenna, the measurement system continuously measures the measurement antenna by laser ranging to obtain the position change of the measurement antenna, and the microwave transmission and the measurement are started and ended synchronously.

[0072] Specifically, the star sensor observation coordinate system, the measurement coordinate system of the laser ranging device, and the measurement antenna coordinate system are established, the relative fixed position relationship between the laser ranging device and the star sensor, and the relative fixed spatial angle relationship between the laser pointing of the laser ranging device and the optical axis pointing of the star sensor are utilized, and the intermediate quantity obtained is converted by continuously measuring the measurement antenna by the laser ranging device, the measurement coordinate system and the measurement antenna coordinate system are converted to the star sensor observation coordinate system for description, and the reference of the overall conversion process is unified.

[0073] The application ingeniously sets up a relatively fixed positional relationship between the spaceborne laser ranging device and the star sensor and radar antenna, and a relatively fixed spatial angle relationship between the laser ranging device and the star sensor, so that the position of the ranging device and the laser pointing vector can be converted to the star sensor observation coordinate system for description. The position change of the measuring antenna is obtained through continuous measurement of the ranging device, and is converted to the star sensor observation coordinate system for expression, so that the intermediate quantities obtained are converted to the star sensor observation coordinate system for description, and the reference of the conversion process is unified. On the basis of the unified reference, the position change of the measuring antenna is introduced into the radar antenna beam pointing fitting process and is equivalent to be removed, so as to eliminate the beam pointing fitting deviation caused by the position change of the measuring antenna in the measurement process, and effectively realize the high-precision acquisition of the radar antenna beam pointing information. Moreover, the application adopts the mode that the microwave emission and the laser ranging start and end synchronously, so that the relative displacement change between the measuring antenna and the radar antenna directly corresponds to the beam pointing measurement process, and there is no time sequence relationship, which can truly reflect the deviation in the beam pointing measurement process, and is beneficial to improving the acquisition precision of the radar antenna beam pointing information.

[0074] The application measures the radar antenna beam pointing by using the measuring antenna, and belongs to a direct method for acquiring the on-orbit beam pointing information of the radar antenna, which is essentially different from the traditional method for acquiring the mechanical pointing of the radar antenna and indirectly approximating the equivalent beam pointing information. Meanwhile, the application adopts the mode that all the radar antenna transmission channels are traversed to emit microwaves, which is not limited by the radar antenna system and configuration form, and can be applied to various radar antennas such as flat panel phased arrays and reflectors, and has strong universality.

[0075] Those skilled in the art know that, in addition to implementing the system, device and each module thereof provided by the application in the form of pure computer readable program code, the same program can be realized in the form of logic gates, switches, special integrated circuits, programmable logic controllers and embedded microcontrollers by logically programming the method steps. Therefore, the system, device and each module thereof provided by the application can be considered as a hardware component, and the modules included therein for realizing various programs can be considered as structures in the hardware component; the modules for realizing various functions can also be considered as both software programs for realizing methods and structures in the hardware component.

[0076] The specific embodiments of the present application are described above. It needs to be understood that the present application is not limited to the specific embodiments described above, and various changes or modifications can be made by those skilled in the art within the scope of the claims, which does not affect the essential content of the present application. The embodiments of the present application and the features in the embodiments can be combined with each other at will without conflict.

Claims

1. A method for obtaining radar antenna beam pointing information using laser ranging, characterized in that: include: Step S1: equipping the satellite system with a radar antenna, a star sensor, a measurement antenna, and a measurement system; Step S2: according to pre-set settings, the laser ranging device in the measurement system is respectively arranged to have a relatively fixed spatial position relationship with the star sensor and the radar antenna, so that the direction of the laser emitted by the laser ranging device in the measurement system and the direction of the optical axis of the star sensor have a relatively fixed spatial angle relationship; Step S3: During on-orbit operation, all transmission channels of the radar antenna transmit microwaves to the measurement antenna one by one, and the measurement antenna receives them one by one; Step S4: Establish a measurement coordinate system for the laser distance measuring device, and use the laser distance measuring device to continuously measure the measurement antenna; record the distance between the measurement antenna and the laser distance measuring device at the start of the measurement, which is recorded as D 测量天线-测距装置 , and continuously obtain the position change of the measurement antenna in the measurement coordinate system, recorded as △ 测量天线-测距装置 ; Step S5: Establishing the star sensor observation coordinate system. Based on the relatively fixed positional relationship between the laser ranging device, the star sensor, and the radar antenna, and the relatively fixed spatial angle relationship between the laser direction emitted by the laser ranging device and the optical axis direction of the star sensor, the position change of the measuring antenna is calculated. 测量天线-测距装置 Converted to the star sensor observation coordinate system, it is expressed as △ 测量天线-星敏感器 , measure the distance D between the antenna and the ranging device at the start of the measurement 测量天线-测距装置 Converted to the star sensor observation coordinate system, it is expressed as D 测量天线-星敏感器 ; Step S6: Establish a measurement antenna coordinate system, and use the results obtained in step S3 to perform radar antenna beam pointing fitting in the measurement antenna coordinate system to obtain beam pointing information, which is recorded as r Rad ; In the above fitting process, the position change of the measuring antenna △ 测量天线-星敏感器 Superimposed on the distance D between the measurement antenna and the star sensor 测量天线-星敏感器 The continuous multiple position quantities of the measurement antenna in the star sensor observation coordinate system are obtained; the position quantities are introduced into the fitting process and equivalently eliminated, and finally the radar antenna beam pointing information in the star sensor observation coordinate system is obtained by fitting.

2. The method for obtaining radar antenna beam pointing information using laser ranging according to claim 1, characterized in that: The measurement antenna includes a satellite-borne beam pointing measurement antenna, and the measurement system includes a satellite-borne laser ranging device for beam pointing measurement.

3. The method for obtaining radar antenna beam pointing information using laser ranging according to claim 1, characterized in that: There is only a one-way microwave transmission and reception relationship between the radar antenna and the measurement antenna, and this one-way transmission and reception relationship is that the radar antenna transmits and the measurement antenna receives.

4. The method for obtaining radar antenna beam pointing information using laser ranging according to claim 1, characterized in that: While the radar antenna transmits microwaves to the measurement antenna, the measurement system uses laser ranging to continuously measure the measurement antenna to obtain the position change of the measurement antenna. The microwave emission and laser ranging measurement start and end synchronously.

5. The method for obtaining radar antenna beam pointing information using laser ranging according to claim 1, characterized in that: The star sensor observation coordinate system, the laser ranging device measurement coordinate system, and the measurement antenna coordinate system are established. By utilizing the relatively fixed positional relationship between the laser ranging device and the star sensor, and the relatively fixed spatial angle relationship between the laser emitted by the laser ranging device and the optical axis of the star sensor, and by continuously measuring the measurement antenna with the laser ranging device, the intermediate quantities obtained are converted, and the measurement coordinate system and the measurement antenna coordinate system are transformed into the star sensor observation coordinate system for description, thereby achieving a unified benchmark for the conversion process.

6. A system for obtaining radar antenna beam pointing information using laser ranging, characterized in that: include: Module M1: The satellite system is equipped with radar antenna, star sensor, measurement antenna and measurement system; Module M2: According to pre-set settings, the laser ranging device in the measurement system is respectively in a relatively fixed spatial position relationship with the star sensor and the radar antenna, and the direction of the laser emitted by the laser ranging device in the measurement system is in a relatively fixed spatial angle relationship with the direction of the optical axis of the star sensor; Module M3: During on-orbit operation, all transmission channels of the radar antenna transmit microwaves to the measurement antenna one by one, and the measurement antenna receives them one by one; Module M4: Establish the measurement coordinate system of the laser distance measuring device, and use the laser distance measuring device to continuously measure the measurement antenna; record the distance between the measurement antenna and the laser distance measuring device at the start of the measurement, recorded as D 测量天线-测距装置 , and continuously obtain the position change of the measurement antenna in the measurement coordinate system, recorded as △ 测量天线-测距装置 ; Module M5: Establish the observation coordinate system of the star sensor. According to the relatively fixed position relationship between the laser ranging device and the star sensor and the radar antenna, and the relatively fixed spatial angle relationship between the laser pointing to the laser ranging device and the optical axis pointing to the star sensor, the position change of the measuring antenna is calculated as △ 测量天线-测距装置 Converted to the star sensor observation coordinate system, it is expressed as △ 测量天线-星敏感器 , measure the distance D between the antenna and the ranging device at the start of the measurement 测量天线-测距装置 Converted to the star sensor observation coordinate system, it is expressed as D 测量天线-星敏感器 ; Module M6: Establish the measurement antenna coordinate system, use the results obtained in module M3 to perform radar antenna beam pointing fitting in the measurement antenna coordinate system, and obtain the beam pointing information, which is recorded as r Rad ; In the above fitting process, the position change of the measuring antenna △ 测量天线-星敏感器 Superimposed on the distance D between the measurement antenna and the star sensor 测量天线-星敏感器 The continuous multiple position quantities of the measurement antenna in the star sensor observation coordinate system are obtained; the position quantities are introduced into the fitting process and equivalently eliminated, and finally the radar antenna beam pointing information in the star sensor observation coordinate system is obtained by fitting.

7. The system for obtaining radar antenna beam pointing information using laser ranging according to claim 6, characterized in that: The measurement antenna includes a satellite-borne beam pointing measurement antenna, and the measurement system includes a satellite-borne laser ranging device for beam pointing measurement.

8. The system for obtaining radar antenna beam pointing information using laser ranging according to claim 6, characterized in that: There is only a one-way microwave transmission and reception relationship between the radar antenna and the measurement antenna, and this one-way transmission and reception relationship is that the radar antenna transmits and the measurement antenna receives.

9. The system for obtaining radar antenna beam pointing information using laser ranging according to claim 6, characterized in that: While the radar antenna transmits microwaves to the measurement antenna, the measurement system uses laser ranging to continuously measure the measurement antenna to obtain the position change of the measurement antenna. The microwave emission and laser ranging measurement start and end synchronously.

10. The system for obtaining radar antenna beam pointing information using laser ranging according to claim 6, characterized in that: The star sensor observation coordinate system, the laser ranging device measurement coordinate system, and the measurement antenna coordinate system are established. By utilizing the relatively fixed positional relationship between the laser ranging device and the star sensor, and the relatively fixed spatial angle relationship between the laser emitted by the laser ranging device and the optical axis of the star sensor, and by continuously measuring the measurement antenna with the laser ranging device, the intermediate quantities obtained are converted, and the measurement coordinate system and the measurement antenna coordinate system are transformed into the star sensor observation coordinate system for description, thereby achieving a unified benchmark for the conversion process.

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