Space target detection method and system based on event camera active exposure
By using an active exposure method based on an event camera and a spatiotemporal joint filtering algorithm, the problem of reduced detection capability of event cameras when detecting relatively stationary spatial targets is solved, and real-time, effective detection and high-precision positioning of spatial targets are achieved.
Patent Information
- Application Number
- CN202510895280.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-30
- Publication Date
- 2025-10-21
AI Technical Summary
Existing event cameras have reduced detection capabilities when detecting relatively stationary targets in space, and cannot meet the requirements for long-term real-time detection.
An active exposure method based on an event camera is adopted, which combines a pointing subsystem, an optical imaging subsystem, and an information processing subsystem. The mechanical shutter component actively exposes within a set interval, triggering the event camera pixels to generate events. Combined with a spatiotemporal joint filtering algorithm to remove noise, real-time detection of space targets is achieved.
It significantly improves the acquisition probability and positioning accuracy of space targets, enables precise capture of high-speed moving targets and preservation of target motion information in complex dynamic scenarios, overcomes the problem of low detection capability of event cameras when dealing with relatively stationary targets, and provides a new solution for space situational awareness.
Smart Images
Figure CN120821132A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of space target detection, and in particular to a space target detection method and system based on active exposure of an event camera. Background Art
[0002] Space target detection refers to the process of detecting and tracking the position, motion parameters, and motion trajectory of space targets through sensors. Space target detection provides technical support for space situational awareness, the safety of space activities, and the development of astronomical science and technology.
[0003] Technical means for space target detection include optical detection, radar detection, and laser ranging. Radar detection has a limited detection range, high cost, and susceptibility to interference, while laser detection has a limited range and relies on a cooperating target. Optical detection allows for direct imaging of space targets, and optical system design allows for control of detection capability and range, making it widely used in space target detection. Optical detection systems primarily consist of the optical system and the imaging sensor. Currently, the most commonly used imaging sensors are charge-coupled devices (CCDs) and complementary metal oxide semiconductors (CMOSs). However, CCD and CMOS sensors suffer from large data volumes, limited temporal resolution, and limited dynamic range, making them inadequate for long-term, real-time detection of space target positions. Therefore, event cameras, with their high temporal resolution, large dynamic range, and low data redundancy, are being used for space target observation. However, event cameras operate in a passive mode, recording and outputting information only when brightness changes meet a preset threshold. Therefore, when the detection system and the target are relatively stationary, such as when observing stellar targets, their detection capability is reduced compared to traditional imaging sensors. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to address the deficiencies in the above-mentioned prior art and provide a space target detection method and system based on active exposure of an event camera, so as to solve the technical problem that the detection capability of the event camera is reduced when used for detecting relatively stationary space targets.
[0005] The purpose of the present invention is achieved by the following technical solutions: In a first aspect, the present invention provides a space target detection system based on active exposure of an event camera, comprising: a pointing subsystem, an optical imaging subsystem, and an information processing subsystem; The pointing subsystem is used to carry the optical imaging subsystem and communicate with the information processing subsystem; the pointing subsystem is used to adjust the pointing direction and track the target according to the steering command received; The optical imaging subsystem is communicatively connected to the information processing subsystem and is used to collect target information; the optical imaging subsystem includes an event camera, which records changes in image brightness in the spatiotemporal dimension to achieve recording of the target spatial position, obtains event stream information, and sends the event stream information to the information processing subsystem; The information processing subsystem is used to process the received event stream information to obtain event frame images, detect the spatial target position based on the event frames, and send pointing instructions to the pointing subsystem.
[0006] As a further improvement of the present invention, the pointing subsystem includes a supporting base and a turntable, the supporting base is used to support the turntable; the turntable carries an optical imaging subsystem, and the turntable rotates and points according to the location of the target to track the target in real time.
[0007] As a further improvement of the present invention, the optical imaging subsystem also includes an optical module and a mechanical shutter assembly; the mechanical shutter assembly is arranged at the position of the aperture stop of the optical module, and is used to actively expose once within a set interval; the optical module is fixed on the pointing subsystem, and is used to image the space target, and the imaging data is collected by an event camera to form an event stream.
[0008] As a further improvement of the present invention, when the mechanical shutter assembly performs active exposure and the image plane brightness change exceeds a preset value, the pixel of the event camera is triggered to generate an event; After the pixels of the triggered event camera generate events to form an event stream, the event frame image is obtained based on the imaging mechanism of the event camera. By detecting the target position, the target activity trajectory is obtained, and real-time detection of spatial targets in the field of view is achieved.
[0009] As a further improvement of the present invention, the detection sensitivity of the space target detection system is:
[0010] in, To detect the system's limiting magnitude, is the optical subsystem clear aperture, is the sensor spectral quantum efficiency in the optical subsystem, Lens transmittance in the optical subsystem, is the photon flux density of the target with magnitude 0, in units of .
[0011] As a further improvement of the present invention, it further includes a single-stage denoising module; the single-stage denoising module is used to remove noise events in the event stream through a spatiotemporal joint filtering algorithm.
[0012] As a further improvement of the present invention, it further includes a multi-stage denoising module; the multi-stage denoising module is used to remove noise events in the event stream through several times of spatiotemporal joint filtering algorithms.
[0013] In a second aspect, the present invention provides a space target detection method based on active exposure of an event camera, characterized by comprising: Build the above-mentioned space target detection system based on active exposure of event camera; Acquiring event flow information in the spatiotemporal dimension according to the event camera in the space target detection system; intercepting the event stream information at different moments to obtain equivalent frame images, and determining the spatial target position according to the equivalent frame images; In the spatial target position, the target motion trajectory is obtained according to the event stream information, thereby realizing the detection of the spatial target in the field of view.
[0014] As a further improvement of the present invention, according to the event camera in the space target detection system, event stream information in the time and space dimensions is obtained, specifically including: When the image brightness changes beyond a preset value, the pixel of the trigger camera generates an event. The trigger mechanism for a single pixel event is as follows:
[0015] in, and are characterized by the photocurrent generated by the space target and the photocurrent generated by the sky, respectively. represents the dark current, TC is the event camera contrast threshold, The index of change in the brightness of the space target.
[0016] As a further improvement of the present invention, the present invention also includes using a spatiotemporal joint filtering algorithm to perform spatiotemporal filtering on the event stream information:
[0017] in, is the i-th event point in the event stream, is the preset spatiotemporal neighborhood, is the spatial neighborhood, is the spatiotemporal neighborhood, ( ) as the reference point.
[0018] The beneficial effects of this invention lie in providing a space target detection system based on active exposure of an event camera. The pointing subsystem preloads orbital parameters via target commands or receives tracking commands in real time, adjusting the pointing direction in advance to cover the target's potential area. The optical imaging subsystem dynamically optimizes event camera parameters (such as field of view and exposure strategy) based on pointing feedback to ensure the target is within the effective sampling range. This closed-loop design of "active pointing-adaptive acquisition-precision processing" significantly improves target capture probability and positioning accuracy (such as sub-pixel position estimation) compared to traditional passive imaging systems (which rely on fixed field of view scanning).
[0019] Event cameras utilize a pixel-level brightness change trigger mechanism (rather than fixed frame rate sampling), achieving microsecond temporal resolution and accurately capturing instantaneous brightness changes in high-speed moving targets (such as high-speed satellite passes and rapidly moving space debris). Combined with an "active exposure" strategy—dynamically adjusting the mechanical shutter's operating mode based on the target's speed and brightness (e.g., active exposure for low-speed targets improves detection capabilities)—they effectively avoid the high-speed motion blur associated with fixed frame rates in traditional frame cameras and significantly enhance the ability to retain target motion information in complex dynamic scenes. Therefore, the present invention enables efficient, real-time, and long-term detection of space targets, overcoming the drawback of event cameras' lower detection capabilities compared to traditional cameras when stationary relative to the space target, providing a new solution for space situational awareness. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0021] Figure 1 The figure is a structural diagram of a space target detection system based on active exposure of an event camera according to the present invention.
[0022] Figure 2 This is a schematic diagram of the optical system design of a space target detection system based on active exposure of an event camera in the present invention.
[0023] Figure 3 This is the event stream data obtained by implementing step 1 in a space target detection system based on active exposure of an event camera according to the present invention.
[0024] Figure 4 The event frame image is formed by event accumulation of the event stream data obtained by implementing step 1 of the space target detection system based on active exposure of an event camera of the present invention.
[0025] Figure 5 Schematic diagram of the relationship between the index of change in space target brightness and detection capability.
[0026] Figure 6 Schematic diagram of events occurring during the operation of a single-pixel mechanical shutter.
[0027] Figure 7 This is an event frame image formed by event accumulation of event stream data obtained by implementing step 2 of a space target detection system based on active exposure of an event camera in the present invention.
[0028] Figure 8 The denoised event stream and event frame image are obtained by implementing step 3 in the space target detection system based on active exposure of an event camera of the present invention.
[0029] Figure 9 This is a schematic diagram of the space target detection result obtained by implementing step 4 of the space target detection system based on active exposure of an event camera in the present invention.
[0030] Figure 1 The description of the accompanying figures is as follows: 1. Steering subsystem; 2. Event camera; 3. Optical module; 4. Mechanical shutter assembly; 5. Information processing subsystem; 11. Turntable; 12. Support base. DETAILED DESCRIPTION
[0031] In order to make the purpose and technical solution of the present invention clearer and easier to understand, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.
[0032] The technical solutions of the present invention will be described clearly and completely below with reference to the accompanying drawings and specific embodiments. The described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.
[0033] Example 1 like Figure 1 As shown, the present invention provides a space target detection system based on active exposure of an event camera. The system mainly includes: a pointing subsystem 1, an optical imaging subsystem and an information processing subsystem 5.
[0034] The pointing subsystem 1 is used to carry the optical imaging subsystem and communicate with the information processing subsystem 5; the pointing subsystem 1 is used to adjust the pointing direction and track the target according to the received target command; The pointing subsystem includes a supporting base 12 and a turntable 11, wherein the supporting base is used to support the turntable; the turntable 11 carries the optical imaging subsystem, and the turntable 11 rotates and points according to the location of the target to track the target in real time.
[0035] The optical imaging subsystem is communicatively connected to the information processing subsystem 5 for collecting target information; the optical imaging subsystem includes an event camera 2, which acquires event stream information in the time and space dimensions and sends the event stream information to the information processing subsystem 5.
[0036] The optical imaging subsystem also includes an optical module 3 and a mechanical shutter assembly 4; the mechanical shutter assembly 4 is set at the aperture stop position of the optical module 3 and is used to actively expose once within a set interval; the optical module 3 is fixed on the pointing subsystem and is used to image the space target. The imaging data is collected by the event camera to form an event stream.
[0037] In this embodiment, event camera 2 detects changes in image plane brightness. When the change exceeds a set threshold, it outputs event information, forming an event stream. This event stream reflects the position and motion parameters of spatial objects. Given the imaging characteristics of the event camera's ability to detect brightness changes, a mechanical shutter is incorporated into the optical system design, enabling active sensor exposure to maximize the system's detection capabilities.
[0038] Specifically, the triggering mechanism of a single pixel event is:
[0039] in, and are characterized by the photocurrent generated by the space target and the photocurrent generated by the sky, respectively. represents the dark current, TC is the event camera contrast threshold, The index of change in the brightness of the space target.
[0040] When the mechanical shutter assembly 4 performs active exposure and the image plane brightness changes by more than a preset value, the pixel of the event camera is triggered to generate an event; After the pixel of the event camera is triggered to generate an event, the event frame image is obtained based on the imaging mechanism of the event camera, and then the target activity trajectory is obtained, realizing real-time detection of spatial targets in the field of view.
[0041] The information processing subsystem 5 is used to process the received event stream information to obtain event frame images, detect the spatial target position based on the event frames, and send steering instructions to the pointing subsystem 1.
[0042] The collected event stream is denoised (distinguishing valid events from noise events) and clustered to identify the target's spatiotemporal position, enabling detection of space targets. The event stream is intercepted in the temporal dimension to obtain equivalent frame images, enabling visual detection of space targets. The event camera 2 features low data redundancy, enabling long-term observation. Compared to traditional imaging sensors, event cameras sample more continuously in the temporal dimension, resulting in lower temporal resolution. Combined with its low-latency data output, this event camera-based space target detection system can achieve effective, real-time, and long-term detection of space targets.
[0043] This embodiment also quantifies the detection capability of the space target detection system. Specifically, the detection sensitivity of the space target detection system is:
[0044] in, To detect the system's limiting magnitude, is the optical subsystem clear aperture, is the sensor spectral quantum efficiency in the optical subsystem, Lens transmittance in the optical subsystem, is the photon flux density of the target with magnitude 0, in units of .
[0045] When the target and the observation system are relatively stationary (or moving at a low speed), the main cause of the brightness change of the space target is atmospheric disturbance, so the exponent α is small, which seriously affects the detection capability of the system. In order to further improve the detection capability of the system, it is necessary to increase the exponent α, so the computer is used to control the mechanical shutter for active exposure, so that the brightness of the target itself becomes the light intensity change value, that is, let α=1, to achieve the detection capability of the detection system. Take the brightness change of a single pixel as an example. When the mechanical shutter is not working, it is affected by atmospheric disturbances and some events are generated on the target. The shutter working process is divided into two processes: closing and opening. The brightness changes from the brightness of the target itself to 0 and then increases to the target brightness. The events generated in this process are as follows: Figure 6 As shown in Figure 1. In order to update the real-time position of the target, the mechanical shutter is set to work once every time T to realize the active exposure of the event camera. The time interval T is set to 10ms to ensure the real-time update of the target position. The event frame image obtained after a single exposure of the event camera is as follows: Figure 7 shown.
[0046] In addition, the detection system of this embodiment also includes a single-stage denoising module; the single-stage denoising module is used to remove noise events in the event stream through a spatiotemporal joint filtering algorithm. The denoising process is:
[0047] in, is the i-th event point in the event stream, is the preset spatiotemporal neighborhood, is the spatial neighborhood, is the spatiotemporal neighborhood, ( ) is used as a reference point. If other events exist in the defined spatiotemporal neighborhood, they are considered valid events and retained. If no other events exist, they are considered noise events and removed. In this project, the target is dim. If only single-stage spatiotemporal filtering is performed, valid events are retained and noise events are removed. Therefore, this embodiment also includes a multi-stage denoising module, which is used to remove noise events from the event stream through multiple spatiotemporal joint filtering algorithms.
[0048] The event results in the event stream reflect the spatial position information of the target in the field of view. By intercepting the event stream at different times, the equivalent frame image can be obtained and the spatial target position can be determined.
[0049] When the target, the space target and the system are relatively stationary, the event pixel position does not change. If there is a relative position change, the target motion trajectory can be obtained through the event stream information to achieve real-time detection of the space target in the field of view, as shown in the following example: Figure 9 The test results shown.
[0050] Example 2 This embodiment provides a space target detection method based on active exposure of an event camera, the main implementation steps of which include: The space target detection system based on active exposure using an event camera, as described in Example 1, is constructed. A mechanical shutter is installed at the aperture stop, and the mechanical shutter is controlled by a computer. This space target detection system images the space target onto the event camera detector via an optical system. The imaging system is fixed to a pointing system, which adjusts the system's pointing direction. The computer is connected to the pointing system to transmit commands and control the system. The event camera is connected to the computer, which provides power to the camera and transmits the collected information to the computer for subsequent data processing.
[0051] The imaging system images the space target, and the event camera collects data and outputs Figure 3 By accumulating events over a period of time, an event frame image is formed as shown in Figure 4 shown.
[0052] According to the event camera in the space target detection system, event flow information in the time and space dimensions is obtained according to the set sampling density; intercepting the event stream information at different moments to obtain equivalent frame images, and determining the spatial target position according to the equivalent frame images; In the spatial target position, the target motion trajectory is obtained according to the event stream information, thereby realizing the detection of the spatial target in the field of view.
[0053] According to the event camera in the space target detection system, event flow information in the time and space dimensions is obtained according to the set sampling density, including: Event camera imaging is only sensitive to brightness changes and generates an event when and only when the brightness change exceeds the set threshold. The triggering mechanism of a single pixel event is:
[0054] in, and are characterized by the photocurrent generated by the space target and the photocurrent generated by the sky, respectively. represents the dark current, TC is the event camera contrast threshold, The index of change in the brightness of the space target.
[0055] Based on the imaging mechanism of the event camera, the detection capability of the detection system is:
[0056] in, To detect the system's limiting magnitude, is the optical subsystem clear aperture, is the sensor spectral quantum efficiency in the optical subsystem, Lens transmittance in the optical subsystem, is the photon flux density of the target with magnitude 0, in units of .
[0057] Among them, the index of change in the brightness of the space target That is, the percentage of target brightness change affects the occurrence of events and thus affects the detection capability of the system. The relationship diagram is as follows: Figure 5 shown.
[0058] When the target and the observation system are relatively stationary (or the moving speed is low), the main reason for the brightness change of the space target is atmospheric disturbance, so the index Small, seriously affecting the system detection capability. In order to further improve the system detection capability, it is necessary to increase the index Therefore, the computer is used to control the mechanical shutter for active exposure, so that the brightness of the target itself becomes the light intensity change value. , to improve the detection capability of the detection system. Take the brightness change of a single pixel as an example. When the mechanical shutter is not working, the target will generate some events due to the influence of atmospheric disturbance. The shutter working process is divided into two processes: closing and opening. The brightness changes from the target brightness itself to 0 and then increases to the target brightness. The event generated in this process is as follows: Figure 6 As shown in Figure 1. In order to update the real-time position of the target, the mechanical shutter is set to work once every time T to realize the active exposure of the event camera. The time interval T is set to 10ms to ensure the real-time update of the target position. The event frame image obtained after a single exposure of the event camera is as follows: Figure 7 shown.
[0059] In addition, there is a lot of noise in the directly acquired event stream. In order to achieve clearer visualization of the target, the event stream information is filtered using a single-stage spatiotemporal joint filtering algorithm to remove noise events:
[0060] in, is an event in the event stream, is the preset spatiotemporal neighborhood, is the spatial neighborhood, A space-time neighborhood.
[0061] Denoising is performed on each event in the event stream. If other events exist in the defined spatiotemporal neighborhood, they are considered valid events and retained. If no other events exist, they are considered noise events and removed. In this project, the target is dim. If only single-stage spatiotemporal filtering is performed, valid events are retained and noise events are removed. Therefore, multi-stage denoising is performed on the event stream information.
[0062] That is, the above denoised event stream is subjected to spatiotemporal joint denoising again:
[0063] The spatiotemporal domain defined for cascade denoising is, in general, based on the reduction of spatiotemporal correlations of noise events that are preserved after denoising. The event stream and event frame images obtained after denoising are as follows: Figure 8 shown.
[0064] The event camera performs dense sampling in the spatiotemporal dimensions, generating a sparse event stream output. The event results in the event stream reflect the spatial position of objects within the field of view. By intercepting the event stream at different moments, equivalent frame images can be obtained, allowing the spatial location of the object to be determined.
[0065] When the target, the space target and the system are relatively stationary, the event pixel position does not change. If there is a relative position change, the target motion trajectory can be obtained through the event stream information to achieve real-time detection of the space target in the field of view, as shown in the following example: Figure 9 The test results shown.
[0066] Through the aforementioned space target detection method, the event camera utilizes a pixel-level brightness change trigger mechanism (rather than fixed frame rate sampling), achieving microsecond temporal resolution. This allows it to accurately capture the instantaneous brightness changes of high-speed moving targets (such as high-speed satellite passes and rapidly moving space debris). Combined with an "active exposure" strategy—dynamically adjusting the mechanical shutter's operating mode based on the target's speed and brightness (e.g., active exposure at low speeds improves detection capabilities)—it effectively avoids the high-speed motion blur associated with fixed frame rates in traditional frame cameras, significantly improving the ability to retain target motion information in complex dynamic scenes.
[0067] The event-triggered mechanism of the event camera only records "changes" rather than full-frame images, resulting in extremely low latency from data acquisition to transmission (typically in the microsecond range). The pointing subsystem rapidly adjusts pointing based on the real-time event stream (for example, through closed-loop control to compensate for target motion), forming a low-latency closed-loop "detection-feedback-adjustment" system. This enables stable tracking of highly dynamic targets (such as maintaining lock on a space target during orbital maneuvers).
[0068] In summary, through the high temporal resolution, low latency characteristics and active exposure adaptive strategy of the event camera, combined with the collaborative optimization of multiple subsystems, it has broken through the limitations of traditional frame camera solutions in terms of high-speed target detection, complex lighting adaptation, and efficient resource utilization, providing a better technical path for real-time detection and tracking of space targets (especially highly dynamic, low-observable targets).
Claims
1. A space target detection system based on active exposure of an event camera, characterized in that: include: Pointing subsystem, optical imaging subsystem, and information processing subsystem; The pointing subsystem is used to carry the optical imaging subsystem and communicate with the information processing subsystem; The pointing subsystem is used to adjust the pointing direction and track the target according to the steering command received; The optical imaging subsystem is communicatively connected to the information processing subsystem for collecting target information; The optical imaging subsystem includes an event camera, which samples brightness changes in the field of view in the temporal and spatial dimensions, records target position information, obtains event stream information, and sends the event stream information to the information processing subsystem; The information processing subsystem processes the received event stream information to obtain event frame images, detects the spatial target position based on the event frames, and uses them to send steering instructions to the pointing subsystem.
2. The space target detection system based on event camera active exposure according to claim 1, characterized in that: The pointing subsystem includes a supporting base and a turntable, wherein the supporting base is used to support the turntable; the turntable carries the optical imaging subsystem, and the turntable rotates and points according to the location of the target to track the target in real time.
3. The space target detection system based on event camera active exposure according to claim 2, characterized in that: The optical imaging subsystem also includes an optical module and a mechanical shutter assembly; the mechanical shutter assembly is arranged at the aperture stop of the optical module and is used to actively expose once within a set interval; the optical module is fixed on the pointing subsystem and is used to image the space target, and the imaging data is collected by the event camera to form an event stream.
4. The space target detection system based on event camera active exposure according to claim 3, characterized in that: When the mechanical shutter assembly performs active exposure and the image plane brightness changes beyond the preset value, the corresponding pixel of the event camera is activated and an event is generated; After the pixels of the event camera generate an event, the output forms event stream information. Based on the imaging mechanism of the event camera, the event frame image is obtained. By detecting the target position, the target activity trajectory is obtained, and real-time detection of spatial targets in the field of view is achieved.
5. The space target detection system based on event camera active exposure according to claim 1, characterized in that: The detection sensitivity of the space target detection system is: in, To detect the system's limiting magnitude, is the optical subsystem clear aperture, is the sensor spectral quantum efficiency in the optical subsystem, Lens transmittance in the optical subsystem, is the photon flux density of the target with magnitude 0, in units of .
6. The space target detection system based on event camera active exposure according to claim 1, characterized in that: It also includes a single-stage denoising module; the single-stage denoising module is used to remove noise events in the event stream through a spatiotemporal joint filtering algorithm.
7. The space target detection system based on event camera active exposure according to claim 1, characterized in that: It also includes a multi-stage denoising module; the multi-stage denoising module is used to remove noise events in the event stream through several times of spatiotemporal joint filtering algorithms.
8. A space target detection method based on active exposure of an event camera, characterized in that: include: Building a space target detection system based on active exposure of an event camera as described in any one of claims 1 to 7; Acquiring event flow information in the spatiotemporal dimension according to the event camera in the space target detection system; intercepting the event stream information at different moments to obtain equivalent frame images, and determining the spatial target position according to the equivalent frame images; In the spatial target position, the target motion trajectory is obtained according to the event stream information, thereby realizing the detection of the spatial target in the field of view.
9. The space target detection method based on event camera active exposure according to claim 7, characterized in that: According to the event camera in the space target detection system, event stream information is obtained in the time and space dimensions, specifically including: When the image brightness changes beyond the preset value, the corresponding pixel output event of the event camera is triggered; the triggering mechanism of a single pixel event is: in, and are characterized by the photocurrent generated by the space target and the photocurrent generated by the sky, respectively. represents the dark current, TC is the event camera contrast threshold, The index of change in the brightness of the space target.
10. The space target detection method based on event camera active exposure according to claim 7, characterized in that: It also includes the use of a spatiotemporal joint filtering algorithm to perform spatiotemporal filtering on event stream information: in, is the i-th event point in the event stream, is the preset spatiotemporal neighborhood, is the spatial neighborhood, is the spatiotemporal neighborhood, ( ) as the reference point.