A method for simultaneous observation and real-time monitoring of hydrothermal carbon and radiation flux using an unmanned aerial vehicle

Abstract

The present invention relates to the field of earth observation technology, and provides a method for synchronous observation and real-time monitoring of water, heat, carbon and radiation fluxes of unmanned aerial vehicles. The method is applied to a system for synchronous observation and real-time monitoring of water, heat, carbon and radiation fluxes of unmanned aerial vehicles, and the system includes an airborne observation system and a ground real-time monitoring system. The ground real-time monitoring system is used to store preset user parameters, receive and process in real time a variety of observation data collected by the airborne observation system, and display water, heat, carbon and radiation flux observation results in real time. The method includes: obtaining corresponding observation data based on preset user parameters, and calculating water vapor flux, heat flux, carbon flux, four components of surface radiation and photosynthetically active radiation flux based on the observation data. The method can realize the synchronous observation of water vapor flux, heat flux, carbon flux and four components of surface radiation and regional values ​​of photosynthetically active radiation flux of ecosystems, and provide basic observation conditions for the study of the coupling process of water cycle, carbon cycle and energy cycle of ecosystems.

Description

Technical Field

[0001] The present invention relates to the field of earth observation technology, and in particular to a method for synchronous observation and real-time monitoring of hydrothermal carbon and radiation flux by an unmanned aerial vehicle. Background Art

[0002] The water, heat, carbon flux, four radiation components and photosynthetically active radiation flux between the surface and the atmosphere are key components of the water cycle, energy cycle and carbon cycle of the Earth system. Here, water and heat flux refer to the latent heat flux (convertible into water flux) and sensible heat flux exchanged between the ecosystem and the atmosphere; carbon flux refers to the carbon dioxide flux exchanged between the ecosystem and the atmosphere; the four components of surface radiation include the downward long-wave radiation reaching the surface, the downward short-wave radiation reaching the surface, the short-wave radiation reflected by the surface and the long-wave radiation emitted by the surface, among which the wavelength of short-wave radiation is roughly in the range of 280-4000nm, and the wavelength of long-wave radiation is roughly in the range of 4000-100,000nm; photosynthetically active radiation refers to the radiation absorbed by plants during photosynthesis. In the wavelength range of 400-700nm, the magnitude of photosynthetically active radiation absorbed by vegetation affects the photosynthesis and carbon exchange rate of the vegetation ecosystem. The water cycle, carbon cycle and energy cycle of the ecosystem are not independent cycles, but are closely coupled through processes such as energy exchange, photosynthesis, and transpiration. The coupling of the water cycle, carbon cycle and energy cycle of the ecosystem is a hot topic in the current global change research. The synchronous and accurate measurement of latent heat flux, sensible heat flux, carbon flux and the four components of surface radiation and photosynthetically active radiation flux between the surface and the atmosphere is of great significance to the study of the mechanism of hydrological and ecological processes and model verification. It is a key technology to improve the water use efficiency of the ecosystem, promote the sustainable development and utilization of water resources, and achieve the goal of carbon neutrality. Summary of the invention

[0003] In order to meet the research needs of the coupled process of water cycle, carbon cycle and energy cycle in regional-scale ecosystems, the present invention provides a method for synchronous observation and real-time monitoring of water, heat, carbon and radiation flux by unmanned aerial vehicles. The technical solution proposed by the present invention is as follows:

[0004] In a first aspect, the present invention provides a method for synchronous observation and real-time monitoring of hydrothermal carbon and radiation flux by an unmanned aerial vehicle, which is applied to a synchronous observation and real-time monitoring system for hydrothermal carbon and radiation flux by an unmanned aerial vehicle, wherein the synchronous observation and real-time monitoring system for hydrothermal carbon and radiation flux by an unmanned aerial vehicle comprises an airborne observation system and a ground real-time monitoring system, wherein the ground real-time monitoring system is used to store pre-set user parameters, receive and process in real time a variety of observation data collected by the airborne observation system, and display hydrothermal carbon and radiation flux observation results in real time;

[0005] The method comprises:

[0006] Get pre-set user parameters;

[0007] The corresponding observation data are obtained based on the user parameters, and the water vapor flux, heat flux, carbon flux, four components of surface radiation and photosynthetically active radiation flux are calculated based on the observation data.

[0008] Optionally, the user parameters include: meteorological elements, average time of four components of radiation and photosynthetically active radiation flux, physical boundaries of each observation signal related to the observation site environment, and the starting point position, end point position and average window length for water, heat and carbon flux calculation;

[0009] The method of obtaining corresponding observation data based on user parameters and calculating water vapor flux, heat flux, carbon flux, four components of surface radiation and photosynthetically active radiation flux based on the observation data includes:

[0010] Obtaining the observation data of each observation element within the average time of the meteorological element, the four components of radiation and the photosynthetically active radiation flux to obtain a corresponding data sequence;

[0011] The original observation values ​​in the data sequence that exceed the physical boundaries of each observation signal are regarded as wild points and marked as invalid values;

[0012] Performing linear interpolation on the invalid values ​​in the data sequence to obtain a corrected sequence;

[0013] Calculate the wind speed, temperature, water vapor density, carbon dioxide density, downward shortwave radiation, upward shortwave radiation, downward longwave radiation, upward longwave radiation and photosynthetically active radiation average value according to the correction sequence, the meteorological elements, the four components of radiation and the average time of photosynthetically active radiation flux;

[0014] The water vapor flux, heat flux and carbon flux are calculated based on the correction sequence corresponding to each observation element and the starting point position, ending point position and average window length used for the calculation of water, heat and carbon flux.

[0015] Optionally, each observation element includes a plurality of meteorological elements;

[0016] According to the correction sequence corresponding to each observation element and the starting point position, ending point position and average window length used for water, heat and carbon flux calculation, water vapor flux, heat flux and carbon flux are calculated, including:

[0017] Calculate the window start position and window end position of all hydrothermal carbon flux average windows according to the start point position, end point position and average window length;

[0018] forwardly searching for a data index corresponding to the start position of the window according to the position data of the UAV, and extracting a data sequence between the start position of the window and the end position of the window from the correction sequence of each meteorological element to obtain various meteorological data within the window;

[0019] Perform zero-phase shift filtering on various meteorological data within the window, filter out abnormal points in the data sequence, perform linear interpolation on the abnormal points, and count the number of abnormal points;

[0020] When the number of abnormal points of all data sequences in the window does not exceed a preset ratio, water vapor flux, heat flux and carbon flux are calculated based on various meteorological data in the window.

[0021] Optionally, the various meteorological data include three-dimensional wind speed data, air temperature, water vapor density and carbon dioxide density, and the heat flux includes sensible heat flux and latent heat flux;

[0022] The airborne observation system includes an airspeed meter, an inertial navigation system, an air temperature measurement unit, and a water vapor and carbon dioxide density measurement unit. The three-dimensional wind speed data is calculated based on the air flow data collected by the airspeed meter installed at the front end of the UAV fuselage and extending along the longitudinal axis of the UAV fuselage, and the UAV ground flight speed and attitude angle in the earth coordinate system collected by the inertial navigation system installed at the center of gravity of the UAV in the cabin. The air temperature is collected by the air temperature measurement unit installed below the airspeed meter, and the water vapor density and the carbon dioxide density are collected by the water vapor and carbon dioxide density measurement unit installed vertically upward at the front end of the UAV fuselage.

[0023] The calculation of water vapor flux, heat flux and carbon flux based on various meteorological data in the window includes:

[0024] Perform coordinate rotation on the three-dimensional wind speed data in the window to obtain the rotated three-dimensional wind speed;

[0025] Calculate the spatial average values ​​of the rotated three-dimensional wind speed, air temperature, water vapor density, and carbon dioxide density in the window;

[0026] Subtract the corresponding spatial average values ​​from the rotated three-dimensional wind speed, the air temperature, the water vapor density, and the carbon dioxide density to obtain corresponding three-dimensional wind speed pulsation values, air temperature pulsation values, water vapor density pulsation values, and carbon dioxide density pulsation values; wherein the three-dimensional wind speed pulsation values ​​include the vertical wind speed component pulsation values;

[0027] Obtaining air density and air specific heat at constant pressure, and calculating sensible heat flux according to the air density, the air specific heat at constant pressure, the vertical wind speed component pulsation value, and the air temperature pulsation value;

[0028] Calculate the water vapor flux based on the eddy covariance method and the WPL correction method according to the vertical wind speed component pulsation value, the water vapor density pulsation value, the air temperature pulsation value, the spatial average value corresponding to the water vapor density and the spatial average value corresponding to the air temperature;

[0029] Acquire latent heat of vaporization, and calculate latent heat flux based on the latent heat of vaporization and the water vapor flux based on an eddy covariance method and a WPL correction method;

[0030] The carbon flux is calculated based on the eddy covariance method and the WPL correction method according to the vertical wind speed component pulsation value, the carbon dioxide density pulsation value, the water vapor density pulsation value and the air temperature pulsation value.

[0031] Optionally, the air fluid data includes static pressure, dynamic pressure, angle of attack and sideslip angle; and the three-dimensional wind speed data is determined by:

[0032] Based on static pressure and dynamic pressure, calculate the absolute value of relative wind speed;

[0033] Based on the angle of attack, sideslip angle and absolute value of relative wind speed, calculate the relative wind speed component in the UAV coordinate system;

[0034] Based on the UAV's flight speed over the ground and its attitude angle in the earth coordinate system, the relative wind speed component is converted into three-dimensional wind speed data in the earth coordinate system.

[0035] Optionally, the three-dimensional wind speed pulsation value further includes a wind speed component pulsation value along the wind direction and a horizontal wind speed component pulsation value perpendicular to the wind speed component along the wind direction; the method further includes:

[0036] The friction velocity is calculated based on the eddy covariance method according to the pulsation value of the vertical wind speed component, the pulsation value of the wind speed component along the wind direction and the pulsation value of the horizontal wind speed component perpendicular to the wind speed component along the wind direction;

[0037] The air density is obtained, and the momentum flux is calculated according to the air density and the friction velocity.

[0038] In a second aspect, the present invention provides a UAV hydrothermal carbon and radiation flux synchronous observation and real-time monitoring device, which is applied to a UAV hydrothermal carbon and radiation flux synchronous observation and real-time monitoring system, wherein the UAV hydrothermal carbon and radiation flux synchronous observation and real-time monitoring system comprises an airborne observation system and a ground real-time monitoring system, wherein the ground real-time monitoring system is used to store pre-set user parameters, receive and process in real time a variety of observation data collected by the airborne observation system, and display hydrothermal carbon and radiation flux observation results in real time;

[0039] The device comprises:

[0040] An acquisition module, used to acquire preset user parameters;

[0041] The calculation module is used to obtain corresponding observation data based on user parameters, and calculate water vapor flux, heat flux, carbon flux, four components of surface radiation and photosynthetically active radiation flux based on the observation data.

[0042] In a third aspect, the present invention provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the method for synchronous observation and real-time monitoring of hydrothermal carbon and radiation flux of a UAV as described in the first aspect is implemented.

[0043] In a fourth aspect, the present invention provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for simultaneous observation and real-time monitoring of hydrothermal carbon and radiation flux by a UAV as described in the first aspect.

[0044] In a fifth aspect, the present invention provides a computer program product, including a computer program, which, when executed by a processor, implements the method for simultaneous observation and real-time monitoring of hydrothermal carbon and radiation flux by a UAV as described in the first aspect.

[0045] Based on the above technical solution, the beneficial effects of the present invention compared with the prior art are as follows:

[0046] The method for synchronous observation and real-time monitoring of water, heat, carbon and radiation fluxes by unmanned aerial vehicles provided by the present invention obtains pre-set user parameters; obtains corresponding observation data based on the user parameters, and calculates water vapor flux, heat flux, carbon flux, four components of surface radiation and photosynthetically active radiation flux based on the observation data. It can realize the synchronous observation of water vapor flux, heat flux, carbon flux and four components of surface radiation and regional values ​​of photosynthetically active radiation flux in ecosystems, provide basic observation conditions for the study of the coupled processes of water cycle, carbon cycle and energy cycle in ecosystems, and provide key technical support for research and application in related fields such as improving ecology, improving water resource utilization efficiency and achieving carbon neutrality goals.

[0047] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description, claims and drawings.

[0048] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0050] Figure 1 It is a structural schematic diagram of the UAV hydrothermal carbon and radiation flux synchronous observation and real-time monitoring system provided by the present invention.

[0051] Figure 2 It is one of the flow diagrams of the method for simultaneous observation and real-time monitoring of hydrothermal carbon and radiation flux by an unmanned aerial vehicle provided by the present invention.

[0052] Figure 3 This is the second flow chart of the method for simultaneous observation and real-time monitoring of hydrothermal carbon and radiation flux by an unmanned aerial vehicle provided by the present invention.

[0053] Figure 4 It is a structural schematic diagram of the UAV hydrothermal carbon and radiation flux synchronous observation and real-time monitoring device provided by the present invention.

[0054] Figure 5 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] As important processes of material and energy circulation in the soil-vegetation-atmosphere continuum, latent heat flux, sensible heat flux, carbon flux, and surface radiation flux are closely related to meteorological conditions, surface vegetation cover type, vegetation growth, soil characteristics, atmospheric boundary layer state and other factors, and show obvious spatial and temporal differences in different regions and different underlying surfaces. In the atmospheric boundary layer, turbulent transport is the dominant form of water, heat and carbon flux exchange between the surface and the atmosphere. For the observation of this complex exchange process, it is necessary to coordinate multiple instruments and conduct multi-factor synchronous measurement. At present, the most widely used turbulent flux observation method with a relatively complete theoretical basis is the eddy covariance method. The eddy covariance method for measuring material and energy fluxes can be divided into two types: in-situ measurement method based on ground tower stations and measurement method based on airborne mobile platforms. Among them, the water, heat, carbon and radiation flux measurement system based on an airborne mobile platform can form a spatially continuous sampling sequence for three-dimensional wind vectors, air temperature and humidity, water vapor, carbon dioxide density and atmospheric pressure in a short time, which is convenient for studying the spatial variation of non-uniform surface water, heat and carbon flux. It is currently the only means to obtain regional-scale turbulent water, heat and carbon flux.

[0057] In the existing technology, in terms of coordinated observation of water, heat, carbon flux, four components of radiation and photosynthetically active radiation flux of ecosystems at the regional scale, the observation system based on manned aircraft is relatively mature, but it has disadvantages such as high requirements for take-off and landing sites, high costs, and high risks to personnel safety. Due to the limitations of factors such as the stability, load, and technology of drones, there are currently few systems that can perform synchronous and high-precision observations of water, heat flux, carbon flux, four components of surface radiation, and photosynthetically active radiation flux. The development of a synchronous observation system for ecosystem water, heat flux, carbon flux, four components of surface radiation, and photosynthetically active radiation flux that can be carried on a drone platform has high practical value.

[0058] The inventor found in the work that at present, the eddy covariance flux in-situ observation system installed on the ground tower station, such as the EC150 eddy covariance flux observation system, can perform high-frequency sampling in the time domain of fixed points for three-dimensional wind speed, air temperature, water vapor and carbon dioxide density, atmospheric pressure, etc. through fast-response instruments and equipment. Based on the eddy covariance method and Reynolds decomposition, these original observation data can be used to calculate the average latent heat flux, sensible heat flux, carbon flux and momentum flux over a period of time (for example, half an hour) on the target underlying surface. In addition, combined with a surface radiometer installed at the same site, such as NR01, synchronous observation of the four components of radiation at the site can be achieved. However, the spatial representativeness of the observation data obtained by this in-situ observation system based on the ground tower station is limited (only at the hundred-meter level), and it cannot directly provide the observation values ​​and spatial differences of the latent heat flux, sensible heat flux, carbon flux and radiation four components and photosynthetically active radiation flux on the heterogeneous underlying surface at the regional scale.

[0059] At present, the eddy covariance flux observation system based on manned aircraft, such as the Skyarrow 650 ERA system, can realize the simultaneous observation of latent heat flux, sensible heat flux and carbon flux. In terms of radiation measurement, the publicly reported manned eddy covariance flux observation system can only obtain the total net radiation, but not the four components of radiation. In addition, due to the shortcomings of high requirements for take-off and landing sites, high costs, and high personnel safety risks, the eddy covariance flux observation system based on manned aircraft is greatly limited in practical application.

[0060] At present, the existing UAV-based flux observation technology is not yet mature and the system design is not yet perfect. Due to the limitations of UAV stability, load, instrument integration and other technologies, the publicly reported UAV flux observation systems can usually only achieve synchronous observation of a few fluxes, such as the SUMO system and the MASC system, and cannot achieve synchronous observation of latent heat flux, sensible heat flux, carbon flux, four-component flux of surface radiation and photosynthetically active radiation flux, and cannot meet the needs of ecosystem water-carbon-energy coupling process and the material and energy balance of the Earth system.

[0061] The above-mentioned prior arts cannot meet the expectations of the inventors, and the inventors have made the present invention after further research and development.

[0062] Combine the following Figure 1-Figure 3 The present invention describes the UAV hydrothermal carbon and radiation flux synchronous observation and real-time monitoring method.

[0063] The energy cycle, water cycle and carbon cycle of the ecosystem are interconnected and closely coupled. Aiming at the research needs of the coupled process of water cycle-carbon cycle-energy cycle in the regional scale ecosystem, this paper designs a UAV water, heat, carbon and radiation flux synchronous observation and real-time monitoring system. Figure 1 It is a structural schematic diagram of the UAV water, heat and carbon flux synchronous observation and real-time monitoring system provided by the present invention. The system is a multi-sensor collaborative, water, heat and carbon flux and radiation four-component and photosynthetically active radiation flux synchronous observation system that can be carried on a fixed-wing UAV, and has the characteristics of low cost, flexibility, ease of use and high reliability.

[0064] Reference Figure 1 As shown, the UAV water, heat, carbon and radiation flux synchronous observation and real-time monitoring system includes a water, heat, carbon and radiation flux synchronous observation system integrated in the UAV (hereinafter referred to as the airborne observation system), and a ground real-time data analysis and monitoring system (hereinafter referred to as the ground real-time monitoring system). The airborne observation system is used to collect a variety of observation data, and the ground real-time monitoring system is used to store pre-set user parameters, and receive and process in real time a variety of observation data collected by the airborne observation system.

[0065] The above-mentioned drones are suitable for measuring multi-type surface water flux, heat flux, carbon flux, radiation component flux and photosynthetically active radiation flux at regional scales. They need to have the following basic characteristics: minimum disturbance to the flow field around the fuselage during air flight, good platform stability, flexible operation and low requirements for take-off and landing sites. Therefore, the rear-propelled propeller combined with an electric vertical take-off and landing fixed-wing drone is the preferred original model. At the same time, in order to meet the requirements of sample density and length for near-ground level flight observations, vertical profile observations and turbulent flux observations, the drone platform should be able to cruise at a speed of 25-40 meters per second within an altitude of 100 meters from the ground, can fly vertically with a diameter of 1 kilometer, and have a single flight endurance of more than 4 hours. In addition, in order to meet the needs of carrying relevant necessary instruments, the net load of the drone should reach 20 kilograms or more. At present, there are many models of drone platforms that meet this technical requirement, such as the Zongheng CW100 vertical take-off and landing fixed-wing drone.

[0066] First, the airborne observation system provided by the present invention is described:

[0067] (1) The composition of the airborne observation system is as follows:

[0068] Since the exchange of water, heat flux and carbon flux between the surface and the atmosphere is mainly completed in the form of turbulent transport, the airborne observation system realizes the observation of water flux, heat flux and carbon flux based on the eddy covariance theory. In order to meet the basic conditions for calculating turbulent fluxes by the eddy covariance flux observation method and realize high-precision observation of the four components of radiation and photosynthetically active radiation flux on a mobile platform, the airborne observation system needs to have the following basic observation capabilities: high-frequency three-dimensional wind speed observation, high-frequency air temperature and humidity observation, high-frequency carbon dioxide density observation, and short-time response observation of the four components of radiation and photosynthetically active radiation flux. Therefore, the UAV water, heat, carbon and radiation flux synchronous observation and real-time monitoring system includes multiple measurement units, data acquisition units, control units and power supply units. The above-mentioned multiple measurement units include wind speed measurement units, air temperature measurement units, water vapor and carbon dioxide density measurement units, radiation measurement units and auxiliary measurement units. Figure 1 The structure of the airborne observation system provided by the present invention is shown, and each unit of the system is introduced as follows.

[0069] a) The sensors of the wind speed measurement unit include an airspeed meter and an inertial navigation system: the airspeed meter can be a differential pressure airspeed meter, which provides high-frequency observations of the measured air fluid flow rate, angle of attack, sideslip angle, static pressure and dynamic pressure, and supports the calculation of high-frequency three-dimensional relative wind speed. The inertial navigation system provides high-frequency observations of the UAV position, the UAV's ground flight speed and the attitude in the earth coordinate system. Based on the observations provided by the inertial navigation system, the three-dimensional relative wind speed can be converted into a three-dimensional wind speed in the earth coordinate system. The differential pressure airspeed meter and inertial navigation system suitable for vertical take-off and landing fixed-wing UAVs should have the characteristics of a measurement frequency of not less than 50Hz, small size, light weight, high precision, fast response and strong anti-interference. For the differential pressure airspeed meter, models such as FTB-1, ADP55, ADS-9 and ADS-12 can be selected; and for the inertial navigation system, models such as APX-15 UAV, NAV992 and LN-200 can be selected. To improve the safety and reliability of the system, the inertial navigation system used for wind speed calculation should be independent of the inertial navigation system of the UAV platform.

[0070] b) The sensors of the air temperature measurement unit include two types of thermometers: one is a thermometer with fast response and high sensitivity to temperature changes (i.e. Figure 1 The other is a thermometer with a higher absolute temperature measurement accuracy (i.e. Figure 1 Low-frequency thermometers in the air temperature measurement. Thermometers with fast response and high sensitivity to temperature changes can provide high-frequency temperature change information related to turbulent heat transport, while thermometers with high absolute temperature measurement accuracy (such as 110PV thermistors) can provide high-precision absolute values ​​of air temperature. In the data post-processing part, the data of the two thermometers are merged to obtain more accurate information on air temperature and its changes. For thermometers with fast response and high sensitivity to temperature changes, the measurement frequency is not less than 50Hz, and platinum resistance thermometers, such as TP100, can be selected.

[0071] c) The water vapor and carbon dioxide density measurement unit is an integrated water vapor and carbon dioxide analyzer. The water vapor and carbon dioxide analyzer suitable for vertical take-off and landing fixed-wing UAVs should have the characteristics of measuring frequency not less than 50Hz, small size, light weight, high accuracy, fast response and good stability. The LI-7500RS open-path gas analyzer is preferred.

[0072] d) The radiation measurement unit includes the four components of long-wave and short-wave radiation and the photosynthetically active radiation flux measurement unit:

[0073] i) The sensors of the long- and short-wave radiation four-component measurement unit include two hemispherical short-wave radiometers and two hemispherical long-wave radiometers. The two hemispherical short-wave radiometers are installed respectively above and below the center of gravity of the fuselage to measure the downward short-wave radiation of the hemispherical space and the short-wave radiation reflected upward from the surface. The two hemispherical long-wave radiometers are also installed respectively above and below the center of gravity of the fuselage to obtain the downward long-wave radiation of the hemispherical space and the long-wave radiation emitted from the surface. The net radiation flux of the surface can be calculated from the measurements of the above hemispherical short-wave and long-wave radiometers. The hemispherical short-wave and long-wave radiometers suitable for vertical take-off and landing fixed-wing UAVs should have the characteristics of short-time response, small size, light weight and high precision. For short-wave radiometers, SP510 and SP610 radiometers can be selected; for long-wave radiometers, SL510 and SL610 radiometers can be selected.

[0074] ii) The sensor of the photosynthetically active radiation flux measurement unit includes two photosynthetically active radiometers installed directly above and below the center of gravity of the fuselage, respectively, to obtain photosynthetically active radiation downward in the hemispherical space and photosynthetically active radiation reflected from the ground surface. The photosynthetically active radiometer suitable for vertical take-off and landing fixed-wing UAVs should have the characteristics of short-time response, small size, light weight and high accuracy. The SQ100 photosynthetically active radiometer can be selected.

[0075] e) The sensors of the auxiliary measurement unit mainly include laser altimeter, thermal infrared camera and CCD camera. The laser altimeter, thermal infrared camera and CCD camera are all installed under the fuselage, and are used to measure the real-time relative altitude of the drone from the ground, the surface temperature and the visible light band information respectively. The laser altimeter, thermal infrared camera and CCD camera suitable for vertical take-off and landing fixed-wing drones should have the characteristics of small size, light weight and high precision. For the laser altimeter, the measurement frequency should not be less than 1Hz, and Livox Mid-40 / Mid-100 laser radar, SICK LMS1XX series laser rangefinder, etc. can be selected. For the thermal infrared imager, it should have the characteristics of wide field of view, high resolution, high sensitivity and wide dynamic temperature detection range, and FLIR Vue Pro R thermal imaging camera, ThermalCapture camera, etc. can be selected. For the CCD camera, it should have the characteristics of high resolution and multi-channel measurement with infrared measurement flux to meet the needs of detecting ecosystem vegetation characteristics, and Sequoia camera and MicaSense RedEdge-MX camera can be selected.

[0076] f) The data acquisition unit consists of an analog / digital converter and a data collector. The analog / digital converter is connected to the sensor and the data collector to convert the analog signals measured by the airspeed meter, thermometer and radiometer into digital signals and transmit them to the data collector. The data collector is used to collect data from each sensor. The instrument analog / digital converter should have the characteristics of multi-channel, low power consumption and high-speed data conversion. The multi-channel, differential input type ADS series high-precision analog / digital converter can be selected. The data collector should have internal clock synchronization, external clock synchronization, data alignment and correction capabilities to ensure the synchronization of data acquisition and processing of each sensor. At the same time, the data collector should have effective power management, voltage conversion, current control and other functions to ensure stable and effective power supply when each sensor is working. Data collectors can choose CR1000 series and CR6 series high-performance data collectors.

[0077] g) The control unit consists of a small control computer, storage device and wireless communication module installed on the drone. The control computer, storage device and wireless communication module installed on the drone are used for processing and transferring the data of each sensor and for data communication with the ground real-time monitoring system.

[0078] h) The power supply unit provides the required power for each sensor and control unit component. The power supply unit should be distinguished from the power supply system that drives the UAV's own motor, flight control system, and communication equipment, and designed separately without interfering with each other.

[0079] (2) The integration scheme of the airborne observation system of the present invention is as follows:

[0080] The airspeed meter is installed at the front end of the UAV and extends outward along the longitudinal axis of the fuselage. The water vapor and carbon dioxide analyzer is installed vertically upward at the front end of the UAV. The thermometer with fast response and high sensitivity to temperature changes and the thermometer with high absolute temperature measurement accuracy are installed below the airspeed meter, and are protected by a radiation shield to protect their measurements from the influence of the external environment. The installation position of the airspeed meter, water vapor and carbon dioxide analyzer and thermometer should avoid mutual interference between the instruments, and should be as far away from the UAV power system as possible to avoid interference of the observation data by the fuselage and the power system. A set of long-wave, short-wave and effective photosynthetic radiometers are installed above the center of gravity of the fuselage to measure the long-wave, short-wave and photosynthetically active radiation downward in the hemispherical space; another set of long-wave, short-wave and effective photosynthetic radiometers are installed below the center of gravity of the fuselage to measure the long-wave radiation emitted by the surface, the short-wave and photosynthetically active radiation reflected by the surface. The laser altimeter, thermal infrared camera and CCD camera are installed in the window below the fuselage, close to the radiometer below the fuselage. The inertial navigation system is installed at the center of gravity of the drone in the cabin, and the antenna is installed on the upper surface of the wing. Other equipment is installed in the cabin, and the antenna of the wireless communication module is installed under the fuselage and extends out of the cabin.

[0081] By installing the airspeed meter at the front end of the UAV and extending it outward along the longitudinal axis of the fuselage, the interference of the UAV itself on the airflow can be minimized to the greatest extent, ensuring the accuracy of the airspeed meter measurement. By installing the water vapor and carbon dioxide analyzers vertically upward, the direct impact of dust or other ground pollutants on the analyzer air inlet during the flight of the UAV can be reduced, thereby improving the accuracy of the measurement data. In addition, vertical upward can effectively avoid the fuselage or wings from blocking the analyzer's field of view. By installing the thermometer below the airspeed meter, the thermometer is protected from direct radiation and changes in the external environment. By installing the radiometer above and below the center of gravity of the fuselage, the radiation from the hemispheric space and the surface can be fully measured, including long waves, short waves, and photosynthetically active radiation, providing detailed data support for subsequent research.

[0082] Laser altimeters, thermal infrared cameras, and CCD cameras require a clear view of the ground. The location of the window below the fuselage avoids obstruction by the upper structure of the drone, ensuring the clarity and accuracy of the image and data. At the same time, proximity to the radiometer allows for simultaneous acquisition and comparison of multi-source data. The inertial navigation system is located at the center of gravity in the cabin, which helps reduce the impact of changes in the drone's attitude on the navigation system and improves navigation accuracy. The upper surface of the wing is usually relatively flat and away from other electronic equipment on the body. Installing the antenna on the upper surface of the wing is conducive to the antenna's signal reception and transmission and reduces interference. By installing the wireless communication module antenna under the fuselage and extending it out of the cabin, this position helps to achieve longer-distance signal transmission, while reducing the shielding effect of the drone body on the signal, and improving the stability and reliability of data transmission.

[0083] In summary, this layout design takes into account both measurement accuracy and data comprehensiveness, ensuring that various types of environmental data can be collected efficiently and reliably.

[0084] The airborne observation system designed by the present invention is designed to be carried on a vertical take-off and landing fixed-wing UAV, which can reduce the application difficulty and application cost of regional-scale airborne water, heat flux, carbon flux and four-component surface radiation and photosynthetically active radiation flux observation on non-uniform and non-flat surfaces. In addition, the design focuses on the collaborative observation capability of multiple sensors, and adopts a data collector with internal clock synchronization, external clock synchronization, data alignment and correction capabilities to ensure the synchronization of data collection and processing of each sensor, reduce the wind speed and flux observation errors that often occur due to data asynchrony, and improve system reliability.

[0085] Next, the ground real-time monitoring system of the present invention is described:

[0086] The ground real-time monitoring system is used to store and process the observation data on the real-time receiver, and to display the observation position, meteorological element values ​​and flux calculation results in real time. The ground real-time monitoring system provided by the present invention is distinguished from the ground control system of the UAV flight, and is designed separately without interfering with each other.

[0087] The ground real-time monitoring system consists of four parts: wireless communication module, data storage unit, data processing center and user interface.

[0088] i) The wireless communication module is used to receive real-time observation data from the drone, including: relative air velocity, static pressure, dynamic pressure, air temperature, water vapor density, carbon dioxide density, four components of radiation, photosynthetically active radiation flux, drone geographic location, speed, attitude and relative altitude data.

[0089] ii) The data storage unit is used to store the observation data received by the wireless communication module.

[0090] iii) The data processing center mainly refers to data processing and analysis software and hardware, which are used to perform real-time online data processing on the received observation data according to the parameters set by the user (hereinafter referred to as user parameters), and calculate the average values ​​of various meteorological elements (three-dimensional wind speed, air temperature, water vapor density, carbon dioxide density), water, heat and carbon flux, four components of radiation and photosynthetically active radiation flux.

[0091] iv) The user interface is used to transmit user parameters during real-time online data processing and display the real-time observation position, relative altitude, meteorological elements and water, heat, carbon flux, four components of radiation and photosynthetically active radiation flux corresponding to the observation position.

[0092] The ground real-time monitoring system designed by the present invention can provide real-time synchronous observation of meteorological elements and average flux, which is convenient for observers to monitor system status and data changes in real time and make timely adjustments to the observation plan based on this. It can realize real-time online processing of original observation data and real-time display of meteorological elements and average flux, providing users with comprehensive and timely monitoring services.

[0093] The workflow execution subject of the ground real-time monitoring system designed by the present invention is the above-mentioned data processing center, and the process of real-time online data processing performed by the data processing center is as follows: Figure 2 As shown, it can be divided into the following steps:

[0094] Step S101: Obtain preset user parameters.

[0095] The user parameters for real-time online data processing transmitted through the above user interface include: the physical boundaries of each observation signal related to the observation site environment, meteorological elements, the average time of the four components of radiation and the photosynthetically active radiation flux, the starting point position of the water, heat and carbon flux calculation, the ending point position of the water, heat and carbon flux calculation, and the average window length of the water, heat and carbon flux calculation.

[0096] Step S102: acquiring corresponding observation data based on user parameters, and calculating water vapor flux, heat flux, carbon flux, four components of surface radiation and photosynthetically active radiation flux based on the observation data.

[0097] First, the corresponding observation data is obtained from the above-mentioned data storage unit according to the above-mentioned user parameters set. Based on the obtained observation data, the water vapor flux is calculated using the eddy covariance method, which estimates the turbulent transport of water vapor by calculating the covariance of wind speed pulsation and water vapor density pulsation in the air. The eddy covariance method is also used, focusing on the covariance of wind speed pulsation and temperature pulsation to estimate the turbulent transport of sensible heat flux. Similarly, the carbon flux is calculated by calculating the covariance of wind speed pulsation and carbon dioxide density pulsation using the eddy covariance method. The above-mentioned four components of surface radiation include downward shortwave radiation, upward shortwave radiation, downward longwave radiation and upward longwave radiation. These components can be directly measured by a radiation observation system. Photosynthetically active radiation flux refers to the part of solar radiation that is effective for photosynthesis, usually in the wavelength range of 400-700 nanometers, and can be measured by a specific radiation sensor.

[0098] Calculating the above-mentioned water vapor flux, heat flux, and carbon flux data will help us gain a deeper understanding of the material and energy exchange process between the ecosystem and the atmosphere. The data of the four components of surface radiation and photosynthetically active radiation flux are of great significance for assessing the surface energy balance, the impact of climate change, and crop growth models. It can provide basic observation conditions for the study of the coupled processes of the water cycle, carbon cycle, and energy cycle of the ecosystem, and provide key technical support for research and application in related fields such as improving ecology, improving water resource utilization efficiency, and achieving carbon neutrality goals.

[0099] In summary, by obtaining the corresponding observation data based on user parameters and calculating the water vapor flux, heat flux, carbon flux, four components of surface radiation and photosynthetically active radiation flux, it is possible to achieve synchronous, low-cost and high-precision observation of the four components of ecosystem water, heat flux, carbon flux and radiation and regional values ​​of photosynthetically active radiation flux, which can provide basic observation conditions for the study of the coupled processes of ecosystem water cycle, carbon cycle and energy cycle.

[0100] In an optional embodiment, the above S102 acquires corresponding observation data based on user parameters, and calculates water vapor flux, heat flux, carbon flux, four components of surface radiation and photosynthetically active radiation flux based on the observation data, including:

[0101] S1021. Obtain the observation data of each observation element within the average time of the meteorological element, the four radiation components and the photosynthetically active radiation flux to obtain a corresponding data sequence.

[0102] The observation values ​​of each observation element (including air temperature, water vapor density, carbon dioxide density, four components of radiation, downward and upward photosynthetically active radiation flux, relative altitude above the ground, static pressure, dynamic pressure, angle of attack, sideslip angle, UAV's flight speed over the ground and UAV's attitude angle in the earth coordinate system) in a specific time period, that is, the average time of the above meteorological elements, four components of radiation and photosynthetically active radiation flux, are extracted to form a corresponding data sequence.

[0103] S1022. Original observation values ​​in the data sequence that exceed the physical boundaries of each observation signal are regarded as outliers and marked as invalid values.

[0104] Analyze each data series and identify and mark raw observations that are outside the physical boundaries of each observation signal as outliers. The physical boundaries are based on instrument specifications, environmental common sense, or statistical analysis of historical data. Outliers may be caused by instrument failure, extreme weather conditions, or data transmission errors, which can seriously affect the accuracy of subsequent data analysis and flux calculations.

[0105] S1023. Perform linear interpolation on the invalid values ​​in the data sequence to obtain a corrected sequence.

[0106] Linear interpolation is performed on the wild points marked as invalid values, and the reasonable values ​​of the wild points are estimated based on the valid observations before and after the wild points. The interpolated data sequence, i.e. the corrected sequence, will be used in the subsequent calculation of flux and radiation components to ensure the accuracy and reliability of the results.

[0107] S1024. Calculate the wind speed, temperature, water vapor density, carbon dioxide density, downward shortwave radiation, upward shortwave radiation, downward longwave radiation, upward longwave radiation and the average value of photosynthetically active radiation according to the correction sequence, the meteorological elements, the four components of radiation and the average time of photosynthetically active radiation flux.

[0108] S1025. Calculate water vapor flux, heat flux and carbon flux according to the correction sequence corresponding to each observation element, the water, heat and carbon flux calculation start point position, the water, heat and carbon flux calculation end point position and the water, heat and carbon flux average window length in the user parameters.

[0109] Using the corrected data series, water vapor flux, heat flux and carbon flux are calculated according to the eddy covariance method or other applicable physical models.

[0110] The present invention effectively removes outliers in the original data through wild point detection and linear interpolation correction, thereby improving the integrity and accuracy of the data sequence. The corrected data can better reflect the actual environmental conditions and provide a reliable basis for subsequent scientific analysis and model prediction. The flux and radiation components calculated based on the corrected data sequence are more accurate and reliable, which helps to reduce analysis errors caused by data quality problems.

[0111] The present invention collects the air flow data and the UAV ground flight speed through the airspeed meter. and the attitude angle in the earth coordinate system Determine 3D wind speed data. Air flow data including static pressure , dynamic pressure , Angle of attack , Sideslip Angle . 3D wind speed data Determined by:

[0112] S201, based on static pressure and dynamic pressure , use formula (1) and formula (2) to calculate the absolute value of relative wind speed :

[0113] (1)

[0114] (2)

[0115] in, is the Mach number, is a dimensionless constant with a value of approximately 1.4. is the gas constant of air, is the air temperature.

[0116] S202, based on angle of attack , Sideslip Angle and the absolute value of relative wind speed , use formula (3) to calculate the relative wind speed component in the drone coordinate system ;

[0117] (3)

[0118] S203, based on the UAV's ground flight speed and the attitude angle in the earth coordinate system , use formula (4) to convert the relative wind speed component Convert to three-dimensional wind speed data in the earth coordinate system :

[0119] (4)

[0120] in, Three-dimensional wind speed data exist The weight of the axis, is the rotation matrix determined by the attitude angle of the UAV in the earth coordinate system, and its calculation formula is:

[0121] (5)

[0122] in, , , They are the yaw angle, pitch angle and roll angle of the drone respectively.

[0123] Based on the three-dimensional wind speed components, the average wind speed is calculated according to formula (6): :

[0124] (6)

[0125] In an optional embodiment, the calculation of water vapor flux, heat flux and carbon flux in the above step S1025 according to the correction sequence corresponding to each observation element and the starting point position, end point position and average window length for calculating water, heat and carbon flux is specifically calculated according to the correction sequence of each meteorological element in each observation element. Each meteorological element includes three-dimensional wind speed, air temperature, water vapor density and carbon dioxide density.

[0126] The present invention extracts data in a specific time period, i.e., a window, from the correction sequence of multiple meteorological elements, performs further data processing, and finally calculates water vapor flux, heat flux, and carbon flux, given user parameters (including the starting point position of water, heat, and carbon flux calculation, the ending point position of water, heat, and carbon flux calculation, and the average window length of water, heat, and carbon flux). The calculation process is as follows:

[0127] S301, according to the starting point position for hydrothermal carbon flux calculation in the user parameters , End point position and the average window length , calculate the start and end positions of all hydrothermal carbon flux averaging windows. These windows will cover the entire study period, and the length of each window is determined by the average window length.

[0128] (7)

[0129] in, For the The starting position of the window, For the The ending position of the window.

[0130] First Take a window as an example, when the drone reaches After the position, start The calculation steps of the hydrothermal carbon flux are as follows:

[0131] S302: forward search corresponding to the window start position according to the drone position data The data index is extracted from the correction sequence of each meteorological element and The data sequences between the windows are used to obtain various meteorological data within the window, including the data sequences of air temperature, water vapor density, carbon dioxide density and the data sequences of calculated three-dimensional wind speed data.

[0132] S303, perform zero phase shift filtering on various meteorological data in the window to remove high-frequency noise and abnormal points in the data sequence, ensure that no phase offset is introduced during the filtering process, and thus maintain the original time characteristics of the data. After filtering, check the abnormal points in the data sequence again (which may not be completely removed by filtering or newly generated), perform linear interpolation on these abnormal points, and count the number of abnormal points for subsequent evaluation of data quality.

[0133] S304: If the number of abnormal points in any data sequence in S303 exceeds a preset ratio, the flux calculation is stopped and the flux of the window is marked as a null value. If the number of abnormal points in all data sequences in the window does not exceed a preset ratio, the data quality in the window is considered to be good, and the water vapor flux, heat flux and carbon flux can be calculated based on various meteorological data in the window.

[0134] The present invention allows users to customize the starting point position, end point position and average window length for water, heat and carbon flux calculations. The process provides higher data processing flexibility, enabling it to adapt to different research needs and the characteristics of data sets. Through zero-phase shift filtering and outlier interpolation processing, the quality of the data in the window is effectively improved, and the impact of noise and outliers on flux calculations is reduced. The data quality assessment step ensures that flux calculations are only performed when the data quality meets certain standards, thereby improving the accuracy and reliability of the calculation results. Based on high-quality meteorological data sequences, accurate physical models such as the eddy covariance method are used to calculate water vapor flux, heat flux and carbon flux, which helps to obtain more accurate flux estimates. Accurate water vapor flux, heat flux and carbon flux data are of great significance for evaluating the carbon sink function of ecosystems, optimizing water resources management, monitoring climate change, etc., and help improve the utilization efficiency and management level of natural resources.

[0135] The heat flux includes sensible heat flux and latent heat flux. The calculation of water vapor flux, heat flux and carbon flux based on various meteorological data in the window in step S304 includes:

[0136] S400: The high-frequency air temperature data collected by the high-frequency thermometer and the low-frequency thermometer are and low frequency air temperature data Formula (8) is used to perform fusion processing to obtain the above air temperature , in order to improve the accuracy of observation of average air temperature and pulsation:

[0137] (8)

[0138] in, , Represents high frequency air temperature data , low frequency air temperature data The average value of .

[0139] S401, three-dimensional wind speed data in the window , use formula (9) to rotate the coordinates so that the absolute value of the wind speed component along the wind direction after rotation is equal to the average wind speed, and the average values ​​of the horizontal wind speed component and the vertical wind speed component perpendicular to the wind speed component along the wind direction are approximately 0, and the three-dimensional wind speed after rotation is obtained:

[0140] (9)

[0141] in, is the three-dimensional wind speed after rotation, , , Respectively The average value of .

[0142] S402, calculating the spatial average values ​​of the three-dimensional wind speed, air temperature, water vapor density, and carbon dioxide density after rotation in the window :

[0143] (10)

[0144] in, Represents the sampled value of the target physical quantity for which the spatial average value needs to be calculated within the window. is the number of samples in the window, Indicates the number of sampling points, represents the time interval between two adjacent samples. and Respectively represent the instantaneous speed of the UAV and the average speed of the UAV in the window, Indicates time. The target physical quantity refers to the three-dimensional wind speed, air temperature, water vapor density, and carbon dioxide density after the above rotation.

[0145] S403, subtracting the corresponding spatial average values ​​from the rotated three-dimensional wind speed, the air temperature, the water vapor density, and the carbon dioxide density to obtain corresponding three-dimensional wind speed pulsation values, air temperature pulsation values, water vapor density pulsation values, and carbon dioxide density pulsation values; wherein one component of the three-dimensional wind speed pulsation value is the vertical wind speed component pulsation value;

[0146] (11)

[0147] in, Indicates the pulsation value of the target physical quantity.

[0148] S404, obtaining air density and air specific heat at constant pressure, and calculating sensible heat flux using formula (12) based on the air density, the air specific heat at constant pressure, the vertical wind speed component pulsation value and the air temperature pulsation value based on the eddy covariance method :

[0149] (12)

[0150] in, is the air density, is the constant pressure specific heat of air, is the vertical wind speed component pulsation value, is the air temperature pulsation value.

[0151] S405, according to the vertical wind speed component pulsation value , the water vapor density pulsation value , the air temperature pulsation value , the spatial average value corresponding to water vapor density and the spatial average value corresponding to air temperature, and the water vapor flux is calculated using formula (13) and formula (14) based on the eddy covariance method and WPL correction method respectively: and latent heat flux :

[0152] (13)

[0153] (14)

[0154] in, is the pulsating value of water vapor density, is the ratio of water vapor density to dry air density, is the ratio of the molecular weight of dry air to the molecular weight of water vapor, is the latent heat of vaporization, Indicates water vapor density The corresponding spatial average value is Indicates air temperature The corresponding spatial average.

[0155] S406: According to the vertical wind speed component pulsation value , the carbon dioxide density pulsation value , the water vapor density pulsation value and the air temperature pulsation value , carbon flux is calculated based on eddy covariance method and WPL correction method :

[0156] (15)

[0157] in, is the density of carbon dioxide, is the density of dry air, is the carbon dioxide density pulsation value, is the density of carbon dioxide The corresponding spatial average value is is the density of carbon dioxide The corresponding spatial average value. All parameters of the present invention are indicated by a horizontal bar indicating the average value of the parameter.

[0158] In an optional embodiment, the three-dimensional wind speed pulsation value also includes two other components, namely, a pulsation value of a wind speed component along the wind direction and a pulsation value of a horizontal wind speed component perpendicular to the wind speed component along the wind direction; the method also includes:

[0159] According to the vertical wind speed component pulsation value , Wind speed component pulsation value along wind direction The horizontal wind speed component pulsation value perpendicular to the wind speed component along the wind direction Based on the eddy covariance method, the friction velocity is calculated using formula (16) and formula (17) respectively: and momentum flux :

[0160] (16)

[0161] (17)

[0162] In summary, the process of the drone hydrothermal carbon and radiation flux observation data monitoring method provided by the present invention is as follows: Figure 3 As shown, it can be divided into the following steps:

[0163] (1) Based on the meteorological elements, four radiation components and photosynthetically active radiation flux average time set by the user , starting from the data processing center, every interval Data is collected from the data storage center once a day, including: air temperature, water vapor density, carbon dioxide density, radiation four components , downward and upward photosynthetically active radiation flux , relative altitude from the ground , static pressure , dynamic pressure , Angle of attack , Sideslip Angle , UAV ground flight speed and the attitude angle of the drone in the earth coordinate system , stored in the buffer, awaiting further processing;

[0164] (2) For the data collected in step (1), according to the set user parameters, the original observations that exceed the physical boundary are regarded as wild points and marked as invalid values;

[0165] (3) performing linear interpolation on the invalid values ​​in step (2) to obtain a corrected sequence of the collected observation data;

[0166] (4) Each interval , based on the four components of air temperature, water vapor density, carbon dioxide density, and radiation obtained in step (3) , downward and upward photosynthetically active radiation flux , static pressure and relative altitude from the ground Corrected sequence calculation The corresponding average value within the period;

[0167] (5) Each interval , based on the static pressure obtained in step (3) , dynamic pressure The correction sequence is used to calculate the absolute value of relative wind speed using formula (1) and formula (2) ;

[0168] (6) Based on the angle of attack obtained in step (3) , Sideslip Angle The correction sequence of the data is calculated using formula (3) to calculate the relative wind speed component in the drone coordinate system: ;

[0169] (7) The UAV’s ground speed obtained in step (3) , attitude angle in the earth coordinate system The correction sequence is as follows: the relative wind speed calculated in step (6) is converted into three-dimensional wind speed data in the earth coordinate system using formula (4);

[0170] (8) The three-dimensional wind speed components obtained in step (7) are added to the cache, and each interval , calculate the average wind speed according to formula (6) :

[0171] (9) The above calculated values ​​for each interval During each time period, air temperature, water vapor density, carbon dioxide density, atmospheric pressure, relative altitude, wind speed, four components of radiation, and average value of photosynthetically active radiation are transmitted to the user interface for real-time display;

[0172] (10) The starting point for the hydrothermal carbon flux calculation set by the user and end point position and the average window length of the hydrothermal carbon flux , the sequence of the start and end positions of the average window of hydrothermal carbon flux is calculated using formula (7);

[0173] (11) Taking a window as an example, the calculation steps of hydrothermal carbon flux are as follows:

[0174] (11.1) When the drone reaches the After the position, start The flux calculation of the window is forward searched according to the drone position data corresponding to The data index of the location and extract to The positions are connected by the air temperature observations, water vapor density observations, the corrected sequence of carbon dioxide density obtained in step (3) and the three-dimensional wind speed data calculated in steps (4-7).

[0175] (11.2) Perform zero-phase-shift filtering on the air temperature, water vapor density, carbon dioxide density, and three-dimensional wind speed data extracted in step (11.1), filter out the abnormal points in the data sequence, perform linear interpolation on the abnormal points, and count the number of abnormal points.

[0176] (11.3) If the number of abnormal points in any data sequence in step (11.2) exceeds 10%, the flux calculation is stopped and the flux of the window is marked as a null value. Otherwise, go to step (11.4) to continue the calculation.

[0177] (11.4) The high frequency air temperature and low frequency air temperature Formula (8) is used for fusion processing to improve the accuracy of observation of the average value and pulsation of air temperature;

[0178] (11.5) The three-dimensional wind speed data in the window is rotated using formula (9) so that the absolute value of the first component after rotation is equal to the average wind speed, and the average value of the wind speed component along the wind direction and the horizontal wind speed component perpendicular to the wind speed component along the wind direction is approximately 0, and the three-dimensional wind speed after rotation is obtained;

[0179] (11.6) For the rotated three-dimensional wind speed obtained in step (11.5) and the air temperature, water vapor density and carbon dioxide density obtained in step (11.2), calculate their respective spatial averages using formula (10);

[0180] (11.7) Calculate the three-dimensional wind speed, air temperature, water vapor density and carbon dioxide density pulsation value after rotation according to formula (11);

[0181] (11.8) Based on the eddy covariance method, the sensible heat flux is calculated using formula (12): ;

[0182] (11.9) Based on the eddy covariance method and the WPL correction method, the water vapor flux is calculated using formula (13) and formula (14) respectively: and latent heat flux ;

[0183] (11.10) Based on the eddy covariance method and the WPL correction method, the carbon dioxide flux is calculated using formula (15): ;

[0184] (11.11) Based on the eddy covariance method, the friction velocity is calculated using formula (16) and formula (17) respectively. and momentum flux ;

[0185] (11.12) The calculated sensible heat flux, latent heat flux, carbon flux, and momentum flux are transmitted to the user interface for display.

[0186] The following is a description of the UAV hydrothermal carbon and radiation flux observation real-time data monitoring device provided by the present invention. The UAV hydrothermal carbon and radiation flux observation real-time data monitoring device described below and the UAV hydrothermal carbon and radiation flux observation real-time data monitoring method described above can be referenced to each other.

[0187] The device is applied to a UAV water, heat, carbon and radiation flux synchronous observation and real-time monitoring system, which includes an airborne observation system and a ground real-time monitoring system. The ground real-time data analysis and processing system is used to store pre-set user parameters, receive and process in real time a variety of observation data collected by the airborne observation system, and display water, heat, carbon and radiation flux observation results in real time.

[0188] Reference Figure 4 As shown, the device comprises:

[0189] The acquisition module 501 is used to acquire preset user parameters;

[0190] The calculation module 502 is used to obtain corresponding observation data based on user parameters, and calculate water vapor flux, heat flux, carbon flux, four components of surface radiation and photosynthetically active radiation flux based on the observation data.

[0191] Figure 5 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 5 As shown, the electronic device may include: a processor 610, a communications interface 620, a memory 630 and a communication bus 640, wherein the processor 610, the communications interface 620 and the memory 630 communicate with each other through the communication bus 640. The processor 610 may call the logic instructions in the memory 630 to execute the method for synchronous observation and real-time monitoring of hydrothermal carbon and radiation flux of a drone.

[0192] In addition, the logic instructions in the above-mentioned memory 630 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0193] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the UAV hydrothermal carbon and radiation flux synchronous observation and real-time monitoring method provided by the above methods.

[0194] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the UAV hydrothermal carbon and radiation flux synchronous observation and real-time monitoring method provided by the above-mentioned methods.

[0195] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0196] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0197] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for synchronous observation and real-time monitoring of hydrothermal carbon and radiation flux by unmanned aerial vehicle, which is applied to a synchronous observation and real-time monitoring system for hydrothermal carbon and radiation flux by unmanned aerial vehicle, characterized in that: The UAV water, heat, carbon and radiation flux synchronous observation and real-time monitoring system includes an airborne observation system and a ground real-time monitoring system, wherein the ground real-time monitoring system is used to store pre-set user parameters, receive and process in real time a variety of observation data collected by the airborne observation system, and display water, heat, carbon and radiation flux observation results in real time; The method comprises: Obtaining pre-set user parameters; the user parameters include: meteorological elements, four components of radiation and photosynthetically active radiation flux average time, physical boundaries of each observation signal related to the observation site environment, and the starting point position, end point position and average window length for water, heat and carbon flux calculation; Obtain the observation data of each observation element within the average time of the meteorological element, the four components of radiation and the photosynthetically active radiation flux to obtain the corresponding data sequence; regard the original observation values ​​in the data sequence that exceed the physical boundaries of each observation signal as wild points and mark them as invalid values; perform linear interpolation on the invalid values ​​in the data sequence to obtain a corrected sequence; calculate the wind speed, temperature, water vapor density, carbon dioxide density, downward shortwave radiation, upward shortwave radiation, downward longwave radiation, upward longwave radiation and photosynthetically active radiation average value according to the corrected sequence, the meteorological element, the four components of radiation and the photosynthetically active radiation flux average time; each observation element includes multiple meteorological elements; according to the starting point The position, end point position and average window length are used to calculate the window start position and window end position of all water, heat and carbon flux average windows; forward search the data index corresponding to the window start position according to the UAV position data, and extract the data sequence between the window start position and the window end position from the correction sequence of each meteorological element to obtain various meteorological data in the window; zero-phase shift filtering is performed on the various meteorological data in the window to filter out abnormal points in the data sequence, linear interpolation is performed on the abnormal points, and the number of abnormal points is counted; when the number of abnormal points of all data sequences in the window does not exceed the preset ratio, the water vapor flux, heat flux and carbon flux are calculated based on the various meteorological data in the window.

2. The method for simultaneous observation and real-time monitoring of hydrothermal carbon and radiation flux by unmanned aerial vehicle according to claim 1 is characterized in that: The various meteorological data include three-dimensional wind speed data, air temperature, water vapor density and carbon dioxide density, and the heat flux includes sensible heat flux and latent heat flux; the airborne observation system includes an airspeed meter, an inertial navigation system, an air temperature measurement unit, and a water vapor and carbon dioxide density measurement unit. The three-dimensional wind speed data is calculated based on the air fluid data collected by the airspeed meter installed at the front end of the UAV fuselage and extending along the longitudinal axis of the UAV fuselage, and the UAV ground flight speed and attitude angle in the earth coordinate system collected by the inertial navigation system installed at the center of gravity of the UAV in the cabin. The air temperature is collected by the air temperature measurement unit installed below the airspeed meter, and the water vapor density and the carbon dioxide density are collected by the water vapor and carbon dioxide density measurement unit installed vertically upward at the front end of the UAV fuselage; The calculation of water vapor flux, heat flux and carbon flux based on various meteorological data in the window includes: Perform coordinate rotation on the three-dimensional wind speed data in the window to obtain the rotated three-dimensional wind speed; Calculate the spatial average values ​​of the rotated three-dimensional wind speed, air temperature, water vapor density, and carbon dioxide density in the window; Subtract the corresponding spatial average values ​​from the rotated three-dimensional wind speed, the air temperature, the water vapor density, and the carbon dioxide density to obtain corresponding three-dimensional wind speed pulsation values, air temperature pulsation values, water vapor density pulsation values, and carbon dioxide density pulsation values; wherein the three-dimensional wind speed pulsation values ​​include the vertical wind speed component pulsation values; Obtaining air density and air specific heat at constant pressure, and calculating sensible heat flux according to the air density, the air specific heat at constant pressure, the vertical wind speed component pulsation value, and the air temperature pulsation value; Calculating water vapor flux according to the vertical wind speed component pulsation value, the water vapor density pulsation value, the air temperature pulsation value, the spatial average value corresponding to the water vapor density and the spatial average value corresponding to the air temperature; Acquiring latent heat of vaporization, and calculating latent heat flux according to the latent heat of vaporization and the water vapor flux; The carbon flux is calculated according to the vertical wind speed component pulsation value, the carbon dioxide density pulsation value, the water vapor density pulsation value and the air temperature pulsation value.

3. The method for simultaneous observation and real-time monitoring of hydrothermal carbon and radiation flux by unmanned aerial vehicle according to claim 2 is characterized in that: The air flow data includes static pressure, dynamic pressure, angle of attack and sideslip angle; the three-dimensional wind speed data is determined by: Based on static pressure and dynamic pressure, calculate the absolute value of relative wind speed; Based on the angle of attack, sideslip angle and absolute value of relative wind speed, the relative wind speed component in the UAV coordinate system is calculated; Based on the UAV's flight speed over the ground and its attitude angle in the earth coordinate system, the relative wind speed component is converted into three-dimensional wind speed data in the earth coordinate system.

4. The method for simultaneous observation and real-time monitoring of hydrothermal carbon and radiation flux by unmanned aerial vehicle according to claim 2 is characterized in that: The three-dimensional wind speed pulsation value also includes a wind speed component pulsation value along the wind direction and a horizontal wind speed component pulsation value perpendicular to the wind speed component along the wind direction; the method also includes: The friction velocity is calculated based on the eddy covariance method according to the vertical wind speed pulsation value, the wind speed component pulsation value along the wind direction and the horizontal wind speed component pulsation value perpendicular to the wind speed component along the wind direction; The air density is obtained, and the momentum flux is calculated according to the air density and the friction velocity.

5. A UAV hydrothermal carbon and radiation flux synchronous observation and real-time monitoring device for realizing the UAV hydrothermal carbon and radiation flux synchronous observation and real-time monitoring method as claimed in any one of claims 1 to 4, applied to a UAV hydrothermal carbon and radiation flux synchronous observation and real-time monitoring system, characterized in that: The UAV water, heat, carbon and radiation flux synchronous observation and real-time monitoring system includes an airborne observation system and a ground real-time monitoring system, wherein the ground real-time monitoring system is used to store pre-set user parameters, receive and process in real time a variety of observation data collected by the airborne observation system, and display water, heat, carbon and radiation flux observation results in real time; The device comprises: An acquisition module is used to acquire preset user parameters; the user parameters include: meteorological elements, four components of radiation and average time of photosynthetically active radiation flux, physical boundaries of each observation signal related to the observation site environment, and the starting point position, end point position and average window length for water, heat and carbon flux calculation; A calculation module is used to obtain the observation data of each observation element within the average time of the meteorological elements, four radiation components and photosynthetically active radiation flux to obtain a corresponding data sequence; the original observation values ​​in the data sequence that exceed the physical boundaries of each observation signal are regarded as wild points and marked as invalid values; the invalid values ​​in the data sequence are linearly interpolated to obtain a corrected sequence; the wind speed, temperature, water vapor density, carbon dioxide density, downward shortwave radiation, upward shortwave radiation, downward longwave radiation, upward longwave radiation and photosynthetically active radiation average value are calculated according to the corrected sequence, the meteorological elements, the four radiation components and the photosynthetically active radiation flux average time; each observation element includes multiple meteorological elements; according to the The starting point position, the ending point position and the average window length are used to calculate the window starting position and the window ending position of all water, heat and carbon flux average windows; the data index corresponding to the window starting position is forward searched according to the UAV position data, and the data sequence between the window starting position and the window ending position is extracted from the correction sequence of each meteorological element to obtain various meteorological data in the window; zero-phase shift filtering is performed on the various meteorological data in the window to filter out abnormal points in the data sequence, linear interpolation is performed on the abnormal points, and the number of abnormal points is counted; when the number of abnormal points in all data sequences in the window does not exceed the preset ratio, the water vapor flux, heat flux and carbon flux are calculated based on the various meteorological data in the window.

6. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, it implements the method for simultaneous observation and real-time monitoring of hydrothermal carbon and radiation flux by a UAV as described in any one of claims 1 to 4.

7. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by the processor, the method for simultaneous observation and real-time monitoring of hydrothermal carbon and radiation flux by a UAV as described in any one of claims 1 to 4 is implemented.

8. A computer program product, comprising a computer program, characterized in that When the computer program is executed by the processor, the method for simultaneous observation and real-time monitoring of hydrothermal carbon and radiation flux by a UAV as described in any one of claims 1 to 4 is implemented.

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