Space laser target pointing test method and system

Abstract

The invention discloses a space laser target pointing test method and system. The method comprises the steps that the laser intensity of an initial light source is attenuated; performing beam expansion on the attenuated initial light source; converging the initial light source after beam expansion so as to form a laser spot; and positioning the laser spot, windowing the imaging position of the laser spot to improve the acquisition frequency of the mass center of the laser spot, and outputting the position of the mass center in real time. By attenuating the laser intensity, the method can be better applied to a weak light detection type fine tracking laser detection camera; by performing beam expansion and convergence on an initial light source, large-view-field detection can be realized conveniently, and laser spot imaging in a detection target surface is ensured. The imaging position of the laser spot is windowed, and the acquisition frequency is improved, so that high-frequency and high-precision real-time output of the position of the mass center can be realized.

Description

Technical Field

[0001] The invention relates to the field of space photoelectric measurement technology, and in particular to a space laser target pointing test method and system. Background Art

[0002] Space laser communication refers to the use of laser as an information carrier for space (including atmospheric space, low orbit, medium orbit, synchronous orbit, interstellar space, and outer space) communication.

[0003] As a technology for direct bidirectional transmission of voice, data and image information in space, space laser communication has many advantages such as large transmission capacity, low transmission power and strong anti-interference ability. With the widespread application of a large number of high-bandwidth instruments on satellites, the demand for satellite information transmission is growing exponentially, and space laser communication is becoming an ideal choice for realizing large-capacity and high-bitrate satellite communications. A high-performance space laser target pointing test system is one of the key technologies for realizing space laser communication.

[0004] With the current trend of satellite payloads developing towards small size, light weight and low power consumption, higher requirements are placed on the design of space laser communication system terminals. In order to further reduce the overall design pressure of satellites and meet the frequency and accuracy requirements of satellite communications, space laser communication system terminals that can meet the requirements of high precision, high frequency, and light weight are required, which also puts higher requirements on the design of space laser target pointing test systems and methods. Summary of the invention

[0005] The purpose of the present invention is to provide a space laser target pointing test method and system, which is used to meet the current satellite requirements for high precision, high frequency, and light weight for space laser communication system terminals. By attenuating the laser intensity of the initial light source, it is better applied to the precision tracking laser detection camera of the weak light detection type, which is conducive to the realization of a light weight design. By opening a window for the imaging position of the laser spot and increasing the acquisition frequency, the center of mass position can be output in real time with high frequency and high precision, thereby realizing high-precision detection of laser target pointing.

[0006] In order to achieve the above objectives, the present invention is implemented by the following technical solutions:

[0007] A first aspect of the present invention provides a space laser target pointing test method, comprising:

[0008] Attenuating the laser intensity of the initial light source;

[0009] Expanding the attenuated initial light source;

[0010] Converging the expanded initial light source to form a laser spot;

[0011] The laser spot is positioned, and the acquisition frequency of the centroid of the laser spot is increased by windowing the imaging position of the laser spot, and the position of the centroid is output in real time.

[0012] Optionally, the initial light source is a 1550nm laser.

[0013] Optionally, by windowing the imaging position of the laser spot, the acquisition frequency of the centroid is increased to 2 kHz or 4 kHz.

[0014] Optionally, the position to which the laser target points is corrected in real time according to the position of the center of mass output in real time and the position calibrated on the ground.

[0015] A second aspect of the present invention provides a space laser target pointing test system, comprising:

[0016] Initial light source;

[0017] LiDAR cameras;

[0018] A laser attenuator, which is used to attenuate the laser intensity of the initial light source so that the laser intensity meets the sensitivity requirement of the laser detection camera;

[0019] A laser beam expander, which is used to expand the attenuated initial light source, reduce the laser divergence angle of the initial light source, and meet the field of view range requirement of the detection target surface of the laser detection camera; and

[0020] A laser lens, wherein the laser lens is used to converge the initial light source after beam expansion to form a laser spot within the detection target surface of the laser detection camera;

[0021] The laser detection camera is used to locate the laser spot and to open a window for the imaging position of the laser spot, so as to increase the acquisition frequency of the centroid of the laser spot and output the position of the centroid in real time.

[0022] Optionally, the initial light source is a 1550nm laser.

[0023] Optionally, the laser lens is a high-transmittance laser lens in the 1550nm band.

[0024] Optionally, a laser detection camera is used to open a window for the imaging position of the laser spot to increase the acquisition frequency of the centroid to 2 kHz or 4 kHz.

[0025] Optionally, the laser detection camera uses an InGaAs-PIN photodiode detector and has a multi-spot detection function;

[0026] The accuracy of the laser detection camera is less than 1 / 10 pixel.

[0027] Optionally, the control mechanism of the optical axis position is used to correct the position where the laser target points in real time according to the position of the center of mass output by the laser detection camera in real time and the position calibrated on the ground.

[0028] The present invention has at least one of the following technical effects:

[0029] By attenuating the laser intensity of the initial light source first, the laser intensity of the initial light source can reach the required value of the camera sensitivity index, which can be better applied to the precision tracking laser detection camera of the weak light detection type;

[0030] By expanding and converging the initial light source, it is easy to achieve large field of view detection, ensuring that the laser spot can be imaged within the detection target surface of the detection device. The imaging position of the laser spot is windowed to increase the acquisition frequency, so that the high-frequency and high-precision real-time output of the center of mass position can be achieved. The present invention can fully meet the needs of future space laser target pointing detection tasks and provide a good technical means for space laser communication link detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram of a flow chart of a space laser target pointing test method provided by an embodiment of the present invention;

[0032] Figure 2 A logical schematic diagram of a space laser target pointing test system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0033] The following is a further detailed description of a space laser target pointing test method and system proposed by the present invention in combination with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention. In order to make the purposes, features and advantages of the present invention more obvious and easy to understand, please refer to the accompanying drawings. It should be noted that the structure, proportion, size, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention, so they have no technical substantive significance. Any modification of the structure, change in the proportional relationship or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope of the technical content disclosed by the present invention.

[0034] like Figure 1As shown, the first aspect of this embodiment provides a space laser target pointing test method, including: attenuating the laser intensity of an initial light source; expanding the attenuated initial light source; converging the expanded initial light source to form a laser spot; positioning the laser spot, increasing the acquisition frequency of the center of mass of the laser spot by windowing the imaging position of the laser spot, and outputting the position of the center of mass in real time.

[0035] Specifically, for example, the laser attenuator can reduce the power of the initial light source by absorbing, reflecting or scattering the laser energy of the initial light source, thereby attenuating the laser intensity of the initial light source. The initial light source can be, for example, a 1550 nm laser. The laser attenuator can be, for example, a laser attenuation prism pair, a wedge-shaped beam splitter, an adjustable polarization beam splitter / attenuator, a dual polarizer attenuator, a neutral density filter, or other structures or machines that can achieve laser attenuation.

[0036] By attenuating the laser intensity of the initial light source, the laser intensity can meet the sensitivity requirements of the laser detection camera. The laser detection camera is lightweight and can detect the laser target pointing with high precision, which is conducive to the lightweight design of the space laser communication system terminal. Since the precision tracking laser detection camera is usually a weak light detection camera, it is necessary to reduce the power and intensity of the initial light source through the laser attenuator.

[0037] After the initial light source is attenuated, it is necessary to further expand the attenuated initial light source. Specifically, the attenuated initial light source can be expanded by using a laser beam expander. The laser beam expander can not only expand the diameter of the laser beam, but also reduce the divergence angle of the laser beam. It is usually used for long-distance lighting, projection and focusing systems. The divergence angle of the laser beam expanded by the laser beam expander varies inversely proportional to the expansion ratio. By reducing the laser divergence angle of the initial light source, it can meet the field of view requirements of the detection target surface of the laser detection camera, which is convenient for the laser detection camera to detect.

[0038] Furthermore, after the attenuated initial light source is expanded, a laser lens can be used to converge the expanded initial light source. The laser lens can be a spherical lens or a non-spherical lens. By determining the parameters such as the focal length, aperture and curvature radius of the laser lens, the initial light source can be better focused so that the laser spot formed by the initial light source can be imaged within the detection target surface of the laser detection camera.

[0039] After the laser spot is detected by the detection target surface of the laser detection camera, the laser detection camera can locate the laser spot. The laser detection camera can, for example, have a windowing function of 20 Hz, 2 kHz, and 4 kHz frame rates, so that the acquisition frequency of the centroid of the laser spot can be increased by windowing the imaging position of the laser spot, for example, the acquisition frequency of the centroid can be increased to 2 kHz or 4 kHz.

[0040] Through the above-mentioned spatial laser target pointing test method, the laser detection camera can output the position of the center of mass in real time with high frequency and high precision. The position information of the center of mass can include, for example, the x-coordinate and y-coordinate of the center of mass on the detection target surface of the laser detection camera. Furthermore, the control mechanism of the optical axis position can, for example, correct the position of the laser target pointing in real time according to the position of the center of mass output in real time by the laser detection camera and the position calibrated on the ground, and finally realize the high-precision detection and position determination of the laser target pointing, which has great engineering application value.

[0041] In order to implement the above-mentioned space laser target pointing test method, in other aspects, this embodiment also provides a space laser target pointing test system. Figure 2 As shown, the space laser target pointing test system includes an initial light source, a laser detection camera, a laser attenuator, a laser beam expander, a laser lens and a data processing computer.

[0042] Specifically, Figure 2 As shown, the initial light source sent by the control mechanism of the optical axis position is received through the rear optical path receiving link, and the initial light source is, for example, a 1550nm laser. Compared with the 905nm laser, the 1550nm laser has higher safety and a longer detection distance. In addition, due to the longer wavelength of the 1550nm laser, it has better penetration in adverse weather conditions such as rainy and foggy days, and is safer for the human eye. In addition, the 1550nm laser can allow higher power output, thereby increasing the detection distance and point cloud resolution.

[0043] The received initial light source can be attenuated by the laser attenuator to meet the sensitivity requirements of the laser detection camera. The laser attenuator can be, for example, a laser attenuation prism pair, a wedge-shaped beam splitter, an adjustable polarization beam splitter / attenuator, a dual polarizer attenuator, a neutral density filter, or other structures or machines that can achieve laser attenuation.

[0044] Furthermore, the initial light source attenuated by the laser attenuator enters the laser beam expander for beam expansion, thereby reducing the laser divergence angle of the initial light source, meeting the field of view range requirement of the detection target surface of the laser detection camera, and realizing large field of view detection.

[0045] The initial light source expanded by the laser beam expander is converged by the laser lens to form the laser spot in the detection target surface of the laser detection camera. In order to improve the convergence effect and facilitate the detection by the laser detection camera, a laser lens with high transmittance in the 1550nm band can be selected as the laser lens according to the initial light source of 1550nm laser.

[0046] The laser detection camera can, for example, use an InGaAs (indium gallium arsenide)-PIN photodiode detector. As a direct bandgap semiconductor material, the bandgap width of InGaAs can be adjusted by the ratio between In and Ga to achieve detection of light signals of different wavelengths. It is one of the ideal materials for realizing high-speed and high-response photodetectors. The laser detection camera can have the function of simultaneous multi-spot detection, thereby achieving multi-target detection and improving the speed and efficiency of spot detection. The accuracy of the laser detection camera can, for example, be less than 1 / 10 pixel, ensuring detection accuracy and fully meeting the accuracy requirements of future space laser detection missions.

[0047] The laser detection camera may also have the function of adaptively opening windows for the imaging position of the laser spot. The laser detection camera may, for example, have adaptive windowing functions for frame rates of 20 Hz, 2 kHz, and 4 kHz. After positioning the laser spot formed in the detection target surface, the laser detection camera may open windows for the imaging position of the laser spot to increase the acquisition frequency of the center of mass of the laser spot. For example, the acquisition frequency of the center of mass may be increased to 2 kHz or 4 kHz, and the position of the center of mass may be output to the data processing computer in real time. The position information of the center of mass may, for example, include the x-coordinate and y-coordinate of the center of mass on the detection target surface of the laser detection camera.

[0048] The data processing computer may include, for example, a central processing unit, a main memory, an input-output interface, and peripheral devices, and may be used to perform operations such as classification, merging, storage, retrieval, and calculation on data and input and output data. The data processing computer may be used to store the position information of the centroid input by the laser detection camera and further process the position information.

[0049] After processing the position information input by the laser detection camera, the data processing computer can input the position information to the main controller. The main controller can correct the position of the laser target in real time by sending instructions to the control mechanism for controlling the optical axis position according to the input position information of the center of mass. In this way, the laser beam position of the tracking optical path and the signal optical path is corrected, and the closed-loop control of the entire back-end optical path is further realized.

[0050] The present invention can make the laser intensity of the initial light source reach the required value of the camera sensitivity index by attenuating the laser intensity of the initial light source, and can be better applied to the precision tracking laser detection camera of the weak light detection type, which is conducive to the lightweight design of the space laser communication system terminal. By expanding and converging the initial light source, it is convenient to realize large field of view detection, and ensure that the laser spot can be imaged within the detection target surface of the detection device. The imaging position of the laser spot is windowed to increase the acquisition frequency, so that high-frequency and high-precision real-time output of the center of mass position can be achieved. The present invention can fully meet the needs of future space laser target pointing detection tasks, provide a good technical means for space laser communication link detection, and has significant progress compared with the existing technology.

[0051] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0052] It should be noted that the devices and methods disclosed in the embodiments of this article can also be implemented in other ways. The device implementation described above is only schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of this article. In this regard, each box in the flowchart or block diagram can represent a part of a module, program or code, and the module, program segment or part of the code contains one or more executable instructions for implementing the specified logical function, and the module, program segment or part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented by a dedicated hardware-based system for performing a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0053] Although the content of the present invention has been described in detail through the above preferred embodiments, it should be appreciated that the above description should not be considered as a limitation of the present invention. After reading the above content, it will be apparent to those skilled in the art that various modifications and substitutions of the present invention will occur. Therefore, the protection scope of the present invention should be limited by the appended claims.

Claims

1. A space laser target pointing test method, characterized in that: include: Attenuating the laser intensity of the initial light source; Expanding the attenuated initial light source; Converging the expanded initial light source to form a laser spot; The laser spot is positioned, and the acquisition frequency of the centroid of the laser spot is increased by windowing the imaging position of the laser spot, and the position of the centroid is output in real time.

2. The space laser target pointing test method according to claim 1, characterized in that: The initial light source is a 1550nm laser.

3. The space laser target pointing test method according to claim 1, characterized in that: By windowing the imaging position of the laser spot, the acquisition frequency of the centroid is increased to 2 kHz or 4 kHz.

4. The space laser target pointing test method according to claim 1, characterized in that: The position where the laser target is pointing is corrected in real time according to the real-time output position of the center of mass and the position calibrated on the ground.

5. A space laser target pointing test system, characterized in that: include: Initial light source; LiDAR cameras; A laser attenuator, which is used to attenuate the laser intensity of the initial light source so that the laser intensity meets the sensitivity requirement of the laser detection camera; A laser beam expander, which is used to expand the attenuated initial light source, reduce the laser divergence angle of the initial light source, and meet the field of view range requirements of the detection target surface of the laser detection camera; and A laser lens, wherein the laser lens is used to converge the initial light source after beam expansion to form a laser spot within the detection target surface of the laser detection camera; The laser detection camera is used to locate the laser spot and to open a window for the imaging position of the laser spot, so as to increase the acquisition frequency of the centroid of the laser spot and output the position of the centroid in real time.

6. The space laser target pointing test system according to claim 5, characterized in that: The initial light source is a 1550nm laser.

7. The space laser target pointing test system according to claim 6, characterized in that: The laser lens is a 1550nm band high-transmittance laser lens.

8. The space laser target pointing test system according to claim 5, characterized in that: The laser detection camera is used to open a window for the imaging position of the laser spot, thereby increasing the acquisition frequency of the centroid to 2 kHz or 4 kHz.

9. The space laser target pointing test system according to claim 5, characterized in that: The laser detection camera uses an InGaAs-PIN photodiode detector and has the function of multi-spot detection; The accuracy of the laser detection camera is less than 1 / 10 pixel.

10. The space laser target pointing test system according to claim 5, characterized in that: The control mechanism of the optical axis position is used to correct the position of the laser target in real time according to the position of the center of mass output by the laser detection camera in real time and the position calibrated on the ground.

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