Method and system for tracking and imaging civil aviation passenger aircraft by satellite

Abstract

The application provides a satellite tracking and imaging method and system for a civil aviation passenger plane, comprising the following steps: step one, receiving an ADS-B message broadcast by the civil aviation passenger plane; step two, extracting the ICAO address, position, speed and height information of each plane message; step three, sorting the planes according to the message update frequency of the planes, the distance between the positions of the planes and the target point, the speed of the planes or the flight height information of the planes; step four, specifying the strategy of outputting guide information; step five, eliminating the wild value in the message and sending the guide information to a pose and orbit control subsystem; step six, receiving the guide information by the pose and orbit control subsystem and performing trajectory fitting; step seven, rapidly pointing and tracking based on the guide information; and step eight, sending an instruction to a camera subsystem by a comprehensive electronic subsystem, and the camera starts imaging the target. The application realizes the continuous tracking and imaging of the civil aviation passenger plane flying in the air by the satellite, and greatly improves the success probability of the imaging of the plane.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of satellite tracking and imaging of civil aviation passenger planes, and particularly relates to a satellite tracking and imaging method and system for civil aviation passenger planes. BACKGROUND

[0002] The ADS-B system is a new air traffic control monitoring technology based on satellite positioning and air-ground and air-air data link communication to complete traffic monitoring and information transmission. The technology can monitor (obtain) information such as the position, height, speed, heading, take-off / landing state of an aircraft, and is associated with the flight call sign with a globally unique ICAO identifier. The ADS-B message of each aircraft is identified by the flight call sign, that is, the ICAO number, and will not be confused with the messages of other aircraft. An external receiving system can calculate the position, speed, and heading information of a civil aviation aircraft according to these information, so as to master its motion trajectory.

[0003] At present, there is no effective technical means for high-resolution imaging of aircraft in the air. Generally, the surrounding of the airport is imaged by opportunity measurement, so that the probability of capturing the aircraft in flight is extremely low. The satellite carries an ADS-B receiving processor, which can receive wide-area ADS-B signals from the satellite orbit, and can cover remote areas such as the polar region, desert, and ocean at a low cost. Through the ADS-B search guide subsystem installed on the satellite, the ADS-B signals in the air can be obtained continuously and in real time. By matching the unique ICAO number of each civil aviation aircraft with its corresponding position, height, heading, and other information, the tracking of the whole process of the civil aviation passenger plane can be completed, and the continuous monitoring and imaging of important civil aviation targets can be realized. At present, there is no feasible technical means for optical high-resolution imaging of aerial targets.

[0004] A Chinese patent document with publication number CN108768492A discloses an air target tracking method based on a special ADS-B text message on a satellite, which receives ADS-B messages on the satellite and transmits them to the ground for ground search and rescue information support, and does not involve on-satellite application.

[0005] A Chinese patent document with patent number CN210640878U discloses an ADS-B signal receiving device and system, which is applied to an ADS-B load of a satellite, can receive ADS-B signals and convert them into digital signals, and does not involve on-satellite guidance and tracking.

[0006] A Chinese patent document with granted publication number CN109920080B discloses a method for maintaining a black and white list of aircraft targets based on real-time ADS-B, which is related to a method for maintaining a black and white list of aircraft targets based on real-time ADS-B in the field of aircraft target selection, and does not involve on-satellite guidance and tracking.

[0007] The Chinese patent document with publication number CN111585639A discloses a satellite-borne ADS-B message monitoring method, device and storage medium. In view of the problem that existing ADS-B messages are returned to the ground through a data transmission channel, and the satellite lacks real-time monitoring of the processing capability of the ADS-B satellite-borne load, a monitoring method, device and storage medium are invented;

[0008] The Chinese patent document with publication number CN115164825A discloses an automatic digital guidance system based on ADS-B, which calculates the distance between the position information in the received ADS-B signal and the station, and guides the theodolite of the ground station to track the target. It does not involve satellite application. There is no existing technology related to satellite guidance, tracking and imaging of civil aviation aircraft. SUMMARY

[0009] In view of the defects in the prior art, the purpose of the present application is to provide a satellite tracking and imaging method and system for civil aviation aircraft. The satellite carries a broadcast automatic dependent surveillance and monitoring system receiving processor to receive ADS-B messages broadcast by civil aviation aircraft, and realizes continuous tracking and imaging of specified civil aviation aircraft, and can monitor the flight status of important aircraft.

[0010] According to the satellite tracking and imaging method for civil aviation aircraft provided by the present application, the following steps are included:

[0011] Step one, the satellite carries an ADS-B receiving processor to receive ADS-B messages broadcast by civil aviation aircraft, and punches the messages into the accurate time scale of the receiving time;

[0012] Step two, analyze the ADS-B message and extract the aircraft ICAO address, position, speed and height information in each aircraft message;

[0013] Step three, count all the received aircraft message information, and sort the aircraft according to the aircraft message update frequency, the distance between the aircraft position and the target point, the aircraft speed or the aircraft flight height information;

[0014] Step four, send the guidance information output instruction from the satellite integrated electronic subsystem to the ADS-B receiving processor to specify the output guidance information strategy;

[0015] Step five, the ADS-B receiving processor eliminates outliers in the message, and the ADS-B receiving processor sends guidance information to the attitude and orbit control subsystem through the RS422 interface;

[0016] Step six, the attitude and orbit control subsystem receives the guidance information, accumulates more than 5 valid guidance information, and then performs trajectory fitting, and continuously updates the fitted trajectory using the latest 5 guidance information;

[0017] Step seven, the attitude control subsystem controls the satellite to point to the aircraft according to the fitted trajectory, and informs the satellite integrated electronic subsystem after the satellite points to the aircraft;

[0018] Step eight, the integrated electronic subsystem sends instructions to the camera subsystem, and the camera starts imaging the target.

[0019] Preferably, the message receiving in step one includes antenna receiving, radio frequency signal processing and digital information processing;

[0020] The radio frequency signal processing is filtering, amplifying and analog-to-digital conversion of the ADS-B radio frequency signal received by the antenna to form a sample signal;

[0021] The digital information processing is processing of the original sample signal, including demodulation, header detection, time management processing, and extracting effective ADS-B messages from the signal and noise.

[0022] Preferably, the ADS-B message analysis in step two is decoding the ADS-B original message, calculating the target information according to the ADS-B standard protocol, including position, height and speed information.

[0023] Preferably, the message information statistics in step three is classifying or sorting the aircraft in multiple dimensions;

[0024] The satellite first receives aircraft message information for more than 15s, and uses the received message information as a sample. The sample is classified according to the flight number of the aircraft, and the sample is sorted according to the message update frequency of the message, the distance between the aircraft position and the target point, the speed of the aircraft or the flight height of the aircraft, to form a sorting table.

[0025] Preferably, the guidance information output instruction in step four includes two types:

[0026] One is to set the satellite to search according to the flight number of the aircraft to realize tracking of the specified aircraft;

[0027] The other is to select the aircraft with the highest update frequency, the closest aircraft position, the fastest aircraft speed or the highest flight height from the sorting table for searching.

[0028] Preferably, the outlier rejection in step five includes aircraft outside the field of view rejection and position jump interference message rejection;

[0029] The aircraft outside the field of view rejection adopts a distance constraint-based judgment method to reject the aircraft deviating from the field of view too far. First, the central point longitude and latitude of the task are specified by the ground instruction, , the longitude and latitude of the message are compared with the central point longitude and latitude of the task, and the aircraft outside the field of view is rejected. latitude If the following conditions are met simultaneously, it is considered that the message is within the field of view,

[0030]

[0031] If it is not within the above range, it is not put into the target library for tracking, but it is still transmitted through the data channel;

[0032] The interference message with too large position jump is removed by using the speed constraint criterion. The abnormal aircraft message with too fast position jump is removed. To prevent the jump phenomenon of the aircraft message from affecting tracking, the flight speed of 3 Mach is used as the threshold to perform a round of jump judgment on the output guide information. The judgment method is as follows:

[0033] The time, longitude, latitude, and height of the latest guide information ( , , , ) are subtracted from the time, longitude, latitude, and height of the last frame ( , , , ), and the flight speed V is obtained:

[0034]

[0035] Among them, the longitude and latitude units are radians,

[0036] If , the guide information "update state" is set to 0xF1: the guide information has jump.

[0037] Preferably, after removing the wild value, the safety of the guide information is enhanced, and the guide information sending frequency is 1 Hz, which is consistent with the ADS-B message broadcast frequency.

[0038] Preferably, in step six, the trajectory fitting is performed by combining the position message and the speed message. First, more than five aircraft position points are used to derive the first-order term and the second-order term of the flight trajectory, and the aircraft speed is used for constraint to modify the second-order term. The calculation formula is:

[0039] The latest five times, longitudes, latitudes, and heights ( , , , ) (i=1, 2, 3, 4, 5, wherein i=5 is the latest frame) are calculated according to the monomial quadratic polynomial to calculate the fitting coefficients of longitude, latitude, and height

[0040]

[0041] Wherein, the time matrix T is calculated as follows:

[0042] .

[0043] Preferably, the camera imaging instruction in step eight is sent according to the satellite tracking state, and imaging is not realized in the rapid pointing process, and imaging is started after tracking is completed.

[0044] A satellite tracking imaging system for a civil aviation passenger plane, comprising:

[0045] Module one is used for satellite carrying an ADS-B receiving processor, receiving ADS-B messages broadcast by a civil aviation passenger plane, and punching the message into an accurate time scale at the receiving time;

[0046] Module two is used for analyzing the ADS-B message, extracting the aircraft ICAO address, position, speed and height information in each aircraft message;

[0047] Module three is used for counting all received aircraft message information, and sorting the aircraft according to the aircraft message update frequency, the distance of the aircraft position from the target point, the speed of the aircraft or the flight height information of the aircraft;

[0048] Module four is used for sending a guide information output instruction from the satellite integrated electronic subsystem to the ADS-B receiving processor, and specifying the output guide information strategy;

[0049] Module five is used for the ADS-B receiving processor to eliminate wild values in the message, and the ADS-B receiving processor sends guide information to the attitude and orbit control subsystem through an RS422 interface;

[0050] Module six is used for the attitude and orbit control subsystem to receive the guide information, and to perform trajectory fitting after accumulating more than 5 valid guide information, and to continuously update the fitted trajectory using the latest 5 guide information;

[0051] Module seven is used for the attitude and orbit control subsystem to control the attitude according to the fitted trajectory, so that the satellite points to the aircraft, and the attitude and orbit control subsystem controls the satellite to point to the position, and then notifies the satellite integrated electronic subsystem;

[0052] Module eight is used for the integrated electronic subsystem to send an instruction to the camera subsystem, and the camera starts imaging the target.

[0053] Compared with the prior art, the application has the following beneficial effects:

[0054] 1. The application can complete wide-range search and capture of civil aviation aircraft, and improve the capture probability of low-orbit high-resolution optical satellites for aircraft;

[0055] 2. The technical method of this application enables satellite to continuously track and image civil airliners flying in the air, which greatly improves the success rate of aircraft imaging and can achieve aircraft tracking and imaging at low cost and with high reliability.

[0056] 3. The technical method of this application can be applied to the in-flight status monitoring and imaging of key civil aircraft;

[0057] 4. This application enables satellites to autonomously complete search, guidance, and tracking imaging without ground intervention, making it suitable for satellite platforms of various sizes and highly applicable.

[0058] 5. The system described in this application is stable, reliable, and flexible, and does not lose target during rapid target pointing. Once tracking is stable, it ensures high-resolution imaging. It offers multiple strategies for selecting aircraft targets, demonstrating high flexibility and targeted capabilities, and possesses significant application value. Attached Figure Description

[0059] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0060] Figure 1 This is a flowchart of a satellite tracking and imaging method for civil airliners. Detailed Implementation

[0061] The present application will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present application, but do not limit the present application in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present application. These all fall within the protection scope of the present application.

[0062] A satellite tracking and imaging method for civil airliners according to the present invention includes the following steps:

[0063] Step 1: The satellite carries an ADS-B receiver processor to receive ADS-B messages broadcast by civil aviation passenger planes and inserts the messages with the precise time stamp of the reception time.

[0064] Message reception includes antenna reception, radio frequency signal processing, and digital information processing. Radio frequency signal processing involves filtering, amplifying, and converting the ADS-B radio frequency signal received by the antenna into an analog-to-digital signal to form a sampled signal. Digital information processing involves demodulating, header detection, and time management of the original sampled signal to extract the valid ADS-B messages from the signal and noise.

[0065] Step 2: Parse the ADS-B messages and extract the aircraft's ICAO address, position, speed, and altitude information from each aircraft message.

[0066] ADS-B message analysis is to decode the ADS-B original message, and calculate the target information according to the ADS-B standard protocol, including: position, height, speed information.

[0067] Step three, statistics of all received aircraft message information, according to the aircraft message update frequency, the distance between the aircraft position and the target point, the speed of the aircraft or the flight height information of the aircraft, the aircraft is sorted.

[0068] Message information statistics is to classify or sort aircraft in multiple dimensions. The satellite first receives aircraft message information for more than 15s, accumulates enough message information as a sample, classifies the information of the same aircraft according to the aircraft flight number, and sorts the sample according to the message update frequency, the distance between the aircraft position and the target point, the speed of the aircraft or the flight height of the aircraft, respectively, to form a sorting table.

[0069] Step four, send the guide information output instruction to the ADS-B receiving processor from the satellite integrated electronic subsystem, and specify the output guide information strategy;

[0070] The guide information output instruction has two types. One is to set the satellite to search according to the aircraft flight number, to realize the tracking of the specified aircraft. The other is to select the aircraft with the highest update frequency, the closest aircraft position, the fastest aircraft speed or the highest flight height from the sorting table for searching.

[0071] Step five, the ADS-B receiving processor eliminates the wild value in the message, and the ADS-B receiving processor sends the guide information to the attitude and orbit control subsystem through the RS422 interface.

[0072] There are wild values in the ADS-B received civil aviation aircraft message in orbit: ADS-B may receive aircraft message with strong energy outside the field of view; civil aviation aircraft message may have large position jump. The following wild value elimination scheme is adopted:

[0073] 1) Out-of-field aircraft elimination:

[0074] The distance constraint based judgment method is adopted to eliminate the aircraft that deviates too far from the field of view. First, by ground instruction, the central point longitude and latitude of the task are determined (φ0, λ0), and the longitude , and latitude , in the message satisfy the following conditions at the same time, it is considered to be the message within the field of view,

[0075]

[0076] If the target is not within the range of the above formula, it will not be included in the target tracking library, but it will still be transmitted through the data transmission channel.

[0077] 2) Removal of interference packets with excessively large position jumps:

[0078] An abnormal aircraft message with excessively rapid position changes is eliminated using a speed constraint criterion.

[0079] To prevent aircraft message transitions from affecting tracking, a transition check is performed on the output guidance information using a flight speed of Mach 3 (1020 m / s) as the threshold. The check method is as follows:

[0080] The latest guidance information includes time, longitude, latitude, and altitude. , , , ) and the previous time, longitude, latitude, and altitude ( , , , Calculate the difference between the two values ​​and find the flight speed V.

[0081]

[0082] Longitude and latitude are measured in radians.

[0083] like If the "Update Status" setting is set to 0xF1, it indicates a change in the boot message.

[0084] Removing outliers enhances the security of the guidance information. The guidance information is sent at a frequency of 1 Hz, consistent with the broadcast frequency of ADS-B messages.

[0085] Step 6: The attitude and trajectory control system receives guidance information, accumulates more than 5 frames of valid guidance information, performs trajectory fitting, and continuously updates the fitted trajectory using the latest 5 frames of guidance information.

[0086] The trajectory fitting is performed using a combination of position and velocity messages. First, the first and second order terms of the flight trajectory are derived using more than five aircraft position points. The second order term is then corrected by constraining the aircraft speed.

[0087] The latest 5 frames of time, longitude, latitude, and altitude ( , , , (i=1,2,3,4,5, where i=5 is the latest image) Calculate the fitting coefficients for longitude, latitude, and altitude using a quadratic polynomial.

[0088]

[0089] The time matrix T is calculated as follows:

[0090] .

[0091] Step seven, the attitude and orbit control subsystem controls the satellite to point to the aircraft according to the fitted trajectory, and informs the satellite integrated electronic subsystem after the satellite points to the aircraft.

[0092] Step eight, the integrated electronic subsystem sends an instruction to the camera subsystem, and the camera starts imaging the target.

[0093] The camera imaging instruction is sent after the satellite tracking state is judged, and no imaging is performed in the process of rapid pointing to the target. Imaging is started after tracking is completed.

[0094] The application also provides a satellite tracking and imaging system for a civil aviation passenger aircraft. The satellite tracking and imaging system for a civil aviation passenger aircraft can be implemented by performing the process steps of the satellite tracking and imaging method for a civil aviation passenger aircraft. That is, those skilled in the art can understand the satellite tracking and imaging method for a civil aviation passenger aircraft as a preferred implementation of the satellite tracking and imaging system for a civil aviation passenger aircraft. The satellite tracking and imaging method for a civil aviation passenger aircraft includes:

[0095] Module one is used for satellite carrying an ADS-B receiving processor, receiving ADS-B messages broadcast by a civil aviation passenger aircraft, and punching the messages into an accurate time scale of a receiving time;

[0096] Module two is used for analyzing the ADS-B messages and extracting aircraft ICAO addresses, positions, speeds and height information in each aircraft message;

[0097] Module three is used for counting all received aircraft message information, sorting the aircraft according to the message update frequency of the aircraft, the distance of the aircraft position from the target point, the speed of the aircraft or the flight height information of the aircraft;

[0098] Module four is used for sending a guide information output instruction from the satellite integrated electronic subsystem to the ADS-B receiving processor to specify an output guide information strategy;

[0099] Module five is used for the ADS-B receiving processor to eliminate wild values in the messages. The ADS-B receiving processor sends guide information to the attitude and orbit control subsystem through an RS422 interface;

[0100] Module six is used for the attitude and orbit control subsystem to receive the guide information, perform trajectory fitting after accumulating more than 5 valid guide information, and continuously update the fitted trajectory using the latest 5 guide information;

[0101] Module seven, for the attitude control subsystem according to the fitted trajectory, the satellite pointing to the aircraft, the attitude control subsystem controls the satellite pointing to the position, informs the satellite integrated electronic subsystem;

[0102] Module eight, for the integrated electronic subsystem to the camera subsystem sends instructions, the camera starts to image the target.

[0103] Those skilled in the art know that, in addition to the system provided by the present application and each device, module, unit thereof is realized in the form of pure computer readable program code, it can be realized by logical programming method steps to make the system provided by the present application and each device, module, unit to realize the same function in the form of logic gate, switch, application specific integrated circuit, programmable logic controller and embedded microcontroller. Therefore, the system provided by the present application and each device, module, unit can be considered as a hardware component, and the device, module, unit included therein for realizing various functions can also be considered as the structure in the hardware component; the device, module, unit for realizing various functions can also be considered as both software module realizing the method and structure in the hardware component.

[0104] The specific embodiments of the present application are described above. It needs to be understood that the present application 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 essential content of the present application. In the case of no conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A satellite tracking and imaging method for civil airliners, characterized in that, include: Step 1: The satellite carries an ADS-B receiver processor to receive ADS-B messages broadcast by civil aviation passenger planes and inserts the messages with the precise time stamp of the reception time. Step 2: Parse the ADS-B messages and extract the aircraft ICAO address, location, speed, and altitude information from each aircraft message; Step 3: Analyze all received aircraft messages and sort the aircraft according to their message update frequency, distance from the target point, speed, or altitude. Step four: The satellite integrated electronic subsystem sends a guidance information output command to the ADS-B receiver processor, specifying the strategy for outputting guidance information; Step 5: The ADS-B receiver processor removes outliers from the message and sends guidance information to the attitude and orbit control subsystem via the RS422 interface. Step 6: The attitude and trajectory control system receives guidance information, accumulates more than 5 frames of valid guidance information, performs trajectory fitting, and continuously updates the fitted trajectory using the latest 5 frames of guidance information. Step 7: The attitude and orbit control subsystem performs attitude control based on the fitted trajectory to make the satellite point towards the aircraft. After the attitude and orbit control subsystem controls the satellite to point in the correct position, it notifies the satellite integrated electronic subsystem. Step 8: The integrated electronic subsystem sends a command to the camera subsystem, and the camera begins to image the target.

2. The satellite tracking and imaging method for civil airliners according to claim 1, characterized in that, The message reception described in step one includes antenna reception, radio frequency signal processing, and digital information processing; The radio frequency signal processing involves filtering, amplifying, and performing analog-to-digital conversion on the ADS-B radio frequency signal received by the antenna to form a sampled signal; The digital information processing involves processing the original sampled signal, including demodulation, header detection, time management processing, and extraction of valid ADS-B messages from the signal and noise.

3. The satellite tracking and imaging method for civil airliners according to claim 1, characterized in that, The ADS-B message parsing described in step two involves decoding the original ADS-B message and calculating the target information, including position, altitude, and speed, according to the ADS-B standard protocol.

4. The satellite tracking and imaging method for civil airliners according to claim 1, characterized in that, The message information statistics described in step three involve classifying or sorting aircraft across multiple dimensions; The satellite first receives aircraft message information for more than 15 seconds and uses the received message information as a sample. The sample is then classified according to the aircraft's flight call sign, and the sample is sorted according to the message update frequency, the distance of the aircraft from the target point, the aircraft's speed, or the aircraft's flight altitude to form a sorting table.

5. The satellite tracking and imaging method for civil airliners according to claim 4, characterized in that, The boot information output instructions mentioned in step four include two types: One method is to set up satellites to search for aircraft based on their flight call signs, thereby enabling the tracking of designated aircraft. Another method is to filter based on a sorting table, selecting the aircraft with the highest update frequency, the closest aircraft position, the fastest aircraft speed, or the highest flight altitude for the search.

6. The satellite tracking and imaging method for civil airliners according to claim 1, characterized in that, The outlier removal mentioned in step five includes the removal of out-of-view aircraft and the removal of interference messages with excessive position jumps; The elimination of out-of-view aircraft employs a distance-constrained judgment method, eliminating aircraft that deviate too far from the field of view. First, ground commands are issued specifying the longitude and latitude of the mission's center point. , Longitude in the message ,latitude A message is considered to be within the field of view if it meets all of the following conditions: If the target is not within the range of the above formula, it will not be included in the target library to be tracked, but it will still be transmitted through the data transmission channel. Interference messages with excessively large position jumps are eliminated using a speed-constrained criterion. Abnormal aircraft messages with excessively rapid position jumps are removed. To prevent aircraft message jumps from affecting tracking, a jump judgment is performed on the guidance information to be output using a flight speed of Mach 3 as the threshold. The judgment method is as follows: The latest guidance information includes time, longitude, latitude, and altitude. , , , ) and the previous time, longitude, latitude, and altitude ( , , , Find the flight speed V by taking the difference between the two values. The units for longitude and latitude are radians. like If the "Update Status" setting is 0xF1, then the boot message indicates a change in the boot message.

7. The satellite tracking and imaging method for civil airliners according to claim 1, characterized in that, After removing outliers, the security of the guidance information is enhanced. The guidance information is sent at a frequency of 1Hz, which is consistent with the broadcast frequency of ADS-B messages.

8. The satellite tracking and imaging method for civil airliners according to claim 1, characterized in that, The trajectory fitting described in step six is ​​performed using a combination of position and velocity messages. First, the first and second order terms of the flight trajectory are derived using at least five aircraft position points. The second order term is then corrected using aircraft velocity as a constraint. The calculation formula is as follows: The latest 5 frames of time, longitude, latitude, and altitude ( , , , (i=1,2,3,4,5, where i=5 is the latest image) Calculate the fitting coefficients for longitude, latitude, and altitude using a quadratic polynomial. The time matrix T is calculated as follows: 。 9. The satellite tracking and imaging method for civil airliners according to claim 1, characterized in that, The camera imaging command mentioned in step eight is sent after the satellite tracking status is determined, so that imaging does not occur during the rapid pointing to the target, and imaging begins after tracking is completed.

10. A satellite tracking and imaging system for civil airliners, characterized in that, include: Module 1 is used by the satellite-mounted ADS-B receiver processor to receive ADS-B messages broadcast by civil aviation passenger aircraft and to insert the messages with the precise time stamp of the reception time. Module 2 is used to parse ADS-B messages and extract the aircraft's ICAO address, location, speed, and altitude information from each aircraft message; Module 3 is used to collect statistics on all received aircraft messages and sort the aircraft based on their message update frequency, distance from the target point, speed, or altitude. Module 4 is used to send guidance information output instructions from the satellite integrated electronic subsystem to the ADS-B receiver processor, specifying the strategy for outputting guidance information; Module 5 is used by the ADS-B receiver processor to remove outliers from the messages. The ADS-B receiver processor sends guidance information to the attitude and orbit control subsystem through the RS422 interface. Module 6 is used by the attitude and trajectory control system to receive guidance information, accumulate more than 5 valid guidance information frames, perform trajectory fitting, and continuously update the fitted trajectory using the latest 5 guidance information frames. Module 7 is used by the attitude and orbit control subsystem to perform attitude control based on the fitted trajectory, so that the satellite points towards the aircraft. After the attitude and orbit control subsystem controls the satellite to point in the correct position, it notifies the satellite integrated electronic subsystem. Module 8 is used by the integrated electronic subsystem to send instructions to the camera subsystem, so that the camera can start imaging the target.

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