A Space Debris Sensing Method Based on Wide-Angle Staring Radar

Abstract

A space debris sensing method based on wide-angle staring radar, belonging to the field of spacecraft technology, includes the following steps: A wide-angle staring radar is installed on a satellite, with its power supply, communication, and timing provided by other onboard subsystems; debris is detected using the wide-angle staring radar; after detection, the radar stores multi-channel raw echo signals containing debris information in a storage medium, and transmits the raw echo signal data to a ground control system after rendezvous; the ground control system calculates the relative motion trajectory parameters of the debris, the coordinates of the debris target passing through the measurement plane, and the time. This invention is unaffected by ambient light, ground shadows, or weather conditions, has high detection efficiency, and its measurement range and accuracy are not limited by debris movement or ground station distance. It can cover space debris in different directions, has a wide detection range, and improves the accuracy of space debris positioning.

Description

Technical Field

[0001] This invention belongs to the field of spacecraft technology, specifically relating to a space debris sensing method based on wide-angle staring radar. Background Technology

[0002] With the development of human space activities, the amount of debris in space is increasing, posing a serious threat to spacecraft. The safe operation of spacecraft in space requires high-precision tracking, monitoring, and measurement of space debris, a process known as space debris sensing. Currently, commonly used space debris sensing methods employ visible light, laser, and radar detectors for detection and location. However, visible light detectors are affected by factors such as sunlight and target reflection, resulting in low detection efficiency; laser detectors have narrow beams and strong directionality, making them unable to cover space debris from different directions; and traditional radar detectors have low detection accuracy and sensitivity, leading to low accuracy in locating space debris. Summary of the Invention

[0003] To address the problems of low detection efficiency, inability to cover space debris in different directions, and low accuracy in locating space debris in existing space debris sensing methods that use visible light, laser, and radar detectors, this invention provides a space debris sensing method based on wide-angle staring radar.

[0004] The technical solution adopted by this invention to solve the technical problem is as follows:

[0005] The present invention provides a space debris sensing method based on wide-angle staring radar, which mainly includes the following steps:

[0006] S1: The wide-angle staring radar is installed on the satellite, and its power supply, communication and timing are provided by other subsystems on the satellite;

[0007] S2: Utilize wide-angle staring radar to detect debris. After the wide-angle staring radar detects debris, it stores the multi-channel raw echo signal with debris information into a storage medium and transmits the raw echo signal data to the ground command and control system after the rendezvous is completed.

[0008] S3: Calculate the relative motion trajectory parameters of the debris, the coordinates and time of the debris target passing through the measurement plane through the ground command and control system;

[0009] Define the measurement coordinate system: Origin O B O is the geometric center outside the satellite. B X B O B Y B O B Z B Passing through the origin O respectively B And it is parallel to and points in the same direction as the OX, OY, and OZ axes of the satellite's coordinate system; OB Y B Z B A plane is defined as a measurement plane;

[0010] Let the position of the transmitting antenna in the wide-angle staring radar transceiver array be (x, y) in the measurement coordinate system. T y T , z T The coordinates of the i-th receiving antenna are (x... i y i , z i If the coordinates of the debris's position across the measurement plane are (0, y0, z0), then the coordinates of the debris's scattering point at any time t are:

[0011]

[0012] In the formula, L0 is the distance between the debris and the position of the measured plane at t=0, V represents the relative velocity between the debris and the satellite, β represents the tilt angle, and α represents the deflection angle; when the wide-angle staring radar emits electromagnetic waves with wavelength λ, according to the Doppler effect, the Doppler frequency of the debris echo received by each antenna is... for:

[0013]

[0014] Among them, V T (t), V i (t) represents the radial velocity of the fragment relative to the transmitting antenna and the i-th receiving antenna, respectively:

[0015] V T (t)=[x T -x(t)]Vcosβcosα+[y T -y(t)]Vcosβsinα-[z T -z(t)]Vsinβ (3)

[0016] V i (t)=[x i -x(t)]Vcosβcosα+[y i -y(t)]Vcosβsinα-[z i -z(t)]Vsinβ (4)

[0017] Where, r T (t), r i (t) represents the slant distance from the transmitting antenna and the i-th receiving antenna to the debris, respectively:

[0018]

[0019] Because the slant distances from the debris to each receiving antenna are different, there is a phase difference between the debris echoes received by different receiving antennas at the same time; the phase difference between the debris echoes of the i-th and j-th (i≠j) receiving antennas is:

[0020]

[0021] Where, r j (t) represents the slant distance from the j-th receiving antenna to the debris:

[0022]

[0023] Where the coordinates of the j-th receiving antenna are (x... j ,y j ,z j );

[0024] The actual changes in the Doppler frequency of the debris echo and the phase difference between the receiving antennas over time during the rendezvous of the debris and the wide-angle staring radar were measured. An optimization method was then used to perform optimal fitting to obtain the measurement results of the debris's trajectory parameters. This represents the estimated Y-axis coordinate of the fragment's position in the measurement plane within the measurement coordinate system. This represents the estimated Z-axis coordinate of the fragment's position in the measurement plane within the measurement coordinate system. This represents an estimate of the relative velocity between the debris and the satellite. This represents the estimated distance between the debris and the position of the over-measured plane at time t=0. This represents the estimated value of the deflection angle. } represents the estimated inclination angle;

[0025] Using the relative velocity estimates between debris and satellite And the estimated distance between the debris and the over-measured plane at time t=0 The calculated time when the fragment passes through the measurement plane is:

[0026]

[0027] If the absolute time of the satellite timing is T when the fragment is at the position corresponding to L0. s Then the absolute time for the fragment to pass through the measuring plane is:

[0028]

[0029] Furthermore, in step S1, the power supply, data transmission interface, and CAN communication design of the wide-angle staring radar are specifically as follows:

[0030] (1) The power supply of the wide-angle staring radar is controlled by the whole satellite. The on-board power supply subsystem adopts a semi-regulated bus voltage regulation method to provide the wide-angle staring radar with a primary power supply of 33~48.5V and a primary bus power supply. At the same time, the whole satellite provides a +28V command power supply. The whole satellite controls the power-on operation of the wide-angle staring radar through OC commands. The satellite service provides two indirect OC commands to the wide-angle staring radar subsystem, namely the power-on command and the power-off command. The data commands are sent by the satellite service through the CAN bus.

[0031] (2) The data processor interface of the on-board data transmission subsystem adopts the LVDS interface. The FPGA of the wide-angle staring radar signal processor is connected to the on-board data transmission subsystem through two LVDS interfaces. When the wide-angle staring radar is working, it outputs two hot backup LVDS signals to connect to the main data transmission channel and the backup data transmission channel respectively. The main data transmission channel is connected to the main multiplexer, and the backup data transmission channel is connected to the backup multiplexer.

[0032] (3) The wide-angle staring radar signal processor receives the power-on and power-off commands from the satellite operator to control the power-on of the equipment. It transmits data commands, telemetry parameters, satellite broadcast time and GPS parameters through the CAN bus interface, and can output analog telemetry responses for wide-angle staring radar status monitoring. The wide-angle staring radar signal processor and the satellite operator transmit data commands through the CAN bus. The FPGA of the wide-angle staring radar signal processor and the CAN bus controller are connected through the low-frequency connector SN74LVTH245APW. The CAN bus controller adopts SJA1000. The CAN bus controller SJA1000 and the satellite operator are connected through the CAN bus level conversion chip PCA82C50. At the same time, two CAN bus paths are designed to back each other up.

[0033] Furthermore, in step S1, the specific process of CAN communication for the wide-angle staring radar is as follows:

[0034] S1.2.1: Rapid Polling Command: The satellite service sends a rapid polling command at a fixed frequency to inquire whether there is debris and the status of the wide-angle staring radar signal processor. The wide-angle staring radar needs to reply whether there is debris and send back the status of the wide-angle staring radar signal processor.

[0035] S1.2.2: Fragment Polling Command: When the satellite service receives a reply from the wide-angle staring radar indicating that there is fragmentation, it issues a fragment polling command. The wide-angle staring radar needs to reply with the gate frequency information. During transmission, the frame may be interrupted by the GNSS whole-second broadcast signal.

[0036] S1.2.3: Slowly varying polling command: The satellite service sends slowly varying polling commands at a fixed frequency to inquire about the status of the wide-angle staring radar signal processor. The wide-angle staring radar needs to transmit the working status of each module back. During transmission, the frame may be interrupted by the GNSS full-second broadcast signal.

[0037] S1.2.4: Indirect command: The wide-angle staring radar signal processor sends a control signal to the pulse transmitter to control the pulse transmitter to turn on and off, and at the same time sets the operating parameters of the wide-angle staring radar. The wide-angle staring radar must respond to the indirect command.

[0038] S1.2.5: GNSS full-second broadcast signal, sent once per second, with the highest priority, which may interrupt other communications. Wide-angle staring radar does not need to reply.

[0039] S1.2.6: Star service broadcast time, sent once per second, wide-angle staring radar does not need to reply.

[0040] Furthermore, in step S1, the specific procedures for time synchronization and timekeeping of the wide-angle staring radar are as follows:

[0041] S1.3.1: Continuously monitor the falling edge of the second pulse. If the falling edge of the second pulse is valid, determine whether the local timekeeping count is faster or slower than the second pulse. If the local timekeeping is faster than the second pulse, the second count remains unchanged and the microsecond counter is cleared to zero. Otherwise, it means that the local timekeeping is slower than the second pulse. In this case, the second count is incremented by 1 and the microsecond counter is cleared to zero. Once the second pulse is detected and the GNSS whole-second time synchronization flag is received, the system enters GNSS mode and assigns the second time to the second timer for second time update. Local timekeeping continues, and the satellite broadcast time will not be used for time synchronization in the future.

[0042] S1.3.2: If the second pulse is invalid, continue local timekeeping and monitor the satellite broadcast time update flag. If the satellite broadcast time update flag is valid, assign the second time of the satellite broadcast to the second counter, and assign the millisecond time of the satellite broadcast to the microsecond counter after conversion, perform satellite second and millisecond time updates, and continue local timekeeping; if the satellite broadcast time update flag is invalid, directly perform local timekeeping and continue to monitor the falling edge of the second pulse and the satellite broadcast time update flag.

[0043] S1.3.3: If the second pulse, GNSS whole second time synchronization flag, and satellite broadcast time update flag have been invalid since power-on, local timekeeping will continue.

[0044] Furthermore, in step S2, the typical workflow of wide-angle staring radar when detecting debris is as follows:

[0045] A typical workflow is used in scenarios where only one fragment is known to enter the detection range of a wide-angle staring radar at a specific time. The specific workflow is as follows:

[0046] S2.1.1: The satellite sends a power-on command to the wide-angle staring radar OC, powering on the wide-angle staring radar;

[0047] S2.1.2: After the wide-angle staring radar is powered on, it performs system initialization and self-test and then enters standby mode. During this period, the satellite service periodically polls the status of the wide-angle staring radar through the slow-change polling command and transmits the status of the wide-angle staring radar to the ground.

[0048] S2.1.3: According to the list of execution instructions, the satellite service sends a pulse transmitter power-on command to the wide-angle staring radar, and the wide-angle staring radar enters normal working mode;

[0049] S2.1.4: After entering normal working mode, the wide-angle staring radar automatically performs debris detection and echo data cyclic storage;

[0050] S2.1.5: After detecting debris, the wide-angle staring radar ends the DDR cyclic storage. When the rapid polling command arrives, it replies to the satellite service by setting the debris detection indication through the rapid polling response frame, and replies to the satellite service by setting the valid data storage flag bit of the storage area through the slow polling response frame.

[0051] S2.1.6: When the satellite operator detects debris in the rapid polling response frame, the satellite operator sends a debris polling command. The wide-angle staring radar frames the gate frequency points detected during the debris occurrence period and replies to the satellite operator through the debris polling response frame.

[0052] S2.1.7: After the satellite operator determines that the debris target has passed through the measurement plane, it sends a pulse transmitter shutdown command, and the wide-angle staring radar stops debris detection and returns to standby mode;

[0053] S2.1.8: The satellite service sends an indirect command, namely a data transmission command for the storage area. The wide-angle staring radar responds to the indirect command and transmits the data in the storage area to the fixed storage device of the on-board data transmission subsystem in LVDS transmission format for storage.

[0054] S2.1.9: The satellite service sends an OC shutdown command to power off the wide-angle staring radar;

[0055] S2.1.10: The ground sends a data download command based on the communication link status and the satellite's working status, downloading the data stored in the on-board data transmission subsystem to the ground command and control system. The ground command and control system parses and processes the data to obtain the relative motion trajectory parameters of the debris and the coordinates and time of the debris target passing through the measurement plane.

[0056] Furthermore, in S2.1.4, the pulse transmitter of the wide-angle staring radar transmits a single-frequency pulse signal into space, the radio frequency receiver receives multiple spatial echo signals, and transmits multiple eight-channel intermediate frequency signals to the signal processor. The signal processor processes the intermediate frequency signals sent by the radio frequency receiver, and performs FFT operations on all range gate acquisition signals within the detection range according to the range gate. After non-coherent accumulation of multiple data, the echo signal-to-noise ratio is calculated. The data of the range gate with the highest echo signal-to-noise ratio, as well as the data of three gates, one before and one after the maximum range gate, are written into the DDR for buffering.

[0057] Furthermore, in S2.1.5, if debris appears within the detection area of ​​the wide-angle staring radar, debris echoes will be transmitted to the radio frequency receiver through the receiving antenna. After processing by the radio frequency receiver, multi-channel intermediate frequency signals are generated and sent to the signal processor. When the signal processor performs FFT calculations on all range gates to calculate the echo signal-to-noise ratio, if debris is present, the echo signal-to-noise ratio will be higher than the threshold value. When 3 out of 5 frames exceed the threshold value, it is considered that debris has been detected. At this time, the DDR loop storage ends, and after storing for a period of time, the storage of this storage area ends. The storage area flag in the telemetry state is set to indicate that the current storage area has detected and stored valid data.

[0058] Furthermore, in S2.1.5, DDR storage space is limited, and space debris and satellites are both operating at high speed with short rendezvous times. A storage space with a capacity more than three times the storage rendezvous time is allocated as a debris echo data storage space. Three storage spaces are allocated within the entire DDR, which can store the echo data of three debris targets.

[0059] Furthermore, in step S2, the multi-shot sequential debris detection process of the wide-angle staring radar when detecting debris is as follows:

[0060] S2.2.1: The satellite sends a power-on command to the wide-angle staring radar OC, powering on the wide-angle staring radar;

[0061] S2.2.2: After the wide-angle staring radar is powered on, it performs system initialization and self-test;

[0062] S2.2.3: The satellite operator sends a pulse transmitter power-on command to the wide-angle staring radar, and the wide-angle staring radar enters normal operating mode;

[0063] S2.2.4: After entering normal working mode, the wide-angle staring radar automatically performs target detection and echo data cyclic storage;

[0064] S2.2.5: After detecting a debris target, the wide-angle staring radar completes the storage of one storage area and sets the corresponding storage area marker position;

[0065] S2.2.6: The wide-angle staring radar returns to the initial detection state, begins the detection of the second debris target, and after the second debris target is stored, it returns to the initial detection state again, and records 3 debris targets in sequence, and sets the corresponding storage area marker position.

[0066] S2.2.7: After determining that all three storage areas are full of valid data, the satellite operator sends a pulse transmitter shutdown command, and the wide-angle staring radar stops debris detection and returns to standby mode;

[0067] S2.2.8: The satellite service sends three indirect commands in sequence, namely the data transmission command for the storage area. The wide-angle staring radar responds to the indirect command and transmits the data in the corresponding storage area to the fixed storage device of the on-board data transmission subsystem for storage in LVDS transmission format.

[0068] S2.2.9: The satellite service sends an OC shutdown command to power off the wide-angle staring radar;

[0069] S2.2.10: The ground sends a data download command based on the communication link status and satellite operating status, downloading the data stored in the on-board data transmission subsystem to the ground command and control system. The ground command and control system parses and processes the data to obtain the relative motion trajectory parameters of the debris and the coordinates and time of the debris target passing through the measurement plane.

[0070] Furthermore, in step S2, the manual recording workflow for the wide-angle staring radar when detecting debris is as follows:

[0071] The manual recording mode is used to record the space environment in space for analysis of clutter or interference signals at different distances. In manual recording mode, the wide-angle staring radar no longer performs debris detection. When the wide-angle staring radar receives a manual recording command, it sequentially collects all distance space environment data and stores it in the storage area according to the gate sequence, enabling each gate to have data.

[0072] The beneficial effects of this invention are:

[0073] This invention utilizes a wide-angle staring radar on a space platform to achieve rendezvous and location measurements of small space debris. Specifically, a single-transmitter, multi-receiver wide-angle staring radar is installed on a satellite to stare at the airspace where small space debris may appear, acquiring debris echoes during rendezvous, and obtaining the relative motion trajectory parameters of the small space debris through signal processing. This radio measurement method of the invention is unaffected by ambient light, ground shadows, or weather conditions, resulting in high detection efficiency. Furthermore, the measurement range and accuracy of this invention are not limited by debris movement or ground station distance, allowing it to cover space debris from different directions, providing a wide detection range and improving the accuracy of space debris location. In addition, this invention has no moving parts, simplifying the implementation process and providing an effective detection and location method for high-precision measurement of space debris. Attached Figure Description

[0074] Figure 1 The flowchart of a space debris sensing method based on wide-angle staring radar provided by the present invention is shown.

[0075] Figure 2 This is a schematic diagram illustrating the interaction between the wide-angle staring radar and other onboard subsystems.

[0076] Figure 3 This is a circuit diagram for the CAN bus interface.

[0077] Figure 4 The logic flowchart for time synchronization reception.

[0078] Figure 5 This describes the characteristics of a second pulse signal.

[0079] Figure 6 This is a schematic diagram showing the connection between the wide-angle staring radar and the data transmission subsystem.

[0080] Figure 7 This is a diagram illustrating the address space of the storage area. Detailed Implementation

[0081] The present invention will be further described in detail below with reference to the accompanying drawings.

[0082] The present invention provides a space debris sensing method based on wide-angle staring radar. The measurement principle is as follows: conventional radar systems are difficult to complete debris acquisition and tracking measurement. Wide-angle staring radar is based on the indirect measurement principle of radial velocity-radial distance difference. It uses multi-channel wide-beam staring Doppler radar to detect high-speed space debris (hereinafter referred to as debris), obtains the Doppler frequency of the debris echo and the phase difference change history between receiving antennas, and then completes the measurement of the location, direction and time of the debris and other related trajectory parameters.

[0083] See Figure 1 The present invention provides a spatial debris sensing method based on wide-angle staring radar, the specific implementation process of which is as follows:

[0084] S1: The collaborative workflow between the wide-angle staring radar and other onboard subsystems;

[0085] like Figure 2 As shown, the wide-angle staring radar is installed on a satellite, which differs significantly from ground-based applications. Power supply, communication, and timing are all provided by other onboard subsystems. The wide-angle staring radar's design fully considers its interaction with these other onboard subsystems. Its specific implementation process is as follows:

[0086] S1.1: Power supply;

[0087] The power supply for the wide-angle staring radar is centrally controlled by the entire satellite. The onboard power supply subsystem employs a semi-regulated bus voltage regulation method, providing the wide-angle staring radar with a primary power supply of 33–48.5V (500mV ripple) via the primary bus. Simultaneously, the entire satellite provides a +28V command power supply, which controls the power-on operation of the wide-angle staring radar via OC commands. The satellite administrators provide two indirect OC commands (power-on command and power-off command) to the wide-angle staring radar subsystem. Data commands are transmitted by the satellite administrators via the CAN bus.

[0088] S1.2: CAN communication;

[0089] The wide-angle staring radar signal processor receives power-on / off commands from satellite operators to control the power-on of the equipment. It transmits data commands, telemetry parameters, satellite broadcast times, GPS parameters, and other parameters via the CAN bus interface, and can output analog telemetry data for wide-angle staring radar status monitoring. For example... Figure 3 As shown, the wide-angle staring radar signal processor and the satellite operator transmit data commands via a CAN bus. The FPGA of the wide-angle staring radar signal processor is connected to the CAN bus controller via a low-frequency connector SN74LVTH245APW. The CAN bus controller specifically uses the SJA1000, and the communication protocol must meet the customized communication protocol requirements of the satellite and the wide-angle staring radar. The SJA1000 CAN bus controller is connected to the satellite operator via a CAN bus level conversion chip PCA82C50. To ensure communication reliability, two CAN bus paths (CAN bus A and CAN bus B) are designed, serving as backups for each other to ensure normal communication between the satellite operator and the wide-angle staring radar. Commands sent via CAN bus A require a response via CAN bus A, and commands sent via CAN bus B require a response via CAN bus B.

[0090] The specific implementation process of CAN bus data transmission commands is as follows:

[0091] S1.2.1: Rapid Polling Command: The satellite service sends a rapid polling command at a fixed frequency to inquire whether there is debris and the status of the wide-angle staring radar signal processor. The wide-angle staring radar needs to reply whether there is debris and send back the status of the wide-angle staring radar signal processor.

[0092] S1.2.2: Fragment Polling Command: When the satellite operator receives a fast-changing polling command from the wide-angle staring radar and finds fragments, it issues a fragment polling command. The wide-angle staring radar needs to reply with the gate frequency information. Each transmission of the gate frequency information is 256 bytes, and a total of 38 CAN communication frames are transmitted. During transmission, the frames may be interrupted by the GNSS full-second broadcast signal.

[0093] S1.2.3: Slowly varying polling command: The satellite service sends a slowly varying polling command at a fixed frequency to inquire about the status of the wide-angle staring radar signal processor. The wide-angle staring radar needs to send back the working status of each module. The return is 29 bytes in total, 4 CAN communication frames. During the transmission, the frames may be interrupted by the GNSS full-second broadcast signal.

[0094] S1.2.4: Indirect command: The wide-angle staring radar signal processor sends a control signal to the pulse transmitter to control the pulse transmitter to turn on and off, and at the same time sets the operating parameters of the wide-angle staring radar. The wide-angle staring radar must respond to the indirect command.

[0095] S1.2.5: GNSS whole-second broadcast signal, sent once per second, with the highest priority, which may interrupt other communications. Wide-angle staring radar does not need to reply. In the design, the GNSS whole-second broadcast signal has the highest priority and may interrupt other communications. Only the reply to fragment polling command and the reply to slowly changing polling command are in multiple frames. After the communication is interrupted, the wide-angle staring radar will prioritize receiving the GNSS whole-second broadcast signal and continue to execute the interrupted communication after receiving it.

[0096] S1.2.6: Star service broadcast time, sent once per second, wide-angle staring radar does not need to reply.

[0097] S1.3: Timekeeping and Punctuality;

[0098] To obtain the accurate time when the measured debris passes through the measurement plane, the wide-angle staring radar needs to perform high-precision time synchronization and timekeeping. Time synchronization is provided uniformly by the satellite to ensure that all subsystems of the satellite operate on the same time. The onboard telemetry, tracking, and command (TT&C) subsystem provides a pulse-per-second (PPS), and then within a certain time interval, the satellite administrator broadcasts the corresponding GNSS time and satellite broadcast time to the wide-angle staring radar via the CAN bus. The wide-angle staring radar prioritizes using the pulse-per-second and GNSS time for time synchronization and performs timekeeping.

[0099] The entire logic flow of time synchronization reception is as follows: Figure 4 As shown, after power-on, the wide-angle staring radar performs local timekeeping, and the electrical reset ends at time 0. When the falling edge of the second pulse is valid, its signal waveform requirements are as follows. Figure 5 As shown, the radar collects the second pulse voltage. When the collected voltage is higher than 3V, it is determined to be a high level (1), and when the collected voltage is less than 0.5V, it is determined to be a low level (0). The fall time of the second pulse does not exceed 50ns, and the time range for maintaining the low level is between 0.8ms and 1.2ms.

[0100] The specific implementation process is as follows:

[0101] S1.3.1: Continuously monitor the falling edge of the second pulse. If the falling edge of the second pulse is valid, determine whether the local timekeeping count is faster or slower than the second pulse. The specific criterion is: if the value of the microsecond counter does not exceed 2, it means the local timekeeping is faster than the second pulse by less than 20µs. In this case, the second count remains unchanged, and the microsecond counter is reset to zero. Otherwise, it means the local timekeeping is slower than the second pulse. In this case, the second count is incremented by 1, and the microsecond counter is reset to zero. Once the second pulse is detected and the GNSS integer second synchronization flag is received (i.e., both the second pulse and the GNSS integer second synchronization flag arrive), GNSS mode is entered, and the second time is assigned to the second timer for second time update, continuing local timekeeping. Once GNSS mode is entered, timekeeping will no longer be performed using satellite broadcast time.

[0102] S1.3.2: If the second pulse is invalid, continue local timekeeping and monitor the satellite broadcast time update flag. If the satellite broadcast time update flag is valid, assign the second time of the satellite broadcast to the second counter, and assign the millisecond time of the satellite broadcast to the microsecond counter after conversion, perform satellite second and millisecond time updates, and continue local timekeeping. If the satellite broadcast time update flag is invalid, directly perform local timekeeping and continue monitoring the falling edge of the second pulse and the satellite broadcast time update flag.

[0103] S1.3.3: If the second pulse, GNSS whole second time synchronization flag, and satellite broadcast time update flag have been invalid since power-on, local timekeeping will continue.

[0104] S1.3.4: In addition, once a second pulse or a satellite broadcast time update flag is received, the time synchronization is considered valid, and the normal operation time synchronization indicator flag is set to high level. If the second pulse is detected to be invalid for 3 seconds, the second pulse status is high level. Once the second pulse is valid, it returns to low level and the status of the second pulse continues to be monitored.

[0105] S1.4: Data transmission interface;

[0106] like Figure 6 As shown, the data processor interface of the onboard data transmission subsystem specifically adopts the LVDS interface. The FPGA of the wide-angle staring radar signal processor is connected to the onboard data transmission subsystem through two LVDS interfaces. When the wide-angle staring radar is working, it simultaneously outputs two hot-backup LVDS signals (two LVDS31s) which are connected to the main data transmission channel and the backup data transmission channel respectively. The main data transmission channel is connected to the primary multiplexer, and the backup data transmission channel is connected to the backup multiplexer. The main data transmission channel and the backup data transmission channel are in a cold backup relationship.

[0107] S2: Wide-angle staring radar workflow and application methods;

[0108] All operations of the wide-angle staring radar are controlled by the satellite. Before the mission begins, all execution command lists and execution times are confirmed by the ground command and control system and then uploaded to the satellite via the communication link to complete the command upload. The satellite staff sends all execution commands to the wide-angle staring radar in sequence according to the command list, schedule, or command conditions, so that the wide-angle staring radar enters the corresponding working state.

[0109] To standardize the workflow of wide-angle staring radar, this invention designs three types of workflows: typical workflow, multi-shot sequential fragment detection workflow, and manual recording workflow.

[0110] S2.1: Typical workflow;

[0111] A typical workflow is used in scenarios where only one fragment is known to enter the detection range of a wide-angle staring radar at a specific time. This typical workflow represents the simplest workflow for a wide-angle staring radar mission, and its specific steps are as follows:

[0112] S2.1.1: The satellite sends a power-on command to the wide-angle staring radar OC, powering on the wide-angle staring radar;

[0113] S2.1.2: After the wide-angle staring radar is powered on, it performs system initialization and self-test. The self-test includes self-test of key modules such as the signal processor DDR cache module and ADC initialization self-test. After the self-test is successful, it enters standby mode. During this period, the satellite service periodically polls the status of the wide-angle staring radar through the slow-change polling command and transmits the status of the wide-angle staring radar to the ground.

[0114] S2.1.3: According to the list of execution instructions, the satellite service sends a pulse transmitter power-on command to the wide-angle staring radar, and the wide-angle staring radar enters normal working mode;

[0115] S2.1.4: After entering normal working mode, the wide-angle staring radar automatically performs debris detection and echo data cyclic storage;

[0116] Specifically, the pulse transmitter of the wide-angle staring radar (transmitter 1 or transmitter 2, with 2 transmission signals, selectable between 2 during operation) transmits a single-frequency pulse signal into space. The radio frequency receiver receives 8 spatial echo signals and transmits the 8 eight-channel intermediate frequency signals to the signal processor. The signal processor processes the intermediate frequency signals sent by the radio frequency receiver and performs FFT operations on all range gate acquisition signals within the detection range according to the range gate. After non-coherent accumulation of multiple data, the echo signal-to-noise ratio is calculated. The data of the range gate with the highest echo signal-to-noise ratio, as well as the data of 3 gates (one gate before and one gate after the maximum range gate), are written into the DDR for buffering.

[0117] S2.1.5: After detecting debris, the wide-angle staring radar ends the DDR cyclic storage. When the rapid polling command arrives, it replies to the satellite service by setting the debris detection indication through the rapid polling response frame, and replies to the satellite service by setting the valid data storage flag bit of the storage area through the slow polling response frame.

[0118] Specifically, if debris appears within the detection area of ​​the wide-angle staring radar, debris echoes will be transmitted to the radio frequency receiver through the receiving antenna. After processing by the radio frequency receiver, multi-channel intermediate frequency signals are generated and sent to the signal processor. When the signal processor performs FFT calculations on all range gates to calculate the echo signal-to-noise ratio, if debris is present, the echo signal-to-noise ratio will be higher than the threshold value. When 3 out of 5 frames exceed the threshold value, it is considered that debris has been detected. At this time, the DDR loop storage ends, and after storing for a period of time, the storage of this storage area ends. The storage area flag in the telemetry state is set to indicate that the current storage area has detected and stored valid data.

[0119] Due to limited DDR storage space and the high-speed operation of both space debris and satellites, rendezvous times are short. Therefore, a storage space with a capacity more than three times the rendezvous time is allocated as a debris echo data storage space. Three storage spaces are allocated within the entire DDR, capable of storing echo data from three debris targets. For example, the storage capacity of a single storage area can be set to 64MB, with the first 63MB used as a data storage area for debris echo data, and the last 1MB used as an information storage area for storing current wide-angle staring radar operating parameters, debris target information, and the target's initial storage position.

[0120] Taking the first storage area as an example, this section introduces the fragment echo data storage method, such as... Figure 7As shown, after entering normal operating mode, the wide-angle staring radar selects the three largest gate data and stores them cyclically in the data storage area according to the agreed frame format. When the storage address reaches "Echo Data Physical End Address 0x1F8_0000", it restarts storage from "First Storage Area Physical Start Address 0x000_0000". The data storage area capacity is 63MB. To prevent false alarms, the fragment detection threshold is set high. Therefore, when fragments are at a long distance, even if the wide-angle staring radar has received the echo signal but the echo signal has not exceeded the threshold, this segment of data is still valid. Therefore, in the design, 42MB is stored after fragment detection, and 21MB is reserved before fragment detection. When the storage address when fragment is detected is greater than 21MB, the real time start address of the echo data StartAddr_Time = Target Detection Start Address StartAddr_THD - 21MB; when the storage address when fragment is detected is less than 21MB, the real time start address of the echo data StartAddr_Time = Target Detection Start Address StartAddr_THD + 42MB. The physical end address of the first storage area is 0x200_0000.

[0121] S2.1.6: When the satellite operator detects debris in the rapid polling response frame, the satellite operator sends a debris polling command. The wide-angle staring radar frames the gate frequency points detected during the debris occurrence period and replies to the satellite operator through the debris polling response frame.

[0122] S2.1.7: After the satellite operator determines that the debris target has passed through the measurement plane, it sends a pulse transmitter shutdown command, and the wide-angle staring radar stops debris detection and returns to standby mode;

[0123] S2.1.8: The satellite service sends the indirect command "data transmission in storage area". The wide-angle staring radar responds to the indirect command and transmits the data in storage area to the fixed storage device of the on-board data transmission subsystem in LVDS transmission format for storage.

[0124] S2.1.9: The satellite service sends an OC shutdown command to power off the wide-angle staring radar;

[0125] S2.1.10: The ground sends a "data downlink" command based on the communication link status and satellite operating status, downloading the data stored in the on-board data transmission subsystem to the ground command and control system. The ground command and control system parses and processes the data to obtain the relative motion trajectory parameters of the debris and the coordinates and time of the debris target passing through the measurement plane.

[0126] S2.2: Multiple Sequential Fragmentation Detection Process;

[0127] The wide-angle staring radar's DDR design has three cache intervals, allowing it to store three fragmented targets consecutively. When it is determined that multiple fragmented targets will appear, a continuous multi-shot sequential fragmentation command table can be generated and uploaded during ground command generation.

[0128] Wide-angle staring radar requires detecting the echo signal of each individual debris, therefore it cannot detect multiple debris simultaneously; it can only detect consecutive debris targets spaced at certain intervals. If the interval between debris occurrences is greater than 10 seconds, the gate frequency data can be transmitted to the ground between two debris transmissions. If the interval between two debris transmissions is less than 10 seconds, only the raw echo data is recorded, and the gate frequency data is not transmitted. The gate frequency data is only used for rapid determination of debris trajectories and does not affect the estimation of trajectory parameters.

[0129] The wide-angle staring radar can detect three debris targets. After each detection, the wide-angle staring radar needs to return to the initial detection state to wait for target detection. When all three debris targets are detected, it also returns to the initial detection state, but the storage area is full, and no more data is stored. Multi-shot sequential debris detection follows a similar workflow to typical detection, with data download occurring after the three debris targets are detected. The specific workflow is as follows:

[0130] S2.2.1: The satellite sends a power-on command to the wide-angle staring radar OC, powering on the wide-angle staring radar;

[0131] S2.2.2: After the wide-angle staring radar is powered on, it performs system initialization and self-test;

[0132] S2.2.3: The satellite operator sends a power-on command for transmitter 1 or transmitter 2 to the wide-angle staring radar, and the wide-angle staring radar enters normal operating mode;

[0133] S2.2.4: After entering normal working mode, the wide-angle staring radar automatically performs target detection and echo data cyclic storage;

[0134] S2.2.5: After detecting a debris target, the wide-angle staring radar completes the storage of one storage area and sets the corresponding storage area marker position;

[0135] S2.2.6: The wide-angle staring radar returns to the initial detection state, begins the detection of the second debris target, and after the second debris target is stored, it returns to the initial detection state again, and records 3 debris targets in sequence, and sets the corresponding storage area marker position.

[0136] S2.2.7: After determining that all three storage areas are full of valid data, the satellite operator sends a pulse transmitter shutdown command, and the wide-angle staring radar stops debris detection and returns to standby mode;

[0137] S2.2.8: The satellite service sends three indirect commands in sequence, "data transmission in storage area". The wide-angle staring radar responds to the indirect command and transmits the data in the corresponding storage area to the fixed storage device of the on-board data transmission subsystem in LVDS transmission format for storage.

[0138] S2.2.9: The satellite service sends an OC shutdown command to power off the wide-angle staring radar;

[0139] S2.2.10: The ground sends a "data downlink" command based on the communication link status and satellite operating status, downloading the data stored in the on-board data transmission subsystem to the ground command and control system. The ground command and control system parses and processes the data to obtain the relative motion trajectory parameters of the debris and the coordinates and time of the debris target passing through the measurement plane.

[0140] S2.3: Manual admission workflow;

[0141] Manual recording is achieved through manual recording commands and can be performed in both standby and normal operating modes. Manual recording mode is used to record the space environment in space for analysis of clutter or interference signals at different distances. When the wide-angle staring radar receives a manual recording command, it sequentially collects all distance space environment data and stores it in the storage area according to the gate sequence.

[0142] During fragmentation detection, an FFT is performed on the echo data within all gates to calculate the echo signal-to-noise ratio (SNR) for each range gate. The data from the range gate with the highest SNR, along with the data from the gates before and after it (a total of three gates), are written to the DDR cache. In manual acquisition mode, the wide-angle staring radar no longer performs fragmentation detection. Upon receiving a manual acquisition command, all gates are divided into three gate segments, and the entire storage area is evenly distributed, ensuring that each gate has data. For example, this invention can be designed with 12 gates, and one storage area can store 680 frames of data. In manual acquisition, frames 1-170 store data for gates 1, 2, and 3; frames 171-340 store data for gates 4, 5, and 6; frames 341-510 store data for gates 7, 8, and 9; and frames 511-680 store data for gates 10, 11, and 12.

[0143] S3: Calculate the relative motion trajectory parameters of the debris, the coordinates of the debris target passing through the measurement plane, and the time;

[0144] Wide-angle staring radar's measurement plane is not constrained by the physical satellite's dimensions, resulting in a wide measurement range. Calculating the relative motion trajectory parameters of debris requires measuring the actual changes in the Doppler frequency of the debris echo and the phase difference between the receiving antennas over time during the intersection of the debris and the radar. Therefore, after detecting debris, it is necessary to store the multi-channel raw echo signal containing debris information in a storage medium. After the intersection, the raw echo signal data is transmitted to the ground command and control system for processing to obtain the debris's relative motion trajectory parameters. The specific implementation process is as follows:

[0145] First, define the measurement coordinate system as follows: Origin O B O is the geometric center outside the satellite. B X B O B Y B O B Z B Passing through the origin O respectively B And it is parallel to and points in the same direction as the OX, OY, and OZ axes of the satellite's coordinate system; O B Y B Z B A plane is defined as a measurement plane.

[0146] Let the position of the transmitting antenna in the wide-angle staring radar transceiver array be (x, y) in the measurement coordinate system. T y T , z T The coordinates of the i-th receiving antenna are (x... i y i , z i If the coordinates of the debris's position across the measurement plane are (0, y0, z0), then the coordinates of the debris's scattering point at any time t are:

[0147]

[0148] In the formula, L0 is the distance between the debris and the position of the measured plane at t=0, V represents the relative velocity between the debris and the satellite, β represents the tilt angle, and α represents the deflection angle. When the wide-angle staring radar emits electromagnetic waves with wavelength λ, according to the Doppler effect, the Doppler frequency of the debris echo received by each antenna is... for:

[0149]

[0150] Among them, V T (t), V i (t) represents the radial velocity of the fragment relative to the transmitting antenna and the i-th receiving antenna, respectively:

[0151] V T (t)=[xT -x(t)]Vcosβcosα+[y T -y(t)]Vcosβsinα-[z T -z(t)]Vsinβ(3)

[0152] V i (t)=[x i -x(t)]Vcosβcosα+[y i -y(t)]Vcosβsinα-[z i -z(t)]Vsinβ(4)

[0153] Where, r T (t), r i (t) represents the slant distance from the transmitting antenna and the i-th receiving antenna to the debris, respectively:

[0154]

[0155] On the other hand, due to the different slant distances from the debris to each receiving antenna, there is a phase difference between the debris echoes received by different receiving antennas at the same time; the phase difference between the debris echoes of the i-th and j-th (i≠j) receiving antennas is:

[0156]

[0157] Where, r j (t) represents the slant distance from the j-th receiving antenna to the debris:

[0158]

[0159] Where the coordinates of the j-th receiving antenna are (x... j ,y j ,z j ).

[0160] As shown in equations (2) and (7), the Doppler frequency of the debris echo and the phase difference between the receiving antennas change with time during the rendezvous between the debris and the wide-angle staring radar. The variation pattern is determined by the coordinates (y0, z0) across the measurement plane, the relative velocity V between the debris and the satellite, the deflection angle α, and the tilt angle β. For different {(y0, z0), V, L0, α, β}, the variation patterns of the Doppler frequency and the phase difference between the receiving antennas with time are also different. Therefore, as long as the actual variation curves of the Doppler frequency of the debris echo and the phase difference between the receiving antennas with time are measured during the rendezvous between the debris and the wide-angle staring radar, and the optimal fitting is performed using an optimization method, the measurement results of the debris's trajectory parameters can be obtained. in, This represents the estimated Y-axis coordinate of the fragment's position in the measurement plane within the measurement coordinate system. This represents the estimated Z-axis coordinate of the fragment's position in the measurement plane within the measurement coordinate system. This represents an estimate of the relative velocity between the debris and the satellite. This represents the estimated distance between the debris and the position of the over-measured plane at time t=0. This represents the estimated value of the deflection angle. This represents the estimated tilt angle.

[0161] Using the relative velocity estimates between debris and satellite And the estimated distance between the debris and the over-measured plane at time t=0 The time when the fragment passes through the measuring plane can be calculated as follows:

[0162]

[0163] If the absolute time of the satellite timing is T when the fragment is at the position corresponding to L0. s Then the absolute time for the fragment to pass through the measuring plane is:

[0164]

[0165] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for spatial debris perception based on wide-angle staring radar, characterized in that, Includes the following steps: S1: The wide-angle staring radar is installed on the satellite, and its power supply, communication and timing are provided by other subsystems on the satellite; S2: Utilize wide-angle staring radar to detect debris. After the wide-angle staring radar detects debris, it stores the multi-channel raw echo signal with debris information into a storage medium and transmits the raw echo signal data to the ground command and control system after the rendezvous is completed. S3: Calculate the relative motion trajectory parameters of the debris, the coordinates and time of the debris target passing through the measurement plane through the ground command and control system; Define the measurement coordinate system: Origin O B O is the geometric center outside the satellite. B X B O B Y B O B Z B Passing through the origin O respectively B And it is parallel to and points in the same direction as the OX, OY, and OZ axes of the satellite's coordinate system; O B Y B Z B A plane is defined as a measurement plane; Let the position of the transmitting antenna in the wide-angle staring radar transceiver array be (x, y) in the measurement coordinate system. T y T , z T The coordinates of the i-th receiving antenna are (x... i y i , z i If the coordinates of the debris's position across the measurement plane are (0, y0, z0), then the coordinates of the debris's scattering point at any time t are: In the formula, L0 is the distance between the debris and the position of the measured plane at t=0, V represents the relative velocity between the debris and the satellite, β represents the tilt angle, and α represents the deflection angle; When a wide-angle staring radar emits electromagnetic waves with wavelength λ, according to the Doppler effect, the Doppler frequency of the debris echo received by each antenna will be... for: Among them, V T (t), V i (t) represents the radial velocity of the fragment relative to the transmitting antenna and the i-th receiving antenna, respectively: V T (t)=[x T -x(t)]Vcosβcosα+[y T -y(t)]Vcosβsinα-[z T -z(t)]Vsinβ (3) V i (t)=[x i -x(t)]Vcosβcosα+[y i -y(t)]Vcosβsinα-[z i -z(t)]Vsinβ (4) Where, r T (t), r i (t) represents the slant distance from the transmitting antenna and the i-th receiving antenna to the debris, respectively: Because the slant distances from the debris to each receiving antenna are different, there is a phase difference between the debris echoes received by different receiving antennas at the same time; the phase difference between the debris echoes of the i-th and j-th (i≠j) receiving antennas is: Where, r j (t) represents the slant distance from the j-th receiving antenna to the debris: Where the coordinates of the j-th receiving antenna are (x... j ,y j ,z j ); The actual changes in the Doppler frequency of the debris echo and the phase difference between the receiving antennas over time during the rendezvous of the debris and the wide-angle staring radar were measured. An optimization method was then used to perform optimal fitting to obtain the measurement results of the debris's trajectory parameters. This represents the estimated Y-axis coordinate of the fragment's position in the measurement plane within the measurement coordinate system. This represents the estimated Z-axis coordinate of the fragment's position in the measurement plane within the measurement coordinate system. This represents an estimate of the relative velocity between the debris and the satellite. This represents the estimated distance between the debris and the position of the over-measured plane at time t=0. This represents the estimated value of the deflection angle. This represents the estimated inclination angle; Using the relative velocity estimates between debris and satellite And the estimated distance between the debris and the over-measured plane at time t=0 The calculated time when the fragment passes through the measurement plane is: If the absolute time of the satellite timing is T when the fragment is at the position corresponding to L0. s Then the absolute time for the fragment to pass through the measuring plane is:

2. The space debris sensing method based on wide-angle staring radar according to claim 1, characterized in that, In step S1, the power supply, data transmission interface, and CAN communication design of the wide-angle staring radar are specifically as follows: (1) The power supply of the wide-angle staring radar is controlled by the whole satellite. The on-board power supply subsystem adopts a semi-regulated bus voltage regulation method to provide the wide-angle staring radar with a primary power supply of 33~48.5V and a primary bus power supply. At the same time, the whole satellite provides a +28V command power supply. The whole satellite controls the power-on operation of the wide-angle staring radar through OC commands. The satellite service provides two indirect OC commands to the wide-angle staring radar subsystem, namely the power-on command and the power-off command. The data commands are sent by the satellite service through the CAN bus. (2) The data processor interface of the on-board data transmission subsystem adopts the LVDS interface. The FPGA of the wide-angle staring radar signal processor is connected to the on-board data transmission subsystem through two LVDS interfaces. When the wide-angle staring radar is working, it outputs two hot backup LVDS signals to connect to the main data transmission channel and the backup data transmission channel respectively. The main data transmission channel is connected to the main multiplexer, and the backup data transmission channel is connected to the backup multiplexer. (3) The wide-angle staring radar signal processor receives the power-on and power-off commands from the satellite operator to control the power-on of the equipment. It transmits data commands, telemetry parameters, satellite broadcast time and GPS parameters through the CAN bus interface, and can output analog telemetry responses for wide-angle staring radar status monitoring. The wide-angle staring radar signal processor and the satellite operator transmit data commands through the CAN bus. The FPGA of the wide-angle staring radar signal processor and the CAN bus controller are connected through the low-frequency connector SN74LVTH245APW. The CAN bus controller adopts SJA1000. The CAN bus controller SJA1000 and the satellite operator are connected through the CAN bus level conversion chip PCA82C50. At the same time, two CAN bus paths are designed to back each other up.

3. The space debris sensing method based on wide-angle staring radar according to claim 1, characterized in that, In step S1, the specific process of CAN communication for the wide-angle staring radar is as follows: S1.2.1: Rapid Polling Command: The satellite service sends a rapid polling command at a fixed frequency to inquire whether there is debris and the status of the wide-angle staring radar signal processor. The wide-angle staring radar needs to reply whether there is debris and send back the status of the wide-angle staring radar signal processor. S1.2.2: Fragment Polling Command: When the satellite service receives a reply from the wide-angle staring radar indicating that there is fragmentation, it issues a fragment polling command. The wide-angle staring radar needs to reply with the gate frequency information. During transmission, the frame may be interrupted by the GNSS whole-second broadcast signal. S1.2.3: Slowly varying polling command: The satellite service sends slowly varying polling commands at a fixed frequency to inquire about the status of the wide-angle staring radar signal processor. The wide-angle staring radar needs to transmit the working status of each module back. During transmission, the frame may be interrupted by the GNSS full-second broadcast signal. S1.2.4: Indirect command: The wide-angle staring radar signal processor sends a control signal to the pulse transmitter to control the pulse transmitter to turn on and off, and at the same time sets the operating parameters of the wide-angle staring radar. The wide-angle staring radar must respond to the indirect command. S1.2.5: GNSS full-second broadcast signal, sent once per second, with the highest priority, which may interrupt other communications. Wide-angle staring radar does not need to reply. S1.2.6: Star service broadcast time, sent once per second, wide-angle staring radar does not need to reply.

4. A spatial debris sensing method based on wide-angle staring radar according to claim 1, characterized in that, In step S1, the specific procedures for time synchronization and timekeeping of the wide-angle staring radar are as follows: S1.3.1: Continuously monitor the falling edge of the second pulse. If the falling edge of the second pulse is valid, determine whether the local timekeeping count is faster or slower than the second pulse. If the local timekeeping is faster than the second pulse, the second count remains unchanged and the microsecond counter is cleared. Otherwise, it means that the local timekeeping is slower than the second pulse. In this case, the second count is incremented by 1 and the microsecond counter is cleared. Once the second pulse is detected and the GNSS whole-second time synchronization flag is received, the system enters GNSS mode and assigns the second time to the second timer for second time update. Local timekeeping continues, and the satellite broadcast time will no longer be used for time synchronization. S1.3.2: If the second pulse is invalid, continue local timekeeping and monitor the satellite broadcast time update flag. If the satellite broadcast time update flag is valid, assign the second time of the satellite broadcast to the second counter, and assign the millisecond time of the satellite broadcast to the microsecond counter after conversion, perform satellite second and millisecond time updates, and continue local timekeeping; if the satellite broadcast time update flag is invalid, directly perform local timekeeping and continue to monitor the falling edge of the second pulse and the satellite broadcast time update flag. S1.3.3: If the second pulse, GNSS whole second time synchronization flag, and satellite broadcast time update flag have been invalid since power-on, local timekeeping will continue.

5. A spatial debris sensing method based on wide-angle staring radar according to claim 1, characterized in that, In step S2, the typical workflow of wide-angle staring radar when detecting debris is as follows: A typical workflow is used in scenarios where only one fragment is known to enter the detection range of a wide-angle staring radar at a specific time. The specific workflow is as follows: S2.1.1: The satellite sends a power-on command to the wide-angle staring radar OC, powering on the wide-angle staring radar; S2.1.2: After the wide-angle staring radar is powered on, it performs system initialization and self-test and then enters standby mode. During this period, the satellite service periodically polls the status of the wide-angle staring radar through the slow-change polling command and transmits the status of the wide-angle staring radar to the ground. S2.1.3: According to the list of execution instructions, the satellite service sends a pulse transmitter power-on command to the wide-angle staring radar, and the wide-angle staring radar enters normal working mode; S2.1.4: After entering normal working mode, the wide-angle staring radar automatically performs debris detection and echo data cyclic storage; S2.1.5: After detecting debris, the wide-angle staring radar ends the DDR cyclic storage. When the rapid polling command arrives, it replies to the satellite service by setting the debris detection indication through the rapid polling response frame, and replies to the satellite service by setting the valid data storage flag bit of the storage area through the slow polling response frame. S2.1.6: When the satellite operator detects debris in the rapid polling response frame, the satellite operator sends a debris polling command. The wide-angle staring radar frames the gate frequency points detected during the debris occurrence period and replies to the satellite operator through the debris polling response frame. S2.1.7: After the satellite operator determines that the debris target has passed through the measurement plane, it sends a pulse transmitter shutdown command, and the wide-angle staring radar stops debris detection and returns to standby mode; S2.1.8: The satellite service sends an indirect command, namely a data transmission command for the storage area. The wide-angle staring radar responds to the indirect command and transmits the data in the storage area to the fixed storage device of the on-board data transmission subsystem in LVDS transmission format for storage. S2.1.9: The satellite service sends an OC shutdown command to power off the wide-angle staring radar; S2.1.10: The ground sends a data download command based on the communication link status and the satellite's working status, downloading the data stored in the on-board data transmission subsystem to the ground command and control system. The ground command and control system parses and processes the data to obtain the relative motion trajectory parameters of the debris and the coordinates and time of the debris target passing through the measurement plane.

6. A spatial debris sensing method based on wide-angle staring radar according to claim 5, characterized in that, In S2.1.4, the pulse transmitter of the wide-angle staring radar transmits a single-frequency pulse signal into space. The radio frequency receiver receives multiple spatial echo signals and transmits multiple eight-channel intermediate frequency signals to the signal processor. The signal processor processes the intermediate frequency signals sent by the radio frequency receiver and performs FFT operations on all range gate acquisition signals within the detection range according to the range gate. After non-coherent accumulation of multiple data, the echo signal-to-noise ratio is calculated. The data of the range gate with the highest echo signal-to-noise ratio, as well as the data of three gates (one before and one after the maximum range gate) are written into the DDR for buffering.

7. A spatial debris sensing method based on wide-angle staring radar according to claim 5, characterized in that, In S2.1.5, if debris appears within the detection area of ​​the wide-angle staring radar, debris echoes will be transmitted to the radio frequency receiver through the receiving antenna. After processing by the radio frequency receiver, multi-channel intermediate frequency signals are generated and sent to the signal processor. When the signal processor performs FFT calculations on all range gates to calculate the echo signal-to-noise ratio, if debris is present, the echo signal-to-noise ratio will be higher than the threshold value. When 3 out of 5 frames exceed the threshold value, it is considered that debris has been detected. At this time, the DDR loop storage ends, and after storing for a period of time, the storage of this storage area ends. The storage area flag in the telemetry state is set to indicate that the current storage area has detected and stored valid data.

8. A spatial debris sensing method based on wide-angle staring radar according to claim 5, characterized in that, In S2.1.5, DDR storage space is limited. Space debris and satellites are both operating at high speeds with short rendezvous times. A storage space with a capacity more than three times the rendezvous time is allocated as a debris echo data storage space. Three storage spaces are allocated within the entire DDR, which can store the echo data of three debris targets.

9. A spatial debris sensing method based on wide-angle staring radar according to claim 1, characterized in that, In step S2, the multi-shot sequential debris detection process of the wide-angle staring radar when detecting debris is as follows: S2.2.1: The satellite sends a power-on command to the wide-angle staring radar OC, powering on the wide-angle staring radar; S2.2.2: After the wide-angle staring radar is powered on, it performs system initialization and self-test; S2.2.3: The satellite operator sends a pulse transmitter power-on command to the wide-angle staring radar, and the wide-angle staring radar enters normal operating mode; S2.2.4: After entering normal working mode, the wide-angle staring radar automatically performs target detection and echo data cyclic storage; S2.2.5: After detecting a debris target, the wide-angle staring radar completes the storage of one storage area and sets the corresponding storage area marker position; S2.2.6: The wide-angle staring radar returns to the initial detection state, begins the detection of the second debris target, and after the second debris target is stored, it returns to the initial detection state again, and records 3 debris targets in sequence, and sets the corresponding storage area marker position. S2.2.7: After determining that all three storage areas are full of valid data, the satellite operator sends a pulse transmitter shutdown command, and the wide-angle staring radar stops debris detection and returns to standby mode; S2.2.8: The satellite service sends three indirect commands in sequence, namely the data transmission command for the storage area. The wide-angle staring radar responds to the indirect command and transmits the data in the corresponding storage area to the fixed storage device of the on-board data transmission subsystem for storage in LVDS transmission format. S2.2.9: The satellite service sends an OC shutdown command to power off the wide-angle staring radar; S2.2.10: The ground sends a data download command based on the communication link status and satellite operating status, downloading the data stored in the on-board data transmission subsystem to the ground command and control system. The ground command and control system parses and processes the data to obtain the relative motion trajectory parameters of the debris and the coordinates and time of the debris target passing through the measurement plane.

10. A spatial debris sensing method based on wide-angle staring radar according to claim 1, characterized in that, In step S2, the manual recording workflow of the wide-angle staring radar when detecting debris is as follows: The manual recording mode is used to record the space environment in space to analyze clutter or interference signals at different distances; in the manual recording mode, the wide-angle staring radar no longer performs debris detection. When the wide-angle staring radar receives the manual recording command, it sequentially collects all distance space environment data and stores them in the storage area according to the gate sequence, enabling each gate to have data.

Images