A low-orbit satellite cluster inter-satellite laser communication networking test system and method

Abstract

The present invention discloses a low-orbit star cluster inter-satellite laser communication networking test system and method, belonging to the field of satellite communication technology. The system includes a satellite attitude simulation device, a beam far-field characteristics simulation device, and a ground-side simulation device. The satellite attitude simulation device is used to simulate the orbit, attitude, and vibration changes of the satellite platform in the satellite laser link; the beam far-field characteristics simulation device is used to simulate the distribution state and attenuation dynamic changes of the laser beam in the low-orbit star cluster inter-satellite laser link after long-distance transmission based on the laser signal; the ground-side simulation device is used to receive data on the satellite platform's orbit, attitude, and vibration changes, as well as the distribution state and attenuation dynamic changes of the laser beam after long-distance transmission, and collaborates with the laser communication terminal to complete the performance test of the low-orbit star cluster inter-satellite laser communication network. The present invention can support "one-to-many" low-orbit star cluster inter-satellite laser communication link performance testing and low-orbit star cluster inter-satellite multi-node laser communication network performance testing.

Description

Technical Field

[0001] The present invention relates to the field of satellite communication technology, and in particular to a low-orbit satellite cluster inter-satellite laser communication networking test system and method. Background Art

[0002] Compared with microwave communication, laser communication has outstanding advantages such as large transmission capacity, good confidentiality and strong anti-interference ability. It is not only an important development trend of link data transmission technology between satellites and between satellites and ground stations, but also one of the best ways to solve the problems of high-speed space communication and precise ranging.

[0003] With the continuous advancement of aerospace technology, building a high-speed, stable intersatellite laser communication link information network is an inevitable trend in the networked development of satellite systems. Key characteristics of intersatellite laser communication links, such as frequency selection, signal structure, link establishment method, communication capacity, acquisition time, and tracking accuracy, determine the overall effectiveness of intersatellite information transmission networks. Due to the high-speed movement of low-orbit satellites, laser communication scanning alignment and stable link establishment are placed on higher requirements. Therefore, establishing a ground-based equivalent simulation test system for laser communication for low-orbit satellites is crucial for supporting the on-orbit testing and application of intersatellite laser communication.

[0004] Currently, laser communication terminals and corresponding ground-based testing systems primarily rely on "one-to-one" communication to establish and test point-to-point high-speed communication links. However, this communication method requires a large number of laser communication terminals and suffers from poor network node compatibility. With the development of laser communication networking and scale, "one-to-one" communication can no longer meet communication needs, making it impossible to achieve multi-standard compatible laser communication from a single target to multiple targets, or to test the performance of multi-node laser communication networks between low-orbit constellations. Summary of the Invention

[0005] In order to solve some or all of the technical problems existing in the above-mentioned prior art, the present invention provides a low-orbit star cluster inter-satellite laser communication networking test system and method, which supports the detection of the dynamic capture, tracking, communication and networking capabilities of satellite laser communication terminals under the interference of dynamic environment changes, and supports "one-to-many" low-orbit star cluster inter-satellite laser communication link performance test and low-orbit star cluster inter-satellite multi-node laser communication networking performance test.

[0006] The technical solutions of the present invention are as follows:

[0007] In a first aspect, the present invention provides a low-orbit constellation inter-satellite laser communication networking test system, comprising:

[0008] Satellite attitude simulation equipment, which is used to simulate the orbit, attitude and vibration changes of the satellite platform in the satellite laser link;

[0009] A beam far-field characteristics simulation device, which is used to simulate the distribution state and attenuation dynamic changes of laser beams in inter-satellite laser links of low-orbit constellations after long-distance transmission based on laser signals;

[0010] The ground-side simulation equipment is used to receive the satellite platform orbit, attitude and vibration change data simulated by the satellite attitude simulation equipment and the distribution state and attenuation dynamic change data of the laser beam after long-distance transmission simulated by the beam far-field characteristic simulation equipment, and cooperate with the laser communication terminal to complete the low-orbit star cluster inter-satellite laser communication networking performance test.

[0011] Furthermore, in the above-mentioned low-orbit constellation inter-satellite laser communication networking test system, the satellite attitude simulation device includes:

[0012] A two-dimensional turntable, which is used to simulate the orbit and attitude changes of satellite platforms in a low-orbit constellation laser link;

[0013] A oscillating platform is used to simulate the vibration changes of a satellite platform in a low-orbit constellation laser link.

[0014] Furthermore, in the above-mentioned low-orbit constellation inter-satellite laser communication networking test system, the light beam far-field characteristic simulation device includes:

[0015] A collimator, which is used to obtain a parallel light beam to simulate the long-distance transmission of a laser beam;

[0016] An optical attenuator, which is used to simulate the energy loss of interstellar laser beams during long-distance transmission;

[0017] An optical platform is used to support the collimator, the optical attenuator, and other equipment and components used to support the low-orbit star cluster inter-satellite laser communication networking test.

[0018] Furthermore, in the above-mentioned low-orbit constellation inter-satellite laser communication networking test system, the ground-side simulation device includes:

[0019] an optical antenna, configured to receive a laser signal transmitted by the laser communication terminal;

[0020] an optical signal processing module, configured to convert the laser signal received by the optical antenna into an electrical signal, and perform demodulation and decoding processing on the electrical signal;

[0021] A beam quality analyzer, the beam quality analyzer is used to detect the quality of the parallel light beam generated by the collimator;

[0022] An optical power meter, configured to measure the laser power received by the optical antenna;

[0023] A control module is provided, wherein the control module is used to receive and process data from the satellite attitude simulation device, the light beam far-field characteristic simulation device, and the ground-side simulation device. At the same time, the control module combines the orbit information, attitude information, and vibration information of the satellite in the laser link simulated by the satellite attitude simulation device, the distribution state and attenuation dynamic changes of the laser beam in the low-orbit star cluster inter-satellite laser link simulated by the light beam far-field characteristic simulation device after long-distance transmission, and the information sent and received by the communication link to perform a performance test of the low-orbit star cluster inter-satellite laser communication network.

[0024] In a second aspect, the present invention further provides a method for testing a low-orbit constellation inter-satellite laser communication network, comprising:

[0025] Receive laser signals containing interstellar information of low-orbiting star clusters;

[0026] Convert the received laser signal into an electrical signal to obtain the original information between the stars in the low-orbit star cluster;

[0027] The performance of the low-orbit constellation inter-satellite laser communication network is tested based on the original information obtained and the orbit information, attitude information, vibration information of the satellites in the simulated low-orbit constellation laser link, as well as the distribution state and attenuation dynamic change information of the laser beam after long-distance transmission.

[0028] Furthermore, in the above-mentioned low-orbit star cluster inter-satellite laser communication networking test method, the performance of the low-orbit star cluster inter-satellite laser communication networking tested includes: capture performance, tracking performance, communication rate, packet loss rate and delay performance.

[0029] Furthermore, in the above-mentioned low-orbit star cluster inter-satellite laser communication network testing method, testing the capture performance of the low-orbit star cluster inter-satellite laser communication network includes:

[0030] Initialize the laser communication terminal and ground-side simulation equipment;

[0031] When the ground-side simulation device receives the signal light emitted by the laser communication terminal, the ground-side simulation device is adjusted in a direction so that the signal light of the ground-side simulation device is aimed at the laser communication terminal;

[0032] When the laser communication terminal receives the signal light from the ground-side simulation device, it adjusts its own direction so that the signal light from the laser communication terminal is aimed at the ground-side simulation device;

[0033] When the laser communication terminal and the ground-side simulation equipment stably track the other party's signal light within their own fine tracking field of view or the fine tracking detector continuously detects the optical signal, they switch to the fine tracking mode. At this time, the terminal is judged to have successfully captured, and the number of captures is increased by 1. At this time, the timing value T1 is read, T1-T0 is used as the capture time, and T0 represents the start time of self-scanning; multiple captures are performed, and the number of captures and capture time are recorded at the same time. The number of captures is divided by the total number of tests as the corresponding capture success rate, and the average capture time is taken as the corresponding capture success time.

[0034] Furthermore, in the above-mentioned low-orbit star cluster inter-satellite laser communication network testing method, testing the tracking performance of the low-orbit star cluster inter-satellite laser communication network includes:

[0035] Initialize the laser communication terminal and the ground-side simulation equipment;

[0036] When the ground-side simulation device receives the signal light from the laser communication terminal, the ground-side simulation device adjusts its own direction so that the signal light of the ground-side simulation device is aimed at the laser communication terminal;

[0037] When the laser communication terminal receives the signal light from the ground-side simulation device, it stops scanning and automatically adjusts its own direction so that the signal light of the laser communication terminal is aimed at the ground-side simulation device. The laser communication terminal and the ground-side simulation device stably track each other's signal light within their own precision tracking field of view or when the precision tracking detector continuously detects the optical signal, and then switches to the precision tracking mode.

[0038] The laser communication terminal and the ground-side simulation equipment maintain stable tracking for 60 seconds;

[0039] The laser communication terminal is controlled to rotate at a preset speed, the tracking residual of the capture tracking camera is recorded, the recording is stopped after the preset movement time, the miss distance data during the tracking process is recorded and the standard deviation is calculated as the corresponding tracking accuracy.

[0040] Furthermore, in the above-mentioned low-orbit star cluster inter-satellite laser communication network testing method, testing the communication rate and packet loss rate of the low-orbit star cluster inter-satellite laser communication network includes:

[0041] Initialize the laser communication terminal and the ground-side simulation equipment;

[0042] Maintain stable tracking between the laser communication terminal and the ground-side simulation equipment for 60 seconds;

[0043] Set the laser communication terminal signal light transmission power and link attenuation value;

[0044] Restoring the laser communication terminal to a working state, wherein the laser communication terminal sends an optical signal and sets the communication rate to a preset value;

[0045] Adjust the optical attenuator to minimize the optical signal strength received by the analog device on the ground side.

[0046] The ground-side simulation equipment demodulates the received optical signal, compares it with the transmitted data, and counts the number of received error packets;

[0047] Set different communication rates and calculate the packet loss rates corresponding to different communication rates.

[0048] Furthermore, in the above-mentioned method for testing a low-orbit constellation inter-satellite laser communication network, testing the delay performance of the low-orbit constellation inter-satellite laser communication network includes:

[0049] Initialize the laser communication terminal and the ground-side simulation equipment;

[0050] The laser communication terminal and the ground-side simulation equipment maintain stable tracking for 60 seconds;

[0051] Use network cables to connect multiple ground-side simulation devices, use the laser communication terminal and ground-side simulation devices as nodes, set one of the ground-side simulation devices as the master node, and set the IP addresses and initial states of multiple nodes;

[0052] Set the node configuration table, planning routing table and routing management mode of the current network according to the networking strategy;

[0053] The master node notifies the service data packets that need to be forwarded via the inter-satellite laser link;

[0054] Verify whether the destination node has correctly received the service data packet, record the time when the service data packet is sent and received, and obtain the service data packet forwarding delay performance.

[0055] The main advantages of the technical solution of the present invention are as follows:

[0056] The present invention's low-orbit satellite cluster intersatellite laser communication networking test system and method utilizes a laser communication terminal as the transmitting portion of the laser communication networking test system, transmitting multiple laser signals in a time-sharing manner. Ground-based simulation equipment serves as the receiving portion of the laser communication networking test system, receiving multiple laser signals from the laser communication terminal in a time-sharing manner. The multiple laser signals are converted into electrical signals, which are then demodulated and decoded to obtain the original transmitted information, thereby testing the performance of the low-orbit satellite cluster intersatellite laser communication network. The present invention's low-orbit satellite cluster intersatellite laser communication networking test system can transmit and receive laser signals from multiple low-orbit satellites, enabling performance testing of intersatellite laser communication networks across multiple low-orbit satellites. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The drawings described herein are used to provide a further understanding of the embodiments of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0058] Figure 1 A schematic diagram of the structure of a low-orbit constellation inter-satellite laser communication networking test system provided by one embodiment of the present invention;

[0059] Figure 2 A flowchart of a method for testing inter-satellite laser communication networking in a low-orbit constellation provided by one embodiment of the present invention;

[0060] Figure 3 A schematic diagram of a flow chart for testing capture performance in a method for testing a low-orbit constellation inter-satellite laser communication network according to an embodiment of the present invention;

[0061] Figure 4 A schematic diagram of a flow chart for testing tracking performance in a method for testing a low-orbit constellation inter-satellite laser communication network according to an embodiment of the present invention;

[0062] Figure 5 A schematic diagram of a flow chart for testing communication rate and packet loss rate in a method for testing a low-orbit constellation inter-satellite laser communication network according to an embodiment of the present invention;

[0063] Figure 6 A schematic diagram of a process for testing delay performance in a low-orbit constellation inter-satellite laser communication networking test method provided by one embodiment of the present invention.

[0064] Description of reference numerals:

[0065] 1. Satellite attitude simulation equipment; 2. Beam far-field characteristics simulation equipment; 3. Ground-side simulation equipment;

[0066] 11. Two-dimensional turntable; 12. Oscillating platform;

[0067] 21. Collimator; 22. Optical attenuator; 23. Optical platform;

[0068] 31. Optical antenna; 32. Optical signal processing module; 33. Beam quality analyzer; 34. Optical power meter; 35. Control module. DETAILED DESCRIPTION

[0069] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0070] The technical solutions provided by the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0071] As attached Figure 1 As shown, an embodiment of the present invention provides a low-orbit constellation inter-satellite laser communication networking test system, which includes: a satellite attitude simulation device 1, a beam far-field characteristics simulation device 2 and a ground-side simulation device 3, wherein:

[0072] The satellite attitude simulation device 1 is used to simulate the orbit, attitude and vibration changes of the satellite platform in the satellite laser link; the light beam far-field characteristic simulation device 2 is used to simulate the distribution state and attenuation dynamic changes of the laser beam in the low-orbit star cluster inter-satellite laser link after long-distance transmission based on the laser signal; the ground-side simulation device 3 is used to receive the satellite platform orbit, attitude and vibration change data simulated by the satellite attitude simulation device 1 and the distribution state and attenuation dynamic change data of the laser beam after long-distance transmission simulated by the light beam far-field characteristic simulation device 2, and cooperate with the laser communication terminal to complete the low-orbit star cluster inter-satellite laser communication networking performance test.

[0073] Specifically, a laser communication terminal can be mounted on the satellite attitude simulation device 1 so that the laser communication terminal can receive and store laser signals in real time. The satellite attitude simulation device 1 receives the original motion data between the low-orbit star cluster set by the ground-side simulation device 3 and simulates the orbit information, attitude information and vibration information of the satellite in the laser link; the light beam far-field characteristic simulation device 2 receives the device parameters set by the ground-side simulation device 3, and simulates the distribution state and attenuation dynamic changes of the laser beam in the low-orbit star cluster inter-satellite laser link after long-distance transmission; the ground-side simulation device 3 is connected to the satellite attitude simulation device 1 and the light beam far-field characteristic simulation device 2 through a cable or optical fiber. The ground-side simulation device 3 is used to convert the received laser signal into an electrical signal, and convert the information transmitted by the laser signal into the original information after amplification and demodulation, and combine it with the information sent by the above-mentioned laser communication terminal to perform performance testing of the low-orbit star cluster inter-satellite laser communication network.

[0074] Specifically, the principles of the low-orbit constellation inter-satellite laser communication networking test system of the present invention include:

[0075] By carrying a laser communication terminal on the satellite attitude simulation device 1, the laser communication terminal is used as the sending part of the laser communication networking test system to emit laser signals, and simulate the satellite orbit information, attitude information and vibration information in the laser link according to the satellite motion data set by the received ground-side simulation device 3, and at the same time transmit the deflection angle and other information back to the ground-side simulation device 3 for data analysis; the ground-side simulation device 3 is used as the receiving part of the laser communication networking test system to receive the laser signal emitted by the laser communication terminal on the satellite attitude simulation device 1, and the received laser signal is subjected to photoelectric conversion, decoding, demodulation and other processing to obtain the original transmission information. Combined with the distribution state and attenuation dynamic changes of the far-field beam in the low-orbit star cluster inter-satellite laser link simulated by the beam far-field characteristic simulation device 2 after long-distance transmission, the performance of the low-orbit star cluster inter-satellite laser communication network is tested. At the same time, in the low-orbit star cluster inter-satellite laser communication networking test system of the present invention, the laser communication terminal is used as the sending part of the laser communication networking test system, and multi-channel laser signal transmission is performed in time-sharing, and the ground-side simulation device 3 is used as the receiving part of the laser communication networking test system, and multi-channel laser signals emitted by the above-mentioned laser communication terminal are received in time-sharing. Therefore, the low-orbit star cluster inter-satellite laser communication networking test system of the present invention can send and receive laser signals from multiple low-orbit satellites, thereby realizing the inter-satellite laser communication networking performance test of multiple low-orbit satellites.

[0076] Specifically, the satellite attitude simulation device 1 includes: a two-dimensional turntable 11 and a swing platform 12, wherein:

[0077] The two-dimensional turntable 11 is used to simulate the orbit and attitude changes of the satellite platform in the low-orbit constellation laser link; the swing platform 12 is used to simulate the vibration changes of the satellite platform in the low-orbit constellation laser link.

[0078] In this way, by using the two-dimensional turntable 11 and the swing platform 12 to separately simulate the operating orbit, attitude and vibration conditions of the satellite platform in the low-orbit constellation laser link, different vibration spectrum change parameters can be set to simulate the platform angular vibration, thereby completing the vibration compensation capability test of the laser communication terminal.

[0079] Specifically, the above-mentioned light beam far-field characteristic simulation device 2 includes: a collimator 21, an optical attenuator 22 and an optical platform 23, wherein:

[0080] The collimator 21 is used to obtain a parallel light beam to simulate the long-distance transmission of a laser beam; the optical attenuator 22 is used to attenuate the laser signal sent by the laser communication terminal on the satellite attitude simulation device 1 to simulate the energy loss of the long-distance transmission of the inter-satellite laser beam; the optical platform 23 is used to support the collimator 21, the optical attenuator 22 and other equipment and components used to support the inter-satellite laser communication networking test of the low-orbit constellation.

[0081] In the embodiment of the present invention, other equipment and components for the low-orbit constellation inter-satellite laser communication networking test are set according to actual needs.

[0082] Specifically, the above-mentioned ground-side simulation device 3 includes: an optical antenna 31, an optical signal processing module 32, a beam quality analyzer 33, an optical power meter 34 and a control module 35, wherein:

[0083] The optical antenna 31 is used to receive the laser signal emitted by the laser communication terminal; the optical signal processing module 32 is used to convert the laser signal received by the optical antenna 31 into an electrical signal, and demodulate and decode the electrical signal; the beam quality analyzer 33 is used to detect the quality of the parallel beam obtained by the parallel light tube 21; the optical power meter 34 is used to measure the size of the laser power received by the optical antenna 31; the control module 35 is used to receive and process data from the satellite attitude simulation device 1, the beam far-field characteristics simulation device 2 and the ground-side simulation device 3. At the same time, the control module 35 can also combine the orbit information, attitude information and vibration information of the satellite in the laser link simulated by the satellite attitude simulation device 1, and the distribution state and attenuation dynamic changes of the laser beam in the low-orbit star cluster inter-satellite laser link simulated by the beam far-field characteristics simulation device 2 after long-distance transmission to test the networking performance of the low-orbit star cluster inter-satellite laser communication.

[0084] In some optional implementations of this embodiment, the control module 35 is a host computer.

[0085] It should also be noted that in addition to using the optical antenna 31 to receive the laser signal emitted by the laser communication terminal, the ground-side simulation device 3 in the present invention can also receive the test data fed back by the satellite attitude simulation device 1 and the light beam far-field characteristic simulation device 2 in real time through a cable or optical fiber, which is used to monitor the working mode, aiming angle, capture status, coarse tracking accuracy, fine tracking accuracy and other indicators of the laser communication terminal in real time.

[0086] In summary, the low-orbit star cluster inter-satellite laser communication networking test system of the present invention uses the laser communication terminal as the sending part of the laser communication networking test system, and the ground-side simulation device 3 as the receiving part of the laser communication networking test system. By arranging multiple optical antennas 31 on one laser communication terminal, laser signals can be emitted by different optical antennas 31 at different times. At the same time, multiple ground-side simulation devices 3 process the laser signals after receiving them at different times, thereby achieving the effect of time-sharing communication. In addition, since the test data fed back by the satellite attitude simulation device 1 and the beam far-field characteristic simulation device 2 can be received by the ground-side cable or optical fiber interface to the ground-side simulation device 3, the low-orbit star cluster inter-satellite laser communication networking test system of the present invention can support the detection of the dynamic capture, tracking, communication and networking capabilities of satellite laser communication terminals under the interference of dynamic environment changes, and can also support "one-to-many" low-orbit star cluster inter-satellite laser communication link performance test and low-orbit star cluster inter-satellite multi-node laser communication networking performance test.

[0087] In the second aspect, the present invention also provides a low-orbit satellite cluster inter-satellite laser communication network testing method, such as Figure 2 Shown, including:

[0088] Receive laser signals containing inter-satellite information of the low-orbit star cluster; convert the received laser signals into electrical signals to obtain the original information between the low-orbit star cluster; test the performance of the low-orbit star cluster inter-satellite laser communication network based on the obtained original information and the orbit information, attitude information, vibration information of the satellites in the simulated low-orbit star cluster laser link, and the distribution state and attenuation dynamic change information of the laser beam after long-distance transmission.

[0089] Therefore, a low-orbit star cluster inter-satellite laser communication networking test method of the present invention tests the performance of the low-orbit star cluster inter-satellite laser communication networking by simulating the orbit information, attitude information, vibration information of the satellites in the low-orbit star cluster laser link and the distribution state and attenuation dynamic change information of the laser beam after long-distance transmission, and can simultaneously measure the performance of multiple inter-satellite laser communication links with different orbits and channels.

[0090] Specifically, the performance of the above-mentioned low-orbit constellation inter-satellite laser communication network tested includes at least: capture performance, tracking performance, communication rate, packet loss rate and delay performance.

[0091] The following uses 4 laser beams as an example to illustrate the performance test methods for capture performance, tracking performance, communication rate, packet loss rate, and delay performance.

[0092] Specifically, in combination with the above-mentioned low-orbit star cluster inter-satellite laser communication network test system, the capture performance of the above-mentioned low-orbit star cluster inter-satellite laser communication network is tested, such as Figure 3 Shown, including:

[0093] S101: Place the laser communication terminal on the high-precision two-dimensional turntable 11, and adjust the two-dimensional turntable 11 and the fast reflection mirror respectively so that the optical axes of the four laser communication terminals coincide with the optical axes of the corresponding test collimators 21;

[0094] S102: Adjust the azimuth and elevation directions of the four laser communication terminals, monitor the miss distance output of the tracking camera in real time, and ensure that the camera remains within the capture field of view of the laser communication terminal.

[0095] S103: The laser communication terminal is set to transmit 1540.56nm and receive 1563.05nm laser; the ground-side simulation device 3 is set to transmit 1563.05nm and receive 1540.56nm laser;

[0096] S104: Setting the initial bias values ​​of the laser communication terminal and the ground-side simulation device 3 to 1 mrad;

[0097] S105: According to the scanning-gaze capture and tracking process, the laser communication terminal starts scanning while the ground-side simulation device 3 gazes. The test system monitoring camera monitors the scanning status and counts from the start of the scan as T0;

[0098] S106: After receiving the signal light from the laser communication terminal, the ground-side simulation device 3 automatically adjusts its own direction according to the scanning-gaze capture and tracking process so that its signal light is aimed at the laser communication terminal;

[0099] S107: After the laser communication terminal receives the signal light from the ground-side simulation device 3, it stops scanning according to the scanning-gaze capture and tracking process and automatically adjusts its own direction so that its signal light is aimed at the ground-side simulation device 3. The laser communication terminal and the ground-side simulation device stably track each other's signal light within their own precision tracking field of view. At this time, the terminal is judged to have successfully captured the signal light, and the capture count is increased by 1. At this time, the timing value T1 is read, and T1-T0 is used as the capture time. If the terminal does not complete the signal light capture within a certain time range T (T≥T1), the terminal is judged to have failed to capture the signal light, and the capture count remains unchanged.

[0100] S108: Repeat the above S101-S107 for at least 1000 times, record the number of captures and capture time, divide the number of captures by the total number of tests as the corresponding capture success rate, and take the average of the capture time as the corresponding capture success time.

[0101] Therefore, the performance of the number of capture times and the capture time can be tested by the above method.

[0102] It should be noted that the capture success rate and capture success time are calculated for the above four laser signals respectively.

[0103] Specifically, in combination with the above-mentioned low-orbit star cluster inter-satellite laser communication network test system, the tracking performance of the above-mentioned low-orbit star cluster inter-satellite laser communication network is tested, such as Figure 4 Shown, including:

[0104] S201: Place the laser communication terminal on the high-precision two-dimensional turntable 11, and adjust the two-dimensional turntable 11 and the fast reflection mirror respectively so that the optical axes of the four laser communication terminals coincide with the optical axes of the corresponding test collimators 21, so that the laser communication beams completely enter the collimators 21;

[0105] S202: Adjust the azimuth and elevation directions of the four laser communication terminals, monitor the miss distance output of the tracking camera in real time, and ensure that the camera remains within the capture field of view of the laser communication terminal.

[0106] It should be noted that the aforementioned fast-reflecting mirror plays a role in controlling the beam direction, and the tracking camera can calculate the center of mass of the light spot and output the miss distance in real time. Both are test auxiliary equipment.

[0107] S203: The laser communication terminal is set to transmit 1540.56nm and receive 1563.05nm laser; the ground-side simulation device 3 is set to transmit 1563.05nm and receive 1540.56nm laser;

[0108] S204: Setting the initial bias values ​​of the laser communication terminal and the ground-side simulation device 3 to 1 mrad;

[0109] S205: According to the scanning-gaze capture and tracking process, the laser communication terminal starts scanning while the ground-side simulation device 3 gazes, and the test system monitoring camera monitors the scanning situation;

[0110] S206: After receiving the signal light from the laser communication terminal, the ground-side simulation device 3 automatically adjusts its own direction according to the scanning-gaze capture and tracking process so that its signal light is aimed at the laser communication terminal;

[0111] S207: After receiving the signal light from the ground-side simulation device 3, the laser communication terminal stops scanning according to the scanning-gaze capture tracking process and automatically adjusts its own direction so that its signal light is aimed at the ground-side simulation device 3. The laser communication terminal and the ground-side simulation device stably track each other's signal light within their own fine tracking field of view, or the fine tracking detector continuously detects the optical signal, and then switches to the fine tracking mode.

[0112] S208: The laser communication terminal and the ground-side simulation device 3 maintain stable tracking for 60 seconds;

[0113] S209: Control the azimuth axis / pitch axis of the 2D turntable 11 to move at a speed of 0.1° / s;

[0114] S210: Record the tracking residual of the capture tracking camera, stop recording after 5 minutes of movement, record the miss distance data during the tracking process and calculate the standard deviation as the corresponding tracking accuracy.

[0115] It should be noted that the tracking accuracy is calculated for the above four laser signals separately.

[0116] Specifically, in combination with the above-mentioned low-orbit star cluster inter-satellite laser communication network test system, the communication rate and packet loss rate of the above-mentioned low-orbit star cluster inter-satellite laser communication network are tested, such as Figure 5 Shown, including:

[0117] S301: Place the laser communication terminal on the high-precision two-dimensional turntable 11, and adjust the two-dimensional turntable 11 and the fast reflection mirror respectively so that the optical axes of the four laser communication terminals coincide with the optical axes of the corresponding test collimators 21;

[0118] S302: Adjust the azimuth and elevation directions of the four laser communication terminals, monitor the miss distance output of the tracking camera in real time, and ensure that the camera remains within the capture field of view of the laser communication terminal.

[0119] S303: The laser communication terminal is set to transmit 1540.56nm and receive 1563.05nm laser; the ground-side simulation device 3 is set to transmit 1563.05nm and receive 1540.56nm laser;

[0120] S304: Setting the initial bias values ​​of the laser communication terminal and the ground-side simulation device 3 to 1 mrad;

[0121] S305: According to the scanning-gaze capture and tracking process shown in S205-S207, the laser communication terminal and the ground-side simulation device 3 maintain stable tracking for 60 seconds;

[0122] S306: Setting the laser communication terminal signal light transmission power and link attenuation value;

[0123] S307: The laser communication terminal is restored to a working state, the laser communication terminal sends an optical signal and sets the communication rate to a preset value;

[0124] S308: Gradually adjust the optical attenuator 22 so that the intensity of the optical signal received by the ground-side analog device 3 reaches the minimum value;

[0125] S309: The ground-side simulation device 3 demodulates the received optical signal, continuously receives at least 100 million packets of data, compares the received data with the transmitted data, counts the number of received error packets, and divides the number of received error packets by the number of transmitted packets to obtain the corresponding packet loss rate;

[0126] S310: Set different communication rates, repeat steps S307-S309, and record the corresponding packet loss rate and communication rate.

[0127] Therefore, the performance test of packet loss rate and communication rate can be completed through the above method.

[0128] It should be noted that the packet loss rates of the above four laser signals are calculated separately.

[0129] Specifically, in combination with the above-mentioned low-orbit star cluster inter-satellite laser communication network test system, the delay performance of the above-mentioned low-orbit star cluster inter-satellite laser communication network is tested, such as Figure 6 Shown, including:

[0130] S401: Place the laser communication terminal on the high-precision two-dimensional turntable 11, and adjust the two-dimensional turntable 11 and the fast reflection mirror respectively so that the optical axes of the four laser communication terminals coincide with the optical axes of the corresponding test collimators 21;

[0131] S402: Adjust the azimuth and elevation directions of the four laser communication terminals, monitor the miss distance output of the tracking camera in real time, and ensure that the camera remains within the capture field of view of the laser communication terminal.

[0132] S403: The laser communication terminal is set to transmit 1540.56nm and receive 1563.05nm laser; the ground-side simulation device 3 is set to transmit 1563.05nm and receive 1540.56nm laser;

[0133] S404: Setting the initial bias values ​​of the laser communication terminal and the ground-side simulation device 3 to 1 mrad;

[0134] S405: According to the scanning-gaze capture tracking process, the laser communication terminal and the ground-side simulation device 3 maintain stable tracking for 60 seconds;

[0135] S406: Connect the four ground-side simulation devices 3 with a network cable, use the laser communication terminal and the ground-side simulation device 3 as nodes, set one of the ground-side simulation devices 3 as the master node, and set the IP addresses and initial states of the five nodes in the entire network;

[0136] S407: Setting the node configuration table and planned routing table of the current network according to the networking strategy;

[0137] S408: Setting the routing management mode to ground centralized;

[0138] S409: The master node notifies the service data packet to be forwarded via the inter-satellite laser link, including unicast / multicast / broadcast mode, service priority, destination node information, etc.

[0139] S410: Verify whether the destination node has correctly received the service data packet, record the time when the service data packet is sent and received, and obtain the forwarding delay of the service data packet.

[0140] It should be noted that the above networking strategy includes how to transmit information between the five nodes. The above destination node includes five nodes in the network communication, the master node plays a control role, and any two nodes among the five nodes can be sending or receiving nodes to transmit information.

[0141] In some optional implementations of this embodiment, the above-mentioned networking strategies may include a centralized networking strategy and a distributed networking strategy, and the specific strategy selected is selected according to actual needs.

[0142] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes 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 addition, "front", "back", "left", "right", "upper" and "lower" in this document are all referenced to the placement states shown in the accompanying drawings.

[0143] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A low-orbit satellite cluster inter-satellite laser communication networking test system, characterized in that: The laser communication terminal is used as the transmitting part of the laser communication networking test system to transmit multiple laser signals in a time-sharing manner. The ground-side simulation equipment is used as the receiving part of the laser communication networking test system to receive multiple laser signals from the laser communication terminal in a time-sharing manner, thereby realizing the performance test of the inter-satellite laser communication network of multiple low-orbit satellites. The test system includes: Satellite attitude simulation equipment, which is used to simulate the orbit, attitude and vibration changes of the satellite platform in the satellite laser link; A beam far-field characteristics simulation device, which is used to simulate the distribution state and attenuation dynamic changes of laser beams in inter-satellite laser links of low-orbit constellations after long-distance transmission based on laser signals; The ground-side simulation equipment is used to receive the satellite platform orbit, attitude and vibration change data simulated by the satellite attitude simulation equipment and the distribution state and attenuation dynamic change data of the laser beam after long-distance transmission simulated by the beam far-field characteristic simulation equipment, and cooperate with the laser communication terminal to complete the low-orbit star cluster inter-satellite laser communication networking performance test.

2. The low-orbit constellation inter-satellite laser communication networking test system according to claim 1, characterized in that: The satellite attitude simulation device comprises: A two-dimensional turntable, which is used to simulate the orbit and attitude changes of satellite platforms in a low-orbit constellation laser link; A oscillating platform is used to simulate the vibration changes of a satellite platform in a low-orbit constellation laser link.

3. The low-orbit constellation inter-satellite laser communication networking test system according to claim 1, characterized in that: The light beam far-field characteristic simulation device comprises: A collimator, which is used to obtain a parallel light beam to simulate the long-distance transmission of a laser beam; An optical attenuator, which is used to simulate the energy loss of interstellar laser beams during long-distance transmission; An optical platform is used to support the collimator, the optical attenuator, and other equipment and components used to support the low-orbit star cluster inter-satellite laser communication networking test.

4. The low-orbit satellite cluster inter-satellite laser communication networking test system according to claim 3, characterized in that: The ground-side simulation equipment includes: an optical antenna, configured to receive a laser signal transmitted by the laser communication terminal; an optical signal processing module, configured to convert the laser signal received by the optical antenna into an electrical signal, and perform demodulation and decoding processing on the electrical signal; A beam quality analyzer, the beam quality analyzer is used to detect the quality of the parallel light beam generated by the collimator; An optical power meter, configured to measure the laser power received by the optical antenna; A control module is provided, wherein the control module is used to receive and process data from the satellite attitude simulation device, the light beam far-field characteristic simulation device, and the ground-side simulation device. At the same time, the control module combines the orbit information, attitude information, and vibration information of the satellite in the laser link simulated by the satellite attitude simulation device, the distribution state and attenuation dynamic changes of the laser beam in the low-orbit star cluster inter-satellite laser link simulated by the light beam far-field characteristic simulation device after long-distance transmission, and the information sent and received by the communication link to perform a performance test of the low-orbit star cluster inter-satellite laser communication network.

5. A networking test method using the low-orbit constellation inter-satellite laser communication networking test system according to any one of claims 1 to 4, characterized in that: include: Receive laser signals containing interstellar information of low-orbiting star clusters; Convert the received laser signal into an electrical signal to obtain the original information between the stars in the low-orbit star cluster; The performance of the LEO inter-satellite laser communication network is tested based on the original information obtained and the orbit information, attitude information, vibration information of the satellites in the simulated LEO laser link, as well as the distribution state and attenuation dynamic change information of the laser beam after long-distance transmission; Among them, the performance of the low-orbit constellation inter-satellite laser communication network tested includes: capture performance, tracking performance, communication rate, packet loss rate and delay performance.

6. The method for testing a low-orbit satellite cluster inter-satellite laser communication network according to claim 5, characterized in that: The test of the acquisition performance of the low-orbit constellation inter-satellite laser communication network includes: Initialize the laser communication terminal and ground-side simulation equipment; When the ground-side simulation device receives the signal light emitted by the laser communication terminal, the ground-side simulation device is adjusted in a direction so that the signal light of the ground-side simulation device is aimed at the laser communication terminal; When the laser communication terminal receives the signal light from the ground-side simulation device, it adjusts its own direction so that the signal light from the laser communication terminal is aimed at the ground-side simulation device; When the laser communication terminal and the ground-side simulation equipment stably track the other party's signal light within their own fine tracking field of view or the fine tracking detector continuously detects the optical signal, they switch to the fine tracking mode. At this time, the terminal is judged to have successfully captured, and the number of captures is increased by 1. At this time, the timing value T1 is read, T1-T0 is used as the capture time, and T0 represents the start time of self-scanning; multiple captures are performed, and the number of captures and capture time are recorded at the same time. The number of captures is divided by the total number of tests as the corresponding capture success rate, and the average capture time is taken as the corresponding capture success time.

7. The method for testing a low-orbit satellite cluster inter-satellite laser communication network according to claim 5, characterized in that: Testing of the tracking performance of the low-orbit constellation inter-satellite laser communication network includes: Initialize the laser communication terminal and the ground-side simulation equipment; When the ground-side simulation device receives the signal light from the laser communication terminal, the ground-side simulation device adjusts its own direction so that the signal light of the ground-side simulation device is aimed at the laser communication terminal; When the laser communication terminal receives the signal light from the ground-side simulation device, it stops scanning and automatically adjusts its own direction so that the signal light of the laser communication terminal is aimed at the ground-side simulation device. The laser communication terminal and the ground-side simulation device stably track each other's signal light within their own precision tracking field of view or when the precision tracking detector continuously detects the optical signal, and then switches to the precision tracking mode. The laser communication terminal and the ground-side simulation equipment maintain stable tracking for 60 seconds; The laser communication terminal is controlled to rotate at a preset speed, the tracking residual of the capture tracking camera is recorded, the recording is stopped after the preset movement time, the miss distance data during the tracking process is recorded and the standard deviation is calculated as the corresponding tracking accuracy.

8. The method for testing a low-orbit satellite cluster inter-satellite laser communication network according to claim 5, characterized in that: The communication rate and packet loss rate tests for the low-orbit constellation inter-satellite laser communication network include: Initialize the laser communication terminal and the ground-side simulation equipment; Maintain stable tracking between the laser communication terminal and the ground-side simulation equipment for 60 seconds; Set the laser communication terminal signal light transmission power and link attenuation value; Restoring the laser communication terminal to a working state, wherein the laser communication terminal sends an optical signal and sets the communication rate to a preset value; Adjust the optical attenuator to minimize the optical signal strength received by the analog device on the ground side. The ground-side simulation equipment demodulates the received optical signal, compares it with the transmitted data, and counts the number of received error packets; Set different communication rates and calculate the packet loss rates corresponding to different communication rates.

9. The method for testing low-orbit satellite cluster inter-satellite laser communication networking according to claim 5, characterized in that: The delay performance test of the low-orbit constellation inter-satellite laser communication network includes: Initialize the laser communication terminal and the ground-side simulation equipment; The laser communication terminal and the ground-side simulation equipment maintain stable tracking for 60 seconds; Use network cables to connect multiple ground-side simulation devices, use the laser communication terminal and ground-side simulation devices as nodes, set one of the ground-side simulation devices as the master node, and set the IP addresses and initial states of multiple nodes; Set the node configuration table, planning routing table and routing management mode of the current network according to the networking strategy; The master node notifies the service data packets that need to be forwarded via the inter-satellite laser link; Verify whether the destination node has correctly received the service data packet, record the time when the service data packet is sent and received, and obtain the service data packet forwarding delay performance.

Images