Space debris sensing method based on wide-angle staring radar

Abstract

A space debris sensing method based on a wide-angle staring radar belongs to the technical field of spacecrafts and comprises the following steps that the wide-angle staring radar is installed on a satellite, and power supply, communication and time service of the wide-angle staring radar are all provided by other subsystems on the satellite; a wide-angle staring radar is used for detecting fragments, after the wide-angle staring radar detects the fragments, multi-channel original echo signals with fragment information are stored in a storage medium, and the original echo signal data are transmitted to a ground command and control system after rendezvous is finished; and the ground command and control system calculates relative movement track parameters of the fragments and coordinates and moments of the fragment targets passing through the measurement plane. The method is not influenced by sunshine and shadow and meteorological conditions, the detection efficiency is high, the measurement range and precision are not restricted by debris movement and ground station distance, space debris in different directions can be covered, the detection range is wide, and the space debris positioning accuracy is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of spacecraft, and in particular relates to a space debris sensing method based on wide-angle staring radar. Background Art

[0002] With the development of human space activities, the number 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, which is summarized as space debris perception. Currently, commonly used space debris perception mostly uses visible light, laser, and radar detectors for detection and positioning. Among them, visible light detectors are affected by factors such as sunlight and target reflection, and have low detection efficiency; laser detectors have narrow beams and strong directionality, and cannot cover space debris in different directions; traditional radar detectors have low detection accuracy and sensitivity, resulting in low accuracy in locating space debris. Summary of the invention

[0003] In order to solve the problems of low detection efficiency, inability to cover space debris in different directions, and low accuracy in locating space debris in the existing space debris perception using visible light, laser, and radar detectors for detection and positioning, the present invention provides a space debris perception method based on wide-angle staring radar.

[0004] The technical solution adopted by the present 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: Install the wide-angle staring radar on the satellite. The power supply, communication and timing of the wide-angle staring radar are provided by other subsystems on the satellite.

[0007] S2: Use wide-angle staring radar to detect debris. After the wide-angle staring radar detects the debris, it stores the multi-channel original echo signal with the debris information in the storage medium, and transmits the original 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 when the debris target passes through the measurement plane through the ground command and control system;

[0009] Define the measurement coordinate system: coordinate origin O B is the geometric center of the satellite, O B X B , O B Y B , O B Z B Passing through the origin O B And it is parallel to the OX, OY, and OZ axes of the satellite body coordinate system and points in the same direction;B Y B Z B The plane is defined as the measurement plane;

[0010] Assume that in the measurement coordinate system, the position of the transmitting antenna in the wide-angle staring radar transceiver antenna array is (x T ,y T , z T ), the coordinates of the i-th receiving antenna are (x i ,y i , z i ), the coordinates of the fragment's position through the measurement plane are (0, y0, z0), then the coordinates of the fragment's scattering point at any time t are:

[0011]

[0012] Where L0 is the distance between the debris and the position of the measurement plane at time t = 0, V is the relative speed between the debris and the satellite, β is the inclination, and α is the deflection. When the wide-angle staring radar emits electromagnetic waves with a wavelength of 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) are the radial velocities of the debris 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] Among them, r T (t), r i (t) are the slant distances from the transmitting antenna and the i-th receiving antenna to the debris:

[0018]

[0019] Since 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 of the debris echo between the i-th and j-th (i≠j) receiving antennas is:

[0020]

[0021] Among them, r j (t) is the slant distance from the jth receiving antenna to the debris:

[0022]

[0023] Among them, the coordinates of the jth receiving antenna are (x j ,y j ,z j );

[0024] The actual variation curve of the Doppler frequency of the debris echo and the phase difference between the receiving antennas over time during the rendezvous between the debris and the wide-angle staring radar is measured, and the optimal fitting is performed using the optimization method to obtain the measurement results of the motion trajectory parameters of the debris. It represents the estimated Y-axis coordinate of the debris position through the measurement plane in the measurement coordinate system. It represents the estimated Z-axis coordinate of the debris position through the measurement plane in the measurement coordinate system. represents the estimated relative velocity between the debris and the satellite, represents the estimated distance between the debris and the position of the measurement plane at time t = 0, represents the estimated value of the deflection angle, } represents the estimated value of the inclination;

[0025] Using the relative velocity estimate between the debris and the satellite and the estimated distance between the debris and the position of the through-measurement plane at time t = 0 The time when the fragment passes through the measurement plane is calculated as:

[0026]

[0027] If the debris is at the corresponding position of L0, the absolute time of the whole satellite timing is T s , then the absolute time for the debris to pass through the measurement 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 uniformly controlled by the entire satellite. The onboard power supply subsystem adopts a semi-regulated bus voltage regulation method to provide a primary power supply of 33~48.5V and a primary bus power supply to the wide-angle staring radar. At the same time, the entire satellite provides a +28V command power supply. The entire 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 command is sent by the satellite service through the CAN bus.

[0031] (2) The data processor interface of the satellite data transmission subsystem adopts the LVDS interface, and the wide-angle staring radar signal processor FPGA is connected to the satellite data transmission subsystem through two LVDS interfaces; when the wide-angle staring radar is working, two hot backup LVDS signals are output simultaneously to connect the main digital transmission channel and the backup digital transmission channel respectively, and the main digital transmission channel is connected to the main multiplexer, and the backup digital transmission channel is connected to the backup multiplexer;

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

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

[0034] S1.2.1: Rapidly changing polling command: The satellite service sends a rapidly changing 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 transmit the status of the wide-angle staring radar signal processor back;

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

[0036] S1.2.3: Slowly changing polling command: The satellite service sends a slowly changing 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 frames during transmission 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 set the working 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: Satellite broadcast time, sent once per second, wide-angle staring radar does not need to reply.

[0040] Furthermore, in step S1, the specific process of timing and time keeping of the wide-angle staring radar is 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. Otherwise, it means that the local timekeeping is slower than the second pulse. At this time, add 1 to the second count and clear the microsecond counter. Once the second pulse is detected and the GNSS whole second synchronization mark is received, enter the GNSS mode, assign the second time to the second timer to update the second time, and continue to keep local time. Subsequently, the satellite service broadcast time will not be used for timekeeping.

[0042] S1.3.2: If the second pulse is invalid, continue to keep local time 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, update the satellite second and millisecond time, and continue to keep local time. If the satellite broadcast time update flag is invalid, directly keep local time 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 be performed all the time.

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

[0045] A typical workflow usage scenario is to determine a scenario where it is known that only one fragment enters the wide-angle staring radar detection range at a specific time. The specific workflow is as follows:

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

[0047] S2.1.2: After the wide-angle staring radar is powered on, it will enter standby mode after system initialization and self-test. During this period, the satellite service will periodically poll the wide-angle staring radar status through slowly changing polling instructions and transmit the wide-angle staring radar status to the ground;

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

[0049] S2.1.4: After entering the 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 fast-changing polling instruction comes, the detected debris indication is replied to the satellite service by setting the fast-changing polling response frame, and the valid data storage flag of the storage area is replied to the satellite service by setting the slow-changing polling response frame status;

[0051] S2.1.6: The satellite service determines that the rapid variable polling response frame detects debris, and the satellite service sends a debris polling command. The wide-angle staring radar frames the gate frequencies detected during the period when the debris appears in sequence and replies to the satellite service through the debris polling response frame;

[0052] S2.1.7: After the satellite service determines that the debris target passes 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, i.e., a storage area data transmission command. 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 satellite data transmission subsystem in accordance with the LVDS transmission format for storage;

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

[0055] S2.1.10: The ground sends data download instructions based on the communication link status and satellite working status, downloading the data stored in the onboard data transmission subsystem to the ground command and control system. The ground command and control system parses and processes the data to obtain the debris relative motion trajectory parameters and the coordinates and time when the debris target passes 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 RF 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 signal sent by the RF receiver, and performs FFT operation 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, and the range gate with the largest echo signal-to-noise ratio and the data of the three gates before and after the maximum range gate are selected and written into the DDR for caching.

[0057] Furthermore, in S2.1.5, if debris appears in the wide-angle staring radar detection area, the debris echo will be transmitted to the RF receiver through the receiving antenna. After being processed by the RF receiver, a multi-channel intermediate frequency signal is generated to the signal processor. When the signal processor performs FFT operation on all range gates to solve the echo signal-to-noise ratio, if there is debris, the echo signal-to-noise ratio will be higher than the threshold value. When 3 frames out of 5 frames exceed the threshold value, it is considered that fragments are detected. At this time, the cyclic storage in the DDR ends, and the storage of the storage area ends after a period of time, and the storage area flag in the telemetry state is set to indicate that the current storage area detects and stores valid data.

[0058] Furthermore, in S2.1.5, the DDR storage space is limited, the space debris and the satellite are both running at high speed, and the rendezvous time is short. A storage space with a capacity of more than 3 times the rendezvous time is opened up as a debris echo data storage space. Three storage spaces are opened up in the entire DDR, which can store 3 debris target echo data.

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

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

[0061] S2.2.2: After the wide-angle staring radar is powered on, the system is initialized and self-checked;

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

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

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

[0065] S2.2.6: The wide-angle staring radar returns to the initial detection state and starts detecting the second debris target. After completing the storage of the second debris target, it returns to the initial detection state, records three debris targets in sequence, and sets the corresponding storage area flags;

[0066] S2.2.7: After the satellite service determines that all three storage areas are full of valid data, it 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 instructions in sequence, namely, the storage area data transmission instructions. The wide-angle staring radar responds to the indirect instructions and transmits the data in the corresponding storage area in accordance with the LVDS transmission format to the fixed storage device of the onboard data transmission subsystem for storage;

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

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

[0070] Furthermore, in step S2, the manual recording workflow of 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 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 instruction, it collects all distance space environment data in sequence according to the gate order and stores them in the storage area, so that each gate has data.

[0072] The beneficial effects of the present invention are:

[0073] The present invention uses a wide-angle staring radar for a space platform to achieve rendezvous and positioning 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, obtain the debris echoes during the rendezvous process, and obtain the relative motion trajectory parameters of the small space debris through signal processing. This radio measurement method of the present invention is not affected by sky light, ground shadows, and meteorological conditions, and has high detection efficiency. At the same time, the measurement range and accuracy of the present invention are not restricted by the movement of debris and the distance from the ground station, and can cover space debris in different directions. The detection range is wide, and the accuracy of positioning space debris is improved. In addition, the present invention has no moving parts, and the implementation process is simple, which provides an effective detection and positioning method for high-precision measurement of space debris. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] Figure 1 A flow chart of a space debris perception method based on wide-angle staring radar provided by the present invention.

[0075] Figure 2 Schematic diagram of the interaction between the wide-angle staring radar and other subsystems on board.

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

[0077] Figure 4 This is the logical flow chart of timing reception.

[0078] Figure 5 It is the characteristic of pulse-per-second signal.

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

[0080] Figure 7 A schematic diagram of the storage area address. DETAILED DESCRIPTION

[0081] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0082] The present invention provides a space debris sensing method based on wide-angle staring radar, and its measurement principle is that conventional radar systems are difficult to complete debris capture and tracking measurement. The wide-angle staring radar is based on the radial velocity-radial distance difference indirect measurement principle, and uses a multi-channel wide-beam staring Doppler radar to detect high-speed space debris (hereinafter referred to as debris), obtain the Doppler frequency of the debris echo and the phase difference change history between receiving antennas, and then complete the measurement of relevant trajectory parameters such as the position, direction and time of the debris.

[0083] See also Figure 1 To illustrate, a method for sensing space debris based on a wide-angle staring radar according to the present invention has the following specific implementation process:

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

[0085] like Figure 2 As shown in the figure, the wide-angle staring radar is installed on the satellite, which is quite different from the ground application. The power supply, communication and timing are all provided by other subsystems on the satellite. The wide-angle staring radar fully considers the interactive work design with other subsystems on the satellite. The specific implementation process is as follows:

[0086] S1.1: Power supply;

[0087] The power supply of the wide-angle staring radar is uniformly controlled by the whole satellite. The on-board power supply subsystem adopts a semi-regulated bus voltage regulation method to provide a primary power supply of 33-48.5V (ripple 500mV) and a primary bus power supply to the wide-angle staring radar. At the same time, the whole satellite provides a +28V command power supply, and 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 (power-on command and power-off command) to the wide-angle staring radar subsystem, and the data command is sent by the satellite service through the CAN bus.

[0088] S1.2: CAN communication;

[0089] The wide-angle staring radar signal processor receives the on / off command from the star service to control the power on of the equipment, transmits data command, telemetry parameters, the time of star service broadcast, GPS and other parameters through the CAN bus interface, and can output analog telemetry for wide-angle staring radar status monitoring. Figure 3 As shown in the figure, the wide-angle staring radar signal processor transmits data instructions to the satellite service through the CAN bus, and the wide-angle staring radar signal processor FPGA is connected to the CAN bus controller through the low-frequency connector SN74LVTH245APW. The CAN bus controller specifically adopts SJA1000, and the communication protocol must meet the customized communication protocol requirements of the satellite and the wide-angle staring radar. The CAN bus controller SJA1000 is connected to the satellite service through the CAN bus level conversion chip PCA82C50. In order to ensure the reliability of communication, two CAN bus channels (CAN bus A and CAN bus B) are designed, including A and B channels, which backup each other to ensure normal communication between the satellite service and the wide-angle staring radar. Instructions sent through CAN bus A need to be replied through CAN bus A, and instructions sent through CAN bus B need to be replied through CAN bus B.

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

[0091] S1.2.1: Rapidly changing polling command: The satellite service sends a rapidly changing 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 transmit the status of the wide-angle staring radar signal processor back;

[0092] S1.2.2: Fragment polling command: When the satellite service receives the wide-angle staring radar reply that there are fragments in the rapid change polling command, it issues a fragment polling command. The wide-angle staring radar needs to reply with the gate frequency information. The gate frequency information is 256 bytes per transmission, and a total of 38 CAN communication frames are transmitted. The frames during transmission may be interrupted by the GNSS full-second broadcast signal.

[0093] S1.2.3: Slowly changing polling command: The satellite service sends a slowly changing 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. The frames may be interrupted by the GNSS full-second broadcast signal during transmission.

[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 set the working parameters of the wide-angle staring radar. The wide-angle staring radar must respond to the indirect command;

[0095] S1.2.5: GNSS full-second broadcast signal, sent once per second, has the highest priority, may interrupt other communications, wide-angle staring radar does not need to reply; in the design, GNSS full-second broadcast signal has the highest priority, may interrupt other communications, only reply fragment polling command and reply slow-variable polling command are multi-frame, after the communication is interrupted, wide-angle staring radar will give priority to receiving GNSS full-second broadcast signal, and continue the interrupted communication after receiving it;

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

[0097] S1.3: Timing and timekeeping;

[0098] In order to obtain the exact moment when the measured debris passes through the measurement plane, the wide-angle staring radar needs to complete high-precision timing and timekeeping. The timing is provided uniformly by the satellite to ensure that the time of all subsystems of the entire satellite is unified. The onboard measurement and control subsystem provides a second pulse (1PPS), and then within a certain period of time, the satellite service broadcasts the corresponding GNSS time and the satellite service broadcast time through the CAN bus to the wide-angle staring radar. The wide-angle staring radar preferentially uses the second pulse and GNSS time to complete the timing and keep time.

[0099] The logical process of the entire timing reception is as follows: Figure 4 As shown in the figure, after power-on, the wide-angle staring radar performs local timekeeping, and the end time of power reset is time 0. When the falling edge of the second pulse is effective, its signal waveform is required to be as follows Figure 5 As shown, the radar collects second pulse voltage. When the collected voltage is higher than 3V, it is judged as a high level 1, and when the collected voltage is less than 0.5V, it is judged as 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: Keep monitoring the falling edge of the second pulse. If the falling edge of the second pulse is valid, it is necessary to determine whether the local timekeeping count is faster or slower than the second pulse. The specific judgment standard is that if the value of the microsecond counter does not exceed 2, it means that the local timekeeping is faster than the second pulse and the faster time is less than 20us. At this time, the second count remains unchanged and the microsecond counter is cleared; otherwise, it means that the local timekeeping is slower than the second pulse. At this time, the second count is increased by 1 and the microsecond counter is cleared. Once the second pulse is detected and the GNSS whole second synchronization mark is received, that is, the second pulse and the GNSS whole second synchronization mark are all received, the GNSS mode is entered, and the second time is assigned to the second timer to update the second time, and the local timekeeping continues. Once the GNSS mode is entered, the satellite broadcast time will no longer be used for timekeeping.

[0102] S1.3.2: If the second pulse is invalid, continue to keep local time 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, update the satellite second and millisecond time, and continue to keep local time. If the satellite broadcast time update flag is invalid, directly keep local time and continue to monitor 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 be performed all the time.

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

[0105] S1.4: data transmission interface;

[0106] like Figure 6 As shown, the data processor interface of the satellite data transmission subsystem specifically adopts the LVDS interface, and the wide-angle staring radar signal processor FPGA is connected to the satellite data transmission subsystem through two LVDS interfaces. When the wide-angle staring radar is working, it simultaneously outputs two hot backup LVDS signals (two LVDS31) to connect the main data transmission channel and the backup data transmission channel respectively, and the main data transmission channel is connected to the main multiplexer, and the backup data transmission channel is connected to the backup multiplexer, wherein 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;

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

[0109] In order to standardize the workflow of the wide-angle staring radar, the present invention designs three types of workflows, namely: a typical workflow, a multiple sequential fragmentation detection workflow, and a manual recording workflow.

[0110] S2.1: Typical workflow;

[0111] The typical workflow usage scenario is to determine the scenario where it is known that only one debris enters the detection range of the wide-angle staring radar at a specific time. The typical workflow is the simplest workflow when the wide-angle staring radar performs a task. The specific workflow is as follows:

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

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

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

[0115] S2.1.4: After entering the 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, 2-way transmission signal, 1 out of 2 when working) transmits a single-frequency pulse signal to the space, the RF receiver receives 8-way spatial echo signals, and transmits 8-way eight-channel intermediate frequency signals to the signal processor, the signal processor processes the intermediate frequency signal sent by the RF receiver, and performs FFT operation on all range gate acquisition signals within the detection range according to the range gate, calculates the echo signal-to-noise ratio after non-coherent accumulation of multiple data, selects the range gate with the largest echo signal-to-noise ratio and the data of 3 gates, 1 gate before and after the maximum range gate, and writes them into the DDR for cache.

[0117] S2.1.5: After detecting debris, the wide-angle staring radar ends the DDR cyclic storage. When the fast-changing polling instruction comes, the detected debris indication is replied to the satellite service by setting the fast-changing polling response frame, and the valid data storage flag of the storage area is replied to the satellite service by setting the slow-changing polling response frame status;

[0118] Specifically, if debris appears in the wide-angle staring radar detection area, the debris echo will be transmitted to the RF receiver through the receiving antenna. After being processed by the RF receiver, a multi-channel intermediate frequency signal is generated to the signal processor. When the signal processor performs FFT operation on all range gates to solve the echo signal-to-noise ratio, the echo signal-to-noise ratio will be higher than the threshold value if there is debris. When 3 frames out of 5 frames exceed the threshold value, it is considered that fragments are detected. At this time, the DDR ends the circular storage, and after continuing to store for a period of time, the storage of the storage area is ended, and the storage area flag in the telemetry state is set to indicate that the current storage area detects and stores valid data.

[0119] DDR storage space is limited, and both space debris and satellites are running at high speed, so the rendezvous time is short. A storage space with a capacity of more than three times the rendezvous time is opened as a storage space for debris echo data. Three storage spaces are opened in the entire DDR to store three debris target echo data. For example, the storage capacity of a single storage area can be set to 64MB, of which the first 63MB is used as a data storage area to store debris echo data, and the last 1MB is used as an information storage area to store the current wide-angle staring radar working parameters, debris target information, and target storage starting position and other information.

[0120] Take the first storage area as an example to introduce the storage method of fragment echo data. Figure 7As shown, after entering the normal working mode, the wide-angle staring radar selects the three largest wave gate data and stores them in the data storage area in a circular manner according to the agreed frame format. When the storage address reaches the "echo data physical end address 0x1F8_0000", it starts to store again from the "first storage area physical start address 0x000_0000". The data storage area capacity is 63MB. In order to prevent false alarms, the debris detection threshold is set high. Therefore, when the debris is at a long distance, the wide-angle staring radar has received the echo signal but the echo signal has not exceeded the threshold. This segment of data is also valid data. Therefore, in the design, 42MB is stored after the fragment is detected, and 21MB is reserved before the fragment is detected. When the storage address when the fragment is detected is greater than 21MB, the real time start address of the echo data StartAddr_Time = the detected target start address StartAddr_THD-21MB; when the storage address when the fragment is detected is less than 21MB, the real time start address of the echo data is StartAddr_Time = the detected target start address StartAddr_THD+42MB. Among them, the physical end address of the first storage area is 0x200_0000.

[0121] S2.1.6: The satellite service determines that the rapid variable polling response frame detects debris, and the satellite service sends a debris polling command. The wide-angle staring radar frames the gate frequencies detected during the period when the debris appears in sequence and replies to the satellite service through the debris polling response frame;

[0122] S2.1.7: After the satellite service determines that the debris target passes 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 an indirect command "storage area data transmission", and 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 onboard data transmission subsystem in LVDS transmission format for storage;

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

[0125] S2.1.10: The ground sends a "data download" command based on the communication link status and the satellite working status to download the data stored in the onboard data transmission subsystem to the ground command and control system. The ground command and control system parses and processes the data to obtain the debris relative motion trajectory parameters and the coordinates and time when the debris target passes through the measurement plane.

[0126] S2.2: Multiple sequential fragmentation detection process;

[0127] The DDR of the wide-angle staring radar is designed with three buffer intervals, so it can store three debris targets continuously. When it is determined that there will be multiple debris targets, a continuous multiple-shot sequential debris instruction table can be generated and uploaded when the ground instruction is generated.

[0128] Wide-angle staring radar needs to detect the echo signal of each fragment, so it cannot detect multiple fragments at the same time, and can only detect continuous fragment targets with a certain interval. If the interval between the fragments is greater than 10s, the gate frequency data can be transmitted to the ground between the two fragments. If the interval between the two fragments is less than 10s, only the original echo data is recorded and the gate frequency data is not transmitted. The gate frequency data is only used for rapid judgment of the debris trajectory and does not affect the estimation of trajectory parameters.

[0129] The wide-angle staring radar can complete the detection of 3 debris targets. After each detection is completed, the wide-angle staring radar needs to return to the initial detection state to wait for the target to be detected. When the detection of 3 debris targets is completed, it also returns to the initial detection state, but the storage area is full and no longer stores data. The multiple sequential debris detection is basically the same as the typical workflow. The data download time can be placed after the detection of 3 debris targets is completed. The specific workflow is as follows:

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

[0131] S2.2.2: After the wide-angle staring radar is powered on, the system is initialized and self-checked;

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

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

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

[0135] S2.2.6: The wide-angle staring radar returns to the initial detection state and starts detecting the second debris target. After completing the storage of the second debris target, it returns to the initial detection state, records three debris targets in sequence, and sets the corresponding storage area flags;

[0136] S2.2.7: After the satellite service determines that all three storage areas are full of valid data, it 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 "storage area data transmission" in sequence. 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 onboard data transmission subsystem in LVDS transmission format for storage;

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

[0139] S2.2.10: The ground sends a "data download" command based on the communication link status and the satellite working status to download the data stored in the onboard data transmission subsystem to the ground command and control system. The ground command and control system parses and processes the data to obtain the debris relative motion trajectory parameters and the coordinates and time when the debris target passes through the measurement plane.

[0140] S2.3: Manual admission workflow;

[0141] The manual recording mode is realized by manual recording instructions, and manual recording can be performed in both standby mode and normal working mode. The manual recording mode is used to record the space environment in space to analyze clutter or interference signals at different distances. When the wide-angle staring radar receives the manual recording instruction, it collects all distance space environment data in sequence according to the gate order and stores them in the storage area.

[0142] During the fragment detection, after performing FFT operation on the echo data in all gates, the echo signal-to-noise ratio of each distance gate is calculated, and the data of the distance gate with the largest echo signal-to-noise ratio and the gates before and after the maximum distance gate, a total of three gates, are written into the DDR cache interval. In the manual recording mode, the wide-angle staring radar no longer performs fragment detection. After receiving the manual recording instruction, all gates are divided into three gate segments, and the entire storage area is evenly distributed, so that each gate can have data. For example, 12 gates can be designed in the present invention, and one storage area can store 680 frames of data. Then, during manual recording, the 1st to 170th frames store the data of gates 1, 2, and 3, the 171st to 340th frames store the data of gates 4, 5, and 6, the 341st to 510th frames store the data of gates 7, 8, and 9, and the 511st to 680th frames store the data of gates 10, 11, and 12.

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

[0144] The measurement plane of the wide-angle staring radar is not restricted by the size of the physical satellite plane and has a wide measurement range. The wide-angle staring radar needs to measure the actual change curve of the fragment echo Doppler frequency and the phase difference between the receiving antennas over time during the rendezvous between the fragments and the wide-angle staring radar in order to solve the relative motion trajectory parameters of the debris. Therefore, after the debris is detected, the multi-channel original echo signal with the debris information needs to be stored in the storage medium, and after the rendezvous is completed, the original echo signal data needs to be transmitted to the ground command and control system for processing to obtain the relative motion trajectory parameters of the debris. The specific implementation process is as follows:

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

[0146] Assume that in the measurement coordinate system, the position of the transmitting antenna in the wide-angle staring radar transceiver antenna array is (x T ,y T , z T ), the coordinates of the i-th receiving antenna are (x i ,y i , z i ), the coordinates of the fragment's position through the measurement plane are (0, y0, z0), then the coordinates of the fragment's scattering point at any time t are:

[0147]

[0148] Where L0 is the distance between the debris and the position of the measurement plane at time t = 0, V is the relative speed between the debris and the satellite, β is the inclination, and α is the deflection. When the wide-angle staring radar emits electromagnetic waves with a wavelength of 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) are the radial velocities of the debris 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] Among them, r T (t), r i (t) are the slant distances from the transmitting antenna and the i-th receiving antenna to the debris:

[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 of the debris echo between the i-th and j-th (i≠j) receiving antennas is:

[0156]

[0157] Among them, r j (t) is the slant distance from the jth receiving antenna to the debris:

[0158]

[0159] Among them, the coordinates of the jth receiving antenna are (x j ,y j ,z j ).

[0160] It can be seen from equations (2) and (7) that 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, and the change law is determined by the coordinates (y0, z0) of the measurement plane, the relative speed V between the debris and the satellite, the deflection angle α and the inclination angle β. Corresponding to different {(y0, z0), V, L0, α, β}, the change law of the Doppler frequency and the phase difference between the receiving antennas with time is also different. Therefore, as long as the actual change curve of the Doppler frequency of the debris echo and the phase difference between the receiving antennas with time during the rendezvous between the debris and the wide-angle staring radar is measured, and the optimal fit is made using the optimization method, the measurement results of the debris motion trajectory parameters can be obtained. in, It represents the estimated Y-axis coordinate of the debris position through the measurement plane in the measurement coordinate system. It represents the estimated Z-axis coordinate of the debris position through the measurement plane in the measurement coordinate system. represents the estimated relative velocity between the debris and the satellite, represents the estimated distance between the debris and the position of the measurement plane at time t = 0, represents the estimated value of the deflection angle, Represents the estimated value of the inclination angle.

[0161] Using the relative velocity estimate between the debris and the satellite and the estimated distance between the debris and the position of the through-measurement plane at time t = 0 The time when the fragment passes through the measurement plane can be calculated as:

[0162]

[0163] If the debris is at the corresponding position of L0, the absolute time of the whole satellite timing is T s , then the absolute time for the debris to pass through the measurement plane is:

[0164]

[0165] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A space debris perception method based on wide-angle staring radar, characterized in that: The following steps are involved: S1: The wide-angle staring radar is installed on the satellite. The power supply, communication and timing of the wide-angle staring radar are provided by other subsystems on the satellite. S2: Use wide-angle staring radar to detect debris. After the wide-angle staring radar detects the debris, it stores the multi-channel original echo signal with the debris information in the storage medium, and transmits the original 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 when the debris target passes through the measurement plane through the ground command and control system; Define the measurement coordinate system: coordinate origin O B is the geometric center of the satellite, O B X B , O B Y B , O B Z B Passing through the origin O B And it is parallel to the OX, OY, and OZ axes of the satellite body coordinate system and points in the same direction; B Y B Z B The plane is defined as the measurement plane; Assume that in the measurement coordinate system, the position of the transmitting antenna in the wide-angle staring radar transceiver antenna array is (x T ,y T , z T ), the coordinates of the i-th receiving antenna are (x i ,y i , z i ), the coordinates of the fragment's position through the measurement plane are (0, y0, z0), then the coordinates of the fragment's scattering point at any time t are: Where L0 is the distance between the debris and the position of the measurement plane at time t = 0, V is the relative speed between the debris and the satellite, β is the inclination, and α is the declination; When the wide-angle staring radar emits electromagnetic waves with a wavelength of λ, according to the Doppler effect, the Doppler frequency of the debris echo received by each antenna is for: Among them, V T (t), V i (t) are the radial velocities of the debris 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) Among them, r T (t), r i (t) are the slant distances from the transmitting antenna and the i-th receiving antenna to the debris: Since 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 of the debris echo between the i-th and j-th (i≠j) receiving antennas is: Among them, r j (t) is the slant distance from the jth receiving antenna to the debris: Among them, the coordinates of the jth receiving antenna are (x j ,y j ,z j ); The actual variation curve of the Doppler frequency of the debris echo and the phase difference between the receiving antennas over time during the rendezvous between the debris and the wide-angle staring radar is measured, and the optimal fitting is performed using the optimization method to obtain the measurement results of the motion trajectory parameters of the debris. It represents the estimated Y-axis coordinate of the debris position through the measurement plane in the measurement coordinate system. It represents the estimated Z-axis coordinate of the debris position through the measurement plane in the measurement coordinate system. represents the estimated relative velocity between the debris and the satellite, represents the estimated distance between the debris and the position of the measurement plane at time t = 0, represents the estimated value of the deflection angle, represents the estimated value of the inclination angle; Using the relative velocity estimate between the debris and the satellite and the estimated distance between the debris and the position of the through-measurement plane at time t = 0 The time when the fragment passes through the measurement plane is calculated as: If the debris is at the corresponding position of L0, the absolute time of the whole satellite timing is T s , then the absolute time for the debris to pass through the measurement plane is:

2. The space debris perception method based on wide-angle staring radar according to claim 1 is 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 uniformly controlled by the entire satellite. The onboard power supply subsystem adopts a semi-regulated bus voltage regulation method to provide a primary power supply of 33~48.5V and a primary bus power supply to the wide-angle staring radar. At the same time, the entire satellite provides a +28V command power supply. The entire 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 command is sent by the satellite service through the CAN bus. (2) The data processor interface of the satellite data transmission subsystem adopts the LVDS interface, and the wide-angle staring radar signal processor FPGA is connected to the satellite data transmission subsystem through two LVDS interfaces; when the wide-angle staring radar is working, two hot backup LVDS signals are output simultaneously to connect the main digital transmission channel and the backup digital transmission channel respectively, and the main digital transmission channel is connected to the main multiplexer, and the backup digital transmission channel is connected to the backup multiplexer; (3) The wide-angle staring radar signal processor receives the on / off command from the satellite service to control the power-on of the equipment, transmits data commands, telemetry parameters, the time and GPS parameters broadcast by the satellite service through the CAN bus interface, and can output analog telemetry data for wide-angle staring radar status monitoring; the wide-angle staring radar signal processor transmits data commands to the satellite service through the CAN bus; the wide-angle staring radar signal processor FPGA is connected to the CAN bus controller through the low-frequency connector SN74LVTH245APW; the CAN bus controller adopts SJA1000, and the CAN bus controller SJA1000 is connected to the satellite service through the CAN bus level conversion chip PCA82C50, and two CAN bus paths are designed to back up each other.

3. The space debris sensing method based on wide-angle staring radar according to claim 1 is characterized in that: In step S1, the specific process of CAN communication of the wide-angle staring radar is as follows: S1.2.1: Rapidly changing polling command: The satellite service sends a rapidly changing 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 transmit the status of the wide-angle staring radar signal processor back; S1.2.2: Fragment polling command: When the satellite service receives the wide-angle staring radar reply that there is a fragment in the rapid change polling command, it issues a fragment polling command. The wide-angle staring radar needs to reply with the gate frequency information. The transmission frame may be interrupted by the GNSS full-second broadcast signal. S1.2.3: Slowly changing polling command: The satellite service sends a slowly changing 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 frames during transmission 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 set the working parameters of the wide-angle staring radar. The indirect command requires the wide-angle staring radar to reply; 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: Satellite broadcast time, sent once per second, wide-angle staring radar does not need to reply.

4. The space debris perception method based on wide-angle staring radar according to claim 1 is characterized in that: In step S1, the specific process of timing and time keeping of the wide-angle staring radar is 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. At this time, add 1 to the second count and clear the microsecond counter. Once the second pulse is detected and the GNSS whole second synchronization mark is received, enter the GNSS mode, assign the second time to the second timer to update the second time, and continue to keep local time. Subsequently, the satellite service broadcast time will no longer be used for timekeeping. S1.3.2: If the second pulse is invalid, continue to keep local time 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, update the satellite second and millisecond time, and continue to keep local time. If the satellite broadcast time update flag is invalid, directly keep local time 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 be performed all the time.

5. The space debris sensing method based on wide-angle staring radar according to claim 1 is characterized in that: In step S2, the typical workflow of wide-angle staring radar when detecting debris is as follows: A typical workflow usage scenario is to determine a scenario where it is known that only one fragment enters the wide-angle staring radar detection range at a specific time. The specific workflow is as follows: S2.1.1: The satellite sends the wide-angle staring radar OC power-on command to power on the wide-angle staring radar; S2.1.2: After the wide-angle staring radar is powered on, it will enter standby mode after system initialization and self-test. During this period, the satellite service will periodically poll the wide-angle staring radar status through slowly changing polling instructions and transmit the wide-angle staring radar status to the ground; S2.1.3: The satellite service sends a pulse transmitter power-on command to the wide-angle staring radar according to the execution command list, and the wide-angle staring radar enters the normal working mode; S2.1.4: After entering the 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 fast-changing polling instruction comes, the detected debris indication is replied to the satellite service by setting the fast-changing polling response frame, and the valid data storage flag of the storage area is replied to the satellite service by setting the slow-changing polling response frame status; S2.1.6: The satellite service determines that the rapid variable polling response frame detects debris, and the satellite service sends a debris polling command. The wide-angle staring radar frames the gate frequencies detected during the period when the debris appears in sequence and replies to the satellite service through the debris polling response frame; S2.1.7: After the satellite service determines that the debris target passes 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, i.e., a storage area data transmission command. 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 satellite data transmission subsystem in accordance with the LVDS transmission format for storage; S2.1.9: The satellite service sends the OC shutdown command to shut down the wide-angle staring radar; S2.1.10: The ground sends data download instructions based on the communication link status and satellite working status, downloading the data stored in the onboard data transmission subsystem to the ground command and control system. The ground command and control system parses and processes the data to obtain the debris relative motion trajectory parameters and the coordinates and time when the debris target passes through the measurement plane.

6. The space debris sensing method based on wide-angle staring radar according to claim 5 is 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 RF 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 signal sent by the RF receiver, and performs FFT operation on the collected signals of all range gates within the detection range according to the range gate. After non-coherent accumulation of multiple data, the echo signal-to-noise ratio is calculated, and the range gate with the largest echo signal-to-noise ratio and the data of the three gates before and after the maximum range gate are selected and written into the DDR for cache.

7. The space debris sensing method based on wide-angle staring radar according to claim 5 is characterized in that: In S2.1.5, if there are debris in the wide-angle staring radar detection area, the debris echo will be transmitted to the RF receiver through the receiving antenna. After being processed by the RF receiver, a multi-channel intermediate frequency signal is generated to the signal processor. When the signal processor performs FFT operation on all range gates to solve the echo signal-to-noise ratio, the echo signal-to-noise ratio will be higher than the threshold value if there are debris. When 3 frames out of 5 frames exceed the threshold value, it is considered that the debris is detected. At this time, the cyclic storage in the DDR ends, and the storage of the storage area ends after a period of time, and the storage area flag in the telemetry state is set to indicate that the current storage area detects and stores valid data.

8. The space debris perception method based on wide-angle staring radar according to claim 5 is characterized in that: In S2.1.5, the DDR storage space is limited. Both the space debris and the satellite are running at high speed, and the rendezvous time is short. A storage space with a capacity more than three times the rendezvous time is opened up as a debris echo data storage space. Three storage spaces are opened up in the entire DDR, which can store three debris target echo data.

9. The space debris sensing method based on wide-angle staring radar according to claim 1 is characterized in that: In step S2, the multiple sequential debris detection process of the wide-angle staring radar when detecting debris is as follows: S2.2.1: The satellite sends the wide-angle staring radar OC power-on command to power on the wide-angle staring radar; S2.2.2: After the wide-angle staring radar is powered on, the system is initialized and self-checked; S2.2.3: The satellite service sends a pulse transmitter power-on command to the wide-angle staring radar, and the wide-angle staring radar enters the normal working mode; S2.2.4: After entering the normal working mode, the wide-angle staring radar automatically performs target detection and cyclic storage of echo data; S2.2.5: After detecting a debris target, the wide-angle staring radar completes the storage of a storage area and sets the corresponding storage area flag position; S2.2.6: The wide-angle staring radar returns to the initial detection state and starts detecting the second debris target. After completing the storage of the second debris target, it returns to the initial detection state, records three debris targets in sequence, and sets the corresponding storage area flags; S2.2.7: After the satellite service determines that all three storage areas are full of valid data, it 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 instructions in sequence, namely, the storage area data transmission instructions. The wide-angle staring radar responds to the indirect instructions and transmits the data in the corresponding storage area in accordance with the LVDS transmission format to the fixed storage device of the onboard data transmission subsystem for storage; S2.2.9: The satellite service sends the OC shutdown command to shut down the wide-angle staring radar; S2.2.10: The ground sends data download instructions based on the communication link status and satellite working status, downloading the data stored in the onboard data transmission subsystem to the ground command and control system. The ground command and control system parses and processes the data to obtain the debris relative motion trajectory parameters and the coordinates and time when the debris target passes through the measurement plane.

10. The space debris perception 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 instruction, it collects all distance space environment data in sequence according to the gate order and stores them in the storage area, so that each gate has data.

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