Low-cost and high-precision unmanned aerial vehicle-mounted low-altitude atmospheric temperature and humidity profile observation device and method

Abstract

The invention discloses a low-cost and high-precision unmanned aerial vehicle-mounted low-altitude atmospheric temperature and humidity profile observation device and method. The device comprises a ventilation anti-radiation cover, a base and a button type temperature and humidity recorder. The ventilation anti-radiation cover comprises a plurality of annular sunshade layers which are horizontally arranged, and gaps between the adjacent annular sunshade layers and the hollow structure at the bottom of the base form an air flowing channel; the temperature and humidity data collected by the button type temperature and humidity recorder are matched with the flight data of the unmanned aerial vehicle according to the timestamp information, the temperature and humidity data corresponding to different flight heights are obtained, the temperature and humidity data corresponding to the different flight heights are corrected by combining the flight speed and the ventilation anti-radiation cover structure, and the corrected temperature and humidity data are obtained; and a high-precision low-altitude atmospheric temperature and humidity profile is generated. According to the invention, atmospheric vertical convection exchange of the temperature and humidity sensor is fully considered, a correction equation of an observation result is constructed through comparative observation, and accurate measurement of low-altitude atmospheric temperature and humidity vertical distribution is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of unmanned aerial vehicles, and particularly relates to a low-cost high-precision unmanned aerial vehicle-mounted low-altitude atmospheric temperature and humidity profile observation device and method. BACKGROUND

[0002] Temperature and humidity are basic meteorological elements for characterizing the state of the atmosphere, and their vertical distribution characteristics (temperature and humidity profile) play an irreplaceable important role in atmospheric science research and meteorological business applications. In particular, the temperature and humidity profile of the low-altitude atmospheric layer not only plays a key role in applications such as atmospheric pollutant diffusion and transport simulation, aviation meteorological safety guarantee, and urban local thermal environment monitoring, but also provides important data support for scientific research work such as analysis of the structural characteristics of the atmospheric boundary layer, energy exchange between the ground and the atmosphere, and numerical weather prediction model research.

[0003] At present, the commonly used atmospheric temperature and humidity profile monitoring methods mainly include sounding balloons, microwave radiometers and laser radars, etc. However, these detection methods have different degrees of limitations. The sounding balloon is one of the most commonly used methods for obtaining atmospheric temperature and humidity profile, and has the advantages of wide vertical detection range and high data precision. However, it is complex to operate, needs to be launched by professional personnel on site, the equipment is disposable, the cost is high, and it is easily affected by weather factors such as wind speed, and the trajectory is uncontrollable. The microwave radiometer can realize continuous automatic observation, but the device is expensive, and its inversion accuracy is greatly affected by atmospheric liquid water content, and the error significantly increases in cloudy and rainy weather. The laser radar has high temporal and spatial resolution and can capture detailed boundary layer changes, but the cost is also high, and the detection capability is limited in low visibility or complex weather conditions, and the application scenarios are limited. The above-mentioned observation devices have high costs, are usually arranged at fixed observation sites such as meteorological stations, and require high human and material resources for construction and maintenance, and can only detect the atmospheric temperature and humidity profile at fixed points, which cannot meet the requirements of rapid, low-cost and flexible observation. The development of unmanned aerial vehicle technology provides a new way for atmospheric temperature and humidity profile observation. By installing temperature and humidity sensors on unmanned aerial vehicles, convenient and efficient atmospheric temperature and humidity profile observation can be realized. However, the existing design only simply installs temperature and humidity sensors in the radiation shield carried by the unmanned aerial vehicle, which can shield the influence of solar radiation, but does not fully consider the ventilation condition. In the case of insufficient air convection, the temperature and humidity sensors in the radiation shield cannot accurately and timely capture the atmospheric temperature and humidity conditions at the height of the unmanned aerial vehicle, resulting in large errors in the observation results. In order to realize ventilation, some radiation shields are also provided with ventilation holes or ventilation devices, but the existing ventilation devices are not optimized and can only slightly improve the observation result precision, and the observation precision is extremely unstable.

[0004] The invention disclosed in the invention with the publication number CN220391534U discloses a unmanned aerial vehicle high-altitude meteorological detection nacelle, proposes a ventilation cover assembly, the ventilation cover assembly is fixed below the lower shell of the top cover, including ventilation cover upper cover, ventilation cover middle cover and ventilation cover lower cover connected by fixed columns from top to bottom. However, the ventilation cover structure proposed by the invention is to effectively alleviate the wind force when the wind enters through the louver structure, to avoid the direct blowing of high-altitude wind on the temperature and humidity sensor, and to prevent the temperature and humidity sensor from overheating. The invention is a device for high-altitude meteorological detection, and is not applicable to low altitude. In the low atmosphere, due to the influence of energy and moisture exchange between it and the ground, the vertical change of temperature and humidity is violent, and the instrument observation accuracy requirement is very high. This structure is quite redundant for temperature and humidity profile detection, and the observation accuracy is low and difficult to quantify and correct due to poor ventilation effect. Therefore, the existing observation devices are difficult to obtain high-precision atmospheric temperature and humidity profile in low altitude due to their respective problems. SUMMARY

[0005] In order to solve the above problems, the present application provides a low-cost high-precision unmanned aerial vehicle low-altitude atmospheric temperature and humidity profile observation device and method which fully considers the ventilation condition and is convenient to deploy. The present application can fully consider the atmospheric vertical convection exchange of the temperature and humidity sensor, and construct a correction equation of the observation result by comparison observation, to realize accurate measurement of the vertical distribution of low-altitude atmospheric temperature and humidity.

[0006] To achieve the above technical purpose, the technical scheme adopted by the present application is as follows: In a first aspect, the present application discloses a low-cost high-precision unmanned aerial vehicle low-altitude atmospheric temperature and humidity profile observation device, which comprises a ventilation and radiation shield, a base and a button type temperature and humidity recorder. The base is installed on the top of the unmanned aerial vehicle, the bottom thereof adopts a fan-shaped hollow structure, the upper surface thereof is provided with a groove, the center of the groove is provided with a fixing seat, and the button type temperature and humidity recorder is detachably installed in the fixing seat and the position thereof exceeds the upper surface of the fixing seat; the outer side surface of the base is provided with external threads, the inner side surface of the ventilation and radiation shield is provided with internal threads, the ventilation and radiation shield is installed above the base in a screwed manner, and the button type temperature and humidity recorder is covered in the ventilation and radiation shield; The ventilation and radiation shield comprises a plurality of horizontally arranged annular sunshade layers, the annular sunshade layers are connected by a plurality of vertically arranged support belts and are spaced and distributed from top to bottom, the outer side wall of each annular sunshade layer is at an angle with the support belt, and the lower edge of the upper sunshade layer is flush with the upper edge of the lower sunshade layer; the gap between adjacent annular sunshade layers and the hollow structure at the bottom of the base form an air flow channel; The button type temperature and humidity recorder collects temperature and humidity data and timestamp information during the flight of the unmanned aerial vehicle, matches the temperature and humidity data with the flight data of the unmanned aerial vehicle according to the timestamp information, obtains temperature and humidity data at different flight altitudes, corrects the temperature and humidity data at different altitudes in combination with the flight speed and the structure of the ventilation and radiation shield, obtains corrected temperature and humidity data, and generates high-precision low-altitude atmospheric temperature and humidity profile.

[0007] Further, the outer side wall of the annular sunshade layer is 45° inclined downward.

[0008] Further, the support belt is provided with a ventilation hole at the contact position with the annular sunshade layer.

[0009] Further, a support part is arranged below the base, a gap is arranged on each side of the support part, and a band or buckle on the unmanned aerial vehicle passes through the gap to fix the base on the unmanned aerial vehicle, and the fan-shaped hollow structure at the bottom of the base has a ventilation gap with the unmanned aerial vehicle.

[0010] In the second aspect, the application discloses a low-cost high-precision unmanned aerial vehicle-borne low-altitude atmospheric temperature and humidity profile observation method, which is based on the device described above and comprises the following steps: According to the load range of the unmanned aerial vehicle and the observation accuracy requirement, a ventilation and radiation shield with a corresponding number of sunshade layers is selected; The button type temperature and humidity recorder is installed in the fixing seat of the base and the position thereof is beyond the upper surface of the fixing seat, and then the ventilation and radiation shield is arranged above the base so that the button type temperature and humidity recorder is arranged in the ventilation and radiation shield. The base is fixed on the unmanned aerial vehicle, the button type temperature and humidity recorder is started, and the unmanned aerial vehicle is controlled to ascend and descend at a constant speed according to the set speed to collect the temperature and humidity during the flight. The temperature and humidity data with timestamps collected by the button type temperature and humidity recorder and the flight data with timestamps sent by the unmanned aerial vehicle are read, the temperature and humidity data and the flight data are matched according to the timestamps, and temperature and humidity data at different flight altitudes are obtained; according to the ventilation channel design of the radiation shield and the base, the convection ventilation of the button type temperature and humidity recorder in the shield is more favorable during the descending stage of the unmanned aerial vehicle; compared with the observation data of the meteorological flux tower, it is proved that the observation result during the descending stage is obviously better than that during the ascending stage; therefore, according to the flight data, only the temperature and humidity observation data during the descending stage of the unmanned aerial vehicle are selected. The temperature and humidity data at different altitudes are corrected in combination with the flight speed and the structure of the ventilation and radiation shield, the corrected temperature and humidity data are obtained, and a low-altitude atmospheric temperature and humidity profile is generated.

[0011] Further, the process of correcting the temperature and humidity data at different altitudes in combination with the flight speed and the structure of the ventilation and radiation shield comprises the following steps: According to the number of layers of the ventilation anti-radiation cover and the flight speed of the unmanned aerial vehicle in the descending stage, corresponding temperature correction functions and humidity correction functions are selected to correct the second temperature and humidity data obtained at different altitudes in the descending stage of the unmanned aerial vehicle, wherein the obtaining process of the temperature correction functions and the humidity correction functions comprises: obtaining first temperature and humidity data recorded by meteorological observation instruments at different altitudes of a meteorological flux tower; using the unmanned aerial vehicle to carry observation devices with different numbers of layers of anti-radiation covers near the meteorological flux tower to perform vertical flight at different flight speeds, and obtaining second temperature and humidity data obtained in the descending stage of the unmanned aerial vehicle corresponding to different flight speeds and anti-radiation cover structures; taking the first temperature and humidity data as a reference, using a least square algorithm to fit the second temperature and humidity data, and taking altitude as a variable to obtain temperature correction functions and humidity correction functions corresponding to different flight speeds and ventilation anti-radiation cover structures.

[0012] Further, the method further comprises the following steps: controlling the unmanned aerial vehicle to repeatedly perform the observation action multiple times, taking the average value of the temperature and humidity data in the descending stage of all times as the final observation data to reduce accidental errors, and then using the temperature correction functions and the humidity correction functions to correct the observation data to obtain corrected temperature and humidity data and generate high-precision low-altitude atmospheric temperature and humidity profiles.

[0013] Compared with the prior art, the present application has the following advantages: The low-cost high-precision unmanned aerial vehicle-mounted low-altitude atmospheric temperature and humidity profile observation device and method of the present application designs a ventilation anti-radiation cover that is flexible and controllable and can simultaneously consider ventilation conditions and anti-radiation effects, according to the vertical flight characteristics of the unmanned aerial vehicle. The ventilation anti-radiation cover fully guarantees the ventilation convection effect of the device on the basis of effectively shielding the influence of solar radiation, greatly improves the accuracy of the air temperature and relative humidity recorded by the built-in temperature and humidity recorder during the flight of the unmanned aerial vehicle, and additionally, a brand-new temperature and humidity data correction method is designed based on the structure of the ventilation anti-radiation cover. The temperature and humidity data recorded by the temperature and humidity recorder are corrected in combination with the ventilation anti-radiation cover structure and the flight speed, and finally a high-precision low-altitude atmospheric temperature and humidity profile is obtained. The present application has the advantages of high precision, simple structure, low cost, flexible application, etc., and can flexibly and quickly carry out observation of low-altitude atmospheric temperature and humidity profiles under various terrains and weather conditions according to requirements. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figures la to lc The drawings are schematic diagrams of the structural components of the unmanned aerial vehicle-mounted low-altitude atmospheric temperature and humidity profile observation device of the present application, wherein, Figure la is a schematic diagram of a ventilation anti-radiation cover, Figure lb is a schematic diagram of a base, Figure lcIt is a schematic view of a button type temperature and humidity recorder; Figure 2 It is a physical map of the ventilation radiation shield of the application; Figure 3 It is a physical map of the base of the installed button type temperature and humidity recorder of the application; Figure 4 It is a top view physical map of the base of the installed button type temperature and humidity recorder of the application; Figure 5 It is a schematic view of an atmospheric temperature and humidity profile observation device installed on a UAV; Figure 6 It is a flow chart of the low-altitude atmospheric temperature and humidity profile processing method of the application; Figure 7 It is a schematic view of the low-altitude atmospheric temperature and humidity profile generated by the application; The reference signs therein are: ventilation radiation shield 1, base 2, button type temperature and humidity recorder 3. DETAILED DESCRIPTION

[0015] The embodiments of the application are further described in detail below with reference to the accompanying drawings.

[0016] The application discloses a low-cost high-precision UAV-borne low-altitude atmospheric temperature and humidity profile observation device, which comprises a ventilation radiation shield, a base and a button type temperature and humidity recorder; The base is installed on the top of the UAV, the bottom thereof adopts a fan-shaped hollow structure, the upper surface is provided with a groove, the center of the groove is provided with a fixing seat, and the button type temperature and humidity recorder is detachably installed in the fixing seat and the position thereof is beyond the upper surface of the fixing seat; the outer side surface of the base is provided with external threads, the inner side surface of the ventilation radiation shield is provided with internal threads, the ventilation radiation shield is installed above the base in a screwed manner, and the button type temperature and humidity recorder is covered in the ventilation radiation shield; The ventilation radiation shield comprises a plurality of horizontally arranged annular sunshade layers, the annular sunshade layers are connected in a spaced distribution from top to bottom through a plurality of vertically arranged support belts, the outer side wall of each annular sunshade layer is at an included angle with the support belt, and the lower edge of the upper sunshade layer is flush with the upper edge of the lower sunshade layer; the gap between adjacent annular sunshade layers and the hollow structure of the bottom of the base form an air flow channel; The button type temperature and humidity recorder collects temperature and humidity data and timestamp information in the flight process of the UAV, matches the temperature and humidity data with the flight data of the UAV according to the timestamp information, obtains temperature and humidity data at different flight altitudes, corrects the temperature and humidity data at different altitudes in combination with the flight speed and the structure of the ventilation radiation shield, obtains corrected temperature and humidity data, and generates high-precision low-altitude atmospheric temperature and humidity profile.

[0017] In order to fully guarantee that the built-in button type temperature and humidity recorder in the ventilation and radiation shield can quickly exchange with the outside atmosphere during the vertical flight of the unmanned aerial vehicle, and guarantee its accurate and real-time recording of atmospheric temperature and humidity information, the design of the ventilation and radiation shield fully considers the sunshade and ventilation. See Figure 2 The sunshade layer of the present example includes four layers, each layer is inclined downward at 45°, the lower edge of the upper sunshade layer is flush with the upper edge of the lower sunshade layer, ensuring that solar radiation cannot directly enter the radiation shield from any angle, preventing heating interference of solar radiation on the temperature and humidity recorder, and improving measurement accuracy. This angle is determined after actual testing of different schemes. For annular sunshade layers at different angles of 25°, 35°, 45°, 55°, and 65°, it is found that the observation accuracy is highest at an angle of 45°. Although a small angle will be beneficial to the ventilation convection between the radiation shield and the outside world, in the morning or evening when the solar elevation angle is low, solar radiation may directly enter the radiation shield through the gap between the sunshade layers, affecting the observation accuracy; while a large angle will interfere with the ventilation convection between the button type temperature and humidity recorder in the shield and the outside world, reducing the observation accuracy.

[0018] The number of layers is limited by the payload of the unmanned aerial vehicle and the observation accuracy requirement. Too few layers will result in limited space in the shield, making it difficult to dissipate heat. At least three layers are needed to effectively ensure ventilation and sunshade. The more layers, the higher the observation accuracy, but too many layers will increase the weight of the entire device, which is not conducive to low payload unmanned aerial vehicles. In practical applications, users can choose the number of layers of the ventilation and radiation shield according to their needs. The number of layers of the annular sunshade layer needs to consider the payload of the unmanned aerial vehicle and the observation accuracy requirement. Too few layers will result in limited space in the shield, making it difficult to dissipate heat. After observation and comparison, it is found that at least three sunshade layers are needed to effectively ensure ventilation and sunshade, and thus to ensure observation accuracy. However, too many layers will result in a linear increase in the weight of the entire device, which is not conducive to low payload unmanned aerial vehicles. In practical applications, users can choose the number of layers of the ventilation and radiation shield according to their needs. The sunshade layers are hollow, connected by three longitudinal support belts, and each support belt has an air hole at the intersection with the annular radiation layer, further enhancing air circulation, so that the temperature and humidity sensor can quickly respond to environmental changes and accurately record atmospheric temperature and humidity.

[0019] See Figure 3 and Figure 4The ventilation base is provided with a groove for stably placing the temperature and humidity recorder, and ensuring that it maintains a good position during measurement. The bottom is provided with a fan blade-shaped hollow structure, which is combined with the hollow layer and ventilation holes of the ventilation and radiation shield to form an up-down ventilation channel, thereby further improving the ventilation efficiency. The top of the base is designed as a threaded structure, which is reliably connected with the radiation shield to ensure the sealing and detachability of the overall structure. The button-type temperature and humidity recorder is installed in the socket in the base and is surrounded by the ventilation and radiation shield, which effectively isolates the interference of external solar radiation and ventilates with the outside through the hollow parts of the ventilation and radiation shield and the base, thereby improving the accuracy and reliability of the measurement data. The support part is connected to the lower part of the base, and two slits are further arranged on the two sides of the support part, so that the observation device can be stably installed on the top of the unmanned aerial vehicle through a band or buckle without affecting the flight performance of the unmanned aerial vehicle, and the firmness and observation safety of the equipment are ensured. Figure 5 The schematic diagram of the atmospheric temperature and humidity profile observation device installed on the unmanned aerial vehicle.

[0020] The button-type temperature and humidity recorder is small in size, light in weight, and packaged with a solid stainless steel, so that it can work stably in various harsh environments. The button-type temperature and humidity recorder can be set to observe temperature and relative humidity at fixed time intervals, and record the observed temperature and humidity and observation time in the built-in storage device. The button-type temperature and humidity recorder is connected with a computer through a connecting device, and the supporting software can be used to start the button-type temperature and humidity recorder to record, set the observation time interval, calibrate the time of the button-type temperature and humidity recorder to avoid misleading the observation record, etc.

[0021] The ventilation and radiation shield and the base can be made by 3D printing, and the button-type temperature and humidity recorder can adopt the existing equipment on the market. Compared with other atmospheric temperature and humidity observation devices, the atmospheric temperature and humidity profile observation device has very low cost. In addition, the weight of the entire device is not more than 300g, so the load requirement of the carried unmanned aerial vehicle platform is very low, and it can be carried on a commonly used consumer-grade multi-rotor unmanned aerial vehicle, which is convenient and flexible to use.

[0022] Referring to Figure 6 The application discloses a low-cost and high-precision unmanned aerial vehicle-mounted low-altitude atmospheric temperature and humidity profile observation method, which is based on the aforementioned device; the method comprises the following steps: According to the load range of the unmanned aerial vehicle and the observation accuracy requirement, a ventilation and radiation shield with a corresponding number of sunshade layers is selected; The button-type temperature and humidity recorder is installed in the fixed seat of the base and the position thereof is beyond the upper surface of the fixed seat, and then the ventilation and radiation shield is rotatably arranged above the base, so that the button-type temperature and humidity recorder is arranged in the ventilation and radiation shield. Fix the base on the UAV, start the button type temperature and humidity recorder, control the UAV to ascend and descend at a constant speed according to the set speed, and collect the temperature and humidity in the flight process. Read the temperature and humidity data with time stamp collected by the button type temperature and humidity recorder and the flight data with time stamp sent by the UAV, match the temperature and humidity data and the flight data according to the time stamp, and obtain the temperature and humidity data at different flight altitudes. Combined with the flight speed and the structure of the ventilation and radiation shield, the temperature and humidity data at different altitudes are corrected to obtain the corrected temperature and humidity data, and the low-altitude atmospheric temperature and humidity profile is generated.

[0023] Before starting observation, connect the button type temperature and humidity recorder with the computer, calibrate its time, set the observation time interval (such as 1 second or 2 seconds), start the button type temperature and humidity recorder to start recording, then insert the button type temperature and humidity recorder into the socket in the base of the temperature and humidity profile observation device, connect the ventilation and radiation shield with the base by screwing, then fix the whole device on the top of the UAV through the gap supported by the base with a belt or buckle, and ensure the stable operation of the device during flight.

[0024] Control the UAV to take off and ascend at a constant speed to a preset height, then descend at a constant speed until landing. After landing, take out the button type temperature and humidity recorder from the device, connect the computer to export the temperature and humidity record data; export the pos data from the UAV, which records the position and attitude of the UAV in flight, including recording time and height information.

[0025] According to the time record in the temperature and humidity data and the time record in the pos data as intermediate variables, match the temperature and humidity recorded by the button type temperature and humidity recorder with the height data recorded by the UAV, and generate the temperature and relative humidity data corresponding to each height in the whole flight process.

[0026] The drone observation included two phases: ascent and descent. To determine which phase recorded more accurate temperature and humidity profiles, a comparative experiment was conducted. A drone equipped with a temperature and humidity profile observation device was used for vertical flight near a meteorological flux tower. Temperature and humidity profiles were acquired during the ascent, descent, and average of the ascent and descent phases, and compared with the meteorological flux tower's observation results. Meteorological instruments were installed every 10 meters on the atmospheric flux tower to record temperature and humidity information at these altitudes. The average temperature and humidity data from the drone's ascent, descent, and ascent-descent phases at these altitudes were extracted and compared with the meteorological flux tower's observation results at the corresponding altitudes. The results showed that the temperature and humidity observed during the descent phase had the smallest difference and the highest accuracy compared to the meteorological tower's observations. This is likely because the observation system's base has a fan-blade-like perforated structure, allowing air to enter rapidly during descent, while the top of the observation system is solid and sealed for sun shading, preventing air from entering during ascent. Based on the comparative observation results and analysis, the temperature and humidity profiles recorded by the drone during the descent phase are more accurate.

[0027] However, there are some discrepancies between the temperature and humidity recorded by the drone's descent observation device and the results observed by the meteorological flux tower.

[0028] To further improve accuracy, a correction equation for the air temperature and relative humidity observation data during the UAV's descent phase is constructed, using meteorological tower observations as a reference. This correction equation relies on the structure of the annular shading layer, which is one of the main purposes of the annular shading layer structure design: to achieve a targeted data correction process through a stable and controllable airflow channel. Analysis shows that in this invention, the more layers of shading layer there are, the higher the observation accuracy; the two exhibit an approximately logarithmic relationship. Flight speed during descent is another major parameter affecting accuracy.

[0029] Based on the aforementioned structure of the ventilation and radiation shield and the flight attitude of the UAV, this invention proposes an effective method for obtaining the correction equation for air temperature and relative humidity observation data during the descent phase of the UAV, specifically including: Acquire the first temperature and humidity data recorded by observation instruments at different heights on the meteorological flux tower; After selecting the ventilation and radiation shield, a drone carrying an observation device was used to fly vertically near the meteorological flux tower to obtain the second temperature and humidity data during the descent phase of the drone at different flight speeds. Using the first temperature and humidity data as a benchmark, the least squares method is used to fit the second temperature and humidity data, and altitude is used as a variable to obtain the temperature correction function and humidity correction function corresponding to different flight speeds.

[0030] In practical applications, after obtaining the temperature and humidity data, only the corresponding temperature correction function and humidity correction function are selected according to the number of layers of the ventilation radiation shield and the flight speed of the unmanned aerial vehicle in the descending stage, so that the second temperature and humidity data obtained at different altitudes in the descending stage of the unmanned aerial vehicle can be corrected.

[0031] As shown in Figure la , Figure lb and Figure lc , the unmanned aerial vehicle-mounted low-altitude atmospheric temperature and humidity profile observation device of the application mainly consists of a ventilation radiation shield 1, a base 2 and a button type temperature and humidity recorder 3.

[0032] In combination with Figure 2 , the sunshade layer of the ventilation radiation shield 1 includes four layers, each layer is inclined downward at 45°, the lower edge of the upper sunshade layer is flush with the upper edge of the lower sunshade layer, so that the sun radiation cannot directly enter the radiation shield from any angle, preventing the sun radiation from heating and interfering with the temperature and humidity recorder. The sunshade layers are hollowed out and connected by three longitudinal support belts, each support belt has four air holes, which effectively enhances air circulation, so that the temperature and humidity sensor can quickly respond to environmental changes and accurately record atmospheric temperature and humidity.

[0033] In combination with Figure 3 and Figure 4 , the bottom of the base 2 adopts a fan-shaped hollow structure, which is combined with the hollow layer and ventilation holes of the ventilation radiation shield 1 to further enhance the air convection effect. A groove is provided in the center to fix the button type temperature and humidity recorder 3, ensuring the stability of the device during flight and the accuracy of data acquisition.

[0034] The iButton DS1923 button type temperature and humidity recorder 3 is used for atmospheric temperature and humidity profile observation. The button type temperature and humidity recorder 3 is inserted into the USB card reader, and the card reader is connected to the computer port. The sampling interval is set to 1 second by Obutton software, the temperature resolution is set to 0.0625 ℃, and the humidity resolution is set to 0.04%. After the parameters are set, the button type temperature and humidity recorder 3 is pulled out of the card reader.

[0035] Subsequently, it is installed in the groove in the base 2, and the ventilation radiation shield 1 and the base 2 are screwed together. Then the whole observation device is fixed on the back of the unmanned aerial vehicle through the two slits supported by the device base Figure 5 ).

[0036] The unmanned aerial vehicle is controlled to take off vertically at a constant speed to a height of 500 m, and then to descend and land at a constant speed. In this process, in order to obtain high vertical resolution atmospheric temperature and humidity records, the speed is set to 1 m / s.

[0037] After the flight task is completed, the temperature and humidity data stored in the button type temperature and humidity recorder 3, including time, temperature and humidity information, are read by a computer. Based on the time field shared by the button type temperature and humidity recorder 3 and the unmanned aerial vehicle camera photos, the two groups of data are matched to obtain the temperature and humidity data corresponding to different altitudes in the unmanned aerial vehicle ascending and descending process.

[0038] The temperature and humidity data collected in the unmanned aerial vehicle descending process are extracted, the temperature and height data are substituted into formula (1) respectively, the relative humidity and height data are substituted into formula (2) for correction, and accurate low-altitude atmospheric temperature and humidity profiles are obtained.

[0039] (1) ; In the formula, T is the corrected air temperature (unit: ℃), is the air temperature measured in the descending stage (unit: ℃), and H is the height (m).

[0040] (2) ; In the formula, RH is the corrected relative humidity (unit: %), is the relative humidity measured in the descending stage (unit: %), and H is the height (m).

[0041] Figure 7 Three atmospheric temperature and humidity profiles obtained by the present application at different times are given, which correspond to (a), (b) and (c) in Figure 7 respectively.

[0042] Although the preferred embodiments of the present application have been described, those skilled in the art can make further changes and modifications to the embodiments once they know the basic inventive concept. Therefore, the appended claims are intended to be interpreted as including all changes and modifications falling within the scope of the present application.

[0043] Obviously, those skilled in the art can make various modifications and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these modifications and variations.

Claims

1. A low-cost high-precision unmanned airborne low-altitude atmospheric temperature and humidity profile observation device, characterized in that, The device comprises a ventilation anti-radiation cover, a base and a button-type temperature and humidity recorder; The base is installed on the top of the unmanned aerial vehicle, the bottom of the base is provided with a fan-shaped hollow structure, the upper surface of the base is provided with a groove, the center of the groove is provided with a fixing seat, and the button-type temperature and humidity recorder is detachably installed in the fixing seat and the position of the button-type temperature and humidity recorder is beyond the upper surface of the fixing seat; the outer side surface of the base is provided with external threads, the inner side surface of the ventilation anti-radiation cover is provided with internal threads, and the ventilation anti-radiation cover is installed above the base in a screwed manner and the button-type temperature and humidity recorder is covered in the ventilation anti-radiation cover. The ventilation anti-radiation cover comprises a plurality of horizontally arranged annular sunshade layers, the annular sunshade layers are connected in a spaced distribution from top to bottom through a plurality of vertically arranged support belts, the outer side wall of each annular sunshade layer is at an angle with the support belt, and the lower edge of the upper sunshade layer is flush with the upper edge of the lower sunshade layer; the gap between adjacent annular sunshade layers and the hollow structure at the bottom of the base form an air flow channel. The button-type temperature and humidity recorder collects temperature and humidity data and timestamp information in the flight process of the unmanned aerial vehicle, then matches the temperature and humidity data with the flight data of the unmanned aerial vehicle according to the timestamp information, obtains temperature and humidity data at different flight altitudes, corrects the temperature and humidity data at different altitudes in combination with the flight speed and the structure of the ventilation anti-radiation cover, obtains corrected temperature and humidity data, and generates a high-precision low-altitude atmospheric temperature and humidity profile.

2. The low-cost high-precision unmanned airborne low-altitude atmospheric temperature and humidity profile observation device according to claim 1, characterized in that, The outer side wall of the annular sunshade layer is inclined downward at an angle of 45°. 3.The low-cost high-precision unmanned airborne low-altitude atmospheric temperature and humidity profile observation device according to claim 1, characterized in that, The support belt is provided with a ventilation hole at the contact position with the annular sunshade layer.

4. The low-cost high-precision unmanned airborne low-altitude atmospheric temperature and humidity profile observation device according to claim 1, characterized in that, The base is provided with a support portion below, a gap is formed on each side of the support portion, and a binding belt or a buckle on the unmanned aerial vehicle passes through the gap to fix the base on the unmanned aerial vehicle and form a ventilation gap between the fan-shaped hollow structure at the bottom of the base and the unmanned aerial vehicle.

5. A low-cost high-precision unmanned airborne low-altitude atmospheric temperature and humidity profile observation method, characterized in that, The method is performed based on the device of any one of claims 1-4; the method comprises the following steps: Selecting a ventilation anti-radiation cover with a corresponding number of sunshade layers according to the load range of the unmanned aerial vehicle and the observation accuracy requirement; Installing the button-type temperature and humidity recorder in the fixing seat of the base and beyond the upper surface of the fixing seat, and then screwing the ventilation anti-radiation cover above the base to cover the button-type temperature and humidity recorder in the ventilation anti-radiation cover; Fixing the base on the unmanned aerial vehicle, starting the button-type temperature and humidity recorder, and controlling the unmanned aerial vehicle to ascend and descend at a constant speed according to the set speed to collect temperature and humidity in the flight process; Reading the temperature and humidity data with timestamps collected by the button-type temperature and humidity recorder and the flight data with timestamps sent by the unmanned aerial vehicle, matching the temperature and humidity data with the flight data according to the timestamps, and obtaining temperature and humidity data at different flight altitudes; Correcting the temperature and humidity data at different altitudes in combination with the flight speed and the structure of the ventilation anti-radiation cover, obtaining corrected temperature and humidity data, and generating a high-precision low-altitude atmospheric temperature and humidity profile.

6. The low-cost high-precision unmanned airborne low-altitude atmospheric temperature and humidity profile observation method according to claim 5, characterized in that, The process of correcting the temperature and humidity data at different altitudes in combination with the flight speed and the structure of the ventilation anti-radiation cover comprises: According to the number of layers of the radiation shield and the flight speed of the UAV in the descending stage, corresponding temperature correction functions and humidity correction functions are selected to correct the second temperature and humidity data obtained at different altitudes during the descending stage of the UAV; wherein the obtaining process of the temperature correction function and the humidity correction function comprises: Obtaining the first temperature and humidity data recorded by the meteorological observation instrument at different altitudes on the meteorological flux tower; Using the UAV to carry the observation device with different numbers of sunshading layers near the meteorological flux tower, flying vertically at different speeds, and obtaining the second temperature and humidity data corresponding to the UAV in the descending stage at different flight speeds and radiation shield structures; Taking the first temperature and humidity data as the reference, using the least square fitting method to fit the second temperature and humidity data, taking the altitude as the variable, and obtaining the temperature correction function and humidity correction function corresponding to different flight speeds and radiation shield structures.

7. The low-cost high-precision unmanned airborne low-altitude atmospheric temperature and humidity profile observation method according to claim 5, characterized in that, The method further comprises the following steps: Controlling the UAV to repeatedly perform the observation action multiple times, averaging the temperature and humidity data in the descending stage of all times to reduce accidental errors, correcting the temperature and humidity data using the temperature correction function and the humidity correction function, obtaining the corrected temperature and humidity data, and generating high-precision low-altitude atmospheric temperature and humidity profiles.

Images