Fire point identification method and system based on satellite image

Abstract

The invention provides a fire point identification method and system based on a satellite image, and relates to the technical field of fire point identification, and the method comprises the steps: obtaining satellite attitude and orbit data when the satellite image is collected; establishing a quick conversion parameter for converting the coordinates of each pixel point in the satellite image into the coordinates of the pixel points in the pixel coordinate system; converting each image coordinate of the satellite image into a world coordinate in a geocentric coordinate system by using the rapid conversion parameter; acquiring longitude and latitude of each world coordinate of the satellite image under the geocentric coordinate system according to the world coordinates; converting the brightness value of a pixel point to be detected in the satellite image into a radiation brightness temperature; when the radiation brightness temperature is greater than a radiation brightness temperature threshold value set according to the longitude and latitude, determining the to-be-detected pixel point as an initial fire point; performing primary screening on the initial fire points according to the radiation brightness temperature difference values of the to-be-detected pixel points at different radiation wavelengths; and performing secondary screening of the cloud water body area on the initial fire point after primary screening by combining the rapid conversion parameters, and retaining a target fire point.

Description

Technical Field

[0001] The present invention relates to the technical field of fire point identification, and in particular to a fire point identification method and system based on satellite images. Background Art

[0002] Fire spot identification based on satellite images is a technology that uses image data captured by satellite sensors to detect surface fires (such as forest fires or grassland fires). This method mainly determines whether there are fire spots on the surface by analyzing satellite image information. Fire spot identification based on satellite images has the significant advantages of wide coverage and fast response speed. It can monitor fire conditions in remote and difficult-to-reach areas in real time, which is crucial for early detection of fires, timely mobilization of rescue resources and reduction of losses caused by fires.

[0003] At present, in the process of identifying fire points based on satellite images, whether it is a fire point is often judged directly by determining the radiation brightness temperature of the satellite image. However, this method cannot eliminate the influence of interference such as warm background, clouds, and water bodies. It has large errors and is prone to misjudgment, which limits its practicality. Summary of the invention

[0004] In order to solve the technical problem that in the prior art, in the process of fire point identification based on satellite images, whether it is a fire point is often directly judged by determining the radiation brightness temperature of the satellite image, but this method cannot eliminate the influence of interference such as warm background, cloud body, water body, etc., has large errors, is prone to misjudgment, and has limited practicality, the present invention provides a fire point identification method and system based on satellite images.

[0005] The technical solution provided by the embodiment of the present invention is as follows:

[0006] First aspect

[0007] An embodiment of the present invention provides a method for identifying fire points based on satellite images, comprising:

[0008] S1: Obtain the satellite attitude and orbit data corresponding to the acquisition of the satellite image, wherein the satellite attitude and orbit data include the satellite speed at the exposure time, the satellite position at the exposure time, and the satellite attitude angle at the exposure time;

[0009] S2: Combined with the satellite attitude and orbit data, establish fast conversion parameters for converting the coordinates of each pixel point in the satellite image into the pixel point coordinates in the pixel coordinate system, where the fast conversion parameters include the coordinates of the center point of the satellite image in the pixel coordinate system and the length of a single pixel point of the satellite image in each coordinate axis direction in the image coordinate system;

[0010] S3: using fast conversion parameters to convert each image coordinate of the satellite image into a world coordinate in the geocentric coordinate system;

[0011] S4: Obtain the longitude and latitude of each world coordinate of the satellite image in the geocentric coordinate system according to the world coordinate;

[0012] S5: converting the brightness value of the pixel to be detected in the satellite image into radiation brightness temperature;

[0013] S6: When the radiation brightness temperature is greater than the radiation brightness temperature threshold set according to the longitude and latitude, the pixel to be detected is determined as an initial fire point;

[0014] S7: Screening the initial fire points according to the radiation brightness temperature difference of the pixel to be detected at different radiation wavelengths;

[0015] S8: Combine the rapid conversion parameters to conduct a secondary screening of the cloud and water area for the initial fire points after the first screening, and retain the target fire points.

[0016] Second aspect

[0017] An embodiment of the present invention provides a fire point identification system based on satellite images, comprising:

[0018] processor;

[0019] A memory having computer-readable instructions stored thereon, wherein when the computer-readable instructions are executed by the processor, the fire point identification method based on satellite images as described in the first aspect is implemented.

[0020] The third aspect

[0021] An embodiment of the present invention provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, the method for identifying fire points based on satellite images as described in the first aspect is implemented.

[0022] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0023] In the present invention, firstly, in combination with the satellite attitude and orbit data, fast conversion parameters are established for converting the coordinates of each pixel point in the satellite image into the coordinates of the pixel point in the pixel coordinate system, so that irrelevant interference at the pixel level can be effectively and quickly filtered out. After the initial fire point is preliminarily determined by the radiation brightness temperature, a screening is performed using the radiation brightness temperature difference of the satellite at different radiation wavelengths to eliminate false fire points caused by the warm background, and the obtained coordinate conversion parameters are used to determine the cloud and water body area, and the initial fire points after the screening belonging to the cloud and water body area are further removed to obtain more accurate fire points, further reduce the fire point misjudgment rate, and increase the practicality of fire point identification based on satellite images. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0025] Figure 1 A schematic diagram of a flow chart of a method for identifying fire points based on satellite images provided by an embodiment of the present invention;

[0026] Figure 2 A schematic structural diagram of a fire point identification system based on satellite images provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0027] The technical solution of the present invention is described below in conjunction with the accompanying drawings.

[0028] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "example" is intended to present the concept in a specific way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either of the two.

[0029] In the embodiments of the present invention, "image" and "picture" can sometimes be used interchangeably. It should be noted that when the difference between them is not emphasized, the meanings they intend to express are the same. "of", "corresponding, relevant" and "corresponding" can sometimes be used interchangeably. It should be noted that when the difference between them is not emphasized, the meanings they intend to express are the same.

[0030] In the embodiments of the present invention, sometimes a subscript such as W1 may be mistakenly written as a non-subscript such as W1. When the difference is not emphasized, the meanings to be expressed are consistent.

[0031] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0032] Reference Manual Attached Figure 1 , showing a flow chart of a fire point identification method based on satellite images provided in an embodiment of the present invention.

[0033] The embodiment of the present invention provides a method for identifying fire points based on satellite images, which can be implemented by a fire point identification device based on satellite images, and the fire point identification device based on satellite images can be a terminal or a server. The processing flow of the method for identifying fire points based on satellite images may include the following steps:

[0034] S1: Obtain the satellite attitude and orbit data corresponding to the satellite image acquisition.

[0035] Among them, the satellite attitude and orbit data include the satellite speed at the exposure time, the satellite position at the exposure time, and the satellite attitude angle at the exposure time.

[0036] Among them, the satellite speed at the exposure time refers to the speed of the satellite at the exact moment of capturing the image. Knowing the satellite speed can help analyze motion blur in satellite images and is very important for subsequent image correction and processing. The satellite position at the exposure time refers to the precise spatial position of the satellite when the image is captured. This information is extremely critical for determining the geographical location corresponding to each pixel in the image, especially when locating and estimating ground features. The satellite attitude angle at the exposure time refers to the specific direction or angle of the satellite relative to the earth. The satellite attitude angle affects the orientation and coverage area of ​​the image, and is particularly important for the geometric correction and analysis accuracy of the image. Obtaining these attitude and orbit data makes the analysis of satellite images more accurate and helps to extract more reliable information from the image, such as terrain analysis, object recognition, etc. In remote sensing technology, the speed, position and attitude data of the satellite are crucial to ensure the consistency of the image with the actual ground conditions, and are the basis for high-quality image processing and analysis.

[0037] S2: Combined with satellite attitude and orbit data, establish fast conversion parameters for converting the coordinates of each pixel point in the satellite image into the coordinates of the pixel point in the pixel coordinate system.

[0038] The fast conversion parameters include the coordinates of the center point of the satellite image in the pixel coordinate system and the length of a single pixel point of the satellite image in each coordinate axis direction in the image coordinate system.

[0039] Among them, the acquisition of fast conversion parameters helps to convert these coordinates into coordinates in the pixel coordinate system. The core purpose of this step is to achieve accurate correspondence and fast conversion of coordinates to facilitate image analysis and processing.

[0040] In a possible implementation, S2 specifically includes:

[0041] S201: Determine the coordinates of four corner points and the center point in the satellite image.

[0042] S202: Obtaining the corner point coordinates and the center point coordinates in the world coordinate system corresponding to the corner point world coordinates and the center point world coordinates according to the satellite attitude and orbit data.

[0043] S203: Substitute the obtained world coordinates of the corner point and the world coordinates of the center point into the association equation between the world coordinate system and the image coordinate system to solve the fast conversion parameter. The association equation is specifically:

[0044]

[0045] in, represents the world coordinates, I and J represent the pixel row number and pixel column number of the satellite image, respectively. represents the world coordinates of the center point, w and h represent the width and height of the satellite image respectively, and They respectively represent the length of a single pixel point of the satellite image in the X-axis direction and the Y-axis direction in the image coordinate system.

[0046] Specifically, first determine the coordinates of the four corner points (upper left, upper right, lower left, and lower right) in the satellite image and the center point of the image. These coordinates are usually positions in the pixel coordinate system and are used to establish the relationship between the image and the actual geographical location. According to the attitude and position data of the satellite, the pixel coordinates in the image determined in S201 are converted into corresponding world coordinates, and the pixel position is converted into the actual geographical location (such as longitude, latitude, and altitude). This conversion depends critically on the real-time attitude and orbit data of the satellite. The world coordinates and image coordinates obtained from S202 are substituted into a predefined association equation to solve the required fast conversion parameters. The solution of these parameters involves matching the position of each pixel point in the image with its actual position on the earth, so that the conversion from image coordinates to world coordinates is both fast and accurate.

[0047] In the actual application process, the current coordinates of the satellite are first obtained, and then the three attitude angles of the satellite are obtained. The direction vector of the z-axis of the satellite sensor is calculated using the three attitude angles and the practical attitude equivalent matrix. A straight line is constructed using the current coordinates of the satellite to obtain the intersection with the earth ellipsoid equation, and then the distance from the imaging center to the ground object converted from the satellite image to the coordinates in the sensor coordinate system is obtained. According to the equivalent matrix after the satellite geometric calibration and the distance from the imaging center to the ground object, the coordinates of the four corner points and the center point of the satellite image in the sensor coordinate system are calculated, and then converted to the coordinates in the orbital coordinate system, and finally converted to the world coordinates in the geocentric coordinate system, that is, the WGS82 coordinate system. The corresponding geodetic coordinates are obtained according to the obtained world coordinates, and the positioning fast conversion parameters can be calculated according to the obtained geodetic coordinates.

[0048] S3: Use fast conversion parameters to convert each image coordinate of the satellite image into world coordinates in the geocentric coordinate system.

[0049] In a possible implementation, S3 specifically includes:

[0050] S301: Using fast conversion parameters to convert image coordinates into pixel coordinates in a pixel coordinate system :

[0051]

[0052] in, represents the image coordinates.

[0053] S302: Calculate the sensor coordinates of the satellite image in the sensor coordinate system by combining the internal orientation element matrix of the satellite infrared payload :

[0054]

[0055] in, Indicates the focal length of the infrared camera's wavelength band. Represents the coordinates of the phase principal point in the phase plane.

[0056] S303: Calculate the orbital coordinates of the image coordinates in the orbital coordinate system in combination with the attitude equivalent matrix of the satellite at the exposure time, and convert the orbital coordinates into world coordinates.

[0057] S304: Calculate the world coordinates of the image coordinates according to the conversion matrix between the orbital coordinate system and the geocentric coordinate system:

[0058]

[0059] in, The world coordinates representing the image coordinates, represents the transformation matrix.

[0060] It should be noted that by using fast transformation parameters, internal orientation element matrix, attitude equivalent matrix and coordinate system transformation matrix, this process can accurately correspond image data to actual geographic location. This transformation not only enhances the spatial accuracy of image data, but also improves the automation and efficiency of data processing.

[0061] S4: Obtain the longitude and latitude of each world coordinate of the satellite image in the geocentric coordinate system according to the world coordinate.

[0062] In a possible implementation, the longitude and latitude of each world coordinate of the satellite image in the geocentric coordinate system obtained by the world coordinates are specifically:

[0063]

[0064] in, Indicates longitude, Indicates latitude.

[0065] Among them, longitude and latitude are the coordinate systems used to determine any location on the earth's surface. Since the radiation brightness temperature is different at different latitudes, the longitude and latitude calculated by accurately obtaining the world coordinates can accurately determine the radiation brightness temperature threshold, thereby making the results of fire point identification based on radiation brightness temperature more accurate and reliable.

[0066] S5: Convert the brightness value of the pixel to be detected in the satellite image into radiation brightness temperature.

[0067] Among them, the brightness value is also called the DN value. The DN value (Digital Number) is the brightness value of the remote sensing image pixel and the grayscale of the recorded ground object. The radiation brightness temperature refers to the temperature of the electromagnetic radiation emitted by an object. It is an apparent temperature estimated based on the radiation intensity emitted by the object. This concept is based on the blackbody radiation theory, in which an ideal blackbody refers to an object that completely absorbs all incident radiation and completely emits radiation. In practical applications, the radiation brightness temperature is used to describe the thermal radiation ability of the surface of an object, and is not necessarily the actual physical temperature of the object.

[0068] It should be noted that the step of converting DN values ​​in satellite images into radiation brightness temperature is crucial for a deep understanding of the surface thermal properties and environmental conditions. This conversion enables scientists and analysts to obtain accurate information about surface temperature from remote sensing data.

[0069] In a possible implementation manner, the radiation brightness temperature is specifically:

[0070]

[0071] Wherein, T represents the radiation brightness temperature, b represents the Wien displacement constant, represents the radiation wavelength, ln represents the natural logarithm, Indicates a given The radiance L at the radiation wavelength, h represents Planck's constant, c represents the speed of light, k represents the Boltzmann constant, G represents the calibration slope, B represents the calibration intercept, DN represents the brightness value of the pixel to be detected, and e represents the base of the natural logarithm.

[0072] It should be noted that the calculated radiation brightness temperature is useful for analyzing surface thermal characteristics, monitoring environmental changes, obtaining information about the state and changes of the earth's environment, and assessing the impact of disasters (such as fire).

[0073] S6: When the radiation brightness temperature is greater than the radiation brightness temperature threshold set according to the longitude and latitude, the pixel to be detected is determined as an initial fire point.

[0074] It should be noted that the environmental and climatic conditions on the earth's surface vary significantly in different geographical locations. For example, factors such as vegetation types, drought or humidity levels, and seasonal changes in different regions may affect normal ground temperature. Therefore, by setting different radiation brightness temperature thresholds for different longitudes and latitudes, real fire points can be identified more accurately to avoid misjudgments caused by environmental factors, such as mistaking high-temperature rock surfaces or high temperatures caused by direct sunlight for fire points. Such settings enhance the applicability and accuracy of fire point detection technology. The radiation brightness temperature of each pixel in the satellite image is compared with the threshold associated with a specific longitude and latitude. If the radiation brightness temperature of a pixel exceeds this threshold, the pixel is preliminarily identified as a fire point. This step is to set different radiation brightness temperature thresholds based on geographical location, thereby improving the accuracy and adaptability of fire point identification, especially under different geographical environments and climatic conditions.

[0075] It should be noted that those skilled in the art can set the radiation brightness temperature threshold value according to actual needs, and the present invention is not limited thereto.

[0076] S7: Screening the initial fire points according to the radiation brightness temperature difference of the pixel points to be detected at different radiation wavelengths.

[0077] Among them, the radiation brightness temperature difference refers to the difference in brightness temperature readings at the same location under different infrared bands. Real flames usually show higher brightness temperatures than the surrounding non-burning areas in specific infrared bands (such as the mid-infrared band). This is because the thermal radiation intensity of the flame is higher than the general natural background. The reason why the method based on the radiation brightness temperature difference is used to eliminate false fire points caused by warm background is mainly based on the significant temperature difference between the flame and its surrounding environment in the infrared spectrum. Flames will produce very high radiation energy in certain infrared bands, which causes the radiation brightness temperature to be significantly higher than the surrounding areas without flames. By comparing the difference in radiation brightness temperature at the same location in different infrared bands, the real fire points can be effectively screened out. This method uses the unique radiation characteristics of flames in specific infrared bands, which are significantly higher than the surrounding environment, thereby eliminating high temperature false alarms caused by natural warm backgrounds or other non-fire source factors. This screening mechanism enhances the accuracy of fire point detection, reduces false alarms, and improves the reliability and practicality of the fire point monitoring system.

[0078] In a possible implementation, S7 specifically includes:

[0079] S701: Obtain the radiation brightness temperature difference of the pixel to be detected in two bands different from the radiation wavelength.

[0080] S702: Determine whether the current time is day or night. If the current time is daytime, proceed to S703; otherwise, proceed to S704.

[0081] S703: When the radiation brightness temperature difference is greater than the first brightness temperature difference threshold, retain the initial fire point corresponding to the pixel to be checked.

[0082] S704: When the radiation brightness temperature difference is greater than the second brightness temperature difference threshold, retain the initial fire point corresponding to the pixel to be checked.

[0083] It should be noted that the different standards for the brightness temperature difference during the day and at night mainly take into account the influence of solar radiation under sunlight conditions. During the day, solar radiation increases the surface temperature of the ground and other objects. Therefore, even non-flame warm objects may have higher infrared radiation, which increases the difficulty of distinction. Therefore, setting a higher temperature difference threshold (such as 30K) helps to more accurately distinguish between real fire points and high temperature points caused by sunlight. In contrast, at night, there is no interference from solar radiation, and a lower brightness temperature difference (such as 15K) is sufficient to distinguish flames from other heat sources. In this way, the number of false alarms can be effectively reduced and the accuracy and reliability of fire point detection can be improved. Correctly identifying fire points is not only related to the efficiency of fire monitoring and early warning systems, but also directly affects the timeliness and effectiveness of fire emergency response and resource allocation.

[0084] It should be noted that those skilled in the art can set the first brightness temperature difference threshold and the second brightness temperature difference threshold according to actual needs, and the present invention is not limited thereto.

[0085] In a possible implementation manner, the first brightness temperature difference threshold is 30K, and the second brightness temperature difference threshold is 15K.

[0086] Here, K represents the Kelvin temperature unit. The higher threshold of 30K is usually used for fire point identification under daytime conditions. Due to sunlight exposure, the surface temperature is generally high during the day, which may lead to an increase in the radiation brightness temperature, thereby increasing the possibility of misjudgment. Setting a higher brightness temperature difference threshold helps to distinguish between real flames and high temperature phenomena caused by direct sunlight or other heat sources. The lower threshold of 15K is often used for fire point identification at night. At night, due to the lack of solar radiation, the temperature of the surface and the environment is usually low, so the difference between the radiation brightness temperature of the flame and the temperature of the background does not need to be large to be clearly distinguished. Therefore, a lower brightness temperature difference threshold helps to effectively identify fire points at night, while avoiding underreporting due to overly strict conditions. With such a setting, the identification strategy can be flexibly adjusted according to different environmental conditions (diurnal changes) to optimize the accuracy and reliability of fire point identification. This method of adjusting the threshold based on time and environmental conditions helps to provide more accurate fire point detection results in different monitoring scenarios.

[0087] S8: Combine the rapid conversion parameters to conduct a secondary screening of the cloud and water area for the initial fire points after the first screening, and retain the target fire points.

[0088] It should be noted that the accuracy of fire point identification is greatly improved by using fast conversion parameters to perform secondary screening of cloud and water areas on the initial fire points that have been screened. This step can effectively avoid misjudgments caused by high reflectivity or other characteristics of these areas by identifying and excluding the influence of cloud and water coverage areas, further reducing the false alarm rate and enhancing the practicality and reliability of the system.

[0089] In a possible implementation, S8 specifically includes:

[0090] S801: Determine the pixel points of the cloud water area on the satellite image.

[0091] S802: Establishing a buffer region discrimination formula for cloud and water region pixel points. The buffer region discrimination formula is specifically:

[0092]

[0093] Among them, m represents the number of pixel unit lengths separated from the cloud and water body area pixels in the x-axis direction, n represents the number of pixel unit lengths separated from the cloud and water body area pixels in the y-axis direction, and km represents the distance in kilometers.

[0094] S803: Determine the buffer area of ​​the pixel points in the cloud water area according to the buffer area discrimination formula.

[0095] S804: Remove the initial fire points after one screening located in the buffer area to obtain the target fire points.

[0096] Specifically, by setting up a buffer zone in the cloud and water area to exclude possible misidentified fire spots, the accuracy of fire detection is greatly improved. In satellite images, the spectral reflectance characteristics of clouds and water bodies may be similar to those of fires, which can easily lead to false alarms. By creating a buffer zone and excluding initial fire spots in these areas, this method effectively avoids misidentification and ensures that only real fire spots are identified and reported, thereby increasing the reliability of the overall fire monitoring system.

[0097] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0098] In the present invention, firstly, satellite attitude and orbit data are combined to establish fast conversion parameters for converting the coordinates of each pixel point in the satellite image into the pixel point coordinates in the pixel coordinate system, so that irrelevant interference at the pixel level can be effectively and quickly filtered out. After the initial fire point is preliminarily determined by the radiation brightness temperature, a screening is performed using the radiation brightness temperature difference of the satellite at different radiation wavelengths to eliminate false fire points caused by the warm background, and the obtained coordinate conversion parameters are used to determine the cloud and water body area, and the initial fire points after the screening belonging to the cloud and water body area are further removed to obtain more accurate fire points, further reduce the fire point misjudgment rate, and increase the practicality of fire point identification based on satellite images.

[0099] Reference Manual Attached Figure 2 , showing a structural schematic diagram of a fire point identification system based on satellite images provided by the present invention.

[0100] The present invention further provides a satellite image-based fire point identification system 20, which is applied to the above-mentioned satellite image-based fire point identification method, comprising:

[0101] Processor 201.

[0102] The memory 202 stores computer-readable instructions. When the computer-readable instructions are executed by the processor 201, the fire point identification method based on satellite images as in the method embodiment is implemented.

[0103] The satellite image-based fire point identification system 20 provided in the present invention can execute the above-mentioned satellite image-based fire point identification method and achieve the same or similar technical effects. To avoid repetition, the present invention will not go into details.

[0104] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0105] In the present invention, firstly, satellite attitude and orbit data are combined to establish fast conversion parameters for converting the coordinates of each pixel point in the satellite image into the pixel point coordinates in the pixel coordinate system, so that irrelevant interference at the pixel level can be effectively and quickly filtered out. After the initial fire point is preliminarily determined by the radiation brightness temperature, a screening is performed using the radiation brightness temperature difference of the satellite at different radiation wavelengths to eliminate false fire points caused by the warm background, and the obtained coordinate conversion parameters are used to determine the cloud and water body area, and the initial fire points after the screening belonging to the cloud and water body area are further removed to obtain more accurate fire points, further reduce the fire point misjudgment rate, and increase the practicality of fire point identification based on satellite images.

[0106] It should be understood that the processor in the embodiment of the present invention may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0107] It should also be understood that the memory in the embodiments of the present invention may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of random access memory (RAM) are available, such as static RAM (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link DRAM (SLDRAM), and direct rambus RAM (DR RAM).

[0108] The above embodiments can be implemented in whole or in part by software, hardware (such as circuits), firmware or any other combination. When implemented by software, the above embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center by wired (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that contains one or more available media sets. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a tape), an optical medium (for example, a DVD), or a semiconductor medium. The semiconductor medium can be a solid-state hard disk.

[0109] It should be understood that the term "and / or" in this article is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship, but it may also indicate an "and / or" relationship. Please refer to the context for specific understanding.

[0110] In the present invention, "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0111] It should be understood that in various embodiments of the present invention, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0112] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0113] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described equipment, devices and units can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0114] In the several embodiments provided by the present invention, it should be understood that the disclosed devices, apparatuses and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0115] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0116] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0117] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, and other media that can store program codes.

[0118] An embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, characterized in that when the program is executed by a processor, the fire point identification method based on satellite images as described in the method embodiment is implemented.

[0119] A computer-readable storage medium provided by the present invention can implement the steps and effects of the fire point identification method based on satellite images in the above method embodiment. To avoid repetition, the present invention will not go into details.

[0120] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least:

[0121] In the present invention, firstly, satellite attitude and orbit data are combined to establish fast conversion parameters for converting the coordinates of each pixel point in the satellite image into the pixel point coordinates in the pixel coordinate system, so that irrelevant interference at the pixel level can be effectively and quickly filtered out. After the initial fire point is preliminarily determined by the radiation brightness temperature, a screening is performed using the radiation brightness temperature difference of the satellite at different radiation wavelengths to eliminate false fire points caused by the warm background, and the obtained coordinate conversion parameters are used to determine the cloud and water body area, and the initial fire points after the screening belonging to the cloud and water body area are further removed to obtain more accurate fire points, further reduce the fire point misjudgment rate, and increase the practicality of fire point identification based on satellite images.

[0122] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

[0123] There are a few points to note:

[0124] (1) The drawings of the embodiments of the present invention only involve structures related to the embodiments of the present invention. Other structures may refer to conventional designs.

[0125] (2) For the sake of clarity, in the drawings used to describe the embodiments of the present invention, the thickness of layers or regions is exaggerated or reduced, that is, these drawings are not drawn according to the actual scale. It is understood that when an element such as a layer, film, region or substrate is referred to as being "on" or "under" another element, the element may be "directly" "on" or "under" the other element or there may be intermediate elements.

[0126] (3) In the absence of conflict, the embodiments of the present invention and the features therein may be combined with each other to obtain new embodiments.

[0127] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A method for identifying fire points based on satellite images, characterized in that: include: S1: Acquire satellite attitude and orbit data corresponding to the acquisition of the satellite image, wherein the satellite attitude and orbit data include satellite speed at the exposure time, satellite position at the exposure time, and satellite attitude angle at the exposure time; S2: In combination with the satellite attitude and orbit data, establish fast conversion parameters for converting the coordinates of each pixel point in the satellite image into the coordinates of the pixel point in the pixel coordinate system, wherein the fast conversion parameters include the coordinates of the center point of the satellite image in the pixel coordinate system and the length of a single pixel point of the satellite image in each coordinate axis direction in the image coordinate system; S3: using the fast conversion parameters to convert each image coordinate of the satellite image into a world coordinate in a geocentric coordinate system; S4: Acquire the longitude and latitude of each world coordinate of the satellite image in the geocentric coordinate system according to the world coordinate; S5: converting the brightness value of the pixel to be detected in the satellite image into a radiation brightness temperature; S6: When the radiation brightness temperature is greater than the radiation brightness temperature threshold set according to the longitude and latitude, the pixel point to be detected is determined as an initial fire point; S7: Screening the initial fire points according to the radiation brightness temperature difference of the pixel points to be detected at different radiation wavelengths; S8: Perform secondary screening of the cloud and water area on the initial fire points after the primary screening in combination with the rapid conversion parameters, and retain the target fire points.

2. The method for identifying fire points based on satellite images according to claim 1, characterized in that: The S2 specifically includes: S201: Determine the coordinates of four corner points and the center point in the satellite image; S202: Acquire the corner point coordinates and the center point coordinates in the world coordinate system corresponding to the corner point world coordinates and the center point world coordinates according to the satellite attitude and orbit data; S203: Substitute the obtained corner point world coordinates and center point world coordinates into the association equation between the world coordinate system and the image coordinate system to solve the fast conversion parameter. The association equation is specifically: ； in, represents the world coordinates, I and J represent the pixel row number and pixel column number of the satellite image, respectively. represents the world coordinates of the center point, w and h represent the width and height of the satellite image respectively, and They respectively represent the length of a single pixel point of the satellite image in the X-axis direction and the Y-axis direction in the image coordinate system.

3. The method for identifying fire points based on satellite images according to claim 2, characterized in that: The S3 specifically includes: S301: Using the fast conversion parameters to convert the image coordinates into pixel coordinates in a pixel coordinate system : ； in, represents the image coordinates; S302: Calculate the sensor coordinates of the satellite image in the sensor coordinate system by combining the internal orientation element matrix of the satellite infrared payload : ； in, Indicates the focal length of the infrared camera’s wavelength band. represents the coordinates of the phase principal point in the phase plane; S303: Calculate the orbital coordinates of the image coordinates in the orbital coordinate system in combination with the attitude equivalent matrix of the satellite at the exposure time, and convert the orbital coordinates into world coordinates; S304: Calculate the world coordinates of the image coordinates according to the conversion matrix between the orbital coordinate system and the geocentric coordinate system: ； in, The world coordinates representing the image coordinates, represents the transformation matrix.

4. The method for identifying fire points based on satellite images according to claim 3, characterized in that: The world coordinates for obtaining the latitude and longitude of each world coordinate of the satellite image in the geocentric coordinate system are specifically: ； in, Indicates longitude, Indicates latitude.

5. The method for identifying fire points based on satellite images according to claim 1, characterized in that: The radiation brightness temperature is specifically: ； Wherein, T represents the radiation brightness temperature, b represents the Wien displacement constant, represents the radiation wavelength, ln represents the natural logarithm, Indicates a given The radiance L at the radiation wavelength, h represents Planck's constant, c represents the speed of light, k represents the Boltzmann constant, G represents the calibration slope, B represents the calibration intercept, DN represents the brightness value of the pixel to be detected, and e represents the base of the natural logarithm.

6. The method for identifying fire points based on satellite images according to claim 1, characterized in that: The S7 specifically includes: S701: Obtaining the radiation brightness temperature difference of the pixel to be detected in two bands different from the radiation wavelength; S702: Determine whether the current time is day or night. If the current time is day, proceed to S703; otherwise, proceed to S704; S703: When the radiation brightness temperature difference is greater than a first brightness temperature difference threshold, retaining the initial fire point corresponding to the pixel to be detected; S704: When the radiation brightness temperature difference is greater than a second brightness temperature difference threshold, retain the initial fire point corresponding to the pixel to be detected.

7. The method for identifying fire points based on satellite images according to claim 6, characterized in that: The first bright temperature difference threshold is 30K, and the second bright temperature difference threshold is 15K.

8. The method for identifying fire points based on satellite images according to claim 1, characterized in that: The S8 specifically includes: S801: Determine pixel points in the cloud and water area on the satellite image; S802: Establishing a buffer region discrimination formula for the cloud and water region pixel points, wherein the buffer region discrimination formula is specifically: ； Wherein, m represents the number of pixel unit lengths spaced from the pixel point of the cloud and water body region in the x-axis direction, n represents the number of pixel unit lengths spaced from the pixel point of the cloud and water body region in the y-axis direction, and km represents the distance unit in kilometers; S803: Determine the buffer area of ​​the pixel points in the cloud and water area according to the buffer area discrimination formula; S804: removing the initial fire points located in the buffer area after a screening, and obtaining the target fire points.

9. A fire point identification system based on satellite images, characterized in that: include: processor; A memory having computer-readable instructions stored thereon, wherein when the computer-readable instructions are executed by the processor, the satellite image-based fire point identification method as described in any one of claims 1 to 8 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the satellite image-based fire point identification method as described in any one of claims 1 to 8 is implemented.

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