Miniaturized drone payload based on hyperspectral remote sensing imaging technology

Abstract

Provide a miniaturized drone payload based on hyperspectral remote sensing imaging technology. 【Solution means】It includes a spectral collection system fixed to the tip of the drone, a non-axial parabolic mirror that collects the zenith reference spectrum and the negative elevation ground scattered light measurement spectrum array and transmits them to the spectrometer through an optical fiber, an imaging auxiliary module that images the detection area and uses the object material as auxiliary information, and a gyro stabilization module that positions the operating azimuth of the drone and the spectral collection system. The spectral system includes a spectrometer that converts the input optical signal into an electrical signal and combines it with information by a microcomputer to perform hyperspectral remote sensing imaging, a semiconductor refrigeration module that refrigerates the spectrometer, and a radiator of the semiconductor refrigeration module. The payload has a higher spatial resolution than satellite remote sensing equipment and ground remote sensing equipment, and can flexibly and quickly monitor the traceability area.

Description

Technical Field

[0001] The present invention belongs to the field of optical remote sensing, and specifically relates to a miniaturized drone payload based on hyperspectral remote sensing imaging technology.

Background Art

[0002] The world's atmospheric environment problems have been threatening people's lives and health all the time. In order to address environmental problems, in addition to measures to prevent and control air pollutants such as optimizing the industrial chain, energy conservation, and emission reduction, effectively monitoring the emissions of pollutants is an important part of environmental countermeasures.

[0003] Currently, high-concentration air pollution emissions often concentrate in industrial areas such as factories and power plants, where there are often concentrated and complex emission sources. All current environmental monitoring means are difficult to effectively monitor and trace. Specifically, environmental remote sensing satellites can conduct extensive monitoring, but the spatio-temporal resolution of satellites is severely insufficient. Blocked by clouds, one industrial park may only correspond to one pixel in satellite imaging, and different plants cannot be distinguished, and further tracing is impossible. For example, in the case of the in-vehicle mobile VOCs and odor gas mass spectrometer and pollution source accurate locking system with publication number CN108415038B, such in-vehicle equipment cannot penetrate deep into the plant for observation, and at the same time, it is easily discovered in the industrial park. It is difficult to suspend the discharge of heavy pollutants in the industrial park, and tracing is also difficult. For example, the remote sensing imaging aerial drone disclosed in publication number CN108016628A has a very limited measurement range of the point-type equipment mounted on the drone, and can only measure the pollutant concentration (target sampling) at the flight altitude of the drone, and the efficiency when monitoring the industrial park is extremely low.

[0004] Therefore, in order to monitor the horizontal distribution of air pollutants in industrial parks with high spatio-temporal resolution, trace the pollutants, and at the same time prevent the equipment from entering the target airspace, a hyperspectral remote sensing imaging load mounted on a drone is required. Also, considering not attracting the attention of air traffic control and plants, fixed-wing drones and large drones are clearly inappropriate. Therefore, in order to fill the gap in the technology of monitoring and tracing air pollutants in industrial plants as soon as possible, the current demand for a miniaturized load that can be mounted on a small drone is extremely urgent.

Summary of the Invention

Problems to be Solved by the Invention

[0005] In view of the above, an object of the present invention is to provide a miniaturized drone load based on hyperspectral remote sensing imaging technology that has a higher spatial resolution (reaching meter-scale resolution) than satellite remote sensing equipment and ground remote sensing equipment, and can flexibly and quickly monitor areas that cannot be traced by various remote sensing equipment and point sampling equipment.

Means for Solving the Problems

[0006] To achieve the above object of the present invention, the miniaturized drone load based on hyperspectral remote sensing imaging technology according to an embodiment of the present invention includes a separately designed spectrum collection system and a spectroscopy system.

[0007] The spectrum collection system is fixed to the tip of the drone and has an unobstructed viewing angle. It includes an off-axis parabolic mirror, an imaging assistance module, a gyro stabilization module, and a motor. The motor drives the on-axis parabolic mirror, the imaging assistance module, and the gyro stabilization module for synchronous adjustment. The off-axis parabolic mirror collects the zenith reference spectrum and the negative elevation ground scattered light measurement spectrum array and transmits them to the spectrometer via an optical fiber. The imaging assistance module images the detection area and recognizes the object material in the detection area as auxiliary information. The gyro stabilization module positions the operating orientation of the drone and the spectrum collection system as correction information.

[0008] The spectroscopy system is fixed below the drone and includes a spectrometer, a circuit control system, a microcomputer, a semiconductor refrigeration module, and a radiator. The spectrometer converts the input optical signal into an electrical signal, and the microcomputer combines the auxiliary information and the correction information to perform hyperspectral remote sensing imaging. The semiconductor refrigeration module cools the spectrometer, the radiator dissipates heat from the semiconductor refrigeration module, and the circuit control system controls the operation of the motor, the spectrometer, the microcomputer, the gyro stabilization module, and the semiconductor refrigeration module.

[0009] Preferably, the off-axis parabolic mirror is used to fold the optical path by 90° to focus the solar scattered light on the end face of the optical fiber, so as to realize the collection of the negative elevation ground scattered light measurement spectrum array and the zenith reference spectrum. The focus axis of the off-axis parabolic mirror is coaxial with the rotation axis of the motor. Also, the parameters of the parabolic mirror need to satisfy the numerical aperture NA of the optical fiber used so that the density of the light beam entering the optical fiber is maximized.

[0010] Preferably, the off-axis parabolic mirror employs an off-axis parabolic mirror plated with an ultraviolet high-reflectivity film.

[0011] Preferably, the imaging assistance module includes, on hardware, a high-definition camera, a small circuit board equipped with an image recognition algorithm and a surface albedo algorithm based on a radiation transmission model. The observation orientation of the high-definition camera is consistent with the detection orientation of the non-axis parabolic mirror, and it can autofocus from 100m to infinity. The captured detection area is used for the mapping of the later hyperspectral trace gas imaging result and the detection area. The image recognition algorithm is installed to recognize the object material of the detection area image. The surface albedo algorithm based on the radiation transmission model calculates the recognized object material to obtain the surface albedo of different objects in different environments. The surface albedo corresponding to the detection area image and the object material is transmitted to the microcomputer as auxiliary information.

[0012] Preferably, the gyro stabilization module is used to feedback the current rotation angle in real time. The feedback current rotation angle is used as the basis for angle adjustment. When the spectral collection system measures a certain elevation angle, the motor can adjust the angle based on the feedback current rotation angle to ensure that the collected certain elevation angle is fixed to the set value.

[0013] The gyro stabilization module is also used to monitor the real-time attitude angle of the hyperspectral drone load in real time. The real-time attitude angle is used as correction information for the geometric correction of hyperspectral remote sensing imaging. The monitoring accuracy of the gyro stabilization module is 0.1° or more.

[0014] Preferably, the spectroscopic system further includes a heat conductor that adopts a metal layer with high thermal conductivity and low weight to completely wrap the outer surface of the spectroscope or partially wrap the outer surface close to the spectroscope CCD, and realizes the cooling of the spectroscope by increasing the heat exchange area between the spectroscope and the semiconductor refrigeration module.

[0015] Preferably, the spectroscopic system further includes a temperature sensor, which feeds back the temperature of the spectroscope to the circuit control system in real time. The circuit control system controls the semiconductor refrigeration module to change the temperature in real time, so that the semiconductor refrigeration module can automatically adjust and ensure a constant temperature of the spectroscope.

[0016] Preferably, the radiator includes a heat dissipation fin array and a heat dissipation fan for blowing external air onto the heat dissipation fin array. The air passes through the heat dissipation fin array, and the flow direction of the air in the heat dissipation fins and the flow direction of the air generated by the drone propeller can form a vortex. Depending on the position of the radiator, the drone propeller can more quickly carry out the air heat obtained by the heat dissipation fins from the semiconductor refrigeration module. Here, the heat dissipation fins are made of a lightweight and high-thermal-conductivity material, and the heat dissipation effect of the heat dissipation fan is greater than the heat generation effect of the semiconductor refrigeration module.

[0017] Preferably, the slits between the spectroscope, the heat conductor, the semiconductor refrigeration module, and the radiator are filled with heat-dissipating silicone grease.

[0018] When assembling, a lightweight heat-insulating material is used to separate the heat conductor and the spectroscope from the outside to prevent heat exchange with the outside.

[0019] Preferably, the spectroscopic system adopts a structure of a skeleton and a housing. A microcomputer, a spectroscope, a circuit control system, a semiconductor refrigeration module, a radiator, and a WIFI module are fixed inside the skeleton, and the outside of the skeleton is fixed to the drone. The housing adopts a plurality of thin carbon fiber flat plates to wrap the entire spectroscopic system, and each carbon fiber flat plate is fixed to the skeleton, and a method of assembling the flat plates together is adopted.

Advantages of the Invention

[0020] Compared with the prior art, the beneficial effects of the present invention include at least the following: Through the lightweight design of the overall load structure of the drone, while ensuring the normal realization of hyperspectral technology, it can be normally installed on a small electric rotor drone with a load of around 2.8 kg, that is, the realization of mounting hyperspectral equipment on the drone. The design of the equipment spectrum collection system can normally measure the zenith reference spectrum, ground measurement spectrum, surface albedo, etc. required by hyperspectral technology, and can ensure its operation stability. The design of the spectroscopic system can maintain the entire spectrum processing system within a temperature change of 0.1 °C, and can ensure the normal operation of the spectroscope and the spectrum imaging quality.

Brief Description of the Drawings

[0021] To more clearly explain the technical solutions in the embodiments of the present invention or the prior art, the following briefly introduces the attached drawings that need to be used in the description of the embodiments or the prior art. Obviously, the attached drawings in the following description are only some embodiments of the present invention. Based on these attached drawings, those skilled in the art can obtain other attached drawings without creative efforts.

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Modes for Carrying Out the Invention

[0022] To make the objectives, technical solutions, and advantages of the present invention more clear, the present invention will be described in more detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not limit the protection scope of the present invention.

[0023] The technical concept of the present invention is to solve the key technical problems that the timeliness, effectiveness, and flexibility of existing pollution source monitoring are low. The embodiments of the present invention provide a miniaturized drone payload based on hyperspectral remote sensing imaging technology, which can perform meter-scale resolution level observation on pollutants in industrial parks, locate the specific positions of emission sources, and achieve effective monitoring. In addition, it can complete one measurement of multiple plants within 20 minutes, realize rapid inspection without giving reaction time to plants, and realize the monitoring of different types of plants without the drone flying into the factory, and realize flexible inspection.

[0024] Based on the above technical concept, the miniaturized drone payload according to the embodiment based on hyperspectral remote sensing imaging technology includes two parts: a spectral collection system and a spectroscopic system, as shown in FIG. 1, and these two parts are designed separately.

[0025] As shown in FIGS. 1 and 2, the spectral collection system includes an off-axis parabolic mirror, an imaging auxiliary module, a gyro stabilization module, and a motor. Here, the off-axis parabolic mirror, as a core component, its rotation is realized by the motor, which folds the optical path by 90° to focus the solar scattered light on the end face of the optical fiber, and is used to realize the collection of the zenith reference spectrum and the negative elevation ground scattered light measurement spectrum array. The use of the optical element of a single off-axis parabolic mirror can reduce the loss of the optical signal of the optical system. At the same time, compared with the lens, when using the off-axis parabolic mirror, spherical aberration and chromatic aberration do not occur, and phase delay and absorption loss are not introduced, further reducing the loss of the optical system to the optical signal.

[0026] The off-axis parabolic mirror is responsible for collecting the zenith reference spectrum and the ground scattered light and focusing the signal light onto the optical fiber. In order to greatly reduce the loss of the optical system for the optical signal and reduce the optical aberration, the present invention employs an off-axis parabolic mirror plated with an ultraviolet high-reflectivity film. Regarding the selection of the off-axis parabolic mirror, it should be noted that mechanically its mass needs to satisfy the moment of the motor. When the focus axis of the off-axis parabolic mirror is coaxial with the rotation axis of the motor, the moment required for the motor is minimized. Also, the off-axis parabolic mirror needs to optically satisfy the numerical aperture NA of the optical fiber. That is, if the acceptance angle of the optical fiber is A degrees (for example, 14°), the image-side opening angle through which the parallel light passes through the off-axis parabolic mirror is larger than A degrees (for example, 14°), and the inverse tangent value of the ratio of the dimensional radius of the off-axis parabolic mirror to its effective focal length is larger than A degrees (14°), ultimately maximizing the density of the signal light beam entering the optical fiber.

[0027] The imaging assistance module is used to image the detection area and recognize the object material of the detection area as auxiliary information. Specifically, on the hardware, it includes a high-definition camera, and a small circuit board equipped with an image recognition algorithm and a surface albedo algorithm based on a radiation transmission model. Here, the observation orientation of the high-definition camera should be consistent with the detection orientation of the non-axis parabolic mirror, ignoring the distance between the two, and the detection field of view of the non-axis parabolic mirror should be in the middle of the observation screen of the high-definition camera. To meet the needs of ground imaging at different heights with different loads of the hyperspectral drone, the high-definition camera should enable automatic autofocus with a focus range from at least 100m to infinity. On the one hand, the imaging assistance module is used to image the detection area collected by the optical signal, and the detection area is used for the mapping of the hyperspectral trace gas imaging result in the later stage and the detection area photographed by the camera. On the other hand, the detection area image collected by the high-definition camera passes through the image recognition algorithm to recognize the object material in the image, and based on the surface albedo algorithm based on the radiation transmission model, the surface albedo of different objects in different environments for assisting hyperspectral imaging is obtained to make the imaging result more accurate. Here, the detection area image and the surface albedo corresponding to the object material are transmitted to the microcomputer as auxiliary information. When considering the surface albedo, the hyperspectral imaging result conforms to the more realistic situation.

[0028] The gyro stabilization module, on the one hand, feeds back the attitude signal of the spectrum collection system, cooperates with the motor, and is used to maintain the stability of the spectrum collection system in real time. On the other hand, it determines the real-time attitude angle of the hyperspectral drone load, which is convenient for correcting the imaging results of the hyperspectral in the later stage. That is, it is used to position the operating azimuth of the drone and the spectrum collection system as correction information. Specifically, it is used to monitor and feedback the current rotation angle in real time. When actually observing, the flight attitude change of the drone is relatively large, and the influence on optical measurement is relatively large. By adopting the gyro stabilization module, the current rotation angle can be accurately feedback in real time. The feedback current rotation angle is used as the basis for angle adjustment. When the spectrum collection system measures a certain elevation angle, the motor can adjust the angle based on the feedback current rotation angle to ensure that the collected certain elevation angle is fixed to the set value.

[0029] In addition, the gyro stabilization module is also used to monitor the real-time attitude angle of the hyperspectral drone load in real time. The real-time attitude angle is used for geometric correction of hyperspectral remote sensing imaging as correction information. The monitoring accuracy of the gyro stabilization module is above 0.1°, and the mass should be as small as possible.

[0030] The non-axis parabolic mirror, the imaging auxiliary module and the gyro stabilization module are fixed together. The total mass and moment of inertia of the three should be smaller than the rated load of the motor. The motor drives the axis parabolic mirror, the imaging auxiliary module and the gyro stabilization module to perform synchronous adjustment. Since the control accuracy of the motor should be smaller than 0.05°, it is appropriate to select a small (micro) stepping motor.

[0031] The above spectral collection system is fixed to the tip of the drone by a fixing device and the viewing angle is not blocked. That is, when the non-axis parabolic mirror and the high-definition camera protrude from the drone to collect the zenith reference spectrum and the ground scattered light, the hyper-spectral drone load can perform normal remote sensing imaging without being blocked by the drone body. For the material selection of the fixing device, it is necessary to use materials that are simple, lightweight, easy to process, and have high strength on a simple and lightweight basis (for example, using aluminum alloy).

[0032] As shown in FIGS. 1 and 3, the spectroscopic system includes a spectroscope, a circuit control system, a microcomputer, a semiconductor refrigeration module, a radiator, a heat conductor, and a temperature sensor. The spectroscope converts the input optical signal into an electrical signal, and the microcomputer combines the auxiliary information and the correction information to perform hyper-spectral remote sensing imaging. The semiconductor refrigeration module refrigerates the spectroscope, controls the overall temperature of the spectroscopic system, and ensures the imaging quality of the hyper-spectral. The radiator dissipates heat from the semiconductor refrigeration module. The circuit control system controls the operation of the motor, the spectroscope, the microcomputer, and the semiconductor refrigeration module. There is also a WIFI module (not shown in FIG. 1) for communication between the ground and the hyper-spectral drone load thereon.

[0033] Since the spectrometer is very sensitive to temperature, temperature can affect spectral non-linear feedback and change the size, shape, and intensity of the spectral image. In the case of hyperspectral technology, the impact of temperature changes on the spectrometer directly affects the imaging effect and the validity of the results. Figure 3 shows two cooled spectroscopic systems. The left side is a full-wrap spectroscopic system, that is, the entire surface of the spectrometer is wrapped with a heat conductor and frozen. The right side is a half-wrap spectroscopic system, that is, a part of the surface of the spectrometer is wrapped with a heat conductor and frozen. Currently, most hyperspectral devices freeze the entire spectrometer and even the entire device. However, considering the significant limitation on the payload of small drones, only the crucial part of the spectrometer, such as the part close to the CCD in the spectrometer, can be frozen.

[0034] Specifically, the heat conductor adopts a metal layer with high thermal conductivity and low weight, such as an aluminum alloy. Since the housing of the spectrometer may be irregular, the heat conductor needs to be designed based on the outer shape and size of the spectrum. The function of the heat conductor is to expand the heat exchange area between the semiconductor refrigeration module and the spectrometer, and realize the refrigeration of the spectrometer through this function.

[0035] The temperature sensor is used to monitor the temperature of a certain part during the selection of each part of the refrigeration system and the load operation of the hyperspectral drone. One or more temperature sensors can be used. Generally, it is arranged near the CCD of the spectrometer, away from the top of the heat conductor (half-wrap refrigeration system). The temperature sensor feeds back the temperature of the spectrometer to the circuit control system in real time. The circuit control system controls the semiconductor refrigeration module to change the temperature in real time, so that the semiconductor refrigeration module can automatically adjust and ensure the temperature of the spectrometer to be constant.

[0036] The semiconductor refrigeration module cools the heat conductor. Considering the quality of the entire device, the semiconductor refrigeration module should, in combination with the temperature feedback of the temperature sensor, stabilize the temperature change of the spectrometer within 0.1 °C, and it is fundamentally necessary to ensure that the hyperspectral imaging results do not vary significantly due to the operation of the spectrometer.

[0037] The radiator includes a heat dissipation fin array and a heat dissipation fan, and plays the role of dissipating heat from the semiconductor refrigeration module. The heat dissipation fan blows external air onto the heat dissipation fin array, and the air, while passing through the heat dissipation fin array, takes out the heat acquired by the heat dissipation fin array from the semiconductor refrigeration module. The selection and position of the heat dissipation fan and the heat dissipation fin array need to consider both quality and heat dissipation effect. To reduce weight, the heat dissipation fins of the radiator adopt a lighter material with a higher thermal conductivity (for example, copper or aluminum, selected according to the actual load mass and the endurance of the drone. When pursuing a higher heat conduction effect, copper can be used; when pursuing lighter weight, aluminum can be used), and the heat dissipation effect of the radiator can be enhanced by increasing the surface area of the heat dissipation fins. The selection of the fan on the radiator needs to consider both mass and power consumption, while the heat dissipation effect of the fan needs to exceed the heat generation effect of the semiconductor refrigeration module.

[0038] The slit between the above-mentioned spectrometer, heat conductor, semiconductor refrigeration module, and radiator is filled with heat dissipation silicone grease to achieve a higher heat dissipation effect. To achieve a higher refrigeration effect, when assembling, it is necessary to separate the heat conductor and the spectrometer part from the outside using a lightweight heat insulation material (such as aerogel) to prevent heat exchange between the spectrometer and the outside.

[0039] The heat dissipation fan of the radiator of the present invention has a certain cooperative effect on the rotor of the drone, as shown in FIG. 4. According to the Bernoulli principle, under the action of the rotor of the drone, the air flow velocity below the rotor is fast, the air flow velocity is large, an upward lift force of the drone is generated, while a low pressure is generated below the rotor, and the surrounding air is replenished below the rotor of the drone. The air flow direction of the radiator at the bottom is away from the side of the radiator after passing through the heat dissipation fan and the heat dissipation fin array from below. Therefore, under the action of the rotor, the air of the heat dissipation fin array entrains heat and accelerates the extraction to the side of the radiator, enhancing the heat dissipation effect on the semiconductor refrigeration module of the radiator. Furthermore, the refrigeration power of the semiconductor refrigeration module can be further increased, and the refrigeration effect of the device can be enhanced.

[0040] The adoption of the lightweight design for the drone load according to the above embodiment mainly appears in two aspects. While all components take mass as an important consideration factor, the separate body design and the skeleton + housing structure are adopted for the hyperspectral drone load.

[0041] The separate body design separates the spectrum collection system and the spectroscopy system. The spectroscopy system is mounted below the drone, and the spectrum collection system is placed at the tip of the drone. Since the spectrometer, heat conductor, and radiator of the spectroscopy system are relatively heavy, mounting them below the drone makes the flight of the small rotor drone more stable. The spectrum collection system is fixed at the tip of the drone, realizing the protrusion of the non-axis parabolic mirror and the high-definition camera from the drone, so that when collecting the zenith reference spectrum and ground scattered light, the hyperspectral drone load can perform normal remote sensing imaging without being blocked by the drone body and the hyperspectral drone load.

[0042] The spectroscopy system adopts a skeleton + housing structure, that is, each element is fixed by a lightweight "skeleton", and a customized thin carbon fiber board is used as the housing to wrap the entire device. The ultimate goal is to significantly reduce the mass of the drone load while ensuring fixation.

[0043] It is shown in Fig. 5. The function of the framework is to fix the microcomputer, the spectrometer, the circuit control system and the WIFI module. Here, the microcomputer, the circuit control system and the WIFI module are fixed to the upper half and cooled by small heat dissipation fans on both sides, and the spectrometer is fixed to the lower half and cooled by a semiconductor module and a radiator. The framework further includes a connector with the drone for the spectroscopic system to be connected to the rotary drone. The housing adopts a thin carbon fiber material. Since the carbon fiber material has low plasticity, a plurality of flat plates are adopted to wrap the entire spectroscopic system. Each carbon fiber flat plate is fixed to the framework, and a method of assembling the flat plates is adopted. The structure wrapped by a plurality of flat plates also has higher expansibility. Based on devices such as different spectrometer model numbers and circuit boards, only a part of the carbon fiber flat plate needs to be designed, and there is no need to redesign the entire housing, which is also convenient for fixing the load to small drones of different model numbers.

[0044] Since the present invention needs to be mounted on a rotary drone with a load of around 2.8 kg, the requirement for weight reduction design is very strict. The framework is made of an aluminum alloy or other lightweight, high-strength and easy-to-process material and carbon fiber, and connects each part of the spectroscopic system in the form of several columns. Finally, the mass of the framework + housing structure should be less than 400 g.

[0045] The results of observing a certain plant using the miniaturized drone load according to the above embodiment are shown in Fig. 6. Strong emissions of NOx and HCHO were observed in the No. 1 area of a certain company, and strong emissions of HCHO were observed in the No. 2 area and the No. 3 area. The observation imaging diagram is smooth as a whole, and the high-value area and the low-value area are prominent, corresponding to a factory building with emissions of air pollutants and an office and farmland without emissions respectively, and the imaging results are consistent with the actual situation.

[0046] Conventional hyperspectral target imaging remote sensing can easily image prominent targets such as chimneys, but observing factories inside plants is very difficult. The drone remote sensing imaging method using the hyperspectral drone load of the present invention compensates for the deficiencies of target imaging remote sensing, obtains the spatial distribution of the meter-scale resolution of pollutants throughout the plant, and can accurately locate the high-value areas within the industrial park.

[0047] The miniaturized drone load based on the hyperspectral remote sensing imaging technology according to the above embodiment realizes a hyperspectral remote sensing imager that can be mounted on a small rotor drone with a load of around 2.8 kg by designing a spectrum collection system, a spectroscopic system, and a lightweight load, and performs meter-scale monitoring on key industrial parks. Through the design of the spectrum collection system, the device can achieve stable observation of hyperspectral remote sensing imaging. Through the design of the refrigeration system, the device can achieve the normal operation of the spectroscope for a long time. Through the lightweight design of the hyperspectral drone load, the device can be stably mounted on a small drone and realize remote sensing imaging of the meter-scale resolution of air pollutants.

[0048] The specific embodiments described above further elaborate on the technical solutions and beneficial effects of the present invention in more detail. However, what is described above is only the optimal embodiment of the present invention and is not intended to limit the present invention. It should be understood that any modifications, supplements, equivalent replacements, etc. made within the principle scope of the present invention should all be included within the protection scope of the present invention.

Claims

1. A miniaturized drone load that applies hyperspectral remote sensing imaging technology, including a spectrum collection system and a spectroscopic system that are separately designed, The spectrum collection system is fixed to the tip of the drone and has an unobstructed viewing angle, and includes an off-axis parabolic mirror, an imaging auxiliary module, a gyro stabilization module, and a motor, the motor drives and synchronously adjusts the off-axis parabolic mirror, the imaging auxiliary module, and the gyro stabilization module, the off-axis parabolic mirror collects a zenith reference spectrum and a negative elevation angle ground scattered light measurement spectrum array, and transmits them to a spectrometer through an optical fiber, the imaging auxiliary module images a detection area and recognizes the object material in the detection area as auxiliary information, and the gyro stabilization module positions the operating orientation of the drone and the spectrum collection system as correction information, The off-axis parabolic mirror is used to fold the optical path by 90° to focus the solar scattered light on the end face of the optical fiber, so as to realize the collection of the negative elevation angle ground scattered light measurement spectrum array and the zenith reference spectrum, the focus axis of the off-axis parabolic mirror is coaxial with the rotation axis of the motor, and the parameters of the off-axis parabolic mirror need to satisfy the numerical aperture NA of the optical fiber used, so as to maximize the density of the light flux entering the optical fiber; The imaging auxiliary module includes a high-definition camera and a small circuit board in hardware, the observation direction of the high-definition camera is consistent with the detection direction of the off-axis parabolic mirror, and can autofocus from 100 m to infinity, the captured detection area is used for subsequent hyperspectral trace gas imaging results and mapping of the detection area, the small circuit board is equipped with an image recognition algorithm and a ground albedo algorithm using a radiation transmission model, the image recognition algorithm is used to recognize the object material of the detection area image, and the ground albedo algorithm using the radiation transmission model is used to calculate the object material recognized to obtain the ground albedo of different objects in different environments, the detection area image and the ground albedo corresponding to the object material are transmitted to a microcomputer as auxiliary information, The spectroscopic system is fixed under the drone and includes the spectrometer, a circuit control system, the microcomputer, a semiconductor refrigeration module, and a heat sink, the spectrometer converts an input optical signal into an electrical signal, and the microcomputer combines the auxiliary information and the correction information to perform hyperspectral remote sensing imaging, the semiconductor refrigeration module freezes the spectrometer, and the heat sink dissipates heat from the semiconductor refrigeration module, and the circuit control system controls the operation of the motor, the spectrometer, the microcomputer, the gyro stabilization module, and the semiconductor refrigeration module; The heat sink includes a heat dissipation fin array and a heat dissipation fan that blows external air onto the heat dissipation fin array, the air passes through the heat dissipation fin array, and the air flow direction in the heat dissipation fin and the air flow direction generated by the drone propeller can form a vortex, and the position of the heat sink allows the drone propeller to more quickly carry away the air heat acquired by the heat dissipation fin from the semiconductor refrigeration module, wherein the heat dissipation effect of the heat dissipation fan is greater than the heat generation effect of the semiconductor refrigeration module.

2. The miniaturized drone load using hyperspectral remote sensing imaging technology as described in claim 1, characterized in that the off-axis parabolic mirror is an off-axis parabolic mirror plated with a high ultraviolet reflectance film.

3. The gyro stabilization module is used to feed back a current rotation angle in real time, and the fed back current rotation angle is used as the basis for adjusting the angle. When the spectrum collection system measures a certain elevation angle, the motor can adjust the angle according to the fed back current rotation angle, and ensure that the collected certain elevation angle is fixed at a set value; The miniaturized drone load applying hyperspectral remote sensing imaging technology of claim 1, characterized in that the gyro stabilization module is also used to monitor the real-time attitude angle of the hyperspectral drone load in real time, and the real-time attitude angle is used as correction information for geometric correction of the hyperspectral remote sensing imaging, and the monitoring accuracy of the gyro stabilization module is not less than 0.1°.

4. The spectroscopic system further includes a thermal conductor that adopts a metal layer having high thermal conductivity and light weight to completely encase the outer surface of the spectrometer or partially encase the outer surface adjacent to the spectrometer CCD, thereby realizing cooling of the spectrometer by increasing the heat exchange area between the spectrometer and the semiconductor cooling module. The miniaturized drone load that applies hyperspectral remote sensing imaging technology as described in claim 1.

5. The miniaturized drone load using hyperspectral remote sensing imaging technology as described in claim 1, characterized in that the spectroscopic system further includes a temperature sensor, which feeds back the temperature of the spectrometer to the circuit control system in real time, and the circuit control system controls the semiconductor refrigeration module to change its temperature in real time, thereby automatically adjusting the semiconductor refrigeration module to ensure a constant temperature of the spectrometer.

6. The slits between the spectrometer, the heat conductor, the semiconductor refrigeration module, and the heat sink are filled with heat dissipating silicone grease; The miniaturized drone load using hyperspectral remote sensing imaging technology as described in claim 4, characterized in that when assembled, a lightweight insulating material is used to isolate the heat conductor and the spectrometer from the outside and prevent heat exchange with the outside.

7. The miniaturized drone load using hyperspectral remote sensing imaging technology as described in claim 1, characterized in that the spectroscopic system adopts a skeleton and housing structure, the microcomputer, the spectrometer, the circuit control system, the semiconductor refrigeration module, the radiator, and the WIFI module are fixed inside the skeleton, and the outside of the skeleton is fixed to the drone. The housing uses multiple thin carbon fiber plates to encase the entire spectroscopic system, and each carbon fiber plate is fixed to the skeleton, and a method of assembling the plates is adopted.

Images