A real-time monitoring and identification system for fireballs

Abstract

The application discloses a real-time monitoring and identifying system for fireball, which comprises a whole-sky monitoring subsystem, a data processing and control subsystem, and an error correction subsystem.The whole-sky monitoring subsystem is used for shooting a whole-sky monitoring image and recording information of an exposure start time and an exposure end time.The data processing and control subsystem is used for controlling a shooting time and an exposure time length of the whole-sky monitoring subsystem, receiving and storing the whole-sky monitoring image and time information shot by the whole-sky monitoring subsystem, and processing and acquiring target position information.The error correction subsystem acquires a real azimuth value and an altitude value of a north star and azimuth values and altitude values of the north star in the whole-sky monitoring image, acquires an angle error, and performs error correction on the target position information to obtain real azimuth values and altitude values of the target.The technical scheme of the application performs error correction on a fireball position acquired by a monitoring system to obtain real azimuth values and altitude values of the fireball.

Description

Technical Field

[0001] This invention relates to the field of astronomical observation technology, and in particular to a real-time monitoring and identification system for fireballs. Background Technology

[0002] Internationally, meteors with a diameter exceeding 1 meter, a magnitude brighter than -3, and a mass greater than 5 grams are called fireballs. They generally originate from small celestial bodies in the solar system entering Earth's atmosphere under its gravitational pull. During this process, the meteor experiences high-speed friction with the air, causing a rapid increase in temperature and producing a dazzling light. Simultaneously, the meteor may disintegrate in the air, and many incompletely ablated meteorites may fall to the ground as impact meteorites. Fireballs primarily originate from near-Earth asteroids or comets within the solar system, where some meteorites detach from their parent bodies and fall to Earth.

[0003] Fireballs disrupt the space environment and aerospace during their entry into the atmosphere. Meteorites that don't completely ablate upon impact with the ground can cause widespread environmental damage, potentially leading to personal injury and property loss. In recent years, numerous fireball events have occurred both domestically and internationally, such as those in Xishuangbanna (Yunnan), Yushu (Qinghai), Songyuan (Jilin), and Chelyabinsk (Russia), attracting widespread global attention. Fireball measurement data is of significant research value in meteorite search, planetary materials in the solar system, the orbital evolution of near-Earth objects, hypersonic flight, and disaster prevention and mitigation. Therefore, it is necessary to monitor fireballs and obtain high-precision location information.

[0004] Currently, the main method for monitoring fireballs involves using photoelectric monitoring equipment pointed at a fixed area of ​​the sky and passively waiting for the fireball to appear. However, fireballs are inherently random, with their location and direction of movement being completely unpredictable, and they move at high speeds. Existing monitoring methods have limited sky coverage, increasing the possibility of missing fireball events. Furthermore, most monitoring systems acquire fireball measurement data with significant errors, failing to achieve full-sky monitoring and high-precision observation of fireballs. Therefore, existing monitoring methods are inefficient and cannot meet the needs of fireball monitoring and related research.

[0005] In conclusion, how to reduce the position monitoring error caused by monitoring fireballs is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] The main objective of this invention is to propose a real-time monitoring and identification system for fireballs, which aims to correct errors in fireballs acquired by an all-sky monitoring system in order to obtain the true azimuth and altitude values ​​of the fireballs.

[0007] The technical solution of the present invention to solve the above-mentioned technical problems is to provide a real-time monitoring and identification system for fireballs, comprising:

[0008] The all-day monitoring subsystem is used to capture all-day monitoring images and record information such as the start and end times of exposure.

[0009] The data processing and control subsystem is used to control the shooting time and exposure duration of the all-day monitoring subsystem, receive and store the all-day monitoring images and time information captured by the all-day monitoring subsystem, and process and acquire target location information.

[0010] The error correction subsystem acquires the true azimuth and altitude values ​​of Polaris and the azimuth and altitude values ​​of Polaris in the all-sky monitoring image, obtains the angle error, corrects the target position information, and obtains the true azimuth and altitude values ​​of the target.

[0011] In one embodiment of the present invention, the flow of the data processing control subsystem includes:

[0012] Receive all-day monitoring images and exposure time information, and obtain the location information of the shooting location;

[0013] Based on the zenith position pixel coordinates (x) of the all-sky area measurement image c y c Establish a Cartesian coordinate system with the origin at (x, y). c y c The x-axis is parallel to the north-south direction, with its positive direction pointing north; the y-axis is parallel to the east-west direction, with its positive direction pointing east. The range of the x-axis is (-m, m), and the range of the y-axis is (-m, m). For the target position (x...) in the image... i y i Its azimuth angle A in the horizontal coordinate system i and elevation angle h i The calculation method is converted as follows:

[0014]

[0015]

[0016] Where m, i, and c are positive integers, and satisfy the conditions i≤m and c≤m.

[0017] In one embodiment of the present invention, the process of the error correction subsystem includes:

[0018] Obtain the position information of the positioning reference star, Polaris, that is, the pixel coordinates of the center of Polaris in the image (x...). s y s The azimuth angle A measured by the method can be obtained through conversion and calculation. s and elevation angle h s ;

[0019] Based on the geographical latitude, longitude, and altitude of the all-sky monitoring subsystem's installation location, the true azimuth value A of Polaris is obtained. p and height value h p The angular error value of the image data obtained by the all-day monitoring subsystem is:

[0020] θ=A p -A s

[0021]

[0022] The star center position (x) of the fireball target in the all-sky monitoring image. obj y obj The measured azimuth value A is obtained by conversion and calculation as described above. obj and height value h obj After performing appropriate error corrections, the true azimuth and altitude values ​​of the target are obtained.

[0023] In one embodiment of the present invention, the real-time monitoring and identification system for fireballs further includes:

[0024] The identification subsystem, based on data from the data processing and control subsystem, uses the Polaris identified in the all-sky monitoring image as a benchmark, compares the brightness of Polaris with that of the target to identify the target fireball; and obtains the position information of the target fireball.

[0025] In one embodiment of the present invention, the process of the identification subsystem includes:

[0026] Using the North Star identified in the all-sky monitoring images as a benchmark, and taking the North Star as the standard star, the brightness of the North Star and the target in the all-sky monitoring images are compared. The target star magnitude that is 4.5 brighter than the North Star is identified as a potential fireball target.

[0027] Based on whether potential fireball targets are elongated in all-sky monitoring images, it is determined whether they are fireball targets.

[0028] If there is a trailing effect, it is a fire meteor target.

[0029] In one embodiment of the present invention, the process of the all-day monitoring subsystem includes:

[0030] Capture images of the entire monitoring area throughout the day;

[0031] Record the start and end times of the exposure.

[0032] In one embodiment of the present invention, the all-sky monitoring subsystem consists of a wide-angle fisheye lens, a high-resolution scientific-grade CCD camera, and a high-precision clock. The wide-angle fisheye lens covers the entire visible field of view, and the high-resolution scientific-grade CCD camera captures images of the entire sky. The time information of the start and end times of the CCD camera exposure, provided by the high-precision clock, is recorded and transmitted to the data processing and control subsystem.

[0033] In one embodiment of the present invention, the target location information includes the location information of the fireball target and the location information of Polaris.

[0034] The technical solution of this invention, by setting up an error correction subsystem, corrects the errors in the image data processed by the data processing and control subsystem. The error correction subsystem calculates the angular error between Polaris in the all-sky detection image and the actual Polaris, using Polaris as the standard. This angular error is then used to correct the true azimuth and altitude values ​​of other targets in the all-sky detection image, thereby obtaining the true azimuth and altitude values ​​of the targets. This reduces the error in the true azimuth and altitude values ​​of fireballs detected by the monitoring system. This invention enables all-sky monitoring of randomly occurring fireball events, achieving automatic identification and rapid processing of fireball targets, and obtaining high-precision location information of fireballs. This is beneficial for research in related fields such as fireball monitoring and discovery, meteorite search, and fireball orbit calculation. This system features wide sky coverage, fast response speed, and high monitoring efficiency. Furthermore, the system has low construction cost, high operational stability, and is easy to install and build into a fireball monitoring network. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the structure of the real-time monitoring and identification system for fireballs described in this invention;

[0037] Figure 2 This is a flowchart illustrating the real-time monitoring and identification system for fireballs described in this invention. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0039] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0040] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "several" or "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0041] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0042] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0043] This invention proposes a real-time monitoring and identification system for fireballs, which aims to correct errors in the fireballs acquired by the monitoring system in order to obtain the true azimuth and altitude values ​​of the fireballs.

[0044] The specific structure of the real-time monitoring and identification system for fireballs proposed in this invention will be described below in specific embodiments:

[0045] In the technical solution of this embodiment, such as Figure 1 As shown, a real-time monitoring and identification system for fireballs includes:

[0046] The all-day monitoring subsystem is used to capture all-day monitoring images and record information such as the start and end times of exposure.

[0047] The data processing and control subsystem is used to control the shooting time and exposure duration of the all-day monitoring subsystem, receive and store the all-day monitoring images and time information captured by the all-day monitoring subsystem, and process and acquire target location information.

[0048] The error correction subsystem acquires the true azimuth and altitude values ​​of Polaris and the azimuth and altitude values ​​of Polaris in the all-sky monitoring image, obtains the angle error, corrects the target position information, and obtains the true azimuth and altitude values ​​of the target.

[0049] Understandably, this invention sets up an error correction subsystem to correct errors in the image data processed by the data processing and control subsystem. The error correction subsystem calculates the angular error between Polaris and the actual Polaris in the all-sky detection image using Polaris as the standard. Then, it corrects the true azimuth and altitude values ​​of other targets in the all-sky detection image using this angular error to obtain the true azimuth and altitude values ​​of the targets. This reduces the error in the true azimuth and altitude values ​​of the fireballs detected in the monitoring system.

[0050] In one embodiment of the present invention, the flow of the data processing control subsystem includes:

[0051] Receive all-day monitoring images and exposure time information, and obtain the location information of the shooting location;

[0052] Based on the zenith position pixel coordinates (x) of the all-sky area measurement image c y c Establish a Cartesian coordinate system with the origin at (x, y). c y c The x-axis is parallel to the north-south direction, with its positive direction pointing north; the y-axis is parallel to the east-west direction, with its positive direction pointing east. The range of the x-axis is (-m, m), and the range of the y-axis is (-m, m). For the target position (x...) in the image... i y i Its azimuth angle A in the horizontal coordinate system i and elevation angle h i The calculation method is converted as follows:

[0053]

[0054]

[0055] Where m, i, and c are positive integers, and satisfy the conditions i≤m and c≤m.

[0056] Understandably, a coordinate system is established with the location of the all-day monitoring subsystem as the origin, and the target coordinates are determined in the coordinate system. In order to obtain the azimuth and elevation angles of the target, the planar coordinates of the target position are transformed using the above formula, thereby obtaining the azimuth and elevation angles of the target.

[0057] In one embodiment of the present invention, the process of the error correction subsystem includes:

[0058] Obtain the position information of the positioning reference star, Polaris, that is, the pixel coordinates of the center of Polaris in the image (x...). s y s The azimuth angle A measured by the method can be obtained through conversion and calculation. s and elevation angle h s ;

[0059] Based on the geographical latitude, longitude, and altitude of the all-sky monitoring subsystem's installation location, the true azimuth value A of Polaris is obtained. p and height value h p The angular error value of the image data obtained by the all-day monitoring subsystem is:

[0060] θ=A p -A s

[0061]

[0062] The star center position (x) of the fireball target in the all-sky monitoring image. obj y obj The measured azimuth value A is obtained by conversion and calculation as described above. obj and height value h obj After performing appropriate error corrections, the true azimuth and altitude values ​​of the target are obtained.

[0063] Understandably, the error correction subsystem uses Polaris as a reference and first obtains the image position (x) of Polaris from the all-sky monitoring images. s y s After data processing by the data processing and control subsystem, the image position can be converted into an azimuth angle A. s and elevation angle h s Based on the geographical location set by the all-sky monitoring subsystem, the true azimuth and altitude values ​​of Polaris relative to the all-sky monitoring subsystem at a specified time (the time when the all-sky monitoring image is captured) are determined. The difference between the position of Polaris in the all-sky monitoring image and the true position of Polaris can be obtained through the above formula. This difference is then used to revise the azimuth value of the target, so as to obtain the true azimuth and altitude values ​​of the target through the target position information in the all-sky monitoring image.

[0064] In one embodiment of the present invention, the real-time monitoring and identification system for fireballs further includes an identification subsystem, which, based on data information from the data processing and control subsystem, compares the brightness of the North Star identified in the all-sky monitoring image with that of the target fireball to identify the target fireball and obtain the position information of the target fireball.

[0065] The process of the identification subsystem includes:

[0066] Using the North Star identified in the all-sky monitoring images as a benchmark, and taking the North Star as the standard star, the brightness of the North Star and the target in the all-sky monitoring images are compared. The target star magnitude that is 4.5 brighter than the North Star is identified as a potential fireball target.

[0067] Based on whether potential fireball targets are elongated in all-sky monitoring images, it is determined whether they are fireball targets.

[0068] If there is a trailing effect, it is a fire meteor target.

[0069] Understandably, when the all-sky monitoring subsystem captures images, it will capture images of artificial celestial bodies such as satellites. To distinguish between artificial satellites and fireballs, this invention uses an identification subsystem to differentiate fireballs from targets in the all-sky monitoring images. Specifically, using Polaris as the standard star, the brightness of targets in the all-sky monitoring images is compared with the brightness of Polaris. Targets with a magnitude 4.5 brighter than Polaris are identified as potential fireball targets. Since the brightness of artificial satellites does not reach the brightness of fireballs or stars, a brightness comparison method can be used to filter out stars and fireballs from the all-sky monitoring images. The location is relatively fixed. When the exposure time is between 1 and 2 seconds during the all-sky monitoring subsystem's shooting, stars will not exhibit a trailing phenomenon. Therefore, to prevent interference from stars, all potential fireball targets are observed in the all-sky monitoring images to check for elongation. If elongation is present, it is a fireball target. When the exposure time is between 1 and 2 seconds during the all-sky monitoring subsystem's shooting, fireballs appear as elongated ellipses in the all-sky monitoring images. Therefore, by comparing the trailing state, stars and fireballs can be distinguished. Potential fireball targets with trailing states are real fireballs.

[0070] In one embodiment of the present invention, the process of the all-day monitoring subsystem includes:

[0071] Capture images of the entire monitoring area throughout the day;

[0072] Record the start and end times of the exposure.

[0073] In one embodiment of the present invention, the all-sky monitoring subsystem consists of a wide-angle fisheye lens, a high-resolution scientific-grade CCD camera, and a high-precision clock. The wide-angle fisheye lens covers the entire visible field of view, and the high-resolution scientific-grade CCD camera captures images of the entire sky. The time information of the start and end times of the CCD camera exposure, provided by the high-precision clock, is recorded and transmitted to the data processing and control subsystem.

[0074] In one embodiment of the present invention, the target location information includes the location information of the fireball target and the location information of Polaris.

[0075] Example 1

[0076] like Figure 1 As shown, a real-time monitoring and identification system for fireballs includes an all-sky monitoring subsystem, a data processing and control subsystem, an identification subsystem, and an error correction subsystem; as shown... Figure 2 As shown, the all-sky monitoring subsystem is used to capture all-sky monitoring images, the data processing and control subsystem processes the data, the identification subsystem identifies fireball targets using Polaris as the reference star, and the error correction subsystem corrects the identified fireball position information to obtain accurate azimuth and elevation values ​​of the fireball.

[0077] Specifically, the all-sky monitoring subsystem employs a wide-angle fisheye lens, monitoring a 180°×360° sky area with a focal length of 16mm. It is equipped with a large-format CCD camera with 4096×4096 pixels and a pixel size of 16μm×16μm, enabling all-sky monitoring. A high-precision clock is provided by a GPS timing card, receiving high-precision time information from GPS to provide the CCD camera with exposure start and end times. The subsystem also receives control commands from the data processing and control subsystem to capture images and transmit the image data to that subsystem.

[0078] The data processing and control subsystem issues control commands to control the start time and exposure duration of the high-resolution CCD camera in the all-sky monitoring subsystem, and receives and processes the captured image data.

[0079] The specific process of the identification subsystem is as follows: compare the star position information in two image data taken at different times, take advantage of the fact that the position of Polaris in the sky remains unchanged, select Polaris as the positioning reference star, identify and extract the position and magnitude brightness information of Polaris in the image, and use it for subsequent image calibration process and fireball target identification process;

[0080] The specific process of identifying fireball targets includes: using Polaris, which is identified in the all-sky monitoring image, as a benchmark, and using differential photometry to compare the magnitude brightness of Polaris with other celestial bodies. Based on the definition of fireball and the standard magnitude of Polaris, targets with a magnitude 4.5 brighter than Polaris are first identified as potential fireball targets. Further, based on whether the target is elongated in the image, it is determined whether it is a fireball target.

[0081] The data processing and control subsystem's data processing procedure includes: based on the zenith position pixel coordinates (x, y, y) of the all-sky monitoring image. c y c The total effective pixel count of the full-sky image is 4096×4096. A Cartesian coordinate system is established with the origin at (x...). c y c The x-axis is parallel to the north-south direction, with its positive direction pointing north; the y-axis is parallel to the east-west direction, with its positive direction pointing east. The range of the x-axis is (-2048, 2048), and the range of the y-axis is (-2048, 2048). For the position of the celestial target in the image (x... i y i ) and its azimuth and altitude values ​​in the horizontal coordinate system (A i h i The conversion calculation method is as follows:

[0082]

[0083]

[0084] Where i and c are positive integers, and satisfy the conditions i≤2048 and c≤2048.

[0085] The error correction subsystem's processing includes: obtaining the position information of the positioning reference star, Polaris, using the previously described process of identifying the positioning reference star, i.e., the pixel coordinates of Polaris's star center in the image are (x... s y s After conversion and calculation, its measured azimuth and elevation values ​​(A) can be obtained. s h s Then, based on the geographical latitude, longitude, and altitude of the all-sky monitoring subsystem's installation location, the true azimuth and altitude values ​​(A) of Polaris are obtained. p h p Therefore, the angular error value of the image data obtained by the all-day monitoring subsystem is:

[0086] θ=A p -A s

[0087]

[0088] The actual location of the fireball is obtained through the identification subsystem, corresponding to the star center position (x) of the fireball target in the all-sky monitoring image. obj y obj The measured azimuth angle A is obtained by conversion and calculation as described above. obj and elevation angle h obj After performing corresponding error corrections, the true azimuth and altitude values ​​of the fireball target are obtained.

[0089] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A real-time monitoring and identification system for fireballs, characterized in that, include: The all-day monitoring subsystem is used to capture all-day monitoring images and record information such as the start and end times of exposure. The data processing and control subsystem is used to control the shooting time and exposure duration of the all-day monitoring subsystem, receive and store the all-day monitoring images and time information captured by the all-day monitoring subsystem, and process and acquire target location information. The error correction subsystem obtains the true azimuth and altitude values ​​of Polaris and the azimuth and altitude values ​​of Polaris in the all-sky monitoring image, obtains the angle error, corrects the target position information, and obtains the true azimuth and altitude values ​​of the target. The identification subsystem, based on data from the data processing and control subsystem, uses the Polaris identified in the all-sky monitoring image as a benchmark, compares the brightness of Polaris with that of the target to identify the target fireball; and obtains the position information of the target fireball.

2. The real-time monitoring and identification system for fireballs according to claim 1, characterized in that, The data processing control subsystem includes the following flow: By receiving monitoring images and exposure time information from the entire day, the location information of the shooting location can be obtained; Based on the zenith position pixel coordinates (x) of the all-sky area measurement image c y c Establish a Cartesian coordinate system with the origin at (x, y). c y c The x-axis is parallel to the north-south direction, with its positive direction pointing north; the y-axis is parallel to the east-west direction, with its positive direction pointing east. The range of the x-axis is (-m, m), and the range of the y-axis is (-m, m). For the target position in the image (x... i y i ) and its azimuth A in the horizontal coordinate system i and elevation angle h i The conversion calculation method is as follows: ； Where m, i, and c are positive integers, and satisfy the conditions i≤m and c≤m.

3. The real-time monitoring and identification system for fireballs according to claim 2, characterized in that, The process of the error correction subsystem includes: Obtain the position information of the positioning reference star, Polaris, that is, the pixel coordinates of the center of Polaris in the image (x...). s y s The measured azimuth value A can be obtained through conversion and calculation. s and height value h s ; Based on the geographical latitude, longitude, and altitude of the all-sky monitoring subsystem's installation location, the true azimuth value A of Polaris is obtained. p and height value h p The angular error value of the image data obtained by the all-day monitoring subsystem is: ； The star center position (x) of the fireball target in the all-sky monitoring image. obj y obj The measured azimuth value A is obtained by conversion and calculation as described above. obj and height angle h obj After performing corresponding error corrections, the true azimuth and altitude values ​​of the target are obtained (A). obj +θ,h obj +φ).

4. The real-time monitoring and identification system for fireballs according to claim 3, characterized in that, The process of the identification subsystem includes: Using the North Star identified in the all-sky monitoring images as a benchmark, and taking the North Star as the standard star, the brightness of the North Star and the target in the all-sky monitoring images are compared. The target star magnitude that is 4.5 brighter than the North Star is identified as a potential fireball target. Based on whether potential fireball targets are elongated in all-sky monitoring images, it is determined whether they are fireball targets. If there is a trailing effect, it is a fire meteor target.

5. The real-time monitoring and identification system for fireballs according to claim 1, characterized in that, The workflow of the all-day monitoring subsystem includes: Capture images of the entire monitoring area throughout the day; Record the start and end times of the exposure.

6. The real-time monitoring and identification system for fireballs according to claim 1, characterized in that, The all-sky monitoring subsystem consists of a wide-angle fisheye lens, a high-resolution scientific-grade CCD camera, and a high-precision clock. The wide-angle fisheye lens covers the entire visible field of view, while the high-resolution scientific-grade CCD camera captures images of the entire sky. The high-precision clock records the start and end times of the CCD camera exposure and transmits these images to the data processing and control subsystem.

7. The real-time monitoring and identification system for fireballs according to claim 1, characterized in that, The target location information includes the location information of the fireball target and the location information of Polaris.

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