Intersatellite laser data transmission method and system under background light interference

Abstract

The invention provides an inter-satellite laser data transmission method and system under background light interference, and the method comprises the steps: a satellite calculates an inter-satellite visible arc segment according to the GNSS information of the satellite and a link building satellite, generates an inter-satellite link building work task package according to an inter-satellite visible effective communication window, and forwards the inter-satellite link building work task package to a laser communication terminal; the laser communication terminal analyzes the inter-satellite link establishment work task package, completes single-machine power-up through autonomous program control, carries out scanning, capturing and tracking, and turns to an autonomous tracking stage; calculating an included angle between the background light vector and the optical axis in real time, judging whether the included angle is smaller than an autonomous avoidance angle, if so, performing autonomous avoidance operation by the laser communication terminal, and finishing a reset capturing and tracking task; if not, the satellites perform inter-satellite data transmission, the background light interference condition is judged in real time during transmission, a shutdown program is executed autonomously after inter-satellite communication is finished, and next inter-satellite link establishment transmission is waited. According to the invention, inter-satellite laser visible calculation, link establishment planning, sun-sun autonomous forecast and avoidance and autonomous program control data transmission are realized.

Description

Technical Field

[0001] The present invention relates to the technical field of intersatellite data transmission, and in particular to an intersatellite laser data transmission method and system under background light interference, and more particularly to a highly reliable intersatellite communication method suitable for autonomous intersatellite laser link planning and autonomous background light avoidance. Background Art

[0002] At present, remote sensing satellite data transmission mainly relies on ground stations and relay satellites. Affected by the layout of satellite ground stations and the need for relays to apply for arc segment mode in advance, the integrity and timeliness of remote sensing satellite data acquisition are poor, and the satellite is basically in single-satellite detection mode. With the rapid development of laser communication technology at home and abroad, remote sensing satellites will shift to system efficiency. More satellites will use laser communication to achieve multi-satellite interconnection and collaborative observation, which will greatly improve the timeliness and application efficiency of satellite data acquisition. However, intersatellite laser communication is susceptible to background light interference, which seriously affects the availability and reliability of intersatellite laser communication, resulting in satellite communication interruption and data loss. At present, satellite laser communication is in the stage of onboard test verification. Intersatellite laser data transmission is mainly planned by the ground in advance and the link establishment work package is uploaded. The background light interference problem mainly relies on the ground to predict the solar eclipse in advance. The time interval of the solar eclipse has been excluded from the available link establishment work package. Satellite laser communication is still far from high reliability and business use in engineering.

[0003] The low-orbit same-orbit intersatellite, low-orbit different-orbit intersatellite, medium-orbit intersatellite, and high-orbit intersatellite lasers have all been verified in orbit. With the deployment of heterogeneous constellations of high and low-orbit satellites and the high requirements for the commercial use of intersatellite lasers in orbit, it is very necessary to carry out autonomous link planning and autonomous solar transit avoidance on the satellite, reduce the frequent operation of the ground system, and achieve highly reliable intersatellite laser data transmission, thereby ensuring the integrity, timeliness and collaborative observation efficiency of remote sensing data. This method reduces the intervention of the ground system and has the advantages of autonomous visible computing on the satellite, access planning, program control, highly reliable communication and easy use.

[0004] The patent document with the announcement number CN114584198A discloses a method, device and medium for satellite-borne laser communication equipment to autonomously avoid solar transit in orbit. The attitude and orbit control subsystem predicts the angle between the intersatellite laser communication link vector and the solar incidence vector at the current time and T seconds later, and the satellite service subsystem sends a solar transit avoidance operation instruction to the laser communication terminal. The device and medium include a memory, a processor and a computer program stored in the memory and run on the processor. This patent does not involve the method and system for autonomous intersatellite link planning, autonomous prediction of solar transit by laser communication terminals, and high-reliability intersatellite data transmission of the entire satellite under laser solar transit.

[0005] The patent document with publication number CN111924132B discloses a method and system for autonomous relay of laser intersatellite link terminals for an orbiting formation, which is characterized in that in order to reliably and stably realize continuous intersatellite laser communication in a multi-satellite formation satellite system with an orbiting configuration, thereby ensuring and improving the mission efficiency of the satellite system, it is necessary to solve the problem of autonomous relay of laser communication terminals, that is, during the 360-degree orbiting flight of the secondary satellite around the primary satellite, the laser communication terminals of the primary and secondary satellites need to be able to achieve field coverage through autonomous relay. This patent does not involve a method and system for intersatellite laser data transmission under background light interference.

[0006] The patent document with the publication number CN111934743B discloses an intersatellite link establishment method of an omnidirectional dynamic microwave laser composite system, including: the intersatellite microwave link and the laser link cooperate to complete the establishment of an omnidirectional intersatellite link, the phased array antennas of the primary and secondary satellites perform microwave antenna pointing solution according to the orbital parameters derived from the orbit, establish the microwave link between the primary and secondary satellites, the primary and secondary satellites exchange relative GNSS navigation information through the microwave link, the laser communication terminals of the primary and secondary satellites scan, complete two-way capture, and complete the establishment of the laser link. This patent does not involve the intersatellite autonomous link establishment access planning, autonomous solar transit avoidance, and highly reliable intersatellite laser data transmission method and system of this patent.

[0007] In the patent document with publication number CN113507314A, a method for intersatellite data transmission is disclosed, including: using intersatellite links to assist in unloading of feed data, satellites send data to be unloaded to landing satellites with spare bandwidth through intersatellite links to utilize feed bandwidth resources; according to MFMC linear programming with subgraph constraints, an iterative algorithm CDD is developed to maximize system throughput and minimize data transmission delay. The intersatellite link in this patent is a microwave transmission system, and does not involve intersatellite laser autonomous link establishment and laser autonomous solar transit avoidance.

[0008] A communication architecture and method suitable for satellite-borne laser communication terminals are disclosed in a patent document with publication number CN114286207A. The communication architecture suitable for satellite-borne laser communication terminals includes a configuration unit and a communication unit; the configuration unit is used to generate selection signals and clock configuration parameters, and the communication unit is used to select the corresponding encoding and decoding mode and working rate to transform the communication data. This method mainly controls and switches the encoding and decoding mode and working rate of the laser communication unit, so as to achieve the purpose of dynamic debugging of the on-orbit laser communication terminal. This patent is mainly for the selection of communication parameters for data transmission inside the laser communication terminal, and does not involve the autonomous program control design of the intersatellite laser on the entire satellite.

[0009] A patent document with publication number CN103457660B discloses a method for rapidly simulating the earth background light of a satellite-to-ground laser communication terminal on board, which mainly involves the field of simulation and suppression of the earth background light of satellite-to-ground laser communication terminals on board, and specifically involves a method for rapidly simulating the earth background light of satellite terminals at different orbital altitudes, which can be applied to the field of simulation of stray light in satellite laser communication. The patent provides a method for rapidly simulating the background light, but does not provide how the satellite laser communication terminal can autonomously avoid the background light, so it does not involve the autonomous solar transit avoidance calculation and autonomous link establishment access planning of intersatellite lasers.

[0010] Therefore, there is no method for intersatellite laser data transmission under background light interference. In view of this situation, a new technical solution needs to be proposed, and research on intersatellite laser data transmission method and system design under background light interference is urgently needed. Summary of the invention

[0011] In view of the defects in the prior art, the object of the present invention is to provide a method and system for inter-satellite laser data transmission under background light interference.

[0012] According to the present invention, a method for intersatellite laser data transmission under background light interference is provided, comprising:

[0013] Step S1: The satellite integrated management unit calculates the inter-satellite visible arc according to the GNSS information of the local satellite and the link-building satellite, generates an inter-satellite link-building task package according to the inter-satellite visible effective communication window, and forwards it to the laser communication terminal;

[0014] Step S2: the laser communication terminal parses the intersatellite link establishment task package, completes the single machine power-on by autonomous program control, and performs scanning, capture and tracking, and enters the autonomous tracking stage;

[0015] Step S3: The laser communication terminal calculates the background light vector and the angle between the optical axis in real time, and determines whether the angle is smaller than the autonomous avoidance angle. If so, the laser communication terminal performs an autonomous avoidance operation, and executes step S4 after completing the reset tracking task; if not, executes step S4;

[0016] Step S4: The satellite performs normal inter-satellite data transmission, determines the background light interference in real time during the transmission, and autonomously executes the shutdown procedure after the inter-satellite communication is completed, waiting for the next inter-satellite link transmission.

[0017] Preferably, the GNSS information includes position, speed and time information;

[0018] The intersatellite visible effective communication window is determined by the satellite integrated management unit according to the actual installation position of the intersatellite laser communication terminal on the satellite, the field of view shielding of satellite components, and the rotation pointing range of the laser communication terminal itself;

[0019] The intersatellite link building task package includes the start time and working duration of the visible arc segment, and is packaged and generated according to the agreed format protocol.

[0020] Preferably, step S2 includes the laser communication terminal parsing the intersatellite link establishment task package format to obtain the start time T0 and working duration Δt of the intersatellite link establishment, and the control communication unit in the laser communication terminal controls the intersatellite laser communication terminal to power on and perform scanning, capturing and tracking tasks according to the self-planned power-on sequence;

[0021] The scanning capture tracking task includes coarse tracking and fine tracking.

[0022] Preferably, the calculation formula for calculating the angle between the background light vector and the optical axis is as follows:

[0023]

[0024] Where θ represents the angle between the optical axis of the laser communication terminal and the background light vector, x1, y1, z1 are the coordinates of the background light vector in the J2000 inertial system, and x2, y2, z2 represent the optical axis vector of the laser communication terminal in the J2000 inertial system.

[0025] Preferably, the autonomous avoidance initial value is 2°;

[0026] The autonomous avoidance operation includes the optical unit in the laser communication terminal pointing to a preset safe angle azimuth, wherein the safe angle defaults to a pitch angle of -20° and an azimuth angle of 90°;

[0027] The reset tracking task includes setting the deflection angle and pointing speed of the laser communication terminal for re-establishing the link, capturing and tracking, re-establishing the inter-satellite two-way link, and entering the autonomous tracking stage.

[0028] According to the present invention, an inter-satellite laser data transmission system under background light interference comprises: a satellite integrated management unit, a laser communication terminal;

[0029] The satellite integrated management unit calculates the inter-satellite visible arc according to the GNSS information of the satellite and the link-building satellite, generates the inter-satellite link-building task package according to the inter-satellite visible effective communication window, and forwards it to the laser communication terminal;

[0030] The laser communication terminal analyzes the intersatellite link establishment task package, completes the single-machine power-on by autonomous program control, and performs scanning, capture and tracking, and enters the autonomous tracking phase;

[0031] The laser communication terminal calculates the background light vector and the angle between the optical axis in real time, and determines whether the angle is less than the autonomous avoidance angle. If not, the satellite performs inter-satellite data transmission, and during the transmission, it determines the background light interference in real time, and waits for the inter-satellite communication to end and autonomously executes the shutdown procedure, waiting for the next inter-satellite link transmission; if so, the laser communication terminal performs an autonomous avoidance operation, and performs inter-satellite data transmission after completing the reset tracking task, and during the transmission, it determines the background light interference in real time, and waits for the next inter-satellite link transmission to end and autonomously executes the shutdown procedure.

[0032] Preferably, the GNSS information includes position, speed and time information;

[0033] The intersatellite visible effective communication window is determined by the satellite integrated management unit according to the actual installation position of the intersatellite laser communication terminal on the satellite, the field of view shielding of satellite components, and the rotation pointing range of the laser communication terminal itself;

[0034] The intersatellite link building task package includes the start time and working duration of the visible arc segment, and is packaged and generated according to the agreed format protocol.

[0035] Preferably, it also includes a data transmission terminal, which outputs the stored data after satellite framing encoding to the inter-satellite laser communication terminal, receives the stored data read and read stop instructions sent by the integrated management unit, and controls the start and stop playback of the stored data;

[0036] The laser communication terminal includes a control communication unit, an amplifier and an optical unit.

[0037] Preferably, the control communication unit is used to interact with the satellite, calculate the angle between the background light incident vector and the optical axis of the laser communication terminal in real time, and determine whether autonomous avoidance is required; analyze the link building task package, implement the power on and off program control operation of the laser communication terminal; complete the coarse and fine capture tracking control; complete the electro-optical conversion task including the signal;

[0038] The amplifier is used to amplify the optical signal of the inter-satellite return laser link;

[0039] The optical unit is used for receiving and sending optical signals of intersatellite bidirectional laser links, realizing large-range two-dimensional rotation of laser communication terminals and accurate tracking of laser links.

[0040] Preferably, the calculation formula for calculating the angle between the background light vector and the optical axis is as follows:

[0041]

[0042] Where, θ represents the angle between the optical axis of the laser communication terminal and the background light vector, x1, y1, z1 are the coordinates of the background light vector in the J2000 inertial system, and x2, y2, z2 represent the optical axis vector of the laser communication terminal in the J2000 inertial system;

[0043] The autonomous avoidance initial value is 2°;

[0044] The autonomous avoidance operation includes the optical unit in the laser communication terminal pointing to a preset safe angle azimuth, wherein the safe angle defaults to a pitch angle of -20° and an azimuth angle of 90°;

[0045] The reset tracking task includes setting the deflection angle and pointing speed of the laser communication terminal for re-establishing the link, capturing and tracking, re-establishing the inter-satellite two-way link, and entering the autonomous tracking stage.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] 1. Aiming at the high reliability and business application requirements of large-scale constellation intersatellite laser data transmission, the present invention proposes for the first time an intersatellite laser data transmission method and system under background light interference, which realizes intersatellite laser visible calculation, link establishment planning, autonomous prediction and avoidance of solar transit, and autonomous program-controlled data transmission on board.

[0048] 2. The present invention has the advantages of highly reliable intersatellite communication and easy use, which can make the intersatellite laser link operate autonomously, continuously and stably, reduce ground intervention, maximize the continuity and stability of the intersatellite laser link, and ensure highly reliable transmission of intersatellite laser data.

[0049] 3. The present invention is innovative and lays a foundation for subsequent intersatellite laser link service applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] 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:

[0051] Figure 1 It is a schematic diagram of the working method of the present invention;

[0052] Figure 2 Schematic diagram of the high-reliability intersatellite laser data transmission system of the present invention;

[0053] Figure 3 This is a task timing diagram of program-controlled power on and off of the intersatellite laser link of the present invention. DETAILED DESCRIPTION

[0054] 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.

[0055] The present invention reduces ground intervention and minimizes the impact of background light on laser communication terminals, which can maximize the availability of inter-satellite laser link establishment and the integrity of communication data. It also has the advantages of on-board autonomous link establishment access planning and program control, highly reliable communication, and ease of use.

[0056] Embodiment 1

[0057] According to a method for intersatellite laser data transmission under background light interference provided by the present invention, Figure 1 As shown, the background light refers to sunlight, and the intersatellite laser data transmission refers to heterogeneous constellation laser communication, such as the intersatellite laser link between the high-orbit Fengyun-4 satellite and the low-orbit Fengyun-3 satellite. The steps include:

[0058] Step S1: The satellite integrated management unit on board calculates the inter-satellite visible arc segment according to the GNSS information of the satellite and the satellite for link building, and generates an inter-satellite link building task package according to the inter-satellite visible effective communication window and forwards it to the laser communication terminal. The GNSS information includes position, speed and time information. The two satellites for inter-satellite link building obtain each other's GNSS information, and the satellite performs autonomous calculation of the inter-satellite visible arc segment and link building planning to obtain the inter-satellite visible effective communication window. The autonomous calculation of the inter-satellite visible arc segment and link building planning means that the satellite required to build the link obtains the inter-satellite visible effective communication window according to the line of sight vector of the body coordinate system, which is completed by the satellite integrated management unit.

[0059] When the intersatellite laser link is established for the first time, the low-orbit satellite obtains the GNSS parameters of the high-orbit by the ground measurement and control system, and the high-orbit satellite obtains the GNSS parameters of the low-orbit by the ground operation and control system. The subsequent GNSS parameter acquisition is carried out by orbit information exchange for each intersatellite link. The satellite integrated management unit determines the visible field of view range and arc duration of the dual satellites according to the actual installation position of the intersatellite laser communication terminal on the satellite, the field of view obstruction of the satellite components, and the rotation and pointing range of the laser communication terminal itself, and obtains the intersatellite effective communication arc window, that is, the intersatellite visible effective communication window.

[0060] The intersatellite link establishment work task package is generated by the satellite according to the intersatellite visible effective communication window, including the starting time and working duration of the visible arc segment, and is packaged and generated into the intersatellite link establishment work task package according to the agreed format protocol. The integrated management unit sends the intersatellite link establishment work task package to the laser communication terminal through the 1553B bus.

[0061] Step S2: The laser communication terminal parses the intersatellite link establishment task package, completes the single-machine power-on by autonomous program control, and performs scanning, capture and tracking, and enters the autonomous tracking stage.

[0062] The laser communication terminal parses the intersatellite link establishment task package format to obtain the start time T0 and working duration Δt of the intersatellite link establishment. The control communication unit in the laser communication terminal controls the intersatellite laser communication terminal power-on and scanning, capturing and tracking tasks according to the self-planned power-on sequence. Specifically, the control communication unit Figure 3 The intersatellite laser link program-controlled task timing controls the intersatellite laser communication terminal power-on and scanning, capturing and tracking tasks. The electronic part of the control communication unit is often powered on in orbit. In order to reduce the impact of single-particle upsets, the integrated management unit sends a software reset command 60 seconds before each laser communication terminal is powered on. From the starting time T0, the laser, optical amplifier and servo driver module are turned on in sequence according to the time interval. The optical unit of the laser communication terminal points to the predetermined angle according to the azimuth and pitch calculation value, and starts the scanning, capturing and tracking task. After the two-way link is successfully established, the communication working parameters are set, and the data transmission terminal starts to play back the stored data on the satellite. At T0+Δt, the satellite autonomously sends a read-stop command to the data transmission terminal, and turns off the laser communication module, amplifier, laser and servo driver module in sequence according to the shutdown sequence. The laser communication terminal is in standby mode.

[0063] The scanning, capture and tracking task adopts a coarse-fine composite tracking and aiming system design to complete the transition to the intersatellite autonomous tracking stage. The coarse tracking system completes large-scale, two-dimensional angular motion, realizes target search, capture and coarse tracking functions, and is used to compensate for satellite orbit and attitude changes. The fine tracking system completes small-scale, high-frame-rate, high-precision, two-dimensional motion, realizes accurate target tracking, and is used to compensate for satellite platform micro-vibration.

[0064] Step S3: The laser communication terminal calculates the angle between the background light vector and the optical axis in real time, and determines whether the angle is less than the autonomous avoidance angle. If so, the laser communication terminal performs an autonomous avoidance operation, and executes step S4 after completing the reset tracking task; if not, execute step S4. The calculation formula for calculating the angle between the background light vector and the optical axis in step S3 is as follows:

[0065]

[0066] Where θ represents the angle between the optical axis of the laser communication terminal and the background light vector, x1, y1, z1 are the coordinates of the background light vector in the J2000 inertial system, and x2, y2, z2 represent the optical axis vector of the laser communication terminal in the J2000 inertial system.

[0067] The laser communication terminal control communication unit calculates the angle between the laser communication terminal optical axis and the solar incident light vector in real time according to the solar vector broadcast by the satellite 1553B bus, and compares it with the autonomous avoidance angle. The initial value of autonomous avoidance is 2°, which can be modified in orbit. If the angle between the laser communication terminal optical axis and the solar incident light vector is less than the autonomous avoidance angle, the laser communication terminal performs an autonomous avoidance operation. The autonomous avoidance operation includes the optical unit in the laser communication terminal pointing to a preset safe angle azimuth, where the safety angle defaults to a pitch angle of -20° and an azimuth angle of 90°. The moment of sunlight interference is calculated on the satellite, and according to the calculated angle θ between the laser communication terminal and the sunlight vector, if the angle θ is less than the autonomous avoidance protection angle of 2°, the corresponding on-satellite moment is the moment of sunlight interference, and the laser communication terminal begins to enter the reset capture and tracking task, including setting the deflection angle and pointing speed of the laser communication terminal for re-establishing the link, capturing and tracking, re-establishing the inter-satellite two-way link, and entering the autonomous tracking stage.

[0068] Step S4: The satellite performs normal intersatellite data transmission, and during the transmission, it judges the background light interference in real time (with a quasi-ban function), and executes the shutdown procedure autonomously after the intersatellite communication is completed, waiting for the next intersatellite link transmission. The intersatellite data transmission is that after the intersatellite two-way link is successfully established, the data transmission terminal outputs the satellite data to the intersatellite laser communication terminal. After the laser communication terminal completes the baseband processing and optical processing, it sends the data to the satellite for link establishment. After the intersatellite visible communication arc ends, the satellite performs the shutdown operation in sequence according to the program control design. The optical processing includes generating an optical signal from the baseband information through a BPSK photoelectric modulator, and the optical signal is transmitted to an optical amplifier through a single-mode optical fiber to amplify the signal to 5W. The amplified optical signal is transmitted to the optical unit of the laser communication terminal through an optical fiber to complete the collimation, and is transmitted to the Kude optical path through optical devices such as advance sights and precision tracking PZT, and then transmitted to the satellite for link establishment by an optical antenna.

[0069] The background light interference is judged in real time during the intersatellite transmission. According to the background light interference test data of the on-orbit satellite, when the intersatellite laser link capture and tracking is successful, the background light will basically not affect the intersatellite link data transmission. Therefore, according to the actual situation on orbit, the satellite retains the allowable and prohibited operation of this function, and the background light interference does not need to be judged during the intersatellite transmission.

[0070] If the angle between the laser communication terminal optical axis and the solar incident light vector is greater than the autonomous avoidance angle, after the intersatellite bidirectional link is successfully established, Figure 3 As shown, before entering the intersatellite effective communication window, the integrated management unit sends the intersatellite link transmission mode and the fixed storage read command to the data transmission terminal in sequence, and the remote sensing information flow follows Figure 2As shown, the data transmission terminal outputs the satellite storage data to the intersatellite laser communication terminal control communication unit at a rate of 500Mbps / 1Gbps through the 2711 serial interface. After the control communication unit completes the baseband processing and electro-optical conversion, it sends the optical signal to the optical amplifier to achieve 5W optical signal amplification output. The optical unit realizes the large-scale two-dimensional rotation of the laser communication terminal and the precise tracking of the laser link, and sends the low-orbit meteorological satellite data to the high-orbit meteorological satellite. The high-orbit meteorological satellite completes the optical signal reception, optoelectronic conversion, demodulation and decoding, and packages the recovered baseband signal in the ground data transmission Ka channel for downlink. When the intersatellite visible communication arc ends, the satellite follows Figure 3 The program control design shown in the figure executes the shutdown operation in sequence, which mainly involves the integrated management unit sending the storage read stop command, the data transmission terminal stopping the playback of remote sensing data, and the laser communication terminal controlling the communication unit to control the shutdown of the photoelectric modulator, the optical amplifier and the servo drive module in sequence. The satellite enters the waiting mode for the next link establishment transmission.

[0071] The present invention realizes intersatellite laser visible calculation, link establishment planning, autonomous prediction and avoidance of solar transit, and autonomous program-controlled data transmission on board the satellite. The method has the advantages of highly reliable intersatellite communication and easy use, and can make the intersatellite laser link operate autonomously, continuously and stably, reduce ground intervention, guarantee the continuity and stability of the intersatellite laser link to the greatest extent, and ensure highly reliable transmission of intersatellite laser data.

[0072] Embodiment 2

[0073] The present invention also provides an inter-satellite laser data transmission system under background light interference. The inter-satellite laser data transmission system under background light interference can be realized by executing the process steps of the inter-satellite laser data transmission method under background light interference, that is, those skilled in the art can understand the inter-satellite laser data transmission method under background light interference as a preferred implementation of the inter-satellite laser data transmission system under background light interference.

[0074] According to the present invention, an inter-satellite laser data transmission system under background light interference includes: a satellite integrated management unit and a laser communication terminal.

[0075] The satellite integrated management unit calculates the intersatellite visible arc segment according to the GNSS information of the satellite and the satellite for link building, and generates the intersatellite link building task package according to the intersatellite visible effective communication window and forwards it to the laser communication terminal. The integrated management unit module mainly completes the calculation of the intersatellite visible communication arc segment, generates the intersatellite link building task package and forwards the task package through the bus. The background light vector is calculated in real time and broadcast through the bus. The data transmission terminal reads and stops the fixed storage according to the intersatellite link building task package timing program. GNSS information includes position, speed and time information. The intersatellite visible effective communication window is determined by the satellite integrated management unit according to the actual installation position of the intersatellite laser communication terminal on the satellite, the field of view occlusion of the satellite components, and the rotation pointing range of the laser communication terminal itself. The intersatellite link building task package includes the starting time and working duration of the visible arc segment, and is packaged and generated according to the agreed format protocol.

[0076] The laser communication terminal parses the intersatellite link establishment task package, completes the single-machine power-on through autonomous program control, and performs scanning, capture and tracking, and enters the autonomous tracking stage. The laser communication terminal calculates the background light vector and the optical axis angle in real time to determine whether the angle is less than the autonomous avoidance angle. If not, the satellite transmits intersatellite data, and during the transmission, it determines the background light interference in real time. After the intersatellite communication is completed, it autonomously executes the shutdown procedure and waits for the next intersatellite link establishment transmission. If so, the laser communication terminal performs autonomous avoidance operations, and after completing the reset and capture task, it transmits intersatellite data. During the transmission, it determines the background light interference in real time. After the intersatellite communication is completed, it autonomously executes the shutdown procedure and waits for the next intersatellite link establishment transmission. The calculation formula for calculating the background light vector and the optical axis angle is as follows:

[0077]

[0078] Where θ represents the angle between the optical axis of the laser communication terminal and the background light vector, x1, y1, z1 are the coordinates of the background light vector in the J2000 inertial system, and x2, y2, z2 represent the optical axis vector of the laser communication terminal in the J2000 inertial system.

[0079] The above-mentioned initial value of autonomous avoidance is 2°; the autonomous avoidance operation includes pointing the optical unit in the laser communication terminal to a preset safety angle, where the safety angle defaults to a pitch angle of -20° and an azimuth angle of 90°; the reset tracking task includes setting the deflection angle and pointing speed of the laser communication terminal for re-establishing the link, capturing and tracking, re-establishing the inter-satellite two-way link, and entering the autonomous tracking stage.

[0080] The laser communication terminal includes a control communication unit, an amplifier and an optical unit. The control communication unit is used to interact with the satellite, calculate the angle between the incident background light vector and the optical axis of the laser communication terminal in real time, and determine whether autonomous avoidance is required; analyze the link building task package, implement the power on and off program control operation of the laser communication terminal; complete the coarse and fine capture tracking control; complete the electro-optical conversion tasks including the signal. The amplifier is used to amplify the optical signal of the intersatellite return laser link. The optical unit is used to receive and send the optical signal of the intersatellite bidirectional laser link, and realize the large-scale two-dimensional rotation of the laser communication terminal and the precise tracking of the laser link.

[0081] The intersatellite laser data transmission system under background light interference of the present invention also includes a data transmission terminal, which outputs the stored data after satellite framing encoding to the intersatellite laser communication terminal, receives the stored data read and read stop instructions sent by the integrated management unit, and controls the start and stop playback of the stored data.

[0082] Those skilled in the art know that, in addition to realizing the system and its various devices, modules, and units provided by the present invention in a purely computer-readable program code, it is entirely possible to realize the same functions in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system and its various devices, modules, and units provided by the present invention can be considered as a hardware component, and the devices, modules, and units included therein for realizing various functions can also be regarded as structures within the hardware component; the devices, modules, and units for realizing various functions can also be regarded as both software modules for realizing the method and structures within the hardware component.

[0083] 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. A method for intersatellite laser data transmission under background light interference, characterized in that: include: Step S1: The satellite integrated management unit calculates the inter-satellite visible arc according to the GNSS information of the local satellite and the link-building satellite, generates an inter-satellite link-building task package according to the inter-satellite visible effective communication window, and forwards it to the laser communication terminal; Step S2: the laser communication terminal parses the intersatellite link establishment task package, completes the single-machine power-on by autonomous program control, and performs scanning, capture and tracking, and enters the autonomous tracking stage; Step S3: The laser communication terminal calculates the background light vector and the angle between the optical axis in real time, and determines whether the angle is smaller than the autonomous avoidance angle. If so, the laser communication terminal performs an autonomous avoidance operation, and executes step S4 after completing the reset tracking task; if not, executes step S4; Step S4: The satellite performs normal inter-satellite data transmission, determines the background light interference in real time during the transmission, and autonomously executes the shutdown procedure after the inter-satellite communication is completed, waiting for the next inter-satellite link transmission.

2. The intersatellite laser data transmission method under background light interference according to claim 1, characterized in that: The GNSS information includes position, speed and time information; The intersatellite visible effective communication window is determined by the satellite integrated management unit according to the actual installation position of the intersatellite laser communication terminal on the satellite, the field of view shielding of satellite components, and the rotation pointing range of the laser communication terminal itself; The intersatellite link building task package includes the start time and working duration of the visible arc segment, and is packaged and generated according to the agreed format protocol.

3. The intersatellite laser data transmission method under background light interference according to claim 1, characterized in that: The step S2 includes the laser communication terminal parsing the intersatellite link establishment task package format to obtain the start time T0 and working duration Δt of the intersatellite link establishment, and the control communication unit in the laser communication terminal controls the intersatellite laser communication terminal to power on and scan, capture and track tasks according to the self-planned power-on sequence; The scanning capture tracking task includes coarse tracking and fine tracking.

4. The intersatellite laser data transmission method under background light interference according to claim 1, characterized in that: The calculation formula for calculating the angle between the background light vector and the optical axis is as follows: Where θ represents the angle between the optical axis of the laser communication terminal and the background light vector, x1, y1, z1 are the coordinates of the background light vector in the J2000 inertial system, and x2, y2, z2 represent the optical axis vector of the laser communication terminal in the J2000 inertial system.

5. The intersatellite laser data transmission method under background light interference according to claim 1, characterized in that: The autonomous avoidance initial value is 2°; The autonomous avoidance operation includes the optical unit in the laser communication terminal pointing to a preset safe angle azimuth, wherein the safe angle defaults to a pitch angle of -20° and an azimuth angle of 90°; The reset tracking task includes setting the deflection angle and pointing speed of the laser communication terminal for re-establishing the link, capturing and tracking, re-establishing the inter-satellite two-way link, and entering the autonomous tracking stage.

6. An intersatellite laser data transmission system under background light interference, characterized in that: include: Satellite integrated management unit, laser communication terminal; The satellite integrated management unit calculates the inter-satellite visible arc according to the GNSS information of the satellite and the link-building satellite, generates the inter-satellite link-building task package according to the inter-satellite visible effective communication window, and forwards it to the laser communication terminal; The laser communication terminal analyzes the intersatellite link establishment task package, completes the single-machine power-on by autonomous program control, and performs scanning, capture and tracking, and enters the autonomous tracking stage; The laser communication terminal calculates the background light vector and the angle between the optical axis in real time, and determines whether the angle is less than the autonomous avoidance angle. If not, the satellite performs inter-satellite data transmission, and during the transmission, it determines the background light interference in real time, and waits for the inter-satellite communication to end and autonomously executes the shutdown procedure, waiting for the next inter-satellite link transmission; if so, the laser communication terminal performs an autonomous avoidance operation, and performs inter-satellite data transmission after completing the reset tracking task, and during the transmission, it determines the background light interference in real time, and waits for the next inter-satellite link transmission to end and autonomously executes the shutdown procedure.

7. The intersatellite laser data transmission system under background light interference according to claim 6, characterized in that: The GNSS information includes position, speed and time information; The intersatellite visible effective communication window is determined by the satellite integrated management unit according to the actual installation position of the intersatellite laser communication terminal on the satellite, the field of view shielding of satellite components, and the rotation pointing range of the laser communication terminal itself; The intersatellite link building task package includes the start time and working duration of the visible arc segment, and is packaged and generated according to the agreed format protocol.

8. The intersatellite laser data transmission system under background light interference according to claim 6, characterized in that: It also includes a data transmission terminal, which outputs the satellite frame-encoded fixed storage data to the inter-satellite laser communication terminal, receives the fixed storage read and read stop instructions sent by the integrated management unit, and controls the start and stop playback of the fixed storage data; The laser communication terminal includes a control communication unit, an amplifier and an optical unit.

9. The intersatellite laser data transmission system under background light interference according to claim 8, characterized in that: The control communication unit is used to interact with the satellite, calculate the angle between the background light incident vector and the optical axis of the laser communication terminal in real time, and determine whether autonomous avoidance is required; analyze the link building task package, implement the power on and off program control operation of the laser communication terminal; complete the coarse and fine capture tracking control; and complete the electro-optical conversion tasks including the signal; The amplifier is used to amplify the optical signal of the inter-satellite return laser link; The optical unit is used for receiving and sending optical signals of intersatellite bidirectional laser links, realizing large-range two-dimensional rotation of laser communication terminals and accurate tracking of laser links.

10. The intersatellite laser data transmission system under background light interference according to claim 6, characterized in that: The calculation formula for calculating the angle between the background light vector and the optical axis is as follows: Where, θ represents the angle between the optical axis of the laser communication terminal and the background light vector, x1, y1, z1 are the coordinates of the background light vector in the J2000 inertial system, and x2, y2, z2 represent the optical axis vector of the laser communication terminal in the J2000 inertial system; The autonomous avoidance initial value is 2°; The autonomous avoidance operation includes the optical unit in the laser communication terminal pointing to a preset safe angle azimuth, wherein the safe angle defaults to a pitch angle of -20° and an azimuth angle of 90°; The reset tracking task includes setting the deflection angle and pointing speed of the laser communication terminal for re-establishing the link, capturing and tracking, re-establishing the inter-satellite two-way link, and entering the autonomous tracking stage.

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