Semi-physical simulation system and simulation method for remote sensing satellite constellation system coordination

Abstract

This invention discloses a semi-physical simulation system and method for collaborative remote sensing satellite constellation systems. The semi-physical simulation system includes a physical platform, a digital system, a high-speed hardware interface conversion device, and a time synchronization device. The time synchronization device is used to perform time calibration on each component of the physical platform and each module of the digital system. The physical platform is used for bidirectional data communication with the digital system, receiving target imaging position information sent by the high-speed hardware interface conversion device. The digital system obtains information processing and fusion results and sends the target imaging position information obtained from payload detection simulation to the high-speed hardware interface conversion device. The semi-physical simulation system of this invention can achieve time consistency between the digital system and the physical system in the semi-physical simulation system, and can be compatible with different target environment simulation tasks and different digital model inputs.

Description

Technical Field

[0001] This invention relates to the field of system simulation and integration verification technology, specifically to a semi-physical simulation system and simulation method for remote sensing satellite constellation system collaboration. Background Technology

[0002] System simulation technology is an effective method to support the entire development process of remote sensing satellites, including design, manufacturing, and integrated testing. To combine the advantages of high confidence and low cost, semi-physical simulation technology has been gradually introduced into the field of remote sensing satellite development.

[0003] Most current semi-physical simulation systems for remote sensing satellites focus on simulating the functions of a single satellite. They incorporate easily simulable physical components such as onboard sensors and moving parts into the simulation loop to achieve realistic physical simulation of motion characteristics. Other onboard functions are implemented through simplified digital simulation. This combination of digital and physical methods simulates the capabilities of a single satellite. For constellation-level simulation, existing system-level constellation co-simulation systems are mostly designed for specific types of remote sensing satellites, lacking a universal simulation platform applicable to different types of remote sensing satellites.

[0004] However, the main drawback of current semi-physical simulation is the lack of system simulation capabilities. It lacks the ability to simulate dozens or even hundreds of constellation clusters, making it difficult to verify the ability of constellation systems to work together.

[0005] In particular, for constellation-level simulations, synchronization between the physical platform and the digital system requires a unified simulation process to synchronize the simulation actions of multiple remote sensing satellites within the system. Without time synchronization, simulation steps between the physical platform and the digital system will exhibit timing mismatches, affecting the overall constellation simulation process. Currently, time synchronization is often achieved using software-defined assignment methods, but these are limited by external factors such as network latency and the program's execution time, and cannot achieve precise time synchronization. Summary of the Invention

[0006] In view of this, the present invention provides a semi-physical simulation system and simulation method for remote sensing satellite constellation system collaboration, which can solve the technical problems of existing technologies that cannot achieve time synchronization between the physical platform and digital system of remote sensing satellite constellations, cannot expand the number of digital satellite nodes of the simulation platform, and cannot adapt to the access of various types of remote sensing satellites.

[0007] To solve the above-mentioned technical problems, the present invention is implemented as follows.

[0008] A semi-physical simulation system for collaborative remote sensing satellite constellation systems includes:

[0009] Physical platform, digital system, high-speed hardware interface conversion equipment, and time synchronization device;

[0010] The time synchronization device is used to perform time calibration on each component of the physical platform and each module of the digital system; the time signal sent by the time synchronization device is sent to the space service processing device of the physical platform and the digital system.

[0011] The physical platform is used for bidirectional data communication with the digital system and to receive target imaging location information sent by the high-speed hardware interface conversion device.

[0012] The digital system is used for bidirectional digital communication with the physical platform, receiving time signals sent by the time synchronization device, converting them into satellite time data, and realizing digital satellite time synchronization; processing and fusing the state information of the digital models of multiple remote sensing satellites to obtain information processing and fusion results; and sending the target imaging position information obtained by the payload detection simulation to the high-speed hardware interface conversion device.

[0013] Preferably, the physical platform is configured with a bus interface card, a space service processing module, and a protocol conversion gateway;

[0014] The bus interface card of the physical platform provides a general bus interface, which is suitable for bus access and data transmission and reception of various remote sensing satellite electrical components; the bus interface card is directly connected to the physical hardware and is used to receive real-time payload data from the physical hardware.

[0015] The satellite processing module is a comprehensive data management system for the physical platform, which integrates the telemetry system, remote control system, and tracking and orbit determination system, and has on-board autonomous management function. It generates data signals to drive other subsystems in the simulation system to perform corresponding actions.

[0016] The protocol conversion gateway defines the field conversion protocol between the information flow of physical hardware and the communication messages of digital networks, realizing bidirectional conversion between hardware interface protocols for physical platforms and network communication protocols for digital systems, thereby enabling data collaboration between physical platforms and digital systems.

[0017] Preferably, the digital system includes a dedicated driver module, a software API interface module, a remote control and telemetry module, and a payload detection information simulation module;

[0018] The dedicated driver module acquires an external digital satellite constellation model formed by a scalable number of external remote sensing satellites for simulation, and generates the status information of the digital satellite constellation; it exchanges data with the protocol conversion gateway of the physical platform through the software API interface module of the digital system, realizing data driving from the digital platform to the physical platform and information feedback from the physical platform to the digital system; it simulates the digital satellite constellation based on the actual remote sensing satellite constellation workflow, and the remote control and telemetry module simulates and generates the remote control and telemetry information of the digital satellite constellation; it acquires the information processing and fusion results of the satellite processing device based on the remote control and telemetry module in the digital system, and transmits the remote control and telemetry information to the satellite processing device of the physical platform in real time; the payload detection information simulation module acquires the position of the observed target on the image plane, i.e., the target imaging position, based on the optical payload imaging principle; and transmits the target imaging position to the physical hardware through the high-speed hardware interface conversion device.

[0019] A semi-physical simulation method for collaborative remote sensing satellite constellation systems, based on the aforementioned semi-physical simulation system, includes:

[0020] Step S21: The time synchronization device of the semi-physical simulation system synchronizes the physical platform and the digital system.

[0021] Step S22: The digital system and the physical platform communicate bidirectionally through the software API interface module and the protocol conversion gateway to set the mission scenario and working mode of the remote sensing satellite constellation;

[0022] Step S23: The physical platform connects to multiple remote sensing satellite digital models to simulate the operation of 1 to N remote sensing satellite digital models. The dedicated driver module drives each remote sensing satellite digital model to perform collaborative simulation of the constellation system; where N is the number of remote sensing satellite digital models connected.

[0023] Step S24: The remote sensing satellite constellation simulates a collaborative observation mission scenario, performs satellite processing, and generates remote control and telemetry signals; based on the optical payload imaging principle, it obtains the position of the observed target on the image plane, i.e., the target imaging position.

[0024] Preferably, the step of obtaining the position of the observed target on the image plane, i.e., the target imaging position, based on the optical payload imaging principle includes:

[0025] Step S31: Based on the conversion formula from the Earth's geodetic coordinate system to the Earth's fixed coordinate system, the Earth's equatorial radius and Earth's ellipticity are introduced. The coordinates r of the observed target in the Earth's inertial coordinate system are then calculated according to the longitude, latitude, and altitude of the observed target. e :

[0026]

[0027] Where, x e y e z e These are the coordinates of the observed target in the x, y, and z directions in the Earth's inertial coordinate system, respectively, and H. r L represents the height of the observed target in the Earth-fixed coordinate system. r Let λ be the latitude of the observed target in the Earth-fixed coordinate system. r R represents the longitude of the observed target in the Earth-fixed coordinate system. N =R e (1+fsin 2 L) is the principal curvature radius of the meridian, R e R is the Earth's equatorial radius, f is the Earth's ellipticity, and R is the Earth's ellipticity. z (·) represents the rotation matrix about the Z-axis, α Gr This represents the rotation angle of the Earth-fixed coordinate system relative to the Earth-inertial coordinate system at the current moment;

[0028] Step S32: Set the satellite coordinates for the observation mission. Substituting the transformation formula from Earth-fixed coordinate system to Earth-inertial coordinate system, we obtain the coordinates of the satellite in the Earth-inertial coordinate system. The line-of-sight vector in the Earth's inertial frame is represented as follows:

[0029]

[0030] Among them, v e r is the line-of-sight vector. e Let r be the coordinates of the observed target in the Earth inertial coordinate system. es The coordinates of the satellite performing the observation mission in the Earth inertial coordinate system. These represent the latitude, longitude, and altitude of the satellite in the Earth-fixed coordinate system.

[0031] Based on the right ascension of the ascending node and the orbital inclination of the satellite, the transformation matrix from the Earth inertial frame to the celestial coordinate system is obtained:

[0032]

[0033] Among them, R z (·) is the rotation matrix about the Z-axis, i is the orbital inclination, Ω is the right ascension of the ascending node of the satellite's orbit, u=ω+θ is the latitude argument, ω is the perigee argument, and θ is the true anomaly angle; R x (·) represents the rotation matrix about the X-axis; Adjust the coordinate axis matrix;

[0034] Step S33: Rotate the line-of-sight vector in the Earth's inertial frame to obtain the line-of-sight vector in the celestial coordinate system:

[0035]

[0036] Where, x s y s z s These are the coordinates of the line-of-sight vector in the x, y, and z directions in the stellar coordinate system;

[0037] Based on the instantaneous attitude of the onboard sensors, v s Perform coordinate rotation to obtain the target line-of-sight vector v in the sensor coordinate system. c :

[0038]

[0039] Where, x c y c z c These represent the coordinates of the line-of-sight vector in the x, y, and z directions within the sensor coordinate system. ψ represents the sensor attitude angle, and R represents the sensor attitude angle. y (.) represents a rotation matrix around the Y-axis;

[0040] After projection transformation, the line-of-sight vector under the sensor intersects with the image plane to obtain the projection point r of the target on the image plane. p , will r p Divide by the pixel size and round to obtain the target imaging position r. m .

[0041] Preferably, the projection point r p and the target imaging position r m The calculation method is as follows:

[0042]

[0043]

[0044] Where x p y p Let x and y represent the coordinates of the projection point of the target onto the image plane, respectively. m y m Let x and y represent the coordinates of the target in the image plane coordinate system, respectively. c y c z c These are the coordinates of the line-of-sight vector in the x, y, and z directions in the sensor coordinate system, respectively. f represents the focal length of the optical sensor, and IFOV represents the instantaneous field of view of the sensor.

[0045] Beneficial effects:

[0046] (1) The present invention can achieve time consistency between the digital system and the physical system in the semi-physical simulation system, realize data interaction within the system, and at the same time, the system can be compatible with different target environment simulation tasks and different digital model inputs, and has the characteristics of general architecture and scalable platform.

[0047] (2) The semi-physical simulation system of the present invention can keep the time of the physical platform and the digital system consistent throughout the entire process from the start of the simulation process to the end of the simulation, driven by the time synchronization device, which significantly improves the timeliness and reliability of the simulation system and realizes the consistent transmission of simulation time to the physical system and the digital system; and solves the problem of the difficulty in synchronizing the time between the digital system and the physical platform.

[0048] (3) The semi-physical simulation system of the present invention can connect the physical platform and the digital system based on the protocol conversion gateway, realize the collaborative interaction between the two, and complete the integration of data information in the form of network communication. Based on the bidirectional conversion of hardware interface protocol and network communication protocol, it realizes data collaboration between physical satellite and digital satellite, and solves the problem of difficult interactive collaboration between physical platform and digital system.

[0049] (4) The semi-physical simulation system of the present invention achieves constellation scalability through the design of a universal bus interface, enabling multiple remote sensing satellites connected to the system to work collaboratively in constellation mode, thereby improving the ability to handle complex tasks. Addressing the shortcomings of existing semi-physical simulation systems in accessing various electrical components of satellites, the present invention designs a universal physical platform, equipped with multiple bus interfaces and universal satellite management software to form a universal physical platform suitable for bus access and data transmission and reception of various remote sensing satellite electrical components.

[0050] (5) In response to the increasingly complex needs of users, this invention provides a semi-physical simulation system that enables collaborative simulation of the system through constellation networking, which greatly reduces the difficulty of task planning and decomposition. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the structure of the semi-physical simulation system for remote sensing satellite constellation collaboration provided by the present invention.

[0052] Figure 2 This is a schematic diagram of the simulation process of the semi-physical simulation system for remote sensing satellite constellation collaboration provided by the present invention. Detailed Implementation

[0053] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0054] This invention is geared towards remote sensing satellite constellation systems, such as... Figure 1 As shown, a semi-physical simulation system for remote sensing satellite constellation collaboration is proposed, including:

[0055] Physical platform, digital system, high-speed hardware interface conversion equipment, and time synchronization device.

[0056] The time synchronization device is used to perform time calibration on each component of the physical platform and each module of the digital system; the time signal sent by the time synchronization device is sent to the space service processing device of the physical platform and the digital system.

[0057] The physical platform is used for bidirectional data communication with the digital system and to receive target imaging location information sent by the high-speed hardware interface conversion device; the physical platform is equipped with a bus interface card, a satellite processing module, and a protocol conversion gateway.

[0058] The digital system is used for bidirectional digital communication with the physical platform, receiving time signals sent by the time synchronization device, converting them into satellite time data, and realizing digital satellite time synchronization; processing and fusing the state information of the digital models of multiple remote sensing satellites to obtain information processing and fusion results; and sending the target imaging position information obtained by the payload detection simulation to the high-speed hardware interface conversion device. The digital system includes a remote control and telemetry module, a software API interface module, a dedicated driver module, and a payload detection information simulation module.

[0059] Furthermore, the input data signal stream from the external physical hardware is acquired through the bus interface card of the physical platform; the satellite processing module is used to receive the time signal, convert the bus format and second pulse, synchronize the time of electrical components in the physical platform, and perform time calibration on other components of the physical platform based on the time signal. Compared with existing remote sensing satellite simulation physical platforms, the satellite processing device of this physical platform can perform information fusion processing on different types of remote sensing satellites, realizing the simulation and deduction of heterogeneous satellite constellations.

[0060] Furthermore, the digital system is used to receive time signals sent by the time synchronization device, convert them into satellite time data, and realize digital satellite time synchronization; it is also used to conduct bidirectional digital communication with the physical platform, acquire an external digital satellite constellation model formed by a scalable number of external remote sensing satellites for simulation based on a dedicated driver module, and generate the status information of the digital satellite constellation; it exchanges data with the protocol conversion gateway of the physical platform through the software API interface module of the digital system, realizing data driving of the physical platform by the digital platform and information feedback of the physical platform to the digital system; it simulates the digital satellite constellation based on the actual remote sensing satellite constellation workflow, and the remote control and telemetry module simulates and generates the remote control and telemetry information of the digital satellite constellation; it acquires the information processing and fusion results of the satellite processing device based on the remote control and telemetry module in the digital system, and transmits the remote control and telemetry information to the satellite processing device of the physical platform in real time; the payload detection information simulation module acquires the position of the observed target on the image plane, i.e., the target imaging position, based on the optical payload imaging principle; and transmits the target imaging position to the physical hardware through the high-speed hardware interface conversion device.

[0061] Furthermore, the physical hardware is used to convert the obtained target imaging position into real-time target position data.

[0062] Furthermore, the physical platform's bus interface card provides a universal bus interface suitable for bus access and data transmission / reception of various remote sensing satellite electrical components. The bus interface card is directly connected to the physical hardware and is used to receive real-time payload data from the physical hardware. The universal bus serves as the communication pathway for information exchange between the various physical electrical component modules of this semi-physical simulation system. Each submodule mounted on the bus receives remote control commands, sends telemetry data, and interacts with other data through various bus types.

[0063] Furthermore, the protocol conversion gateway defines a field conversion protocol for information flow of physical hardware and field conversion of digital network communication messages, enabling bidirectional conversion between hardware interface protocols for physical platforms and network communication protocols for digital systems, thereby achieving data collaboration between physical platforms and digital systems.

[0064] Furthermore, the satellite processing module is a comprehensive data management system for the physical platform, integrating the telemetry system, remote control system, and tracking and orbit determination system, and has on-board autonomous management capabilities, generating data signals to drive other subsystems in the simulation system to perform corresponding actions.

[0065] Furthermore, when multiple remote sensing satellites are connected to the general interface reserved in the digital system, the digital system can perform data-driven simulation of the connected digital satellite constellation.

[0066] The digital system includes a telemetry and remote control module, a payload detection information simulation module, a dedicated driver module, and a software API interface. It can interact with the physical platform for mission data, drive the satellite digital model, simulate the attitude and orbit of the remote sensing satellite, the real-time status of the payload line of sight, and perform the process of telemetry and remote control information interaction with the physical platform.

[0067] This invention achieves collaborative simulation of a remote sensing satellite constellation system by integrating physical hardware and digital satellite models into a semi-physical simulation platform. The physical hardware is the equipment used for simulating the core missions of remote sensing satellites, and in constellation collaborative missions, it generally includes functions such as payload information processing, intra-satellite and inter-satellite mission planning, and inter-satellite network interaction. The satellite digital model provides digital simulation of the satellite's core mission functions and data interfaces.

[0068] This invention represents a high-confidence system-level experimental verification concept. It is a general-purpose semi-physical simulation platform that can play an important role in the research and development, design and development, on-orbit verification, engineering construction, system operation and technology upgrading of remote sensing satellite systems. It can simulate all the detection, processing, application and transmission characteristics of satellites in orbit.

[0069] The block diagram of a semi-physical simulation system for co-simulation of constellation systems is as follows: Figure 1 As shown, the system platform's basic architecture mainly consists of a physical system and a digital platform. The service support network is a 10 Gigabit network system, supporting users to monitor and operate the working status of various semi-physical and digital simulators within the system. A unified time base in the semi-physical system is generated by a time synchronization module, which synchronizes the working time of the semi-physical simulation environment and the digital simulation environment through the service support network, driving the entire semi-physical simulation environment. Data transmission between the semi-physical system and physical hardware is completed by high-speed hardware interface conversion equipment. The digital system transmits the analog signals that generate the load to external loads via high-speed transmission. Communication and data interaction between various system devices are connected through a device information network, which includes an analog bus network (CAN, SPACEWIRE, 1553B, etc.), a protocol conversion gateway, a 2711 interface network, and a 10 Gigabit network. Electrical components achieve physical connection and communication through CAN / SPACEWIRE / 1553B interface cards mounted on the information network. Inter-satellite interaction network electrical components are converted to 10 Gigabit networks via 422 / LVDS interfaces to achieve communication with the digital model.

[0070] The payload detection information simulation module in the digital system consists of a scene generation server, a disk array, and various databases. The scene generation software runs on the scene generation server, reading imaging parameter information from various databases and combining it with orbit simulation information to obtain image information of each payload on each satellite within the constellation at corresponding time points, which is then stored in the disk array. It also has the function of outputting the target position trajectory information in the scene to the mission coordination subsystem according to the onboard interface format. The telemetry and remote control module in the digital system can perform bidirectional data transmission communication with the satellite processing device on the physical platform, enabling remote sensing satellites to receive remote control signals and provide telemetry feedback in a timely manner. The software API interface in the digital system can perform bidirectional data communication with the protocol conversion gateway on the physical platform, serving as the main channel for their collaborative work. Through an open API interface driver, it enables rapid access to hardware board resources, facilitating rapid prototyping of the onboard mission planning system software. The API driver is encapsulated as a library function, which is called through the development environment during algorithm porting, significantly reducing the time required for code engineering. The dedicated driver module in the digital system is responsible for sending instructions to the external digital model, driving the digital model to complete the simulation and deduction according to the desired process.

[0071] The various components of this invention continuously interact during simulation, forming an organic and unified whole. This allows them to exert performance that individual components do not possess, enabling collaborative simulation work under various complex scenarios and tasks.

[0072] like Figure 2 As shown, this invention provides a semi-physical simulation method for collaborative remote sensing satellite constellation systems, using the semi-physical simulation system described above. The simulation method includes the following steps:

[0073] Step S21: The time synchronization device of the semi-physical simulation system synchronizes the physical platform and the digital system.

[0074] Step S22: The digital system and the physical platform communicate bidirectionally through the software API interface module and the protocol conversion gateway to set the mission scenario and working mode of the remote sensing satellite constellation;

[0075] Step S23: The physical platform connects to multiple remote sensing satellite digital models to simulate the operation of 1 to N remote sensing satellite digital models. The dedicated driver module drives each remote sensing satellite digital model to perform collaborative simulation of the constellation system; where N is the number of remote sensing satellite digital models connected.

[0076] Step S24: The remote sensing satellite constellation simulates a collaborative observation mission scenario, performs satellite processing, and generates remote control and telemetry signals; based on the optical payload imaging principle, it obtains the position of the observed target on the image plane, i.e., the target imaging position.

[0077] Furthermore, the step of obtaining the position of the observed target on the image plane, i.e., the target imaging position, based on the optical payload imaging principle, includes:

[0078] Step S31: Based on the conversion formula from the Earth's geodetic coordinate system to the Earth's fixed coordinate system, the Earth's equatorial radius and Earth's ellipticity are introduced. The coordinates r of the observed target in the Earth's inertial coordinate system are then calculated according to the longitude, latitude, and altitude of the observed target. e :

[0079]

[0080] Where, x e y e z e These are the coordinates of the observed target in the x, y, and z directions in the Earth's inertial coordinate system, respectively, and H. r L represents the height of the observed target in the Earth-fixed coordinate system. r Let λ be the latitude of the observed target in the Earth-fixed coordinate system. r R represents the longitude of the observed target in the Earth-fixed coordinate system. N =R e (1+fsin 2 L) is the principal curvature radius of the meridian, R e R is the Earth's equatorial radius, f is the Earth's ellipticity, and R is the Earth's ellipticity. z (·) represents the rotation matrix about the Z-axis, α Gr It represents the rotation angle of the Earth-fixed coordinate system relative to the Earth-inertial coordinate system at the current moment (also known as the Greenwich right ascension angle).

[0081] Step S32: Set the satellite coordinates for the observation mission. Substituting the transformation formula from Earth-fixed coordinate system to Earth-inertial coordinate system, we obtain the coordinates of the satellite in the Earth-inertial coordinate system. The line-of-sight vector in the Earth's inertial frame is represented as follows:

[0082]

[0083] Among them, v e r is the line-of-sight vector. e Let r be the coordinates of the observed target in the Earth inertial coordinate system. es The coordinates of the satellite in the Earth's inertial coordinate system. These represent the latitude, longitude, and altitude of the satellite in the Earth-fixed coordinate system, respectively.

[0084] Based on the right ascension of the ascending node and the orbital inclination of the satellite, the transformation matrix from the Earth inertial frame to the celestial coordinate system is obtained:

[0085]

[0086] Among them, R z (·) is the rotation matrix about the Z-axis, i is the orbital inclination, Ω is the right ascension of the ascending node of the satellite's orbit, u=ω+θ is the latitude argument, ω is the perigee argument, and θ is the true anomaly angle; R x (·) represents the rotation matrix about the X-axis; Adjust the coordinate axis matrix.

[0087] Step S33: Rotate the line-of-sight vector in the Earth's inertial frame to obtain the line-of-sight vector in the celestial coordinate system:

[0088]

[0089] Where, x s y s z s These are the coordinates of the line-of-sight vector in the x, y, and z directions in the celestial coordinate system.

[0090] Based on the instantaneous attitude of the onboard sensors, v s Perform coordinate rotation to obtain the target line-of-sight vector v in the sensor coordinate system. c :

[0091]

[0092] Where, x c y c z c These represent the coordinates of the line-of-sight vector in the x, y, and z directions within the sensor coordinate system. ψ represents the sensor attitude (azimuth and pitch) angles, and R represents the sensor attitude angle (azimuth and pitch). y (.) represents a rotation matrix around the Y-axis.

[0093] After projection transformation, the line-of-sight vector under the sensor intersects with the image plane to obtain the projection point r of the target on the image plane. p , will r p Divide by the pixel size and round to obtain the target imaging position r. m :

[0094]

[0095]

[0096] Where x p y p Let x and y represent the coordinates of the projection point of the target onto the image plane, respectively. m y mLet x and y represent the coordinates of the target in the image plane coordinate system, respectively. c y c z c These are the coordinates of the line-of-sight vector in the x, y, and z directions in the sensor coordinate system, respectively. f represents the focal length of the optical sensor, and IFOV represents the instantaneous field of view of the sensor.

[0097] The specific embodiments described above only illustrate the design principles of the present invention. The shapes and names of the components in this description may differ and are not limited. Therefore, those skilled in the art can modify or make equivalent substitutions to the technical solutions described in the foregoing embodiments; and these modifications and substitutions do not depart from the inventive spirit and technical solutions of the present invention, and should all fall within the protection scope of the present invention.

Claims

1. A semi-physical simulation method for collaborative remote sensing satellite constellation systems, characterized in that, Includes the following steps: Step S21: The time synchronization device of the semi-physical simulation system synchronizes the physical platform and the digital system. Step S22: The digital system and the physical platform communicate bidirectionally through the software API interface module and the protocol conversion gateway to set the mission scenario and working mode of the remote sensing satellite constellation; Step S23: The physical platform connects to multiple remote sensing satellite digital models to simulate the operation of 1 to N remote sensing satellite digital models. The dedicated driver module drives each remote sensing satellite digital model to perform collaborative simulation of the constellation system; where N is the number of remote sensing satellite digital models connected. Step S24: The remote sensing satellite constellation simulates a collaborative observation mission scenario, performs satellite processing, and generates remote control and telemetry signals; based on the optical payload imaging principle, it acquires the position of the observed target on the image plane, i.e., the target imaging position, including: Step S31: Based on the conversion formula from the Earth's geodetic coordinate system to the Earth's fixed coordinate system, the Earth's equatorial radius and Earth's ellipticity are introduced. The coordinates of the observed target in the Earth's inertial coordinate system are then calculated according to the longitude, latitude, and altitude of the observed target. ; Step S32: Set the satellite coordinates for the observation mission. Substituting the transformation formula from Earth-fixed coordinate system to Earth-inertial coordinate system, we obtain the coordinates of the satellite in the Earth-inertial coordinate system. The line-of-sight vector in the Earth's inertial frame is represented as follows: in, The line-of-sight vector. The coordinates of the observed target in the Earth's inertial coordinate system. The coordinates of the satellite in the Earth's inertial coordinate system. , , These represent the latitude, longitude, and altitude of the satellite in the Earth-fixed coordinate system. Based on the right ascension of the ascending node and the orbital inclination of the satellite, the transformation matrix from the Earth inertial frame to the celestial coordinate system is obtained; Step S33: Rotate the line-of-sight vector in the Earth's inertial frame to obtain the line-of-sight vector in the celestial coordinate system. ; Based on the real-time attitude of the onboard sensors, Perform coordinate rotation to obtain the target line-of-sight vector in the sensor coordinate system. ; After projection transformation, the line-of-sight vector under the sensor intersects with the image plane to obtain the projection point of the target on the image plane. ,Will Divide by the pixel size and round to obtain the target imaging position. ; The projection point and the target imaging position The calculation method is as follows: in , These represent the projection points of the target onto the image plane. x, y Coordinates in two directions, , These represent the target's coordinates in the image plane coordinate system. x, y Coordinates in two directions, , , These represent the coordinates of the line-of-sight vector in the x, y, and z directions within the sensor coordinate system. Indicates the focal length of the optical sensor. This represents the instantaneous field of view of the sensor.

2. The semi-physical simulation method as described in claim 1, characterized in that, The coordinates of the observed target in the Earth's inertial coordinate system for: in, , , The observed target is located in the Earth's inertial coordinate system. x, y, z Coordinates in three directions, The height of the observed target in the Earth-fixed coordinate system. The latitude of the observed target in the Earth-fixed coordinate system. The longitude of the observed target in the Earth-fixed coordinate system. Let be the principal curvature radius of the meridian. The radius of the Earth's equator, For Earth's ellipticity, Indicates circling Z The rotation matrix of the axis. This represents the rotation angle of the Earth-fixed coordinate system relative to the Earth-inertial coordinate system at the current moment.

3. The semi-physical simulation method as described in claim 1, characterized in that, The transformation matrix from Earth's inertial frame to celestial coordinate system is: in, To bypass Z The rotation matrix of the axis. For the track inclination angle, The right ascension of the ascending node of the satellite's orbit. Argument of latitude The perigee argument, It is a true near point angle; Indicates circling X The rotation matrix of the axis; Adjust the coordinate axis matrix.

4. The semi-physical simulation method as described in claim 3, characterized in that, Line of sight vector in stellar coordinate system for: in, , , These are the line-of-sight vectors in the stellar coordinate system. x, y, z Coordinates in three directions; Target line-of-sight vector in sensor coordinate system for: in, , , These are the line-of-sight vectors in the sensor coordinate system. x, y, z Coordinates in three directions , , These are the sensor attitude angles, Indicates circling Y Axis rotation matrix.

5. A semi-physical simulation system for remote sensing satellite constellation collaboration, employing the method described in claim 1, characterized in that: include: Physical platform, digital system, high-speed hardware interface conversion equipment, and time synchronization device; The time synchronization device is used to perform time calibration on each component of the physical platform and each module of the digital system; the time signal sent by the time synchronization device is sent to the space service processing device of the physical platform and the digital system. The physical platform is used for bidirectional data communication with the digital system and to receive target imaging location information sent by the high-speed hardware interface conversion device. The digital system is used for bidirectional digital communication with the physical platform, receiving time signals sent by the time synchronization device, converting them into satellite time data, and realizing digital satellite time synchronization; it processes and fuses the state information of the digital models of multiple remote sensing satellites to obtain information processing and fusion results; and it sends the target imaging position information obtained by the payload detection simulation to the high-speed hardware interface conversion device.

6. The semi-physical simulation system as described in claim 5, characterized in that, The physical platform is equipped with a bus interface card, a space service processing module, and a protocol conversion gateway. The physical platform's bus interface card provides a universal bus interface suitable for bus access and data transmission and reception of various remote sensing satellite electrical components; the bus interface card is directly connected to the physical hardware and is used to receive real-time payload data from the physical hardware. The satellite processing module is a comprehensive data management system for the physical platform, which integrates the telemetry system, remote control system, and tracking and orbit determination system, and has on-board autonomous management function. It generates data signals to drive other subsystems in the simulation system to perform corresponding actions. The protocol conversion gateway defines the field conversion protocol between the information flow of physical hardware and the communication messages of digital networks, realizing bidirectional conversion between hardware interface protocols for physical platforms and network communication protocols for digital systems, thereby enabling data collaboration between physical platforms and digital systems.

7. The semi-physical simulation system as described in claim 6, characterized in that, The digital system includes a dedicated driver module, a software API interface module, a remote control and telemetry module, and a payload detection information simulation module; The dedicated driver module acquires an external digital satellite constellation model formed by a scalable number of external remote sensing satellites for simulation, and generates the status information of the digital satellite constellation; it exchanges data with the protocol conversion gateway of the physical platform through the software API interface module of the digital system, realizing data driving from the digital platform to the physical platform and information feedback from the physical platform to the digital system; it simulates the digital satellite constellation based on the actual remote sensing satellite constellation workflow, and the remote control and telemetry module simulates and generates the remote control and telemetry information of the digital satellite constellation; it acquires the information processing and fusion results of the satellite processing device based on the remote control and telemetry module in the digital system, and transmits the remote control and telemetry information to the satellite processing device of the physical platform in real time; the payload detection information simulation module acquires the position of the observed target on the image plane, i.e., the target imaging position, based on the optical payload imaging principle; and transmits the target imaging position to the physical hardware through the high-speed hardware interface conversion device.

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