Field real-time positioning target scoring method based on projectile tail section track observation

Abstract

The invention discloses a field real-time positioning and target scoring method based on projectile tail section trajectory observation, which is characterized in that a direct aiming gun high-speed projectile trajectory in an outdoor live ammunition shooting process is identified based on image and sound fusion, a newly added target landing point is positioned through fusion processing, and real-time accurate target scoring is realized; the method comprises the following steps: when an artillery is shot, a sound acquisition and recognition device acquires a sound signal in the process of exiting from a chamber when the artillery launches a bullet, processes the signal to recognize the sound of bullet launching, generates a trigger signal and sends the trigger signal to a high-speed image acquisition and recognition device; the high-speed image acquisition and identification equipment is used for receiving the trigger signal, calculating and setting high-speed image acquisition parameters, and performing image acquisition to obtain at least N frames of images before the bullet touches the target; and the real position of the projectile target landing point is calculated based on single-frame image fitting, the target landing point positioning precision is optimized based on multiple-frame images, and finally a newly added target landing point is output. According to the invention, the problem that real-time high-precision detection cannot be carried out on the target hitting point of the high-speed projectile is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of shooting training target reporting, and specifically relates to a field real-time positioning target reporting method based on the observation of the projectile's terminal trajectory, which is used for the real-time detection of the projectile hitting the target during the weapon shooting process. Background Art

[0002] Currently, there are few available devices in this field for the real-time detection of the hitting position of direct-fire guns. Generally, the hitting position is detected by ultrasonic waves or image processing. Among them:

[0003] 1) The detection device based on ultrasonic ranging has poor environmental adaptability and low positioning accuracy due to the limitation of its working system. Moreover, the sensor must be set at the target, which is very easy to be destroyed. At the same time, due to the open layout of the sensor, it is greatly affected by the external environment, and it may not work properly in strong winds or rain.

[0004] 2) The method of using a low-frame-rate camera to collect and identify the image of the impact point. Since the target used in direct-fire gun shooting training is usually a rigid skeleton with a white gauze net inside, the gauze net flutters greatly, and the light transmission of the bullet hole background results in an unclear contrast between the bullet hole and the gauze net, so the accuracy of identifying the bullet hole is low. Some devices using a high-frame-rate camera to detect the hitting trajectory mostly detect the projectile trajectory through an array composed of multiple cameras. Due to the high frame rate and limited hardware computing power, they can only collect data on-site and rely on a server for post-processing, so they are all large-scale fixed devices.

[0005] 3) In addition, some devices that perform spatial positioning of the projectile trajectory through binocular vision can only be used in small quantities in the test field due to high power consumption, and are not suitable for field use and large-scale deployment.

[0006] Since there is currently no portable direct-fire weapon target reporting system that can be deployed in the field target range and support real-time detection and target reporting, it cannot meet the accurate evaluation requirements in direct-fire gun shooting training, resulting in almost all the accuracy detection of the hitting position of direct-fire guns relying on manual target viewing, which seriously restricts the improvement of the live firing level.

[0007] Therefore, there is an urgent need to develop a system and method for capturing, identifying, and reporting high-speed projectiles of direct-fire guns to meet the urgent needs of this field. After popularization and use, it will be able to greatly improve the live firing level and effectively reduce the live firing risk. Summary of the Invention

[0008] The object of the present invention is to provide a field real-time positioning and target reporting method based on the observation of the projectile's terminal trajectory. By using monocular vision under strong constraint conditions to detect the projectile's terminal trajectory and accurately calculate the projectile's impact position, the accurate evaluation level of direct-fire artillery shooting training is significantly improved. Combining the military requirement research and analysis carried out for the Army, Navy, and Air Force, through the accurate evaluation and real-time feedback of the projectile's impact position, and based on this, shooting corrections are made and shooting target reporting experiences are formed. While significantly reducing training consumption, the accurate shooting level of shooters can be greatly improved, and the actual combat ability of shooting can be comprehensively enhanced.

[0009] The technical solution adopted by the present invention to achieve the above object is: a field real-time positioning and target reporting method based on the observation of the projectile's terminal trajectory, which uses image and sound fusion to identify the high-speed projectile trajectory of a direct-fire gun during outdoor live ammunition shooting, fuses and processes to locate new impact points, and reports the target in real time and accurately; the method includes the following steps:

[0010] During artillery shooting, the sound acquisition and recognition device acquires the sound signal during the muzzle exit process when the artillery fires a projectile, and the signal is processed to recognize the sound of the shell firing, generating a trigger signal for the high-speed image acquisition and recognition device;

[0011] The high-speed image acquisition and recognition device receives the trigger signal, calculates and sets the high-speed image acquisition parameters, and performs image acquisition to obtain at least N frames of images before the bullet hits the target; taking any three consecutive frames of images as a group, fitting and calculating the true position of the projectile's impact point; optimizing the positioning accuracy of the impact point based on the fitting and calculation results of multiple groups, and finally outputting a new impact point.

[0012] The sound recognized by the signal processing as the sound of the shell firing is: the sound of the shell firing is recognized by the processing module built in the sound acquisition and recognition device through time-domain and frequency-domain characteristics.

[0013] The high-speed image acquisition parameters include: the flight time T of the projectile from launch to impact, the time range of image acquisition, and the image acquisition frame rate.

[0014] The flight time T of the projectile from launch to impact is calculated by querying according to the shooting distance and the muzzle velocity in the firing table.

[0015] The time range of image acquisition is set within the time period of T - X to T + X.

[0016] The fitting and calculation of the true position H' of the projectile's impact point includes:

[0017] Camera calibration to obtain the camera internal parameters;

[0018] Establish two coordinate systems: the geodetic coordinate system and the camera coordinate system;

[0019] Calculate the coordinate transformation relationship R between two coordinate systems by photographing the four corner points of the target with a camera;

[0020] Definition: G is the accurate position of the camera, which is unknown and needs to be solved and located; points D, E, and F are the real projectile trajectory points during the flight of the high-speed projectile, which are unknown and need to be solved and located; points A, B, and C are the corresponding position coordinate points of the projection image points A', B', and C' photographed by the camera in the geodetic coordinate system; among them, A', B', and C' are the projection image points of points D, E, and F in the camera coordinate system respectively;

[0021] The camera photographs the projectile trajectories D, E, and F to obtain the projection image points A', B', and C' in the camera coordinate system, and combines the coordinate transformation relationship R to convert them into points A, B, and C in the geodetic coordinate system;

[0022] Back-calculate the real position G point of the camera in the geodetic coordinate system;

[0023] Solve the real space positions E and D of the projectile in the geodetic coordinate system;

[0024] According to the straight line DE and points A, B, and C, solve the real target-hitting position coordinate H of the projectile in the geodetic coordinate;

[0025] According to the coordinate transformation relationship R, map to obtain the camera coordinate of point H, and obtain the target-hitting position H' in the image.

[0026] The back-calculating the real position G point of the camera in the geodetic coordinate system is to construct a PNP problem by combining the coordinate transformation relationship R between the two coordinate systems, and then obtain the geodetic coordinate position of point G.

[0027] The solving the real space positions E and D of the projectile in the geodetic coordinate system includes:

[0028] Solve the included angle of EDG according to the formula And

[0029] According to the known sides and angles, use trigonometric functions to further obtain the spatial positions of points E and D in the geodetic coordinate system.

[0030] The solving the real target-hitting position coordinate H of the projectile in the geodetic coordinate according to the straight line DE and points A, B, and C is to use the intersection point of the straight line DE and the target plane as H, or use the intersection point of the straight line DE and the straight line AB as H.

[0031] The N is an integer not less than 3.

[0032] The present invention has the following beneficial effects and advantages:

[0033] 1. The present invention solves the problem of being unable to perform real-time high-precision detection of the impact point of a high-speed projectile. In traditional methods, detection devices using ultrasonic sensors have low accuracy, poor environmental adaptability, a positioning accuracy of 10 - 15 cm, and are subject to many environmental interferences, and cannot be detected in strong winds or rain. By collecting the target holes of the target through a low-frame-rate camera, reliable detection cannot be achieved under the influence of factors such as the target cloth fluttering caused by the wind and the interference of the background color of the target holes. For traditional technologies that collect and identify projectiles through high-speed images, real-time detection cannot be achieved due to computing power limitations. This solution is not affected by the above environmental factors, has high detection accuracy and stability. Through three-dimensional simulation and experimental determination, its positioning accuracy is ≤ 5 mm, and the reliability is ≥ 99%, and the detection effect is significantly better than traditional methods.

[0034] 2. The present invention realizes system miniaturization, low power consumption, and field deployability. In this solution, all devices complete image processing at the acquisition end, with high device integration and low power consumption, which is conducive to field layout. By triggering the high-speed acquisition of the impact image through a sound signal, identifying and positioning the projectile impact position, the real-time reporting of the target is good, effectively solving the problems of traditional high-speed imaging technology that can only be processed afterwards, cannot perform real-time detection, and cannot be deployed in a small field. In addition, by arranging high-speed imaging acquisition devices at a certain distance and providing appropriate protection, the problem of the ultrasonic target reporting device being destroyed when the projectile hits the target support frame is solved, and the service life of the device is significantly extended.

[0035] 3. The application of this system can increase the shooting organization efficiency by more than 5 times and improve the shooting hit rate by more than 20%. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a schematic diagram of the working scenario of the present invention;

[0037] Figure 2 is a flowchart of the method of the present invention;

[0038] Figure 3 is a schematic diagram of position calculation. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following specifically describes the specific implementation method of the present invention in conjunction with the drawings. Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the invention. Therefore, the present invention is not limited by the specific implementations disclosed below.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this invention belongs. The terms used in the specification of the invention herein are for the purpose of describing specific embodiments only and are not intended to limit the invention. The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0041] Embodiment 1. The system of the present invention includes: a high-speed image acquisition and recognition device, a sound acquisition and recognition device, a wireless communication device, and a display device. The specific composition of each device is as follows.

[0042] 1-1. High-speed image acquisition and recognition device:

[0043] In this solution, based on monocular vision technology, high-speed imaging technology is used as the image acquisition method, and a low-cost, miniaturized, high-speed parallel processing module is used as the hardware carrier. Since artillery guns are all single-shot and the firing interval between two shots is relatively long, this solution uses a triggering method to collect target images at a high frame rate for a short time and perform high-speed processing on the collected data. Whether or not bullet points are found after the processing is completed, the useless image data stored is deleted, solving the core problems such as the difficulty of long-term storage of high-speed images and the inability of traditional methods to process them in real time and efficiently.

[0044] The high-speed image acquisition and recognition device includes: a high-speed image acquisition module, a high-speed parallel processing module, a large-capacity storage module, and a network communication module. The core of the high-speed image acquisition module is a global shutter CMOS, which is mainly used to collect images at a high frame rate; the core of the parallel processing module is an FPGA, which mainly realizes the real-time storage and processing of high-speed images. In the collected images, the brightness contrast between the bullet and the target image is obvious. Combining the typical shape characteristics of the bullet, the position of the bullet in the image can be accurately identified and located by using pattern recognition. The large-capacity storage module is an SD card used to store the collected image data and the data during and after the processing. The network communication module is one or more of communication methods such as wifi, data transmission radio, 4G, and 5G.

[0045] Due to the large lethality of direct-fire guns, to reduce the risk of the camera being destroyed by bullets and considering the improvement of the recognition effect of bullet impact on the target, the high-speed image acquisition and recognition device is placed in the front side position of the target.

[0046] 1-2. Sound acquisition and recognition device:

[0047] In this solution, the sound recognition technology is used to recognize the sound of artillery firing collected on site. When it is confirmed that the artillery fires, the high-speed image acquisition and recognition module is triggered to perform image acquisition and recognition.

[0048] It includes: a sound acquisition module, a processing module, a storage module, and a network communication module. Among them, the sound acquisition module uses a microphone, the processing module is a pre-compiled signal processing applet for acquiring sound signals, the storage module is an SD card for storing the original sound signals acquired, the sound signals during the processing, and the result sound signals, and the network communication module uses one or more of the communication methods such as wifi, data transmission radio, 4G, and 5G to output the result trigger signal.

[0049] Since during the firing of the artillery, it is necessary to acquire the sound signals during the process of the projectile being launched out of the barrel, the sound acquisition and recognition device is placed near the direct-fire gun to facilitate the acquisition of the sound of the artillery firing.

[0050] 1-3. Wireless communication device:

[0051] The wireless communication method adopted in this solution can be one or more of the communication methods such as wifi, data transmission radio, 4G, and 5G. Since the amount of data transmitted is small, the above communication methods can all meet the requirements of transmission time limit and reliability.

[0052] During field live-fire target reporting, a wireless communication device needs to be placed between the direct-fire gun and the target as a relay data transmission node.

[0053] 1-4. Display device:

[0054] The display device adopted in this solution can be an intelligent terminal such as an ordinary display screen, a tablet, or a mobile phone, with a resolution of 1280*800.

[0055] Since during the firing of the artillery, it is necessary to visually display the target reporting result to the shooter, the display device is placed near the shooter of the direct-fire gun to facilitate the shooter to observe the target reporting effect.

[0056] Embodiment 2, the method of the present invention includes:

[0057] 2-1. During the firing of the artillery, when the sound acquisition and recognition device acquires and recognizes the sound signals during the process of the artillery launching the projectile out of the barrel, it will, through its built-in processing module, identify the sound of the shell firing through time-domain and frequency-domain features, and send a trigger signal to the high-speed image acquisition and recognition device through the wireless communication device.

[0058] 2-2. High-speed image acquisition device:

[0059] a. Image acquisition parameter setting:

[0060] After receiving the trigger signal, the flight time T of the projectile from launch to hitting the target is queried and calculated based on the shooting distance and the muzzle velocity in the firing table. Let X be the time period threshold. Within the relatively short time period from T - X to T + X, images are acquired at high speed and stored in real time in a large-capacity memory. At the same time, the processor starts to process the picture information in the large-capacity memory. Among them, through the error analysis of muzzle velocity calculation, trigger signal transmission delay, and actual tests, in this case, X is 20 ms.

[0061] Through the firing tables (issued with the equipment) of projectiles launched by different weapons, the flight time of the projectile to reach a certain distance and the muzzle velocity of the terminal trajectory can be queried. According to the velocity of the projectile, the time interval from when the projectile enters the camera's field of view to when it hits the target is calculated. Based on the requirement of being able to capture at least 3 frames of images within this time interval, the minimum frame rate required for the camera is calculated.

[0062] Taking a certain 105mm ammunition as an example in this case: When shooting at a distance of 1000 meters, the muzzle velocity of the projectile hitting the target is 800 m / s. An 18mm focal length camera is used and placed at a distance of 11.25 meters. The target is 4 meters * 3 meters, the center of the target is 2 meters above the ground, and the horizontal distance of the ballistic trajectory within the camera's field of view is 4.8 meters. To ensure that at least 3 photos can be captured within the field of view, the frame rate of the camera should be higher than 500 frames. The image resolution is calculated based on data such as the diameter and length of the projectile, as well as the size of the target, meeting the requirement of accurately identifying the projectile in the target background. The resolution in this case is 640 * 480.

[0063] According to the above resolution requirements, after the image device receives the trigger signal, it accumulatively acquires images for 40 ms and stores 20 pictures in total. The processing delay is less than 1 second, which can meet the requirement of real-time target reporting.

[0064] b. Method for solving and positioning the projectile hitting point:

[0065] This solution adopts a monocular vision spatial positioning method based on strong constraints and performs the following calculations based on two coordinate systems.

[0066] b1) Camera calibration: Used to obtain the internal parameters of the camera.

[0067] b2) Establish two coordinate systems: the geodetic coordinate system and the camera coordinate system. The geodetic coordinate system is the coordinate of the real physical position, and the camera coordinate system is the coordinate of the image captured by the camera.

[0068] b3) Obtain the conversion relationship: By obtaining the position coordinates of the four corner points of the target captured by the camera in the camera coordinate system and combining with the known real position coordinates of the four corner points of the target in the geodetic coordinate system, the coordinate conversion relationship R between the two coordinate systems is calculated.

[0069] b4) Position calculation:

[0070] Definition: As Figure 3As shown in the figure, it is a schematic diagram of position calculation in the geodetic coordinate system. G is the accurate position of the camera, which is unknown and needs to be solved and located. Points D, E, and F are the real projectile trajectory points during the flight of the high-speed projectile, which are unknown and need to be solved and located. Points A, B, and C are the corresponding position coordinate points of the projected image points A', B', and C' captured by the camera in the geodetic coordinate system. Among them, A', B', and C' are the projected image points of points D, E, and F in the camera coordinate system respectively.

[0071] The camera captures the projectile trajectories D, E, and F to obtain the projected image points A', B', and C' in the camera coordinate system, and converts them into points A, B, and C in the geodetic coordinate system in combination with the coordinate transformation relationship R.

[0072] b5) Inverse calculation of the real position G point of the camera in the geodetic coordinate system: Construct a PNP problem in combination with the coordinate transformation relationship R between the two coordinate systems, and then obtain the geodetic coordinate position of point G.

[0073] b6) Solve the real space positions E and D of the projectile in the geodetic coordinate system:

[0074] It can be deduced and proved according to the following formula that α is related to θ and related, and

[0075]

[0076] Given the geodetic coordinates of points A, B, C and point G and the strong constraint conditions obtained in the first step, and deduced according to the trigonometric function relationship. The derivation process is as follows. Let EG = P

[0077]

[0078] Let All are known quantities

[0079] sinα = K·sin(180 - m - α) = K·sin(m + α)

[0080] sinα = K·(sinm·cosα + cosm·sinα)

[0081] sinα = K·sinm·cosα + K·cosm·sinα

[0082] (1 - K·cosm)·sinα = K·sinm·cosα

[0083]

[0084] And since the strong constraint conditions set in this case are: the frame rate is pre-calculated and set, and the time interval between each frame is consistent, the flight distance d of the projectile between adjacent frames in the geodetic coordinate system is equivalently consistent, that is, DE = EF = d.

[0085] According to the formula, the included angle α of EDG can be obtained, and the spatial positions of points E and D in the geodetic coordinate system can be further obtained by using trigonometric functions based on the known sides and angles.

[0086] b7) According to the straight line DE and points A, B, and C, solve the true target-hitting position coordinates H of the projectile in the geodetic coordinates.

[0087] Specifically, the true intersection point H of the extension line of the connection of the spatial positions of DE and the target in the geodetic coordinate system can be solved through the straight line equation, or the geodetic coordinates of the intersection point H of the extension line of the straight line DE and the extension line of the straight line AC can be solved through the straight line equation.

[0088] b8) Then, according to the coordinate transformation relationship R mapping, the camera coordinates of point H are obtained, and the target-hitting position H' in the image is obtained.

[0089] b9) Through modeling and simulation and actual measurement, for images with 4 or more frames collected, the positioning points can be solved through 3 consecutive frames of images, and the average value of multiple solved positioning points is used as the final target-hitting point, which can improve the positioning accuracy of the target-hitting point.

[0090] Effect data:

[0091] The present invention solves the problem of being unable to perform real-time high-precision detection on the target-hitting point of high-speed projectiles. This solution is not affected by environmental factors such as strong winds and rain, and has high detection accuracy and stability. Through three-dimensional simulation and experimental determination, its positioning accuracy ≤ 5 mm, and the reliability ≥ 99%. The detection effect is significantly better than the traditional method; the application of this system can increase the shooting organization efficiency by more than 5 times and the shooting target-hitting rate by more than 20%.

[0092] In current training, the method of manually observing the target is generally used for target inspection. After single-gun shooting, the observer goes to the target from a bunker 100 meters away to observe the target and mark the target hole, which takes about 8 - 10 minutes for a round trip; after using this solution, the shooting target-hitting effect can be seen within 1 second. After adjusting the firing data or calibrating the weapon, shooting can continue, and the training efficiency is improved very significantly. In addition, through the real-time feedback of the shooting target-hitting point, the shooter can improve the mastery of shooting conditions and weapon firing data, which will also significantly improve the shooting performance.

[0093] The above is only a preferred embodiment of the present invention, and it does not impose any limitations on the present invention. Any simple modifications, changes, and equivalent structural changes made to the above embodiments according to the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A field real-time positioning and reporting method based on the observation of the terminal trajectory of the projectile, based on the fusion of images and sounds to identify the high-speed projectile trajectory of the direct-aiming gun during outdoor live-fire shooting, and to locate the newly added target point through fusion processing, and to report the target accurately in real time; it is characterized by: The method comprises the following steps: When the artillery is firing, the sound collection and recognition device collects the sound signal of the artillery projectile exiting the barrel, processes the signal to recognize the sound of the artillery shell firing, and generates a trigger signal to the high-speed image collection and recognition device; The high-speed image acquisition and recognition device receives the trigger signal, calculates and sets the high-speed image acquisition parameters, and performs image acquisition to obtain at least N frames of images before the bullet hits the target; any three consecutive frames of images are used as a group to fit and solve the real position of the projectile impact point; the impact point positioning accuracy is optimized based on multiple groups of fitting and solving results, and finally the newly added target impact point is output.

2. The field real-time positioning and reporting method based on the terminal trajectory observation of the projectile according to claim 1 is characterized in that: The signal processing identifies the sound of the artillery shell firing as follows: the processing module built into the sound collection and recognition device identifies the sound of the artillery shell firing through time domain and frequency domain features.

3. The field real-time positioning and reporting method based on the observation of the terminal trajectory of the projectile according to claim 1 is characterized in that: The high-speed image acquisition parameters include: the flight time T of the projectile from launch to target impact, the time range of image acquisition, and the image acquisition frame rate.

4. The field real-time positioning and reporting method based on the observation of the terminal trajectory of the projectile according to claim 3 is characterized in that: The flight time T of the projectile from launch to target impact is calculated based on the shooting distance and the bullet velocity query of the shooting table.

5. The field real-time positioning and reporting method based on the observation of the terminal trajectory of the projectile according to claim 3 is characterized in that: The time range of the image acquisition is set within the time period from TX to T+X.

6. The field real-time positioning and reporting method based on the observation of the terminal trajectory of the projectile according to claim 1 is characterized in that: The fitting solution to calculate the real position H' of the projectile impact point includes: Camera calibration, obtaining camera internal parameters; Establish two coordinate systems: earth coordinate system and camera coordinate system; The coordinate transformation relationship R between the two coordinate systems is calculated by shooting the four corner points of the target with a camera; Definition: G is the exact position of the camera, which is unknown and needs to be solved and positioned; points D, E, and F are the actual projectile trajectory points during the high-speed projectile flight, which are unknown and need to be solved and positioned; points A, B, and C are the corresponding position coordinate points of the projection image points A', B', and C' taken by the camera in the geodetic coordinate system; among them, A', B', and C' are the projection image points of points D, E, and F in the camera coordinate system respectively; The camera captures the projectile trajectories D, E, and F to obtain the projection image points A', B', and C' in the camera coordinate system, and converts them into the three points A, B, and C in the geodetic coordinate system in combination with the coordinate transformation relationship R; Reversely solve the real position G of the camera in the geodetic coordinate system; Solve the real spatial positions of the projectile in the geodetic coordinate system, points E and D; According to the straight line DE and the three points A, B, and C, solve the coordinates H of the actual target position of the projectile in the geodetic coordinates; The camera coordinates of point H are obtained according to the coordinate transformation relationship R mapping, and the target position H' in the image is obtained.

7. The field real-time positioning and reporting method based on the terminal trajectory observation of the projectile according to claim 6 is characterized in that: The reverse solution of the real position G of the camera in the geodetic coordinate system is to construct a PNP problem by combining the coordinate transformation relationship R between the two coordinate systems, and then obtain the geodetic coordinate position of the G point.

8. The field real-time positioning and reporting method based on the terminal trajectory observation of the projectile according to claim 6 is characterized in that: The method of solving the real spatial positions E and D of the projectile in the geodetic coordinate system includes: Solve the angle of EDG according to the formula and According to the known sides and angles, trigonometric functions are used to obtain the spatial positions of points E and D in the geodetic coordinate system.

9. The field real-time positioning and reporting method based on the observation of the terminal trajectory of the projectile according to claim 6 is characterized in that: The actual target position coordinate H of the projectile in geodetic coordinates is solved according to the straight line DE and the three points A, B and C, by using the intersection of the straight line DE and the target plane as H, or using the intersection of the straight line DE and the straight line AB as H.

10. The field real-time positioning and reporting method based on the terminal trajectory observation of a projectile according to any one of claims 1 to 9, characterized in that: N is an integer not less than 3.

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