Intersatellite laser communication imaging and calibration integrated method and system

Abstract

The invention provides an inter-satellite laser communication imaging and calibration integrated method and system. The system comprises a primary mirror, a secondary mirror, a narrow-band filter, an optical imaging and calibration integrated module, an imaging and calibration control module, a laser communication transmitting module, a transmitting fast reflecting mirror, a polarizing beam splitter, a beam splitter, a receiving fast reflecting mirror and a laser communication receiving module. The optical imaging and calibration integrated module performs star imaging and data processing, and corrects star imaging and calibration; scanning and imaging the uncertain area; processing to obtain target and background characteristics; and the laser communication terminal performs bidirectional capture locking, starts communication and transmits data. According to the invention, inter-satellite laser communication, imaging and calibration are integrated, the imaging and calibration time is shortened, the size and weight of the terminal are reduced, visible light image information of a target and a background environment and the pointing error of a calibration device are obtained, an uncertain capture area of the laser communication terminal is reduced, the laser communication link establishment speed is improved, and the communication efficiency is improved. And high-speed inter-satellite laser communication is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of inter-satellite laser communication and optical imaging, and in particular, relates to an inter-satellite laser communication imaging calibration integrated method and system. Background Art

[0002] Lasers are used in the field of wireless communications because of their strong directivity and independence from transmission media in space transmission. The transmitting terminal converts the data signal into an optical signal, and after the laser generates high-energy laser light, the laser light passes through the air or vacuum and reaches the receiving terminal. The receiving terminal decodes the required information after photoelectric conversion. Due to the strong directivity and concentrated energy of lasers, laser communication can achieve longer transmission distances, larger bandwidths, and higher speeds compared to traditional radio communication technology, making it an ideal communication method for space information transmission.

[0003] For intersatellite laser communication, since low-orbit satellites are in constant motion, the positions of the satellite and other satellites are changing all the time, which poses a great challenge to laser communication with high directivity requirements. On the one hand, it is necessary to understand the changing rules of the geometric relationship of the communication link, analyze and estimate the laser pointing in advance, and achieve high-precision tracking and aiming. On the other hand, it is necessary to determine the attitude of the laser communication terminal relative to the inertial coordinate system, achieve high-precision alignment of the laser between the two terminals, and complete intersatellite laser communication.

[0004] However, the current acquisition of the attitude of the laser communication terminal relies on the output of the satellite platform, and the coordinate system is converted through the relative relationship between the two. There are still installation errors and thermal deformation errors between the converted laser communication terminal attitude and its actual attitude, which expands the capture uncertainty area of ​​the laser communication terminal and increases the difficulty of laser communication link establishment. However, the laser communication terminal naturally has all the functions required for imaging and can be used as a means of obtaining image information. By integrating the use of filters, the wavelength required for laser communication and the wavelength required for visible light imaging can be separated, and the laser communication and visible light imaging functions can be integrated in the same terminal to achieve high-speed communication while obtaining target and background environment information. However, the current laser terminal has a very small field of view. During on-orbit operation, it takes a long time to obtain the effective star imaging data required for imaging calibration or to perform full-star attitude orbit control.

[0005] Patent document "A method for rapid on-orbit calibration of laser communication terminal pointing based on parameter optimization" (CN116961751A) discloses a method for rapid on-orbit calibration of laser communication terminal pointing based on parameter optimization, which calculates the theoretical pointing matrix of the laser communication terminal, and calculates the pointing error in combination with the actual pointing matrix to complete the rapid on-orbit calibration of the laser communication terminal pointing. However, it does not have an imaging function and cannot obtain target and background environment information in real time during communication.

[0006] Patent document "A laser communication system compatible with star sensors" (CN217693339U) discloses a laser communication system compatible with star sensors, which can realize the simultaneous use of laser communication and star sensor detection. However, it requires additional integration of star sensors, while the present invention adopts an integrated optical imaging calibration module, which can realize imaging calibration and imaging functions simultaneously without adding new components.

[0007] Patent document "A satellite laser communication system pointing error correction method based on star sensor" (CN115290118A) discloses a satellite laser communication system pointing error correction method based on star sensor, which realizes laser pointing vector error correction by integrating star sensor attitude, optical antenna rotation angle, satellite attitude angle, satellite orbit information and target orbit information. However, the present invention integrates communication, imaging and calibration functions in one optical path, and the equipment is more miniaturized and lightweight. Summary of the invention

[0008] In view of the defects in the prior art, the object of the present invention is to provide an integrated method and system for inter-satellite laser communication imaging calibration.

[0009] An integrated optical imaging calibration method provided by the present invention includes:

[0010] Star scanning step S0: Control the coarse tracking mechanism to scan the area where stars exist.

[0011] Among them, according to the ephemeris and orbit calculation, the azimuth axis and pitch axis of the coarse tracking mechanism of the local communication laser terminal are controlled to scan the area where stars exist.

[0012] Imaging calibration step S1: outputting imaging calibration instructions according to the star image;

[0013] The star image includes an image obtained by imaging a plurality of evenly distributed stars, and the imaging calibration instruction includes an instruction to perform imaging calibration on a local laser communication terminal;

[0014] and / or, including:

[0015] Capturing and locking step S2: outputting a capturing and locking instruction according to the characteristic information data of the target laser communication terminal acquired based on the imaging data;

[0016] The imaging data includes an image obtained by scanning and imaging an uncertain area where a target laser communication terminal where a communication link needs to be established is located, and the capture and lock instruction includes an instruction to instruct a local laser communication terminal to capture and lock a target laser communication terminal.

[0017] Preferably, the imaging calibration step S1 comprises:

[0018] Step S1.1: Plan the optical imaging time according to the satellite orbit and select the stars to be imaged;

[0019] Step S1.2: imaging the selected star to be imaged to obtain a star image;

[0020] Step S1.3: Identify the star data in the star image, extract the center of mass, and record the imaging time, azimuth and elevation angle to obtain the real pointing, and calculate the theoretical azimuth and elevation angle of the star in combination with the attitude information of the local laser communication terminal to obtain the initial pointing;

[0021] Step S1.4: Compare the initial pointing and the actual pointing of the local laser communication terminal, and calculate the initial pointing error correction matrix using the least square method;

[0022] Step S1.5: Use the initial pointing error correction matrix to obtain imaging calibration instructions, verify the validity and calibration accuracy of the initial pointing error correction matrix, and output imaging calibration instructions.

[0023] Preferably, the capture and locking step S2 includes:

[0024] Step S2.1: Scan and image the uncertain area where the target laser communication terminal where the communication link needs to be established is located according to the set orbit and time, and obtain imaging data;

[0025] Step S2.2: Based on the imaging data, information data of the target and its shape, speed and background environment characteristics in the scanned uncertain area are obtained by processing;

[0026] Step S2.3: Output a capture and lock instruction according to the information data.

[0027] According to the present invention, a method for inter-satellite laser communication imaging calibration is provided, which specifically comprises the following steps:

[0028] Step S100: collecting star information through the primary mirror 2;

[0029] Step S200: transmitting the star information from the primary mirror 2 to the narrowband filter 4 via the secondary mirror 3;

[0030] Step S300: Obtaining visible light information in the star information through the narrow-band filter 4 to form a star image;

[0031] Step S400: using the optical imaging calibration method to obtain an imaging calibration instruction according to a star image;

[0032] Step S500: Perform imaging calibration according to the imaging calibration instruction to adjust the posture of the local laser communication terminal.

[0033] Preferably, it also includes:

[0034] Step S600: The laser emitted by the laser communication transmitting module 8 passes through the transmitting fast reflection mirror 7, the polarization beam splitter 6, and the narrow band filter 4 in sequence to reach the telescope system composed of the primary mirror 2 and the secondary mirror 3, and is emitted from the primary mirror 2 to the target laser communication terminal;

[0035] Step S700: The laser received from the target laser communication terminal passes through the telescope system, the narrowband filter 4, the polarization beam splitter 6, the beam splitter 9 and the receiving fast reflection mirror 11 in sequence and is received by the laser communication receiving module 12.

[0036] An optical imaging calibration integrated module 5 provided by the present invention specifically includes the following modules:

[0037] Star scanning module M0: controls the coarse tracking mechanism and scans the area where stars exist.

[0038] Among them, according to the ephemeris and orbit calculation, the azimuth axis and pitch axis of the rough tracking mechanism of the laser terminal are controlled to scan the area where stars exist.

[0039] Imaging calibration module M1: outputs imaging calibration instructions based on star images;

[0040] The star image includes an image obtained by imaging a plurality of evenly distributed stars, and the imaging calibration instruction includes an instruction to perform imaging calibration on a local laser communication terminal;

[0041] and / or, including:

[0042] Capture and lock module M2: outputs a capture and lock instruction according to the characteristic information data of the target laser communication terminal acquired based on the imaging data;

[0043] The imaging data includes an image obtained by scanning and imaging an uncertain area where a target laser communication terminal where a communication link needs to be established is located, and the capture and lock instruction includes an instruction to instruct a local laser communication terminal to capture and lock a target laser communication terminal.

[0044] Preferably, the imaging calibration module M1 comprises:

[0045] Module M1.1: Plan the optical imaging time and select the stars to be imaged according to the satellite orbit;

[0046] Module M1.2: Image the selected stars to be imaged and obtain star images;

[0047] Module M1.3: Identify star data in star images, extract centroids, and record imaging time, azimuth, and elevation to obtain true pointing. Combined with the attitude information of the local laser communication terminal, calculate the theoretical azimuth and elevation of the star to obtain the initial pointing.

[0048] Module M1.4: Compare the initial pointing and the actual pointing of the local laser communication terminal, and use the least squares method to calculate the initial pointing error correction matrix;

[0049] Module M1.5: Use the initial pointing error correction matrix to obtain the imaging calibration instructions, verify the validity and calibration accuracy of the initial pointing error correction matrix, and output the imaging calibration instructions.

[0050] Preferably, the capture and lock module M2 includes:

[0051] Module M2.1: According to the set orbit and time, scan and image the uncertain area where the target laser communication terminal where the communication link needs to be established is located to obtain imaging data;

[0052] Module M2.2: Based on the imaging data, the information data of the target and its shape, speed and background environment characteristics in the scanned uncertain area are processed;

[0053] Module M2.3: Output capture and lock instructions according to information data.

[0054] According to the present invention, an intersatellite laser communication imaging calibration integrated system specifically comprises: a primary mirror 2, a secondary mirror 3, a narrow-band filter 4, an optical imaging calibration integrated module 5, and an imaging calibration control module;

[0055] Primary mirror 2 collects star information;

[0056] The secondary mirror 3 transmits the star information from the primary mirror 2 to the narrowband filter 4;

[0057] The narrowband filter 4 obtains the visible light information in the star information to form a star image;

[0058] The optical imaging calibration integrated module 5 obtains imaging calibration instructions according to the star image;

[0059] The imaging calibration control module performs imaging calibration according to the imaging calibration instruction to adjust the posture of the local laser communication terminal.

[0060] Preferably, it also includes: a laser communication transmitting module 8, a transmitting quick-reflection mirror 7, a polarization beam splitter 6, a beam splitter 9, a receiving quick-reflection mirror 11, and a laser communication receiving module 12;

[0061] The laser emitted by the laser communication transmitting module 8 passes through the transmitting fast reflection mirror 7, the polarization beam splitter 6, and the narrow band filter 4 in sequence to reach the telescope system composed of the primary mirror 2 and the secondary mirror 3, and is emitted from the primary mirror 2 to the target laser communication terminal;

[0062] The laser received from the target laser communication terminal passes through the telescope system, the narrowband filter 4, the polarization beam splitter 6, the beam splitter 9 and the receiving fast reflection mirror 11 in sequence and is received by the laser communication receiving module 12.

[0063] Compared with the prior art, the present invention has the following beneficial effects:

[0064] 1. The present invention adopts an integrated structure of laser communication, imaging and calibration, realizes the miniaturized integration of the three, shortens the imaging calibration time, greatly reduces the occupied satellite platform space and weight, and reduces the size and weight of the terminal.

[0065] 2. By processing and locating the positions of stars in the visible light image, the attitude of the laser communication terminal body can be directly obtained to achieve attitude calibration without the need for conversion through a satellite platform, thus reducing attitude errors.

[0066] 3. Realize the acquisition of visible light image information, process image data, obtain visible light image information, isolate it from laser communication through frequency band, and provide information such as target and background environment information.

[0067] 4. The processing module can not only realize optical imaging, but also extract and analyze the stars in the image, calibrate the pointing error of the device, and reduce the capture uncertainty area of ​​the laser communication terminal.

[0068] 5. The optical path has the functions of transmitting signal light, receiving signal light, tracking signal light, and receiving images. It solves the problems of installation error and thermal deformation error in the attitude data obtained by laser communication terminals from satellite platforms in the past, improves the speed of laser communication link establishment, and realizes high-speed intersatellite laser communication.

[0069] 6. Directly use the optical imaging device in the laser communication terminal for position calibration without the need for a dedicated star detection device, and quickly obtain effective star imaging data by increasing the control steps of the coarse tracking mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0071] Figure 1 This is a schematic diagram of the structure of the inter-satellite laser communication imaging and calibration system.

[0072] Figure 2Schematic diagram of the intersatellite laser communication imaging calibration steps.

[0073] Figure 3 Schematic diagram of the error imaging calibration principle based on the optical imaging calibration integrated module.

[0074] The figure shows:

[0075] DETAILED DESCRIPTION

[0076] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0077] In order to achieve the above-mentioned purpose, the present invention provides an integrated optical imaging calibration method, and the specific implementation method is as follows in combination with the preferred examples:

[0078] Star scanning step S0: Control the coarse tracking mechanism to scan the area where stars exist.

[0079] Among them, according to the ephemeris and orbit calculation, the azimuth axis and pitch axis of the coarse tracking mechanism of the local laser communication terminal are controlled to scan the area where stars exist.

[0080] Imaging calibration step S1: outputting imaging calibration instructions according to the star image;

[0081] The star image includes an image obtained by imaging one or more evenly distributed stars, and the imaging calibration instruction includes an instruction to instruct the local laser communication terminal to perform imaging calibration;

[0082] and / or, including:

[0083] Capturing and locking step S2: outputting a capturing and locking instruction according to the characteristic information data of the target laser communication terminal acquired based on the imaging data;

[0084] The imaging data includes an image obtained by scanning and imaging an uncertain area where a target laser communication terminal where a communication link needs to be established is located, and the capture and lock instruction includes an instruction to instruct a local laser communication terminal to capture and lock a target laser communication terminal.

[0085] In more embodiments, the imaging calibration step S1 includes:

[0086] Step S1.1: Plan the optical imaging time according to the satellite orbit and select the stars to be imaged;

[0087] Step S1.2: imaging the selected star to be imaged to obtain a star image;

[0088] Step S1.3: Identify the star data in the star image, extract the center of mass, and record the imaging time, azimuth and elevation angle to obtain the real pointing, and calculate the theoretical azimuth and elevation angle of the star in combination with the attitude information of the local laser communication terminal to obtain the initial pointing;

[0089] Step S1.4: Compare the initial pointing and the actual pointing of the local laser communication terminal, and calculate the initial pointing error correction matrix using the least square method;

[0090] Step S1.5: Use the initial pointing error correction matrix to obtain imaging calibration instructions, verify the validity and calibration accuracy of the initial pointing error correction matrix, and output imaging calibration instructions.

[0091] In more embodiments, the capture and locking step S2 includes:

[0092] Step S2.1: Scan and image the uncertain area where the target laser communication terminal where the communication link needs to be established is located according to the set orbit and time, and obtain imaging data;

[0093] Step S2.2: Based on the imaging data, information data of the target and its shape, speed and background environment characteristics in the scanned uncertain area are obtained by processing;

[0094] Step S2.3: Output a capture and lock instruction according to the information data.

[0095] According to the present invention, a method for inter-satellite laser communication imaging calibration is provided, which specifically includes:

[0096] Step S100: collecting star information through the primary mirror 2;

[0097] Step S200: transmitting the star information from the primary mirror 2 to the narrowband filter 4 via the secondary mirror 3;

[0098] Step S300: Obtaining visible light information in the star information through the narrow-band filter 4 to form a star image;

[0099] Step S400: using the optical imaging calibration method to obtain an imaging calibration instruction according to a star image;

[0100] Step S500: Perform imaging calibration according to the imaging calibration instruction to adjust the posture of the local laser communication terminal.

[0101] In more embodiments, it also includes:

[0102] Step S600: The laser emitted by the laser communication transmitting module 8 passes through the transmitting fast reflection mirror 7, the polarization beam splitter 6, and the narrow band filter 4 in sequence to reach the telescope system composed of the primary mirror 2 and the secondary mirror 3, and is emitted from the primary mirror 2 to the target laser communication terminal;

[0103] Step S700: The laser received from the target laser communication terminal passes through the telescope system, the narrowband filter 4, the polarization beam splitter 6, the beam splitter 9 and the receiving fast reflection mirror 11 in sequence and is received by the laser communication receiving module 12.

[0104] According to the present invention, an optical imaging calibration integrated module 5 includes:

[0105] Star scanning module M0: controls the coarse tracking mechanism and scans the area where stars exist.

[0106] Among them, according to the ephemeris and orbit calculation, the azimuth axis and pitch axis of the coarse tracking mechanism of the local laser communication terminal are controlled to scan the area where stars exist.

[0107] Imaging calibration module M1: outputs imaging calibration instructions based on star images;

[0108] The star image includes an image obtained by imaging a plurality of evenly distributed stars, and the imaging calibration instruction includes an instruction to perform imaging calibration on a local laser communication terminal;

[0109] and / or, including:

[0110] Capture and lock module M2: outputs a capture and lock instruction according to the characteristic information data of the target laser communication terminal acquired based on the imaging data;

[0111] The imaging data includes an image obtained by scanning and imaging an uncertain area where a target laser communication terminal where a communication link needs to be established is located, and the capture and lock instruction includes an instruction to instruct a local laser communication terminal to capture and lock a target laser communication terminal.

[0112] The present invention directly utilizes the optical imaging device in the laser communication terminal for position calibration. First, a star positioning algorithm is adopted. Second, considering that the field of view of the laser communication terminal itself is only tens of microradians, it is difficult for the optical imaging device to obtain effective star imaging data using this field of view of tens of microradians. Therefore, it is necessary to additionally calculate based on the ephemeris and orbit, control the coarse tracking mechanism, scan the area where stars exist, and obtain effective star imaging data for imaging calibration.

[0113] by Figure 3 This is an embodiment. This embodiment implements the above-mentioned laser communication terminal error correction calibration process based on the optical imaging calibration integrated module. In other words, the imaging calibration module M1 is specifically as follows:

[0114] According to the satellite orbit, appropriate optical imaging time is planned to ensure that multiple evenly distributed stars can be imaged.

[0115] The optical imaging and calibration integrated module images the selected stars in turn to obtain stellar data.

[0116] The integrated optical imaging calibration module identifies star data, extracts the center of mass, and records the imaging time, azimuth, and pitch angle. It calculates the theoretical azimuth and pitch angle of the star based on the attitude information to obtain the true pointing direction.

[0117] The initial pointing and actual pointing of the laser communication terminal to multiple stars are compared, and the initial pointing error correction matrix is ​​calculated using the least squares method.

[0118] The initial pointing error correction matrix is ​​used to complete the pointing correction of the star, and the effectiveness and calibration accuracy of the initial pointing error correction matrix are verified.

[0119] by Figure 2 As an embodiment, the capture and locking module M2 in the optical imaging calibration module embodiment includes:

[0120] The optical imaging calibration module images stars and processes data to correct the star imaging calibration;

[0121] Specifically, multiple evenly distributed stars are imaged, and data processing is performed based on the star information to calibrate the star imaging.

[0122] The optical imaging calibration module scans and images the uncertain area to obtain imaging data;

[0123] Specifically, according to the orbit and time, the integrated optical imaging calibration module scans the uncertain area where the laser communication terminal that needs to establish a communication link is located, and at the same time images the scanned uncertain area to obtain imaging data.

[0124] The optical imaging calibration module processes the imaging data to obtain information data on target and background characteristics;

[0125] Specifically, based on the imaging data, the optical imaging calibration module processes and obtains characteristic information data such as target shape, speed, and background environment in the scanned uncertain area.

[0126] The laser communication terminal captures and locks in both directions, starts communicating, and transmits information data.

[0127] According to the present invention, an intersatellite laser communication imaging calibration integrated system specifically comprises: a primary mirror 2, a secondary mirror 3, a narrowband filter 4, an optical imaging calibration integrated module 5, an imaging calibration module, a laser communication transmitting module 8, a transmitting fast-reflecting mirror 7, a polarization beam splitter 6, a beam splitter 9, a receiving fast-reflecting mirror 11, and a laser communication receiving module 12;

[0128] The primary mirror 2 collects star information; the secondary mirror 3 transmits the star information from the primary mirror 2 to the narrowband filter 4; the narrowband filter 4 obtains the visible light information in the star information to form a star image; the optical imaging calibration integrated module 5 obtains the imaging calibration instruction according to the star image; the imaging calibration module performs imaging calibration according to the imaging calibration instruction and adjusts the posture of the local laser communication terminal.

[0129] The laser emitted by the laser communication transmitting module 8 passes through the transmitting fast reflection mirror 7, the polarization beam splitter 6, and the narrow-band filter 4 in sequence to reach the telescope system composed of the primary mirror 2 and the secondary mirror 3, and is emitted from the primary mirror 2 to the target laser communication terminal.

[0130] The laser received from the target laser communication terminal passes through the telescope system, the narrowband filter 4, the polarization beam splitter 6, the beam splitter 9 and the receiving fast reflection mirror 11 in sequence and is received by the laser communication receiving module 12.

[0131] Specifically, the laser communication terminal captures and locks in both directions, the laser communication tracking module obtains the other party's position and compares it with its own tracking position, and controls the alignment of the receiving optical axis and the system optical axis. When communication starts, the laser communication transmitting module transmits laser light, and the laser communication receiving module receives laser light to transmit data.

[0132] After data transmission is completed, the device returns to standby mode.

[0133] by Figure 1 As an embodiment, this embodiment provides an intersatellite laser communication imaging calibration integrated optical system, including a star 1, a primary mirror 2, a secondary mirror 3, a narrow-band filter 4, an optical path, an optical imaging calibration integrated module 5, a polarization beam splitter 6, a transmitting quick-reflection mirror 7, a laser communication transmitting module 8, a beam splitter 9, a laser communication tracking module 10, a receiving quick-reflection mirror 11 and a laser communication receiving module 12.

[0134] In this embodiment, the materials of the primary mirror 2 and the secondary mirror 3 include beryllium, glass, silicon carbide, silicon, etc., and silicon material is preferred in view of the properties such as density, processing, and cost. In view of the matching of thermal expansion coefficients, the mirror frames of the primary mirror 2 and the secondary mirror 3 are preferably made of aluminum-based silicon carbide material.

[0135] The primary mirror 2 and the secondary mirror 3 form a telescope system with an effective aperture of 100 mm, a length of 150 mm, and an optical field of view of 5 mrad.

[0136] The narrowband filter 4 has a reflection wavelength range of 380 nm to 780 nm and a transmission wavelength range of 1.5 μm to 1.6 μm. The reflection range of 380 nm to 780 nm is used for visible light imaging, and the transmission wavelength range of 1.5 μm to 1.6 μm is used for laser communication.

[0137] The optical imaging calibration module 5 is located on the reflected light path of the narrow-band filter 4, and includes a visible light imaging sensor array and a processing circuit. The visible light imaging sensor array is used to image the reflected light, realize visible light imaging, output the image, and obtain the target and background environment information. The preferred imaging resolution is 512 512, 640 512, 1280 1024.

[0138] ×××

[0139] The processing circuit is used to locate and analyze the stars in the image, extract the center of mass of the stars, and calculate the calibration matrix of the laser device coordinate system, which is used for the pointing accuracy and optical axis consistency calibration of the inter-satellite laser communication and imaging calibration device.

[0140] The polarization beam splitter 6 realizes the combination and isolation of the laser beam, reflects the emitted light, enters the main optical path, and finally transmits it to other laser communication terminals; transmits the received light, enters the main optical path, and finally enters the laser communication receiving module of the main body.

[0141] The emission fast reflection mirror 7 can correct the pointing accuracy of the emission optical axis, improve the capture and tracking speed, and realize rapid laser chain building. The type is preferably a piezoelectric fast reflection mirror, the resonance frequency is preferably above 1kHz, and the execution resolution is preferably in the order of μrad.

[0142] The laser communication transmitting module 8 is located on the reflected light path of the transmitting fast reflection mirror 7, and can realize laser emission with required wavelength, polarization, power and other conditions. Preferably, reflective collimated emission is adopted, the preferred focal length is 35mm, the preferred aperture is 20mm, and the preferred beam divergence angle is 50μrad.

[0143] The reflection wavelength range of the beam splitter 9 is 3 μm to 3.5 μm, and the transmission wavelength range is 1.5 μm to 1.6 μm. The reflection range of 3 μm to 3.5 μm is used for tracking by the laser communication tracking module, and the transmission wavelength range of 1.5 μm to 1.6 μm is used for laser communication.

[0144] The laser communication tracking module 10 is located on the reflected light path of the beam splitter 9, obtains the spot position of the other party's laser communication terminal, and compares it with the tracking position of the other party, controls the alignment of the receiving optical axis and the system optical axis, and can achieve rapid capture and stable tracking of the laser link in the absence of beacon light. The preferred tracking lens form is transmissive, the preferred focal length is 1.5mm, the preferred aperture is 30mm, the preferred detector pixel array is 512×256, and the preferred field of view is 5.12×2.56mrad 2 .

[0145] The receiving fast reflection mirror 11 can correct the pointing accuracy of the receiving optical axis and maintain long-term laser link establishment and communication. The type is preferably a piezoelectric fast reflection mirror, the resonance frequency is preferably above 1kHz, and the execution resolution is preferably in the order of μrad.

[0146] The laser communication receiving module 12 is located on the light path reflected by the receiving fast reflection mirror 11, and can realize laser reception of required wavelength, polarization, power and other conditions. The preferred form is a reflection system, the preferred focal length is 330mm, the preferred aperture is 65mm, and the preferred focal length is 45mm.

[0147] Specifically, the optical imaging calibration integrated module is located on the reflected light path of the narrowband filter, the laser communication transmitting module is located on the reflected light path of the transmitting fast reflection mirror, the laser communication tracking module is located on the reflected light path of the spectroscope, and the laser communication receiving module is located on the reflected light path of the receiving fast reflection mirror.

[0148] The optical path includes an optical imaging calibration optical path, a laser communication transmitting optical path, a laser communication tracking optical path, and a laser communication receiving optical path.

[0149] The narrow-band filter, polarization beam splitter, beam splitter and receiving quick-reflection mirror are located on the same optical axis.

[0150] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. An integrated optical imaging calibration method, characterized in that: include: Star scanning step S0: controlling the coarse tracking mechanism to scan the area where stars exist; Among them, according to the ephemeris and orbit calculation, the azimuth axis and pitch axis of the rough tracking mechanism of the laser terminal are controlled to scan the area where stars exist; Imaging calibration step S1: outputting imaging calibration instructions according to the star image; The star image includes an image obtained by imaging one or more evenly distributed stars, and the imaging calibration instruction includes an instruction to instruct the local laser communication terminal to perform imaging calibration; and / or, including: Capturing and locking step S2: outputting a capturing and locking instruction according to the characteristic information data of the target laser communication terminal acquired based on the imaging data; The imaging data includes an image obtained by scanning and imaging an uncertain area where a target laser communication terminal where a communication link needs to be established is located, and the capture and lock instruction includes an instruction to instruct a local laser communication terminal to capture and lock a target laser communication terminal.

2. The optical imaging calibration method according to claim 1, characterized in that: The imaging calibration step S1 comprises: Step S1.1: Plan the optical imaging time according to the satellite orbit and select the stars to be imaged; Step S1.2: imaging the selected star to be imaged to obtain a star image; Step S1.3: Identify the star data in the star image, extract the center of mass, and record the imaging time, azimuth and elevation angle to obtain the real pointing, and calculate the theoretical azimuth and elevation angle of the star in combination with the attitude information of the local laser communication terminal to obtain the initial pointing; Step S1.4: Compare the initial pointing and the actual pointing of the local laser communication terminal, and calculate the initial pointing error correction matrix using the least square method; Step S1.5: Use the initial pointing error correction matrix to obtain imaging calibration instructions, verify the validity and calibration accuracy of the initial pointing error correction matrix, and output imaging calibration instructions.

3. The optical imaging calibration method according to claim 1, characterized in that: The capture and locking step S2 comprises: Step S2.1: Scan and image the uncertain area where the target laser communication terminal where the communication link needs to be established is located according to the set orbit and time, and obtain imaging data; Step S2.2: Based on the imaging data, information data of the target and its shape, speed and background environment characteristics in the scanned uncertain area are obtained by processing; Step S2.3: Output a capture and lock instruction according to the information data.

4. A method for intersatellite laser communication imaging calibration, characterized in that: include: Step S100: collecting star information through the primary mirror (2); Step S200: transmitting the star information from the primary mirror (2) to the narrowband filter (4) through the secondary mirror (3); Step S300: Obtaining visible light information in the star information through a narrow-band filter (4) to form a star image; Step S400: obtaining an imaging calibration instruction according to a star image using the integrated optical imaging calibration method according to any one of claims 1 to 3; Step S500: Perform imaging calibration according to the imaging calibration instruction to adjust the posture of the local laser communication terminal.

5. The inter-satellite laser communication imaging calibration integrated method according to claim 4, characterized in that: Also includes: Step S600: The laser light emitted by the laser communication transmitting module (8) passes through the transmitting fast reflection mirror (7), the polarization beam splitter (6), and the narrow band filter (4) in sequence to reach the telescope system composed of the primary mirror (2) and the secondary mirror (3), and is emitted from the primary mirror (2) to the target laser communication terminal; Step S700: The laser light received from the target laser communication terminal passes through the telescope system, the narrowband filter (4), the polarization beam splitter (6), the beam splitter (9) and the receiving fast-reflection mirror (11) in sequence and is received by the laser communication receiving module (12).

6. An optical imaging calibration integrated module (5), characterized in that: include: Star scanning module M0: controls the coarse tracking mechanism and scans the area where stars exist; Among them, according to the ephemeris and orbit calculation, the azimuth axis and pitch axis of the rough tracking mechanism of the laser terminal are controlled to scan the area where stars exist; Imaging calibration module M1: outputs imaging calibration instructions based on star images; The star image includes an image obtained by imaging one or more evenly distributed stars, and the imaging calibration instruction includes an instruction to instruct the local laser communication terminal to perform imaging calibration; and / or, including: Capture and lock module M2: outputs a capture and lock instruction according to the characteristic information data of the target laser communication terminal acquired based on the imaging data; The imaging data includes an image obtained by scanning and imaging an uncertain area where a target laser communication terminal where a communication link needs to be established is located, and the capture and lock instruction includes an instruction to instruct a local laser communication terminal to capture and lock a target laser communication terminal.

7. The optical imaging calibration system according to claim 6, characterized in that: The imaging calibration module M1 comprises: Module M1.1: Plan the optical imaging time and select the stars to be imaged according to the satellite orbit; Module M1.2: Image the selected stars to be imaged and obtain star images; Module M1.3: Identify star data in star images, extract centroids, and record imaging time, azimuth, and elevation to obtain true pointing. Combined with the attitude information of the local laser communication terminal, calculate the theoretical azimuth and elevation of the star to obtain the initial pointing. Module M1.4: Compare the initial pointing and the actual pointing of the local laser communication terminal, and use the least squares method to calculate the initial pointing error correction matrix; Module M1.5: Use the initial pointing error correction matrix to obtain the imaging calibration instructions, verify the validity and calibration accuracy of the initial pointing error correction matrix, and output the imaging calibration instructions.

8. The optical imaging calibration system according to claim 6, characterized in that: The capture and lock module M2 includes: Module M2.1: According to the set orbit and time, scan and image the uncertain area where the target laser communication terminal where the communication link needs to be established is located to obtain imaging data; Module M2.2: Based on the imaging data, the information data of the target and its shape, speed and background environment characteristics in the scanned uncertain area are processed; Module M2.3: Output capture and lock instructions according to information data.

9. An intersatellite laser communication imaging calibration system, characterized in that: include: A primary mirror (2), a secondary mirror (3), a narrowband filter (4), an optical imaging calibration integrated module (5), and an imaging calibration control module; The primary mirror (2) collects information about stars; The secondary mirror (3) transmits the star information from the primary mirror (2) to the narrowband filter (4); The narrowband filter (4) obtains the visible light information in the star information to form a star image; The optical imaging calibration integrated module (5) obtains an imaging calibration instruction according to the star image; The imaging calibration control module performs imaging calibration according to the imaging calibration instruction to adjust the posture of the local laser communication terminal.

10. The inter-satellite laser communication imaging calibration integrated system according to claim 9, characterized in that: Also includes: Laser communication transmitting module (8), transmitting fast-reflecting mirror (7), polarizing beam splitter (6), beam splitter (9), receiving fast-reflecting mirror (11), laser communication receiving module (12); The laser light emitted by the laser communication transmitting module (8) passes through the transmitting fast reflection mirror (7), the polarization beam splitter (6), and the narrow band filter (4) in sequence to reach the telescope system composed of the primary mirror (2) and the secondary mirror (3), and is emitted from the primary mirror (2) to the target laser communication terminal; The laser light received from the target laser communication terminal passes through the telescope system, the narrowband filter (4), the polarization beam splitter (6), the beam splitter (9) and the receiving fast-reflection mirror (11) in sequence and is received by the laser communication receiving module (12).

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