A method and system for measuring velocity of a rocket during a launch phase based on an event camera
By using an event camera-based method for estimating the exhaust plume region and extracting the effective region, combined with gradient analysis and Hough transform, the accuracy and robustness issues of rocket launch velocity measurement were resolved, achieving high-precision velocity measurement under strong light interference and exhaust plume disturbances.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HUAZHONG UNIV OF SCI & TECH
- Filing Date
- 2026-02-25
- Publication Date
- 2026-05-12
AI Technical Summary
Existing rocket launch velocity measurement technologies based on event signals suffer from poor accuracy and robustness, especially in complex scenarios with strong light interference and exhaust plume disturbances, making it difficult to achieve robust velocity measurement.
By spatially accumulating ON events captured by the event camera to form an ON event density map, the exhaust flame region is estimated and an effective rocket body region is constructed. By combining OFF events to form a binary map, straight line segments are extracted and displacement-time curves are calculated. Gradient analysis and Hough transform are used to robustly extract the linear structure of the rocket body, and morphological processing is combined to eliminate noise interference.
Under conditions of strong light interference and exhaust plume disturbance, the accuracy and robustness of rocket velocity measurement are significantly improved, achieving high-precision and highly robust velocity measurement, and accurately acquiring the trajectory of the rocket body in complex scenarios.
Smart Images
Figure CN121720329B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of image processing technology, and more specifically, relates to a method and system for measuring the velocity of a rocket during takeoff based on an event camera. Background Technology
[0002] The rocket takeoff phase is a typical high-speed, high-radiation scenario, accompanied by complex phenomena such as strong exhaust plumes, smoke entrainment, and high-brightness nozzle light clusters. Traditional optical measurement methods, such as frame imaging methods based on high-speed cameras, mainly have the following problems: (1) Strong light interference causes image overexposure. The large number of high-brightness areas generated by the rocket exhaust plume can easily cause local saturation of the image sensor, making it impossible to identify the structural features of the rocket body; (2) Exhaust plume disturbances cause instability in contour detection. The transient high-speed pulsation of the exhaust plume makes the contour extraction algorithm based on frame images susceptible to disturbance and unable to obtain a robust motion trajectory; (3) Large data volume makes real-time measurement difficult. High-speed cameras need to generate a large amount of frame data, which is not conducive to deploying a real-time measurement system at the launch site.
[0003] Event cameras are a novel neuromorphic sensor characterized by asynchronous pixel triggering, low latency (microseconds), low data redundancy, and high dynamic range, making them highly valuable in high-speed, wide-dynamic-range imaging. Therefore, event cameras can serve as an effective mode for velocity measurement during rocket launch. However, the event density at the rocket's exhaust plume is extremely high, and the exhaust plume region is mixed with the rocket body region, meaning that directly using event signals for velocity measurement still suffers from poor accuracy and robustness.
[0004] It is evident that existing speed measurement techniques based on event signals suffer from poor accuracy and robustness. Summary of the Invention
[0005] In view of the above-mentioned defects or improvement needs of the existing technology, the present invention provides a method and system for measuring the velocity of a rocket during the takeoff phase based on an event camera, thereby solving the technical problems of poor accuracy and poor robustness of the existing velocity measurement technology based on event signals.
[0006] To achieve the above objectives, according to a first aspect of the present invention, a method for measuring the velocity of a rocket during takeoff based on an event camera is provided, comprising the following steps:
[0007] (1) Spatially accumulate the ON events generated by the rocket exhaust flame captured by the event camera to form an ON event density map. Estimate the exhaust flame region from the ON event density map and obtain the position of the bottom edge of the rocket in the exhaust flame region. Thus, construct an effective region containing only the rocket body.
[0008] (2) Overlay the OFF events in the effective area into a binary image, extract the straight line segments from the binary image, take the displacement of the straight line segments as the displacement of the rocket, combine the timestamp of the binary image to form a displacement-time curve, and calculate the gradient of the displacement-time curve to obtain the velocity-time curve.
[0009] Furthermore, the specific method for estimating the exhaust region is as follows:
[0010] Within a time window, ON events are spatially accumulated to form an ON event density map. A histogram of the ON event density map is constructed. All thresholds are traversed, and the inter-class variance between the high-density and low-density regions of the exhaust plume is calculated for each threshold. The threshold that maximizes the inter-class variance is selected as the optimal threshold. The high-density region of the exhaust plume is extracted from the histogram of the ON event density map. Rectangular fitting or minimum bounding region screening is performed on the high-density region of the exhaust plume. Combined with the rocket nozzle position, candidate regions of the exhaust plume are determined. The position and area changes of the candidate regions of the exhaust plume are detected in adjacent time windows. For candidate regions of the exhaust plume with changes exceeding a preset value, smoothing and weighted averaging are performed to estimate the exhaust plume region.
[0011] Furthermore, the specific method for estimating the exhaust region is as follows:
[0012] Within a time window, ON events are spatially accumulated to form an ON event density map. A histogram of the ON event density map is constructed. All thresholds are traversed, and the information entropy of the high-density and low-density regions of the exhaust plume under each threshold is calculated. The threshold that maximizes the information entropy is selected as the optimal threshold. The high-density region of the exhaust plume is extracted from the histogram of the ON event density map. Rectangular fitting or minimum bounding region screening is performed on the high-density region of the exhaust plume. Combined with the rocket nozzle position, candidate regions of the exhaust plume are determined. The position and area changes of the candidate regions of the exhaust plume are detected in adjacent time windows. For candidate regions of the exhaust plume with changes exceeding a preset value, smoothing and weighted averaging are performed to estimate the exhaust plume region.
[0013] Furthermore, the effective region is extracted in the following manner:
[0014] Combining the width and height equivalent focal length parameters of the event camera The actual width W, actual height H of the rocket body, and distance D from the rocket's center point to the event camera are determined according to the formula. The pixel width of the rocket body in the event frame was calculated. Pixel height First, obtain the position of the bottom edge of the rocket in the exhaust plume area, and then determine the position based on the pixel width. Pixel height Obtain the valid area of the rocket body in the event frame.
[0015] Furthermore, before extracting the straight line segments from the binary graph in step (2), the binary graph is subjected to closing and opening operations in sequence.
[0016] Furthermore, step (2) uses a gradient analysis-based straight line segment detection method or Hough transform to extract straight line segments from the binary image.
[0017] Further, in step (2), multiple straight line segments are extracted from the binary image, and the average displacement of the multiple straight line segments is taken as the displacement of the rocket. Combined with the timestamp of the binary image, a displacement-time curve is formed. The gradient of the displacement-time curve is obtained by first-order difference or polynomial fitting, and the velocity-time curve is obtained.
[0018] According to a second aspect of the present invention, a rocket launch phase velocity measurement system based on an event camera is provided, comprising:
[0019] The rocket body extraction module is used to spatially accumulate ON events generated by the rocket exhaust flame captured by the event camera to form an ON event density map. The exhaust flame region is estimated from the ON event density map, and the position of the bottom edge of the rocket is obtained in the exhaust flame region. Thus, an effective region containing only the rocket body is constructed.
[0020] The velocity measurement module is used to overlay OFF events in the effective area into a binary image, extract straight line segments from the binary image, use the displacement of the straight line segments as the displacement of the rocket, combine the timestamps of the binary image to form a displacement-time curve, and calculate the gradient of the displacement-time curve to obtain the velocity-time curve.
[0021] According to a third aspect of the present invention, an electronic device is provided, comprising a processor and a computer-readable storage medium, wherein:
[0022] The computer-readable storage medium stores program instructions for implementing each step of a rocket launch phase velocity measurement method based on an event camera; the processor, when executing the program instructions, implements the entire process of rocket launch phase velocity measurement.
[0023] According to a fourth aspect of the present invention, a computer-readable storage medium is provided having program instructions stored thereon, which, when executed by a processor, implement a method for measuring the velocity of a rocket during takeoff based on an event camera.
[0024] According to a fifth aspect of the invention, a computer product is provided that, when in operation, enables a computer to execute steps of a method for measuring the velocity of a rocket launch phase based on an event camera.
[0025] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:
[0026] (1) This invention effectively eliminates a large number of invalid event interferences caused by strong tail flame light by combining tail flame region estimation and effective region extraction, significantly improving the event signal quality of the target rocket body; the stacking of OFF events is a near-parallel linear distribution, while the stacking of ON events is more complex, which may be a straight line distribution or an arc structure. Based on this, the OFF events in the effective region are superimposed into a binary image, making the velocity estimation result of the rocket body more robust and accurate; the linear structure of the rocket body is extracted, making the displacement estimation more robust; this invention is the first to apply the event camera to the velocity measurement of the rocket takeoff stage, and can still achieve high robustness and high accuracy velocity measurement of the rocket takeoff stage under complex conditions such as strong light interference and tail flame disturbance.
[0027] (2) This invention uses two methods for estimating the exhaust flame region. The maximum inter-class variance method is suitable for images with significant contrast between the foreground and background and large differences in grayscale distribution. The maximum entropy thresholding method is suitable for images with uneven information distribution, long tails in histograms, or noise interference. Smoothing and weighted averaging are performed on exhaust flame candidate regions whose variations exceed preset values, which can improve the stability of the exhaust flame region estimation results.
[0028] (3) This invention extracts the region where the effective signal is located, reducing the impact of invalid events in regions outside the rocket body on subsequent algorithms. The OFF events in the effective region are superimposed into a binary image, which carries the position information of the key structure of the rocket body. Morphological closing operation is used to fill the discontinuous region of the key structure pixels of the rocket body caused by event sparsity, and then opening operation is used to remove isolated noise points, thereby enhancing the overall coherence of the rocket body structure.
[0029] (4) This invention utilizes the Hough transform to robustly extract the linear structure of the arrow body, making the displacement estimation more robust. The gradient analysis-based straight line segment detection method can achieve fast and accurate detection without manually setting parameters. This invention ultimately uses the average displacement of multiple line segments as the measurement basis, which can effectively suppress local noise and make the velocity-time curve smoother and more accurate. Attached Figure Description
[0030] Figure 1 This is a flowchart of a rocket launch phase velocity measurement method based on an event camera, provided by an embodiment of the present invention.
[0031] Figure 2(a) is a schematic diagram of event overlay provided in Embodiment 1 of the present invention.
[0032] Figure 2(b) is a schematic diagram of the cumulative binary value of the OFF event provided in Embodiment 1 of the present invention.
[0033] Figure 2(c) is a schematic diagram of image morphological preprocessing provided in Embodiment 1 of the present invention.
[0034] Figure 2(d) is a schematic diagram of the straight line extraction result provided in Embodiment 1 of the present invention.
[0035] Figure 3(a) is a displacement-time curve provided in Embodiment 1 of the present invention.
[0036] Figure 3(b) is a speed-time curve provided in Embodiment 1 of the present invention. Detailed Implementation
[0037] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.
[0038] like Figure 1 As shown, a method for measuring rocket launch velocity based on an event camera includes the following steps:
[0039] (1) Spatially accumulate the ON events generated by the rocket exhaust flame captured by the event camera to form an ON event density map. Estimate the exhaust flame region from the ON event density map and obtain the position of the bottom edge of the rocket in the exhaust flame region. Thus, construct an effective region containing only the rocket body.
[0040] (2) Overlay the OFF events in the effective area into a binary image, extract the straight line segments from the binary image, take the displacement of the straight line segments as the displacement of the rocket, combine the timestamp of the binary image to form a displacement-time curve, and calculate the gradient of the displacement-time curve to obtain the velocity-time curve.
[0041] Example 1
[0042] A method for measuring rocket launch velocity during the launch phase based on an event camera includes the following steps:
[0043] (1) Spatially accumulate the ON events generated by the rocket exhaust flame captured by the event camera to form an ON event density map. Estimate the exhaust flame region from the ON event density map and obtain the position of the bottom edge of the rocket in the exhaust flame region. Thus, construct an effective region containing only the rocket body.
[0044] (2) Overlay the OFF events in the effective area into a binary image, extract the straight line segments from the binary image, take the displacement of the straight line segments as the displacement of the rocket, combine the timestamp of the binary image to form a displacement-time curve, and calculate the gradient of the displacement-time curve to obtain the velocity-time curve.
[0045] Specifically, step (1) includes:
[0046] The event data captured by the event camera during rocket ignition and early liftoff were arranged in chronological order to construct an event stream. ,in The location where the event was triggered. For event timestamps, , This represents the number of events captured by the event camera within a cumulative time window (e.g., 30ms). For the polarity of the event, When the light intensity at this pixel changes from dark to bright ,otherwise .
[0047] ON events are spatially accumulated within a 30ms time window to form an ON event density map. The density value is the number of events per unit area. Based on the spatial distribution of the ON event density map, the Otsu method is used to construct an event density map histogram (the horizontal axis of the histogram represents the event density value, and the vertical axis represents the number of pixels corresponding to the event density value) and traverse candidate thresholds. It calculates the inter-class variance and searches for the optimal threshold that maximizes the distinction between high-density areas (exhaust flame) and low-density areas (background), thereby enabling automatic extraction of high-density areas of the exhaust flame.
[0048] For high-density areas, perform rectangular fitting or minimum bounding region filtering to determine the approximate range of the exhaust flame. Within adjacent time windows, the exhaust region The location and area changes are measured, and when the change exceeds a preset value... (e.g., 70%) At that time, historical exhaust region estimation results are introduced, and the current exhaust region parameters are subjected to time smoothing and weighted fusion. The fusion result satisfies
[0049]
[0050] in, This refers to the exhaust region detected within the current time window. The stability estimation results for the previous time window The weighting coefficients are used to obtain continuous and stable exhaust region estimation results in the time dimension.
[0051] Combined with the equivalent focal length parameters of the event camera (Before shooting, the event camera is calibrated using a calibration board, and the equivalent focal length is obtained through a standard camera calibration algorithm.) The actual width W and height H of the rocket body, as well as the distance D from the rocket to the event camera, are calculated using the formula... The pixel width of the rocket body in the event frame was calculated. ,high Finally, based on the rocket's exhaust plume area, the position of the rocket's bottom edge is first determined, and then based on the width... ,high Obtain the narrow vertical region of the rocket body in the event frame.
[0052] Figure 2(a) is a schematic diagram of event frame overlay in Embodiment 1 of the present invention. After performing event response analysis on the extracted effective area, it can be observed that events of different polarities exhibit significant differences in spatial structure. The stacking of OFF events shows an approximately parallel linear distribution, while the stacking of ON events is more complex, potentially exhibiting a straight line distribution or forming an arc structure. Based on the experimental results, we found that using only OFF events for spatiotemporal stacking provides a more robust and accurate velocity estimation result for the rocket body.
[0053] Based on this, step (2) includes:
[0054] As shown in Figure 2(b), in the effective region, OFF events with a duration of 20ms (step size of 5ms) are superimposed to form a binary image, which carries the positional information of the key structures of the rocket body. Figure 2(c) is a schematic diagram of image morphological preprocessing in Embodiment 1 of the present invention. A morphological closing operation with a kernel size of 5×5 is used to fill in the discontinuous pixel regions of the key structures of the rocket body caused by event sparsity, and then an opening operation with a kernel size of 5×5 is used to remove isolated noise points, thereby enhancing the overall coherence of the rocket body structure.
[0055] Figure 2(d) is a schematic diagram of the line extraction result in Embodiment 1 of the present invention. The Hough Line Transform method (e.g., the HoughLinesP method in OpenCV) is performed on the morphologically processed binary image to preserve lines with approximately horizontal orientation (angle offset within 5 degrees) and lengths exceeding a threshold (e.g., set to 10). The line segments are used as structural features of the rocket's outline.
[0056] The coordinates of the two endpoints of line segment M can be obtained using the HoughLinesP method. Used to calculate the center position of a horizontal line segment Figures 3(a) and 3(b) are displacement-time curves and velocity-time curves, respectively, in Embodiment 1 of the present invention. The center positions of the N horizontal line segments extracted at consecutive time points are shown. The average value is used to obtain the global displacement pixels of the rocket body, and the actual displacement distance is calculated using the formula:
[0057]
[0058] in, This represents the actual lateral displacement of the rocket. The equivalent focal length for the camera width. The number of pixels representing the rocket width in the event frame. This represents the actual longitudinal displacement of the rocket. The equivalent focal length of the camera height. The number of pixels representing the rocket's height in the event frame. This represents the actual displacement of the rocket.
[0059] Since the event frames are stacked by a fixed duration (e.g., 3ms), each frame has a corresponding timestamp, an actual displacement-time curve can be constructed. Then, the gradient of the actual displacement-time curve can be obtained by first-order difference or polynomial fitting, thus obtaining the velocity-time curve.
[0060] Takeoff velocity information can be used to assess the operational status of the rocket during ignition and thrust buildup, determine the departure time, and assess early flight stability. If the takeoff velocity is non-uniform acceleration, it can be deduced that the rocket's flame nozzle is not functioning correctly. Compared to traditional frame cameras, event cameras offer advantages in high temporal resolution and high dynamic range, making them more suitable for high-speed, high-light observation scenarios during rocket takeoff.
[0061] This invention provides a method for measuring rocket launch velocity during the launch phase based on an event camera. By employing a combined strategy of exhaust plume region estimation and effective region extraction, it effectively eliminates a large number of invalid event interferences caused by the intense light from the exhaust plume, significantly improving the event signal quality of the target rocket body. Combining event response analysis and morphological processing enhances the continuity and detectability of the rocket body contour. The robust extraction of the rocket body's linear structure using Hough transform provides higher robustness for displacement estimation. Finally, using the average displacement of multiple line segments as the measurement basis effectively suppresses local noise, resulting in a smoother and more accurate velocity-time curve. The overall method maintains reliable performance even under extreme lighting conditions, achieving highly robust and accurate velocity measurement during rocket launch.
[0062] Example 2
[0063] The difference from Example 1 is that the maximum entropy thresholding method is used to estimate the exhaust flame region, and the linear structure of the rocket body is robustly extracted using a gradient analysis-based straight line segment detection method.
[0064] Example 3
[0065] The present invention also relates to an electronic device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the rocket takeoff speed measurement method described above.
[0066] The electronic device can be a desktop computer, laptop, handheld computer, or cloud server, etc. The processor can be a Central Processing Unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The memory can be used to store computer programs and / or modules. The processor performs various functions of the electronic device by running or executing the computer programs and / or modules stored in the memory, and by accessing data stored in the memory.
[0067] Example 4
[0068] The present invention also relates to a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the rocket takeoff speed measurement method described above.
[0069] Specifically, the memory may include high-speed random access memory, as well as non-volatile memory, such as hard disks, RAM, plug-in hard disks, smart media cards (SMC), secure digital (SD) cards, flash cards, at least one disk storage device, flash memory device, or other volatile solid-state storage devices.
[0070] Example 5
[0071] The present invention also relates to a computer program product or computer program, including computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the steps of the rocket launch phase velocity measurement method of the above embodiments of the present invention.
[0072] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A method for measuring the velocity of a rocket during its launch phase based on an event camera, characterized in that, Includes the following steps: (1) Spatially accumulate the ON events generated by the rocket exhaust flame captured by the event camera to form an ON event density map. Estimate the exhaust flame region from the ON event density map and obtain the position of the bottom edge of the rocket in the exhaust flame region. Thus, construct an effective region containing only the rocket body. (2) Overlay the OFF events in the effective area into a binary image, extract the straight line segments from the binary image, take the displacement of the straight line segments as the displacement of the rocket, combine the timestamp of the binary image to form a displacement-time curve, and calculate the gradient of the displacement-time curve to obtain the velocity-time curve. The effective region is extracted in the following way: Combining the width and height equivalent focal length parameters of the event camera The actual width W, actual height H of the rocket body, and distance D from the rocket's center point to the event camera are determined according to the formula. The pixel width of the rocket body in the event frame was calculated. Pixel height First, obtain the position of the bottom edge of the rocket in the exhaust plume area, and then determine the position based on the pixel width. Pixel height Obtain the valid area of the rocket body in the event frame.
2. The method for measuring rocket launch velocity based on an event camera as described in claim 1, characterized in that, The specific method for estimating the exhaust region is as follows: Within a time window, ON events are spatially accumulated to form an ON event density map. A histogram of the ON event density map is constructed. All thresholds are traversed, and the inter-class variance between the high-density and low-density regions of the exhaust plume is calculated for each threshold. The threshold that maximizes the inter-class variance is selected as the optimal threshold. The high-density region of the exhaust plume is extracted from the histogram of the ON event density map. Rectangular fitting or minimum bounding region screening is performed on the high-density region of the exhaust plume. Combined with the rocket nozzle position, candidate regions of the exhaust plume are determined. The position and area changes of the candidate regions of the exhaust plume are detected in adjacent time windows. For candidate regions of the exhaust plume with changes exceeding a preset value, smoothing and weighted averaging are performed to estimate the exhaust plume region.
3. The method for measuring rocket launch velocity based on an event camera as described in claim 1, characterized in that, The specific method for estimating the exhaust region is as follows: Within a time window, ON events are spatially accumulated to form an ON event density map. A histogram of the ON event density map is constructed. All thresholds are traversed, and the information entropy of the high-density and low-density regions of the exhaust plume under each threshold is calculated. The threshold that maximizes the information entropy is selected as the optimal threshold. The high-density region of the exhaust plume is extracted from the histogram of the ON event density map. Rectangular fitting or minimum bounding region screening is performed on the high-density region of the exhaust plume. Combined with the rocket nozzle position, candidate regions of the exhaust plume are determined. The position and area changes of the candidate regions of the exhaust plume are detected in adjacent time windows. For candidate regions of the exhaust plume with changes exceeding a preset value, smoothing and weighted averaging are performed to estimate the exhaust plume region.
4. A method for measuring rocket launch velocity based on an event camera as described in any one of claims 1-3, characterized in that, Before extracting the line segments from the binary graph in step (2), the binary graph is subjected to closing and opening operations in sequence.
5. A method for measuring rocket launch velocity based on an event camera as described in any one of claims 1-3, characterized in that, Step (2) uses a gradient analysis-based straight line segment detection method or Hough transform to extract straight line segments from the binary image.
6. A method for measuring rocket launch velocity based on an event camera as described in any one of claims 1-3, characterized in that, In step (2), multiple straight line segments are extracted from the binary image. The average displacement of the multiple straight line segments is taken as the displacement of the rocket. Combined with the timestamp of the binary image, a displacement-time curve is formed. The gradient of the displacement-time curve is obtained by first-order difference or polynomial fitting, and the velocity-time curve is obtained.
7. A rocket launch phase velocity measurement system based on an event camera, characterized in that, include: The rocket body extraction module is used to spatially accumulate ON events generated by the rocket exhaust flame captured by the event camera to form an ON event density map. The exhaust flame region is estimated from the ON event density map, and the position of the bottom edge of the rocket is obtained in the exhaust flame region. Thus, an effective region containing only the rocket body is constructed. The velocity measurement module is used to overlay OFF events in the effective area into a binary image, extract straight line segments from the binary image, use the displacement of the straight line segments as the displacement of the rocket, combine the timestamp of the binary image to form a displacement-time curve, and calculate the gradient of the displacement-time curve to obtain the velocity-time curve. The effective region is extracted in the following way: Combining the width and height equivalent focal length parameters of the event camera The actual width W, actual height H of the rocket body, and distance D from the rocket's center point to the event camera are determined according to the formula. The pixel width of the rocket body in the event frame was calculated. Pixel height First, obtain the position of the bottom edge of the rocket in the exhaust plume area, and then determine the position based on the pixel width. Pixel height Obtain the valid area of the rocket body in the event frame.
8. An electronic device, characterized in that, Includes a processor and a computer-readable storage medium, wherein: The computer-readable storage medium stores program instructions for implementing each step of the rocket launch phase velocity measurement method based on an event camera as described in any one of claims 1 to 6; the processor, when executing the program instructions, is used to implement the entire process of rocket launch phase velocity measurement.
9. A computer product, characterized in that, When the product is running, it enables the computer to execute the steps of the rocket launch phase velocity measurement method based on an event camera as described in any one of claims 1 to 6.