Satellite-borne radar working state autonomous recovery method

Abstract

The application provides a kind of satellite-borne radar working state autonomous recovery method, comprising the following steps: S1, determine the radar state recovery key variable of the satellite-borne radar;S2, add key variable saving module in the embedded software, for regularly storing the latest data of the radar state recovery key variable, and regularly setting watchdog fly monitoring flag and overall pre-reset instruction flag;S3, add logic branch submodule in the embedded software, for reading the watchdog fly monitoring flag and overall pre-reset instruction flag, and further executing radar normal power-on start initialization branch or watchdog fly reset branch or pre-reset instruction reset branch.The application can make the satellite-borne radar autonomously recover the working state after encountering single event upset failure, avoid causing the interruption of satellite-borne radar target tracking monitoring, improve the reliability of satellite-borne radar product on-orbit operation, and has the simplicity, independence, flexibility and wide applicability of implementation.

Description

Technical Field

[0001] This invention relates to the field of satellite reliability applications, and in particular to a method for autonomous recovery of the operational status of spaceborne radar. Background Technology

[0002] With the rapid development of aerospace technology, large-scale and very large-scale integrated circuits are increasingly widely used in spaceborne radar products. However, the complex space environment seriously affects the high reliability of highly integrated spaceborne radar products, and single-event upsets (SWEs) have become one of the most common failures during the on-orbit operation of spaceborne radar products. SWEs typically have a significant impact on the normal operation of radar systems, and how to take effective measures to restore the radar's working state when encountering non-self-healing SWEs has become one of the key considerations in the design and development of spaceborne radar products. Summary of the Invention

[0003] The purpose of this invention is to provide a method for autonomous recovery of the working state of a spaceborne radar. Applied to a spaceborne radar DSP chip, it can effectively solve the problem of autonomous recovery of the working state of the radar after encountering a single event upset (SOME) fault, avoid the interruption of the radar system's target tracking and monitoring caused by the SOME fault, improve the reliability of the spaceborne radar product in orbit, and has the advantages of simplicity, independence, flexibility and wide applicability.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] A method for autonomous recovery of the operational status of a spaceborne radar, wherein the spaceborne radar is mounted on a satellite and includes a DSP chip and embedded software running within the DSP chip, comprising the following steps:

[0006] S1. Determine the key variables for radar state recovery of the spaceborne radar;

[0007] S2. Add a key variable storage module to the embedded software to periodically store the latest data of the key variables for radar state recovery, and to periodically set the watchdog runaway monitoring flag and the overall pre-reset command flag.

[0008] S3. Add a logic branch submodule to the embedded software to read the watchdog overrun monitoring flag and the overall pre-reset command flag, and then execute the radar normal power-on startup initialization branch, the watchdog overrun reset branch, or the pre-reset command reset branch.

[0009] Preferably, the embedded software, in the order of program execution, includes: a DSP program loading module, an initialization module, a watchdog enable module, a main loop module, a watchdog feeding judgment module, and a watchdog reset module; wherein, the main loop module includes a watchdog feeding step, and the watchdog feeding judgment module determines whether the watchdog is successfully fed in each cycle of the main loop module. If the watchdog is successfully fed, the main loop module returns to the main loop module for repeated execution; otherwise, the watchdog reset module is executed and the system returns to the DSP program loading module for a reset operation; and...

[0010] The key variable storage module mentioned in step S2 is added to the successful dog-feeding process of the embedded software;

[0011] The logical branch submodule mentioned in step S3 is added to the initialization module of the embedded software.

[0012] Preferably, step S2 includes:

[0013] S21. Set the watchdog running away detection flag;

[0014] S22. Determine whether a pre-reset command has been received from the satellite system, and set the overall pre-reset command flag;

[0015] S23. Save the latest data of the key variables for radar state recovery.

[0016] Preferably, the spaceborne radar includes an FPGA RAM, and the watchdog runaway monitoring flag in step S21 is stored in the FPGA RAM.

[0017] Preferably, the spaceborne radar includes an MRAM, and the data of the overall pre-reset command flag and the key variables for radar state recovery in step S22 are stored in the MRAM.

[0018] Preferably, the overall pre-reset command flag and the key variable for radar state recovery in step S22 are both stored in a key variable data packet; wherein, the 0th element of the key variable data packet stores the overall pre-reset command flag.

[0019] Preferably, step S23 includes: sequentially filling the latest data of each of the radar state recovery key variables determined in step S1 into the key variable data packet for packetization, and storing the data packet after the stored overall pre-reset instruction flag.

[0020] Preferably, step S3 includes:

[0021] S31. Read the watchdog runaway monitoring flag stored in the most recent cycle;

[0022] S32. Read the overall pre-reset instruction flag stored in the most recent cycle;

[0023] S33. When the read watchdog runaway monitoring flag indicates that the program is in the watchdog runaway state, and the read overall pre-reset command flag indicates that no pre-reset command has been received, the program enters the watchdog runaway reset branch.

[0024] S34. When the read watchdog runaway monitoring flag indicates that the program is not in the watchdog runaway state, and the read overall pre-reset command flag indicates that a pre-reset command has been received, the program enters the pre-reset command reset branch.

[0025] S35. When the conditions of steps S33 and S34 are not met, the radar enters the normal power-on startup initialization branch and performs the normal power-on startup initialization operation.

[0026] Preferably, the spaceborne radar is also equipped with a watchdog timer for the number of times it has run away and reset.

[0027] Step S33 includes: reading the latest data of the key variables for radar state recovery and restoring the state of the spaceborne radar; and incrementing the watchdog run-and-reset count counter by 1;

[0028] Step S34 includes: reading the latest data of the key variables for radar state recovery and restoring the state of the spaceborne radar; and clearing the overall pre-reset command flag.

[0029] Preferably, in step S2, the storage of the latest data of the watchdog runaway monitoring flag, the overall pre-reset command flag, and the key variables for radar status recovery adopts triple-modular redundancy processing.

[0030] In step S3, the latest data of the watchdog runaway monitoring flag, the overall pre-reset command flag, and the radar state recovery key variables are read back from the three stored addresses and subjected to three judgments and two value selections.

[0031] In summary, compared with the prior art, the autonomous recovery method for the operational status of spaceborne radar provided by this invention has the following beneficial effects:

[0032] 1. By storing and retrieving the key variables required to restore the radar state, the problem of autonomous recovery of the system's working state when encountering a single-event upset fault in a spaceborne radar can be effectively solved.

[0033] 2. Based on software methods, without changing hardware resources, this invention can still be used, especially when the hardware is finalized and cannot be changed in the later stages of the development of spaceborne radar products;

[0034] 3. The degree and depth of the recovery of the operational status of the spaceborne radar can be determined simply by adding or deleting the number and content of the key variables for radar status recovery. The operation is simple and convenient, easy to implement, and easy to debug.

[0035] 4. There are no special requirements for programming languages; C, C++, and other programming languages ​​suitable for embedded software development are all applicable, providing flexibility in implementation.

[0036] 5. Not only is it applicable to the TMS320C6415 DSP chip, but its application can also be extended to other single-core or multi-core digital signal processing chips;

[0037] 6. This method is not only applicable to spaceborne radar products, but also to other types of spaceborne products that can autonomously recover from single-event upset failures. Attached Figure Description

[0038] Figure 1 A flowchart of existing spaceborne radar DSP embedded software;

[0039] Figure 2 This is a schematic diagram illustrating the selection of storage addresses for key variables in this invention;

[0040] Figure 3 This is a flowchart of the autonomous recovery method for the operational status of spaceborne radar according to the present invention. Detailed Implementation

[0041] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a further detailed explanation of the autonomous recovery method for the operational status of a spaceborne radar proposed in this invention. The advantages and features of this invention will become clearer from the following description. It should be noted that the accompanying drawings are in a very simplified form and use non-precise proportions, intended only to facilitate and clarify the illustration of the embodiments of this invention, and are not intended to limit the implementation conditions of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effects and objectives achieved by this invention, should still fall within the scope of the technical content disclosed in this invention.

[0042] It should be noted that, in this invention, relational terms such as "and" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only the expressly listed elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0043] Combined with appendix Figures 1-3 This invention provides a method for autonomously restoring the operational state of a spaceborne radar, used to restore the operational state of the spaceborne radar via software after a single-event upset fault occurs; wherein, the spaceborne radar is carried as a payload on a satellite, and the spaceborne radar includes a DSP (Digital Signal Processing) chip and embedded software running within the DSP chip, the embedded software being as shown in the attached figure. Figure 1 As shown, the program execution order includes: DSP program loading module, initialization module, watchdog enable module, main loop While(1) module, watchdog feeding judgment module, and watchdog reset module; wherein, the main loop While(1) module includes a watchdog feeding step, and the watchdog feeding judgment module is used to determine whether the watchdog is successfully fed in each cycle in the main loop While(1) module (i.e., whether the embedded software in the DSP chip is running normally by whether the watchdog feeding step is executed). If the watchdog is successfully fed, the watchdog feeding success process is entered and the main loop While(1) module is returned to be executed repeatedly; otherwise, the watchdog reset module is executed and the DSP program loading module is returned to perform a reset operation. The method provided by this invention includes the following steps:

[0044] S1. Determine the key variables for radar state recovery of the spaceborne radar;

[0045] Among them, the key variables for radar state recovery are the key variables and parameters that need to be saved for the autonomous recovery of the working state of the spaceborne radar. The number and content of these variables depend on the degree of recovery of the working state of the spaceborne radar. Generally, the deeper the degree of recovery required, the more key variables and the richer the content need to be saved; conversely, the fewer key variables and the simpler the content need to be saved. Furthermore, the key variables saved will vary depending on the spaceborne radar system. If the spaceborne radar system is a two-dimensional phased array, the key variables to be saved include radar working mode, working command, working parameters, beam control command, and beam control parameters. If the spaceborne radar system is a one-dimensional mechanical scan and one-dimensional phase scan, in addition to the key variables of the above categories, key variables such as control commands and control parameters related to the one-dimensional drive mechanism also need to be saved.

[0046] S2. A key variable storage module is added to the embedded software to periodically store the latest data of key variables for radar state recovery, and to periodically set the watchdog runaway monitoring flag and the overall pre-reset command flag. The watchdog runaway monitoring flag is used to indicate whether the DSP program has fed the watchdog normally and whether the program has run away. The overall pre-reset command flag is used to indicate whether the spaceborne radar has received a pre-reset command issued by the satellite (receiving a pre-reset command means that the satellite system needs the FPGA (Field Programmable Gate Array) and DSP software of the spaceborne radar to be reset together). Preferably, in this embodiment, the key variable storage module is added to the watchdog successful feeding process of the embedded software, that is, it is located after the main loop While(1) module. It is executed once in each program running cycle, and the stored key variables for radar state recovery are updated in each frame cycle to ensure that the latest data before the single-event upset fault is called when the working state of the spaceborne radar needs to be restored. The specific steps include:

[0047] S21. Install watchdog running away detection signs;

[0048] In this embodiment, the watchdog timer failure monitoring flag is stored in a designated address in the FPGA RAM (Field Programmable Gate Array Random Access Memory). Specifically, each program cycle writes a fixed value to the designated address in the FPGA RAM as a flag to monitor whether the watchdog timer has failed. When the program is reloaded and the initialization function is executed, the value at that designated address is read. If the value is the fixed value set for each cycle, it indicates that the data stored in the FPGA RAM has not been lost, meaning the FPGA program has not been reloaded. However, the DSP program, due to a single-event fault, has not been periodically fed, causing the FPGA to need to reload the DSP program, and the program is in a watchdog timer failure state. Otherwise, it indicates that the data stored in the FPGA RAM has been lost, meaning that both the FPGA and DSP programs need to be reloaded due to a power-on or overall radar system reset.

[0049] S22. Determine whether a pre-reset command has been received from the satellite system and set the overall pre-reset command flag;

[0050] Given the non-volatile nature of MRAM (Magnetic Random Access Memory) data, this embodiment preferably stores the data of the overall pre-reset command flag and the key variables for radar state recovery in designated addresses within the MRAM. This increases data security and, since the watchdog timer failure monitoring flag is stored in the FPGA RAM, storing them in different memories allows for effective differentiation of the operational status of the spaceborne radar and the operations to be performed, which is simple and easy to implement. In this embodiment, preferably, based on the number of key variables for radar state recovery determined in step S1, an array or structure of appropriate length is defined as a key variable data package to store the data of the overall pre-reset command flag and the key variables for radar state recovery. The 0th element of the key variable data package stores the overall pre-reset command flag, and different values ​​are assigned to the 0th element depending on whether the spaceborne radar has received the overall pre-reset command.

[0051] S23. Save the latest data of key variables for radar status recovery;

[0052] In this embodiment, the latest data of each radar state recovery key variable determined in step S1 is sequentially filled into the key variable data packet for packaging. Its storage location is located after the stored overall pre-reset command flag. When packaging, care should be taken to protect the data accuracy.

[0053] Preferably, as shown in the appendix Figure 2 As shown, in steps S21 to S23, the storage and retrieval of the latest data of the watchdog runaway monitoring flag, the overall pre-reset command flag, and the key variables for radar status recovery all adopt triple-modular redundancy processing. That is, each data is stored in three different addresses when stored, and when retrieved, it is read back from the three addresses and three judgments and two values ​​are taken to ensure the accuracy and anti-interference of the data. The three specific addresses involved are not subject to additional constraints, as long as the space between the three addresses is large enough to effectively store the data that needs to be saved.

[0054] S3. A logic branch submodule is added to the initialization module. The logic branch submodule reads the watchdog overrun monitoring flag and the overall pre-reset command flag, and then executes the radar normal power-on startup initialization branch, the watchdog overrun reset branch, or the pre-reset command reset branch accordingly. The radar normal power-on startup branch is executed after the system powers on. It enters this branch when the watchdog overrun monitoring flag indicates that the program is not in an overrun state and the overall pre-reset command flag indicates that no pre-reset command has been received. When the watchdog overrun monitoring flag indicates that the program is in an overrun state, it enters the watchdog overrun reset branch. When the overall pre-reset command flag indicates that a pre-reset command has been received, it enters the pre-reset command reset branch.

[0055] Including the following steps:

[0056] S31. Read the watchdog runaway detection flag stored in the most recent cycle;

[0057] S32. Read the overall pre-reset instruction flag stored in the most recent cycle;

[0058] S33. When the read watchdog runaway monitoring flag indicates that the program is in a runaway state, and the read overall pre-reset command flag indicates that no pre-reset command has been received, enter the watchdog runaway reset branch, including:

[0059] Based on the number, order, and related data protocols of the key variables involved in the assembly of the key variable data packets, the latest data of the key variables for radar state recovery are read and recovered sequentially to restore the previous working state of the spaceborne radar. Care must be taken to protect data accuracy during the reading process. In some embodiments, the spaceborne radar is also equipped with a watchdog reset counter to indicate the number of watchdog resets, and this counter is incremented by 1, allowing telemetry to detect the number of watchdog resets experienced by the spaceborne radar.

[0060] S34. When the read watchdog runaway monitoring flag indicates that the program is not in a runaway state, and the read overall pre-reset instruction flag indicates that a pre-reset instruction has been received, the program enters the pre-reset instruction reset branch, including:

[0061] According to the relevant data protocols involved in the assembly of key variable data packets, the latest data of key variables for radar status recovery are read and recovered in sequence to restore the previous working state of the spaceborne radar. During the reading, attention should be paid to protecting the accuracy of the data. The overall pre-reset command flag is cleared to prepare for the next reception of the pre-reset command.

[0062] S35. When the conditions of steps S33 and S34 are not met, enter the normal power-on startup initialization branch of the radar and perform the normal power-on startup initialization operation.

[0063] Preferably, when the triple-modular redundancy processing method is adopted in steps S21 to S23 to store data, in steps S31 to S34, the data is read from the three designated addresses of the FPGA RAM to read the watchdog runaway monitoring flag, and from the three designated addresses of the MRAM to read the data of the overall pre-reset instruction flag and the key variables of radar state recovery, and respectively, and performs three-judgment two-processing (as long as the data of two of the addresses are consistent, the correct data can be output), thereby increasing the accuracy and anti-interference of the data.

[0064] The method proposed in this invention is applicable not only to spaceborne radar but also to other satellite payloads. Through software design, it can achieve the effect of resisting single-event upset failures and autonomously restoring the working state.

[0065] Furthermore, in conjunction with the appendix Figure 3 As shown, taking the embedded software of a satellite-borne radar DSP of a certain type of satellite as an example (the DSP used is the TMS320 series product from TI, and the development environment is CCS5.3), a specific embodiment is provided for detailed explanation. The embedded software, in the order of program execution, includes: a DSP program loading module, an initialization module, a watchdog enable module, a main loop While(1) module, a watchdog feeding judgment module, and a watchdog reset module. The main loop While(1) module includes a watchdog feeding step. The watchdog feeding judgment module is used to determine whether the watchdog is successfully fed in each cycle of the main loop While(1) module. If the watchdog is successfully fed, the watchdog feeding success process is entered, and the main loop While(1) module is returned to repeat execution; otherwise, the watchdog reset module is executed, and the process returns to the DSP program loading module for reset operation. The steps are as follows:

[0066] 1. Identify the key radar state recovery variables that need to be saved to restore the radar's operational status.

[0067] 2. Add the key variable saving function fly_data_save() after the main loop While(1) module. This function is executed once in each frame cycle along with the main loop While(1) module.

[0068] 3. In the fly_data_save() function, based on the number of key variables for radar state recovery determined in step 1, an integer array of key variables of corresponding length, mram_keyvariable_save_array[], is defined as the key variable data packet. The 0th element of the key variable data packet is used to store the overall pre-reset instruction flag; if the overall pre-reset instruction is received, 0x88 is stored, otherwise 0x77 is stored. The other elements of the key variable data packet are sequentially assembled and filled by the key variables for radar state recovery to be saved determined in step 1, so that all the key variables for radar state recovery to be saved are saved into the key variable data packet.

[0069] 4. In the fly_data_save() function, write the filled key variable data packet to three different addresses in MRAM. The space between the three addresses needs to be large enough to completely fit the key variable data packet.

[0070] 5. In the fly_data_save() function, 0xAA is written to three specified addresses in the FPGA's RAM during each program cycle as a flag for the FPGA to reset the DSP after the watchdog timer runs out of control when the monitoring program encounters a single-event upset fault.

[0071] 6. After the DSP program loads the module and before entering the main program's while(1) loop, design an initialization function before_initial() (i.e., modify the original initialization module); design different branches in the before_initial() function to ensure that the program can run according to the correct branch in three cases: watchdog timer failure, receipt of overall pre-reset command, or normal radar power-on initialization.

[0072] 7. Design a key variable reading function read_fly_data() for autonomously restoring the radar's operating state. The specific content of this function is designed according to the order of assembling and filling the key variables for radar state restoration in step 3. It reads the contents stored in the key variable data packet in sequence to obtain the key variables for radar state restoration and restore the radar to its operating state.

[0073] 8. In the before_initial() function, first store the data from step 5 on the FPGA. The contents of the three specified addresses in RAM are read and processed using a three-factor judgment and two-factor judgment method. Next, the overall pre-reset instruction flag stored in the three specified addresses of MRAM in step 5 is read and processed using a three-factor judgment and two-factor judgment method. If the watchdog flyover monitoring flag is 0xAA and the overall pre-reset instruction flag is 0x77, it indicates that after a single-event upset (SWE) fault, the FPGA resets the DSP because the watchdog was not periodically fed. In this branch, the critical variable read function is executed to restore the working state of the spaceborne radar before the SWE fault, and the watchdog flyover reset count counter is incremented by 1. If the watchdog flyover monitoring flag is 0x00 and the overall pre-reset instruction flag is 0x88, it indicates that after a SWE fault, the satellite requires a joint reset by the FPGA and DSP software of the spaceborne radar, and a pre-reset instruction has been issued. In this branch, the critical variable read function is executed to autonomously restore the working state of the spaceborne radar before the SWE fault, and the overall pre-reset instruction flag stored in step 3 is cleared to 0. If neither of the above two branches is satisfied, it indicates that the spaceborne radar has been repowered, and the radar normal power-on initialization branch is executed.

[0074] In summary, the autonomous recovery method for the operational state of a spaceborne radar provided by this invention, implemented in software using an FPGA+DSP information processing architecture, is simple, reliable, and easy to implement, with minimal impact on the scale, complexity, coding, and debugging difficulty of the software. Furthermore, when a spaceborne radar product encounters a single-event upset (SWE) fault, by reading the saved key variable data, it can almost instantly restore the radar to its pre-SWE Fault operational state. This avoids the prolonged interruption of target tracking caused by recovery methods involving power-off restarts, re-searching for, intercepting, and tracking the target. The time overhead of this autonomous recovery method is typically in the millisecond range, effectively reducing the impact on the continuity of target monitoring and tracking during the radar's recovery process after encountering a SWE Fault, and effectively preventing mission interruptions caused by spaceborne radar encountering a non-self-healing SWE Fault.

[0075] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. A method for autonomous recovery of the operational status of a spaceborne radar, wherein the spaceborne radar is mounted on a satellite, and the spaceborne radar includes a DSP chip and embedded software running within the DSP chip, characterized in that... Including the following steps: S1. Determine the key variables for radar state recovery of the spaceborne radar; S2. Add a key variable storage module to the embedded software to periodically store the latest data of the key variables for radar state recovery, and to periodically set the watchdog runaway monitoring flag and the overall pre-reset command flag. S3. Add a logic branch submodule to the embedded software to read the watchdog overrun monitoring flag and the overall pre-reset command flag, and then execute the radar normal power-on startup initialization branch or the watchdog overrun reset branch or the pre-reset command reset branch. The embedded software, in the order of program execution, includes: a DSP program loading module, an initialization module, a watchdog enable module, a main loop module, a watchdog feeding judgment module, and a watchdog reset module. The main loop module includes a watchdog feeding step. The watchdog feeding judgment module determines whether the watchdog is successfully fed in each cycle of the main loop module. If the watchdog is successfully fed, the main loop module returns to the main loop module for repeated execution; otherwise, the watchdog reset module is executed, and the system returns to the DSP program loading module for a reset operation. The key variable storage module mentioned in step S2 is added to the successful dog-feeding process of the embedded software; The logical branch submodule mentioned in step S3 is added to the initialization module of the embedded software.

2. The autonomous recovery method for the operational status of spaceborne radar as described in claim 1, characterized in that, Step S2 includes: S21. Set the watchdog running away detection flag; S22. Determine whether a pre-reset command has been received from the satellite system, and set the overall pre-reset command flag; S23. Save the latest data of the key variables for radar state recovery.

3. The method for autonomous recovery of the operational status of spaceborne radar as described in claim 2, characterized in that, The spaceborne radar includes an FPGA RAM, and the watchdog runaway monitoring flag in step S21 is stored in the FPGA RAM.

4. The method for autonomous recovery of the operational status of spaceborne radar as described in claim 2, characterized in that, The spaceborne radar includes an MRAM, and the data of the overall pre-reset command flag and the key variables for radar state recovery in step S22 are stored in the MRAM.

5. The method for autonomous recovery of the operational status of spaceborne radar as described in claim 2, characterized in that, The overall pre-reset command flag and the key variables for radar state recovery mentioned in step S22 are both stored in the key variable data packet; wherein, the 0th element of the key variable data packet stores the overall pre-reset command flag.

6. The method for autonomous recovery of the operational status of a spaceborne radar as described in claim 5, characterized in that, Step S23 includes: sequentially filling the latest data of each of the radar state recovery key variables determined in step S1 into the key variable data packet for packetization, and storing the data packet after the stored overall pre-reset instruction flag.

7. The method for autonomous recovery of the operational status of a spaceborne radar as described in claim 1, characterized in that, Step S3 includes: S31. Read the watchdog runaway monitoring flag stored in the most recent cycle; S32. Read the overall pre-reset instruction flag stored in the most recent cycle; S33. When the read watchdog runaway monitoring flag indicates that the program is in the watchdog runaway state, and the read overall pre-reset command flag indicates that no pre-reset command has been received, the program enters the watchdog runaway reset branch. S34. When the read watchdog runaway monitoring flag indicates that the program is not in the watchdog runaway state, and the read overall pre-reset command flag indicates that a pre-reset command has been received, the program enters the pre-reset command reset branch. S35. When the conditions of steps S33 and S34 are not met, the radar enters the normal power-on startup initialization branch and performs the normal power-on startup initialization operation.

8. The method for autonomous recovery of the operational status of a spaceborne radar as described in claim 7, characterized in that, The spaceborne radar is also equipped with a watchdog timer for the number of times it runs and resets. Step S33 includes: reading the latest data of the key variables for radar state recovery and restoring the state of the spaceborne radar; and incrementing the watchdog run-and-reset count counter by 1; Step S34 includes: reading the latest data of the key variables for radar state recovery and restoring the state of the spaceborne radar; and clearing the overall pre-reset command flag.

9. The method for autonomous recovery of the operational status of a spaceborne radar as described in claim 1, characterized in that, In step S2, the storage of the latest data of the watchdog runaway monitoring flag, the overall pre-reset command flag, and the key variables for radar state recovery adopts triple-modular redundancy processing. In step S3, the latest data of the watchdog runaway monitoring flag, the overall pre-reset command flag, and the radar state recovery key variables are read back from the three stored addresses and subjected to three judgments and two value selections.

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