A method and system for observing thermal radiation directionality

Abstract

The invention discloses a method and system for observing the directivity of thermal radiation. The method comprises: S1, providing an unmanned aerial vehicle equipped with a thermal imager; S2, determining a center point on the ground, obtaining the coordinates of the center point, and laying a gray-scale target cloth at the center point; S3, making the unmanned aerial vehicle fly around the center point of the ground for multiple times at different flight pitch angles, taking pictures at multiple aerial points using a thermal imager to obtain multiple infrared remote sensing images, and obtaining real-time temperature data of the gray-scale target cloth at the same time; S4, extracting the temperatures in multiple thermal infrared remote sensing images obtained at multiple aerial points, and correcting the extracted temperatures and aerial point coordinates by using the center point coordinates and the real-time temperature data; S5, using the corrected temperatures and aerial point coordinates to generate a thermal radiation directivity radar map of a sample area including the center point by interpolation.

Description

Technical Field

[0001] The present invention relates to the field of unmanned aerial vehicle observation, and in particular to an observation method and system for observing the directivity of thermal radiation through an unmanned aerial vehicle. Background Art

[0002] At present, although remarkable results have been achieved in surface temperature inversion, it still faces many difficulties. One major obstacle is the angular effect caused by non-isothermal components and emissivity, which is called thermal radiation directionality. This problem is widely found in vegetation, bare land, urban construction land and other surface types.

[0003] In previous studies, most of the surface temperature was obtained through aerial experiments using airborne thermal imagers at specific test sites and ground experiments using tower crane platforms equipped with infrared thermal imagers. The observation methods were costly, had low flexibility in angle configuration, and could not be used to observe a wide range of different types of ground objects. The airborne platform experiments using drones have the following advantages: large observation range, strong spatial representativeness, avoiding interference between people and equipment in ground experiments, flexible angle configuration, and low cost.

[0004] Therefore, it is necessary to develop a method for applying UAV technology to the directional observation of thermal radiation to obtain the directional surface temperature observation method of thermal radiation, to normalize the angle effect of the surface temperature, and to obtain the surface temperature without the angle effect. Summary of the invention

[0005] In view of the defects existing in the prior art, the purpose of the present invention is to provide an economical and flexible method for observing the directionality of thermal radiation, which is used to solve the problems in the prior art of low flexibility in angle configuration, high observation cost and inability to conduct temperature observation of a large range of different types of land objects, and to achieve normalization of the angle effect of surface temperature to obtain surface temperature without angle effect.

[0006] A brief overview of the disclosure will be given below in order to provide a basic understanding of certain aspects of the disclosure. It should be understood that this overview is not an exhaustive overview of the disclosure. It is not intended to identify key or important parts of the disclosure, nor is it intended to limit the scope of the disclosure. Its purpose is simply to give certain concepts in a simplified form as a prelude to a more detailed description discussed later.

[0007] In order to achieve the above object, the present invention provides:

[0008] A method for observing the directionality of thermal radiation comprises the following steps:

[0009] S1, provides drones equipped with thermal imaging cameras;

[0010] S2, determine a center point on the ground, obtain the coordinates of the center point, and lay a gray-scale target cloth at the center point;

[0011] S3, making the UAV fly around the center point of the ground for multiple times at different flight pitch angles, taking photos with a thermal imager at multiple aerial photography points to obtain multiple infrared remote sensing images, and at the same time obtaining real-time temperature data of the gray-scale target cloth;

[0012] S4, extracting temperatures from a plurality of thermal infrared remote sensing images obtained from a plurality of aerial photography points, and correcting the extracted temperatures and the coordinates of the aerial photography points using the center point coordinates and the real-time temperature data;

[0013] S5, using the corrected temperature and the coordinates of the aerial photography point, generating a thermal radiation directional radar map of the sample area including the center point through interpolation.

[0014] And a thermal radiation directional observation system, comprising:

[0015] A drone equipped with a thermal imaging camera;

[0016] A gray-scale target cloth laid at a central point on the ground;

[0017] The control unit enables the UAV to fly around the center point of the ground multiple times at different flight pitch angles, takes photos at multiple aerial photography points using a thermal imager to obtain multiple infrared remote sensing images, and simultaneously obtains real-time temperature data of the gray-scale target cloth;

[0018] A correction unit extracts temperatures from a plurality of thermal infrared remote sensing images obtained from a plurality of aerial photography points, and corrects the extracted temperatures and the coordinates of the aerial photography points through the coordinates of the center point and the real-time temperature data;

[0019] The generating unit generates a thermal radiation directional radar map of the sample area including the center point by interpolation using the corrected temperature and the coordinates of the aerial photography point.

[0020] Compared with the prior art, the advantages of the present invention are: using unmanned aerial vehicles to collect multi-angle thermal infrared remote sensing images and obtain thermal radiation directional observation data of the center point of the route, avoiding the use of manned aircraft and ground deployment, and reducing the cost of thermal radiation directional observation; eliminating the complex preparation plan for ground deployment and manned aerial observation, simplifying the technical process of thermal radiation directional observation; improving the flexibility of angle configuration and experimental sample areas, and providing the possibility of thermal radiation directional observation for more complex surfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 is a schematic diagram of the observation method of the present invention;

[0023] Figure 2 for Figure 1 Schematic diagram of top view;

[0024] Figure 3 for Figure 1 An enlarged schematic diagram of the grayscale target cloth in FIG.

[0025] Figure 4 It is a schematic diagram of the decomposition of the latitude and longitude offset of the present invention;

[0026] Figure 5 The radar map of thermal radiation direction of the sample area obtained by the observation method of the present invention;

[0027] Figure 6 The temperature comparison between the drone and the ground for 5% and 60% gray-scale targets during the flight mission;

[0028] Figure 7 The thermal radiation directional radar map of the ridge vegetation scene and the discrete forest vegetation scene obtained by the method of the present invention. DETAILED DESCRIPTION

[0029] Hereinafter, exemplary disclosures of the present disclosure will be described in conjunction with the accompanying drawings. For the sake of clarity and conciseness, not all features of implementing the present disclosure are described in the specification. However, it should be understood that many decisions specific to the present disclosure may be made in the process of developing any such implementation of the present disclosure in order to achieve the specific goals of the developer, and these decisions may vary from one disclosure to another. It should also be noted that, in order to avoid obscuring the present disclosure due to unnecessary details, only device structures closely related to the scheme according to the present disclosure are shown in the accompanying drawings, while other details that are not closely related to the present disclosure are omitted.

[0030] In general, it should be understood that the drawings and the various elements depicted therein are not drawn to scale. Furthermore, the use of relative terms such as "above," "below," "top," "bottom," "upper," and "lower" to describe the relationship of various elements to one another should be understood to encompass different orientations of the device and / or elements in addition to the orientation depicted in the drawings.

[0031] It should be understood that the present disclosure is not limited to the described implementation forms due to the following description with reference to the accompanying drawings. Herein, where feasible, features between different embodiments may be replaced or borrowed, and one or more features may be omitted in one embodiment, wherein the same reference numerals represent the same components. It should be understood that the manufacturing steps of the present disclosure are exemplary in the embodiments, and the order of the steps is adjustable.

[0032] Due to the problem of near-ground effect, the measurement scheme includes thermal infrared multi-angle observation scheme and layer temperature observation flight scheme. The thermal infrared multi-angle observation mission collects thermal infrared multi-angle image data to obtain the measurement accuracy of the drone and the thermal radiation directionality of the two vegetation scenes, and the layer temperature observation flight mission is used to reduce the error caused by the near-surface atmosphere in the thermal infrared multi-angle image data.

[0033] In one embodiment of the present invention, a method for observing the directivity of thermal radiation is provided, comprising the following steps:

[0034] S1, provides drones equipped with thermal imaging cameras;

[0035] S2, determine a center point on the ground, obtain the coordinates of the center point, and lay a gray-scale target cloth at the center point;

[0036] S3, making the UAV fly around the center point of the ground for multiple times at different flight pitch angles, taking photos with a thermal imager at multiple aerial photography points to obtain multiple infrared remote sensing images, and at the same time obtaining real-time temperature data of the gray-scale target cloth;

[0037] S4, extracting temperatures from a plurality of thermal infrared remote sensing images obtained from a plurality of aerial photography points, and correcting the extracted temperatures and the coordinates of the aerial photography points using the center point coordinates and the real-time temperature data;

[0038] S5, using the corrected temperature and the coordinates of the aerial photography point, generating a thermal radiation directional radar map of the sample area including the center point through interpolation.

[0039] In this embodiment, the grayscale target cloth includes: a first grayscale target cloth with a reflectivity greater than 50% and a second grayscale target cloth with a reflectivity less than 50%.

[0040] In one embodiment, the center point is an area that matches the area of ​​the grayscale target cloth, the first grayscale target cloth and the second grayscale target cloth are arranged side by side, the dark color has a low reflectivity, and the light color has a high reflectivity. Preferably, the reflectivity of the first grayscale target cloth is 60%, and the reflectivity of the second grayscale target cloth is 5%.

[0041] In this embodiment, when observing the ground temperature, the position of the calibrated center point is first measured using an RTK measuring instrument, and then the temperature of the first grayscale target cloth and the second grayscale target cloth arranged on the center point is measured using a point thermometer.

[0042] In this embodiment, the process also includes downloading the GSP software to the handheld device.

[0043] In this embodiment, the handheld device is connected to the drone and the thermal imager, so that the drone can connect to the wireless network and open the GSP software;

[0044] After entering the drone's flight mode around the center point of the ground, use the GPS software on the handheld device to set the thermal imager's isochronous shooting interval, set the drone's flight radius, set the drone's flight altitude, set the drone's flight pitch angle, measure the center point coordinates, and measure the building height.

[0045] In this embodiment, the drone flies in a circle around a center point, and the isochronous photographing interval is calculated based on the flight radius and the flight speed.

[0046] In one embodiment, if the routes are repeated, the equal-time photo-taking intervals may also be calculated with reference to the heading overlap rate.

[0047] In this embodiment, the center point coordinates set in the GPS software are obtained according to RTK measurement.

[0048] In this embodiment, the step of measuring the real-time temperature data of the first grayscale target cloth and the second grayscale target cloth using a spot thermometer is also included during the flight of the UAV.

[0049] In this embodiment, when setting the flight pitch angle, the difference between each flight pitch angle is equal, and each time the flight pitch angle is set, the drone performs a flight at this angle.

[0050] A specific example of the present invention is described in detail below.

[0051] The present invention provides a temperature observation method and system for observing the directionality of thermal radiation through an unmanned aerial vehicle, see Figure 1 , Figure 2 and Figure 3 , showing a schematic diagram of the observation system of the present invention, including a drone 1 equipped with a thermal imager, a drone handbook device (not shown), a grayscale target cloth 2 at the center point spread on the ground, a point thermometer and a coordinate measuring instrument RTK; a control unit, which makes the drone fly around the center point of the ground for multiple times at different flight pitch angles, takes pictures at multiple aerial points using the thermal imager to obtain multiple infrared remote sensing images, and simultaneously obtains real-time temperature data of the grayscale target cloth; a correction unit, which extracts the temperature from multiple thermal infrared remote sensing images obtained from multiple aerial points, and corrects the extracted temperature and aerial point coordinates through the center point coordinates and the real-time temperature data; a generation unit, which uses the corrected temperature and aerial point coordinates to generate a thermal radiation directional radar map of the sample area including the center point through interpolation.

[0052] Specifically, the drone 1 can be a drone equipped with a thermal imager. The drone 1 obtains centimeter-level thermal infrared remote sensing images through the thermal imager. The handheld device is connected to the drone 1. The flight center coordinates, flight altitude, flight radius, and isochronous photo interval of the drone 1 are set by the handheld device. The drone 1 is controlled to fly around the measurement center point O, and a number of thermal infrared remote sensing images are obtained in multiple angle directions at different zenith angles. By extracting the temperature and flight yaw angle of each thermal infrared remote sensing image, a thermal radiation directional radar map of the center point O is generated by interpolation.

[0053] During observation, the drone 1 sets a grayscale target cloth 2 at the center point of observation. Specifically, the grayscale target cloth 2 includes a first grayscale target cloth and a second grayscale target cloth. Preferably, the first grayscale target cloth can be a grayscale target cloth with a reflectivity of 60%, and the second grayscale target cloth can be a grayscale target cloth with a reflectivity of 5%. The thermometer can be a point thermometer, and the coordinate measuring instrument can be an RTK Real-Time Kinematic (real-time dynamic differential positioning) measuring instrument. When observing the ground temperature, first use the RTK measuring instrument to measure the position coordinates of the calibrated center point, and then use the point thermometer to measure the temperature of the first grayscale target cloth and the second grayscale target cloth arranged on the center point; connect the drone handheld device to the wireless network, open the GSP software, enter the surround mode, set the isochronous shooting interval, flight radius, flight altitude, center point coordinates, building height, flight pitch angle, etc. of the drone 1, use the handheld device to operate the drone 1 to perform multiple surround flights at different flight pitch angles, obtain the centimeter-level thermal infrared remote sensing image of the center point, and extract the temperature and flight yaw angle α of each thermal infrared remote sensing image.

[0054] Specifically, the equal-time photo-taking interval in the GPS software of the handheld device needs to be calculated based on the flight radius, the size of the remote sensing image, the heading overlap rate, and the flight speed.

[0055] In this embodiment, thermal infrared multi-angle observation includes aerial observation and ground observation. Aerial observation uses DJI M210 equipped with XT-2 thermal infrared lens, with grayscale target as the center, adopts a circular route, keeps the distance between the drone platform and the grayscale target at 100m, sets the flight radius, flight altitude, center point coordinates, building height and flight pitch angle, and starts from 0° direction (due north) and performs four circular flights clockwise with only different flight zenith angles. During the flight, take photos at equal intervals of 2s. For example, Figure 1 and Figure 2 The zenith angles of the four flights were 15°, 30°, 45° and 60° respectively. For ground observation, a point thermometer was used to simulate the multi-angle observation of the UAV on the grayscale target to measure the ground multi-point temperature to verify the measurement accuracy of the UAV.

[0056] After the multi-angle observation plan is completed, the layer temperature observation is carried out. Specifically, the drone descends at a uniform speed at an observation altitude of 100 meters and takes pictures of the ground objects in the field of view every 2 seconds. The specific diagram is as follows Figure 3 As shown, the observed temperature of the grayscale target cloth and the surrounding environment at different heights observed by the UAV is obtained. Figure 3 In the figure, the dark color with low reflectivity is the second gray-scale target cloth, and the light color with high reflectivity is the first gray-scale target cloth. The flight data is shown in Table 1:

[0057] Table 1 Observation plan at flight altitude 100m

[0058]

[0059] The spot thermometer is used to measure the real-time temperature data A0, B0 of the first grayscale target cloth and the second grayscale target cloth during the flight of the UAV, and calculate the corrected temperature using formula 1:

[0060]

[0061] Among them, y i is the corrected temperature, x i is the temperature before correction, that is, the temperature of the experimental sample area extracted from each drone aerial photo, A i ,B i are the temperatures of the first grayscale target cloth and the second grayscale target cloth extracted from each aerial photograph, respectively, i=1,…,n (n is the number of all aerial photographs under a certain vegetation scene), A0 and B0 represent the temperatures of the first grayscale target cloth and the second grayscale target cloth obtained by the thermometer, respectively.

[0062] The center point coordinates determined by RTK are used to correct the errors of the drone aerial photography coordinates. Figure 4 As shown in the figure, the same number of rays as the number of aerial photography points are generated through the coordinates, direction angles and flight radius of the aerial photography points. The coordinate offsets are obtained by performing a neighbor analysis between these rays and the center point. The coordinate offsets are decomposed and superimposed on the original aerial photography point coordinates. The corrected latitude is obtained using Formula 2, and the corrected longitude is obtained using Formula 3:

[0063] N=N0-L*SIN(α) (2)

[0064] E=E0+L*COS(α) (3)

[0065] Among them, N is the latitude after correction, N0 is the latitude before correction, L is the longitude and latitude offset, E is the longitude after correction, E0 is the longitude before correction, L is the longitude and latitude offset, and α is the direction angle. Through the corrected coordinates and temperature values ​​of each aerial photography point, the IDW inverse distance weighted interpolation is used to obtain a radar map that can reflect the direction of thermal radiation. The final temperature result of the sample area is as follows Figure 5 shown.

[0066] See also Figure 6 , which is a comparison chart of the UAV and ground temperature measurements under 5% and 60% grayscale targets during flight missions. It can be used to further verify the authenticity of the UAV's measured temperature data after radiation calibration correction, and to perform a correlation test with the actual temperature data measured on the ground. For grayscale targets and vegetation, grayscale targets are more sensitive to temperature, so 5% and 60% grayscale targets are used to perform a correlation analysis between the two. It can be seen that the correlation coefficient r between the UAV and the ground temperature measured with 5% grayscale targets is 0.7821, and the determination coefficient R 2 The correlation coefficient r between the UAV and the ground temperature measured by the 60% grayscale target is 0.7636, and the determination coefficient R 2 It is 0.5831. The difference between the average temperature measured on the ground and the average temperature measured by UAV is only about 1.3K, which shows that the UAV observation data and the ground observation data have the same change trend at different zenith angles and azimuth angles, and can well reflect the directional information of surface thermal radiation.

[0067] Furthermore, the thermal radiation directionality of the ridge vegetation scene and the discrete forest vegetation scene was observed by UAV. The results are as follows: Figure 7 As shown. Through multi-angle observation, the temperature range in the ridge vegetation scene is 5K, and the temperature range in the discrete forest vegetation scene is 6.1K. The observation results show that the high temperature areas of the two vegetation scenes mainly appear between the direction angles of 90° and 150°, and the radiation absorption peak is mainly concentrated in the area within 45° of the zenith angle under this direction angle. And the direction of the high temperature area coincides with the position of the sun at the time of observation, which indicates that the thermal radiation directionality of the two vegetation scenes is significantly affected by solar radiation.

[0068] However, due to the different vegetation structures, the thermal radiation directionality shown by the two is also different. First, in the observation data of ridge vegetation, the distribution of high temperature and low temperature areas shows the characteristics of concentrated patches. However, it is worth noting that the ridge vegetation scene in the study area is northeast-southwest oriented, and the direction is 60°-240°. The high temperature area extends from the radiation absorption peak to other direction angles and zenith angles. In the direction perpendicular to the ridge vegetation scene, its thermal radiation absorption degree has a trend of gradually decreasing from southeast to northwest; second, although it can be seen that the temperature generally decreases with the increase of the zenith angle in all direction angles, however, unlike ridge vegetation, the coverage area of ​​the low temperature area in the thermal radiation directionality of discrete forests is larger, that is, the degree of thermal radiation directional diffusion of discrete forest vegetation scenes is smaller. And the overall temperature is also about 5K lower than that of ridge vegetation. This may be because the canopy component scene of discrete forests is more complex and the vegetation coverage is higher, resulting in a slower warming rate and higher temperature consistency in all directions, so the thermal radiation directionality in the direction of direct sunlight is more obvious.

[0069] In the entire thermal radiation directional observation, controlling the error of the UAV observing LST is the key to ensuring the accuracy of the thermal radiation directional model. Therefore, it is very necessary to perform radiation calibration correction on the temperature data obtained by the UAV observation. In theory, the temperature of the grayscale target should be constant, which can be used as a standard to calibrate the temperature of other experimental sample areas. However, due to the systematic error of the sensor and a series of random errors generated when the UAV is flying, the grayscale target temperature in each thermal radiation photo taken by the aerial camera is different. Therefore, it is very necessary to find out the factors that really affect the accurate observation of the UAV and perform radiation calibration. The errors that have been weakened by the solution of the present invention include the systematic error, random error and near-ground effect error of the UAV.

[0070] This study used a UAV equipped with a thermal infrared camera to perform a multi-angle observation mission, conducted multi-angle LST observation experiments in two scenes: ridge crops and discrete forests, and simulated the thermal radiation directionality results in two types of vegetation scenes. The results show that UAVs, as a new type of observation method in the remote sensing field, can be well applied to multi-angle LST observation experiments.

[0071] In the present invention, through the application of UAV technology in the study of thermal radiation directionality, a thermal radiation directional radar map is established, which solves the current problems of long thermal radiation directional data acquisition cycle, high data acquisition cost, and complex observation scheme, and can be applied to a variety of surface types.

[0072] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0073] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A method for observing the directivity of thermal radiation, characterized in that: The following steps are involved: S1, provides drones equipped with thermal imaging cameras; S2, determine a center point on the ground, obtain the coordinates of the center point, and lay a gray-scale target cloth at the center point; S3, making the UAV fly around the center point of the ground for multiple times at different flight pitch angles, taking photos with a thermal imager at multiple aerial photography points to obtain multiple infrared remote sensing images, and at the same time obtaining real-time temperature data of the gray-scale target cloth; S4, extracting temperatures from a plurality of thermal infrared remote sensing images obtained from a plurality of aerial photography points, and correcting the extracted temperatures and the coordinates of the aerial photography points by using the center point coordinates and the real-time temperature data; S5, using the corrected temperature and the coordinates of the aerial photography point, generating a thermal radiation directional radar map of the sample area including the center point through interpolation.

2. The method for observing the directivity of thermal radiation according to claim 1, characterized in that: The grayscale target cloth comprises: a first grayscale target cloth with a reflectivity greater than 50% and a second grayscale target cloth with a reflectivity less than 50%.

3. The method for observing the directivity of thermal radiation according to claim 1, characterized in that: It also includes providing a handheld device for the drone, wherein the handheld device is connected to the drone and the thermal imager; After entering the drone's flight mode around the center point of the ground, use the GPS software on the handheld device to set the thermal imager's isochronous shooting interval, set the drone's flight radius, set the drone's flight altitude, set the drone's flight pitch angle, measure the center point coordinates, and measure the building height.

4. The method for observing the directivity of thermal radiation according to claim 3, characterized in that: The drone performs circular motion around a center point, and the isochronous photographing interval is calculated based on the flight radius and the flight speed.

5. The method for observing the directivity of thermal radiation according to claim 1, characterized in that: The center point coordinates are obtained according to RTK measurement.

6. The method for observing the directivity of thermal radiation according to claim 2, characterized in that: The reflectivity of the first grayscale target cloth is 60%, and the reflectivity of the second grayscale target cloth is 5%. During the flight of the UAV, a point thermometer is used to measure the real-time temperature data of the first grayscale target cloth and the second grayscale target cloth.

7. The method for observing the directivity of thermal radiation according to claim 1, characterized in that: When setting the flight pitch angle, the difference between each flight pitch angle is equal. Each time the flight pitch angle is set, the drone will perform a circular flight at this angle.

8. The method for observing the directivity of thermal radiation according to claim 3, characterized in that: During the flight of the UAV, the real-time temperature data A0 of the first grayscale target cloth and the real-time temperature data B0 of the second grayscale target cloth are measured, and the corrected temperature is calculated using formula 1: Among them, y i is the corrected temperature, x i is the temperature before correction, that is, the temperature of the experimental sample area extracted from each drone aerial photo, A i ,B i are the temperatures of the first grayscale target cloth and the second grayscale target cloth extracted from each aerial photograph, respectively. i=1,…,n, where n is the number of all aerial photographs in the sample area scene. A0 and B0 represent the real-time temperatures of the first grayscale target cloth and the second grayscale target cloth obtained by a spot thermometer, respectively.

9. The method for observing the directivity of thermal radiation according to claim 1, characterized in that: Correcting the coordinates of the aerial photography points by using the coordinates of the center point in step S4 includes: The same number of rays as the number of aerial points are generated by extracting the coordinates, yaw angles and flight radius of the aerial points in the thermal infrared remote sensing image. The coordinate offset is obtained by performing a nearest neighbor analysis on these rays and the center point. The coordinate offset is decomposed and superimposed on the original aerial point coordinates. The corrected latitude is obtained using Formula 2, and the corrected longitude is obtained using Formula 3: N=N0-L*SIN(α) (2) E=R0+L*COS(α) (3) Among them, N is the latitude after correction, N0 is the latitude before correction, l is the longitude and latitude offset, E is the longitude after correction, E0 is the longitude before correction, and α is the direction angle The thermal radiation directional radar map of the sample area is generated by using the IDW inverse distance weighted interpolation method based on the corrected coordinates and temperature values ​​of each aerial photography point.

10. A thermal radiation directional observation system, characterized in that: include: A drone equipped with a thermal imaging camera; A gray-scale target cloth laid at a central point on the ground; The control unit enables the UAV to fly around the center point of the ground multiple times at different flight pitch angles, and uses a thermal imager to take photos at multiple aerial photography points to obtain multiple infrared remote sensing images, while obtaining real-time temperature data of the gray-scale target cloth; A correction unit extracts temperatures from a plurality of thermal infrared remote sensing images obtained from a plurality of aerial photography points, and corrects the extracted temperatures and the coordinates of the aerial photography points through the coordinates of the center point and the real-time temperature data; The generating unit generates a thermal radiation directional radar map of the sample area including the center point by interpolation using the corrected temperature and the coordinates of the aerial photography point.

Images