A method and device for comprehensive measurement of infrared radiation characteristics of typical highland landforms

Abstract

The application discloses a kind of plateau environment typical landform infrared radiation characteristic comprehensive measurement method and device, belong to infrared radiation characteristic measurement technical field.The method includes: selecting the open area of the typical landform to be measured as test point;Build the measuring device including tripod, two-dimensional turntable and the emissivity measuring instrument installed on two-dimensional turntable and long-wave thermal imager, and the optical axis of the three is parallel;Radiation characteristic measurement is executed, including scanning measurement with test point as center according to a plurality of azimuth angles, fixed azimuth angle is measured by staring, and auxiliary measurement of synchronous acquisition in situ meteorological parameter;Radiance value is obtained based on infrared image and is corrected in atmosphere, and the radiation temperature of typical landform is calculated by combining emissivity measurement data.The application realizes the infrared radiation characteristic comprehensive measurement of plateau typical landform at different time, different azimuth angle by scanning measurement and staring measurement, improves the space-time representativeness and accuracy of measurement data.

Description

Technical Field

[0001] This invention relates to the field of infrared radiation characteristic measurement technology, and in particular to a comprehensive measurement method and device for infrared radiation characteristics of typical landforms in plateau environments. It is especially suitable for simultaneous, multi-angle, in-situ measurement of mid-wave and long-wave infrared radiance, radiant temperature, and emissivity of typical landforms such as bare soil, permafrost, and meadows in plateau environments. Background Technology

[0002] The infrared radiation characteristics of typical plateau landforms (such as bare soil, permafrost, and meadows) are key input parameters for the quantitative application of remote sensing data and the modeling of land surface processes. Obtaining accurate in-situ measurement data is of great significance for the radiometric calibration, atmospheric correction, and verification of land surface temperature retrieval algorithms for spaceborne or airborne remote sensing data.

[0003] Currently, there are some shortcomings in the measurement of infrared characteristics of typical plateau landforms. Conventional measurement methods typically use a single thermal imager to measure surface infrared radiance or an emissivity meter to measure surface emissivity. This approach has several problems: First, the measurement parameters are singular, lacking a systematic and simultaneous acquisition of radiance, temperature, and emissivity. For example, in the prior art, Chinese patent application CN104155007A discloses a multi-angle surface fine emissivity spectrum acquisition system, but it focuses on acquiring the emissivity spectrum and does not systematically integrate and simultaneously measure radiance, radiant temperature, and meteorological parameters used for atmospheric correction. Second, the measurement mode is mostly a fixed-point "staring" measurement. For plateau landforms with strong spatial heterogeneity (such as patchy meadows), the spatiotemporal representativeness of single-point measurements is insufficient, making it difficult to effectively match and verify with the pixel scale of remote sensing images. Furthermore, the plateau environment is characterized by strong solar radiation, large diurnal temperature range, and rapid changes in atmospheric conditions. If radiation measurement, emissivity measurement, and atmospheric parameter measurement lack strict time synchronization, it will lead to large errors in the calculation of derived parameters such as radiation temperature.

[0004] In the prior art, Chinese patent application CN116804622A proposes a method for measuring atmospheric infrared transmittance to reduce environmental radiation interference. This method effectively decouples environmental radiation interference and improves the measurement accuracy of atmospheric transmittance through a dual-target and dual-spectrometer design. However, this method focuses on measuring the atmospheric parameters themselves and does not provide a complete solution on how to combine accurate atmospheric transmittance data with synchronous measurements of surface radiance and emissivity to ultimately obtain high-precision surface radiant temperature and comprehensive radiation characteristics.

[0005] In summary, the existing technology lacks a comprehensive measurement method and device that can synchronously and systematically acquire infrared radiation brightness, radiation temperature and emissivity of typical landforms at different times, under different lighting conditions and different azimuth angles, specifically for the special environment of plateaus. Summary of the Invention

[0006] (a) Purpose of the invention The purpose of this invention is to provide a comprehensive measurement method and device for infrared radiation characteristics of typical landforms in plateau environments. This method enables simultaneous, multi-angle, in-situ measurements of radiance, radiant temperature, and emissivity in the mid-wave and long-wave infrared bands of typical landforms in plateau environments. It effectively improves the spatiotemporal representativeness, parameter integrity, and accuracy of the measurement data, providing more reliable ground truth data for plateau remote sensing data correction and land surface process model verification.

[0007] (II) Technical Solution To achieve the above objectives, in a first aspect, the present invention provides a comprehensive measurement method for the infrared radiation characteristics of typical landforms in plateau environments, comprising the following steps: Step 1: In a plateau environment, select an open area of ​​the typical landform to be tested as the test site; Step 2: Set up a measuring device at the test point. The measuring device includes a tripod, a two-dimensional turntable mounted on the tripod, and a mid-wave thermal imager, a long-wave thermal imager, and an emissivity measuring instrument, all mounted on the two-dimensional turntable. The optical axes of the mid-wave thermal imager, the long-wave thermal imager, and the emissivity measuring instrument are made parallel to each other. Step 3: Perform radiation characteristic measurements, including the following sub-steps performed simultaneously: Scanning measurement sub-step: Control the two-dimensional turntable to scan with the test point as the center according to multiple preset azimuth angles. At each azimuth angle, use the medium-wave thermal imager and the long-wave thermal imager to collect typical landform infrared images of preset duration at preset frequencies. Gazing measurement sub-step: Control the two-dimensional turntable to be fixed at a preset azimuth angle, and use the mid-wave thermal imager and long-wave thermal imager to continuously collect infrared images of typical landforms; Auxiliary measurement sub-steps: During the measurement process, in-situ meteorological parameters are acquired synchronously using a meteorological measuring instrument; Step 4: Process the measurement data, including: Based on infrared images collected from various azimuth angles, the radiance values ​​of typical landforms are obtained. Using the in-situ meteorological parameters, atmospheric correction is applied to the radiance value to obtain the corrected radiance value; From the data obtained by the emissivity measuring instrument, obtain the band emissivity corresponding to the working band of the medium-wave thermal imager or the long-wave thermal imager; Based on the corrected radiance value and the emissivity of the band, the radiant temperature of a typical landform is calculated.

[0008] Optionally, step three further includes: placing a standard plate within the field of view of the measured terrain during the measurement process; the standard plate has a known emissivity and is used as a reference benchmark in the data processing of step four to calculate atmospheric downdraft radiation and / or verify the accuracy of emissivity measurement.

[0009] Optionally, in the scanning measurement sub-step of step three, the preset plurality of azimuth angles are: Multiple azimuth angles are set at 15° intervals within a fan-shaped area centered on the test point, with azimuth angles ranging from -60° to 60°; or Multiple azimuth angles are set at 45° intervals when performing a 360° circular scan with the test point as the center.

[0010] Optionally, in the scanning measurement sub-step, the preset frequency is not less than 10Hz, and the preset duration is not less than 1 minute; and / or In the gaze measurement sub-step, the frequency of continuous acquisition is no greater than 0.1 Hz.

[0011] Optionally, in step three, when the two-dimensional turntable is controlled to rotate, the medium-wave thermal imager, the long-wave thermal imager, and the emissivity measuring instrument rotate synchronously.

[0012] Optionally, in step two: The measurement band of the medium-wave thermal imager is 3.7μm to 4.8μm, the measurement band of the long-wave thermal imager is 7.7μm to 9.3μm, and the measurement band of the emissivity meter covers 2μm to 14μm.

[0013] Optionally, step four specifically includes: Export infrared images acquired at various azimuth angles; Select a typical region in each frame of the image and calculate the average gray value of the pixels in that region. The average gray value is converted into a radiance value using a preset calibration coefficient; Using the in-situ meteorological parameters, atmospheric transmittance and atmospheric path radiation are calculated through an atmospheric transport model, and atmospheric correction is applied to the radiance values ​​to obtain corrected radiance values. From the data obtained by the emissivity measuring instrument, the emissivity spectrum curve of a typical landform is derived, and the band emissivity corresponding to the working band of the medium-wave thermal imager or long-wave thermal imager is calculated. Based on the corrected radiance value and the emissivity of the band, and combined with Planck's formula, the radiant temperature of a typical landform is calculated.

[0014] Optionally, the typical region is an N×N pixel region with a relatively uniform center position in the image; the scaling coefficient includes a gain coefficient. and bias coefficient The average gray value Convert to radiance value The formula is: The formula for atmospheric correction is: in, This is the corrected radiance value. Atmospheric transmittance, This is atmospheric path radiation.

[0015] Secondly, the present invention also provides a comprehensive measurement device for infrared radiation characteristics of typical landforms in plateau environments, used to implement the method described in any one of the first aspects, the device comprising: The support and positioning module includes a tripod and a two-dimensional turntable mounted on the tripod; The infrared radiation measurement module includes a mid-wave thermal imager and a long-wave thermal imager, both mounted on the two-dimensional turntable. The emissivity measurement module includes an emissivity measuring instrument also mounted on the two-dimensional turntable; Environmental parameter measurement module, including meteorological measuring instrument; The control and data processing module includes a data acquisition and control unit and a computer. The data acquisition and control unit is electrically connected to the two-dimensional turntable, the medium-wave thermal imager, the long-wave thermal imager, and the emissivity measuring instrument, respectively, and is used to transmit control commands and acquire data. The computer is used to execute the operation control of the measuring device, data acquisition and storage, and data processing.

[0016] Optionally, the medium-wave thermal imager, long-wave thermal imager, and emissivity meter are all mounted on the two-dimensional turntable via an adapter plate.

[0017] (III) Beneficial Effects The above-mentioned technical solution of the present invention has the following technical effects: This invention integrates radiance measurement, emissivity measurement, and atmospheric parameter measurement into a single system, forming a complete measurement method that can simultaneously acquire infrared radiance, radiant temperature, and emissivity of typical plateau landforms, with strong parameter integrity.

[0018] By combining scanning measurements with staring measurements, it is possible to obtain the infrared radiation characteristics of typical landforms at different times and azimuth angles. Scanning measurements enable multi-angle spatial observation, while staring measurements enable continuous time-series observation, effectively overcoming the limitations of single-point measurements.

[0019] By ensuring the optical axes of all measuring instruments are parallel and employing a measurement control method that synchronizes scanning and staring, combined with subsequent atmospheric correction processing, system errors and environmental impacts are effectively reduced. In particular, correlating radiance data with emissivity data and using it for radiant temperature inversion avoids temperature inversion errors caused by data time mismatch, significantly improving the measurement accuracy of key parameters such as final radiant temperature.

[0020] The method of this invention is applicable to the measurement of infrared radiation characteristics of various typical landforms such as bare soil, permafrost, and meadows on plateaus, and has strong universality and practical value.

[0021] The comprehensive measurement device for infrared radiation characteristics of typical landforms in plateau environments provided by this invention integrates a support and positioning module, an infrared radiation measurement module, an emissivity measurement module, an environmental parameter measurement module, and a control and data processing module into one unit through a modular design. It has the advantages of convenient measurement and disassembly, and suitability for field operations. Attached Figure Description

[0022] The accompanying drawings are provided for illustrative purposes only, and the proportions and quantities of the components in the drawings may not be consistent with the actual product.

[0023] Figure 1 This is an overall flowchart of the measurement method in an embodiment of the present invention; Figure 2 This is a flowchart of measurement data processing in an embodiment of the present invention; Figure 3 This is a schematic diagram of a comprehensive measurement device for infrared radiation characteristics of typical landforms in a plateau environment, as described in an embodiment of the present invention. Figure 4 This is a schematic diagram of the arrangement of test points and measuring devices in an embodiment of the present invention; Figure 5 This is a schematic diagram of the azimuth angle setting for the scanning measurement mode (sector scanning) in an embodiment of the present invention; Figure 6 This is a schematic diagram of the azimuth angle setting for the scanning measurement mode (circular scanning) in an embodiment of the present invention.

[0024] In the picture: 1: Adapter board; 2: Medium-wave thermal imager; 3: Emissivity meter; 4: Long-wave thermal imager; 5: 2D turntable; 6: Power supply; 7: Tripod; 8: Power supply box; 9: Data acquisition and control unit; 10: Standard board; 11: Meteorological measuring instrument; 12: Computer. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] This embodiment provides a comprehensive measurement method for the infrared radiation characteristics of typical landforms in plateau environments. In this embodiment, the comprehensive measurement of infrared radiation characteristics of bare landforms in plateau environments is taken as an example. This method utilizes the comprehensive measurement device for the infrared radiation characteristics of typical landforms in plateau environments provided by this invention. (Refer to...) Figure 1 The overall process is shown below, with the following specific steps: Step 1: Select test sites A typical, large area of ​​bare landform was selected in the plateau region as the test site. Within this area, a relatively open and flat location was chosen as the specific test point. This test point must meet the following requirements: within the required azimuth and viewing angle range centered on this point, when the measuring instrument observes the ground at a certain elevation angle, the field of view is not obstructed by protruding features (such as mounds of earth, rocks, vegetation, etc.). The test point selected in this embodiment meets the above requirements.

[0027] Step 2: Setting up the measuring device Reference Figure 3 and Figure 4 Set up the measuring device.

[0028] First, fully extend and lock the legs of tripod 7 to secure it firmly at the selected test point. Figure 4 Point A is located at the center. Adjust the gimbal of tripod 7 so that its top mounting plane is approximately horizontal. Point B in the diagram is located on the azimuth line extending outward from point A and is an observation target point on the measured terrain.

[0029] Then, the two-dimensional turntable 5 is connected and tightened to the mounting bolts on the top of the tripod 7 through the screw holes on its bottom. The two-dimensional turntable 5 has precise rotation capabilities with two degrees of freedom: azimuth and pitch, and has a built-in photoelectric inertial navigation system for real-time feedback of azimuth and pitch angle data.

[0030] Next, as a preferred installation method, the adapter plate 1 is fixed to the load mounting surface of the two-dimensional turntable 5 with bolts. Then, the mid-wave thermal imager 2, the long-wave thermal imager 4, and the emissivity meter 3 are each fixed to the adapter plate 1 with bolts. As a preferred band configuration, the mid-wave thermal imager 2 is a cooled thermal imager with an operating band of 3.7μm to 4.8μm, the long-wave thermal imager 4 is a cooled thermal imager with an operating band of 7.7μm to 9.3μm, and the emissivity meter 3 is a Fourier transform infrared spectrometer with an operating band covering 2μm to 14μm. During installation, the position and orientation of each instrument must be carefully adjusted to ensure that the optical axes of the mid-wave thermal imager 2, the long-wave thermal imager 4, and the emissivity meter 3 remain parallel to each other. The adapter plate 1 enables the joint installation of the three instruments, ensuring that the medium-wave thermal imager 2, long-wave thermal imager 4, and emissivity measuring instrument 3 can rotate synchronously when the two-dimensional turntable 5 is controlled to rotate, thereby realizing synchronous and same-field observation of the same target by multiple instruments.

[0031] After completing the instrument installation, make the electrical connections. Connect the medium-wave thermal imager 2, long-wave thermal imager 4, emissivity meter 3, and 2D turntable 5 to their respective data interfaces on the data acquisition and control unit 9 using data cables. Then, connect the data acquisition and control unit 9 to the computer 12 using data cables. The data acquisition and control unit 9 is used to receive control commands from the computer 12 and transmit them to each instrument, as well as to acquire measurement data from each instrument and transmit it to the computer 12. Connect the power supply interfaces of the medium-wave thermal imager 2, long-wave thermal imager 4, emissivity meter 3, and 2D turntable 5 to the output ports of the power supply box 8 using power cables. Finally, connect the input ports of the power supply box 8 to an external power source 6, such as a diesel generator or a high-capacity battery pack, using power cables.

[0032] In addition, a meteorological measuring instrument 11 is set up at a suitable location near the test site to simultaneously record in-situ meteorological parameters such as temperature, air pressure, relative humidity, wind speed and wind direction.

[0033] As an alternative, a standard plate 10 with a known emissivity is placed at the edge of the field of view of the bare landform to be measured, ensuring that the standard plate 10 can be captured by the thermal imager and emissivity meter along with the bare landform during measurement. The standard plate 10 has a known emissivity and can be used as a reference benchmark in subsequent data processing to calculate atmospheric downdraft radiation and / or verify the accuracy of emissivity measurements.

[0034] Before the actual measurement, a self-test can be performed on the measuring device to ensure that all equipment is functioning properly. This includes: First, point the zero mark of the two-dimensional turntable 5 to due north, turn on the power supply 6, and power on the measuring device. The two-dimensional turntable 5 begins self-testing by rotating 360° in the azimuth direction and rotating to the maximum pitch angle range in the pitch direction. After the turntable completes its self-test, turn on the emissivity measuring instrument 3, the medium-wave thermal imager 2, and the long-wave thermal imager 4 respectively, and wait for the medium-wave thermal imager 2 and the long-wave thermal imager 4 to complete their cooling.

[0035] Then, using the turntable control software installed on computer 12, the azimuth and pitch angles of the turntable are input to control the 2D turntable 5 to perform angular rotation, verifying whether the 2D turntable 5 can work normally. Simultaneously, it is checked whether the azimuth and pitch angle data of the photoelectric inertial navigation system change accordingly with the rotation of the 2D turntable 5. When the 2D turntable 5 is controlled normally and the photoelectric inertial navigation data output is normal, after the thermal imager completes cooling, the thermal imager control software is used to check whether the image acquired by the thermal imager is normal; the emissivity meter control software is used to check whether the spectrum acquired by the emissivity meter is normal.

[0036] Finally, control the 2D turntable 5, adjust the thermal imager integration time, and check the images acquired by the thermal imager to determine whether the thermal imager's image is complete and unobstructed, and whether the data is valid and unsaturated within the required pitch and azimuth angle range.

[0037] Step 3: Measurement of radiation characteristics This embodiment employs both scanning and staring measurement methods. Before the measurement begins, the meteorological measuring instrument 11 is activated to continuously record meteorological data.

[0038] Scan measurement sub-step: Use the control software on computer 12 to set up an automatic measurement sequence.

[0039] As a preferred implementation method for scanning measurement (sector scanning), such as Figure 5 As shown, test point O (i.e. Figure 4 Centered on point A, the two-dimensional turntable 5 is programmed to scan within a sector range of -60° to 60° azimuth, with a step size of 15°. At each angular position (i.e., -60°, -45°, -30°, -15°, 0°, 15°, 30°, 45°, 60°), the mid-wave thermal imager 2 and the long-wave thermal imager 4 are triggered to acquire images. Figure 5 In the diagram, N represents true north (0° azimuth reference), and B1~B8 represent multiple measurement azimuth directions set at 15° intervals. This setup enables multi-angle observation of the directional radiation characteristics of bare landforms.

[0040] As another preferred implementation of scanning measurement (circumferential scanning), such as Figure 6 As shown, test point O (i.e. Figure 4Using point A as the center, the two-dimensional turntable 5 is programmed to scan within an azimuth range of 0° to 360° in 45° increments. At each angular position (0°, 45°, 90°, 135°, 180°, 225°, 270°, 315°), the mid-wave thermal imager 2 and the long-wave thermal imager 4 are triggered to acquire images. Figure 6 In the diagram, N represents true north (0° azimuth reference), and B1~B8 represent eight measurement azimuth directions set at 45° intervals. This setup can comprehensively acquire the directional radiation characteristics of typical terrain features.

[0041] The two scanning modes mentioned above can be selected according to the on-site testing conditions and measurement requirements. There are no fewer than 8 measurement angles, which can effectively obtain the infrared radiation characteristics of typical landforms at different azimuth angles.

[0042] As a preferred measurement parameter setting, in the above scanning measurement, the acquisition frequency of the medium-wave thermal imager 2 and the long-wave thermal imager 4 is set to be no less than 10Hz, and the acquisition time at each angular position is set to be no less than 1 minute.

[0043] Gaze measurement sub-steps: Before, during, or at intervals between scan measurement sequences, the two-dimensional turntable 5 is fixedly pointed to a preset azimuth angle (e.g., true north, i.e., 0° azimuth). As a preferred measurement parameter setting, the medium-wave thermal imager 2 and the long-wave thermal imager 4 are set to perform long-term, continuous image acquisition at a frequency not exceeding 0.1 Hz (e.g., 0.05 Hz, i.e., acquiring one frame every 20 seconds) to obtain the continuous evolution of the infrared radiation characteristics of bare landforms over time (especially with changes in solar altitude angle). Through staring measurements, data on the changes in infrared radiation characteristics of typical landforms at different times and under different lighting conditions can be obtained.

[0044] Auxiliary measurement sub-steps: Throughout the measurement process, if a standard plate 10 has been placed, it remains within the field of view. Its response in the infrared image and emissivity spectral data will be used for subsequent data quality checks and calibration. The meteorological instrument 11 continuously and synchronously records environmental meteorological data, including air temperature, air pressure, relative humidity, wind speed and direction, for subsequent atmospheric correction calculations.

[0045] Step 4: Measurement Data Processing Reference Figure 2 The process shown is for data processing. The following explanation uses a single frame of mid-wave infrared image acquired at a specific azimuth angle as an example.

[0046] (1) Data export and image selection: Export all raw data files stored on computer 12 during field measurements. Based on the timestamp file and image file name recorded by 2D turntable 5, locate the mid-wave infrared image file acquired at an azimuth angle of 0°.

[0047] (2) Gray value extraction: As a preferred processing method, a relatively uniform area with no outliers and uniform ground features is selected at the center of the image frame as a typical area, such as an N×N pixel area of ​​40×40 pixels. Using image processing software or a self-written program, the arithmetic mean of the gray values ​​DN of all pixels in this area is calculated to obtain the average gray value DN.

[0048] (3) Radiance conversion: The calibration coefficients, including the gain coefficients, were obtained using this mid-wave thermal imager during laboratory radiometric calibration. and bias coefficient The average gray value is converted using the following linear transformation formula. Convert to the corresponding radiance value : in, and These are the calibration coefficients obtained in advance through laboratory radiation calibration.

[0049] (4) Atmospheric correction: Meteorological data, including temperature, air pressure, and humidity, precisely corresponding to the acquisition time of the image frame are extracted and input into atmospheric radiative transfer models such as MODTRAN to calculate the atmospheric transmittance at that time and along that measurement path. and atmospheric radiation Then, the radiance value is calculated using the following formula. Perform atmospheric correction: in, This is the corrected radiance value, which represents the radiance value of the actual emitted radiation from the bare soil surface.

[0050] (5) Emittance acquisition: From the spectral data file acquired by emissivity meter 3, find the measurement data closest to the aforementioned measurement time and derive the emissivity spectral curve of the bare landform. Based on the operating wavelength of the mid-wave thermal imager (3.7μm to 4.8μm), integrate or weighted average the spectral emissivity within this wavelength range to calculate the average emissivity of this wavelength range. ε .

[0051] As an optional means of ensuring data quality, if the standard plate 10 is used in the measurement process, the measurement data of the standard plate 10 can be used as a reference benchmark to verify the accuracy of emissivity measurement or to calculate atmospheric downdraft radiation.

[0052] (6) Calculation of radiation temperature: Based on the corrected radiance value and band emissivity ε By combining Planck's formula and using numerical iteration or a pre-established lookup table of "radiance-emissivity-temperature", the corresponding radiation temperature T can be solved. For example, the lookup table records a series of blackbody radiance values ​​B(T) at temperature T, while the radiance of real objects satisfies... By comparison and This allows us to find the most suitable temperature T as the radiation temperature of the bare landform at that moment and in that observation direction.

[0053] Repeat steps (1) to (6) to process all infrared image data acquired by scanning and staring measurements. For processing long-wave infrared image data, the process is the same as that for processing mid-wave infrared image data, only requiring the use of the calibration coefficients and working bands corresponding to the long-wave thermal imager.

[0054] The final result is a complete dataset containing mid-wave and long-wave infrared radiance, radiant temperature, and emissivity of the bare landforms of the plateau at different times and azimuth angles. This dataset can be directly used for radiometric calibration verification of high-resolution remote sensing images or parameter optimization of land surface process models.

[0055] It should be noted that, in the above embodiments, the self-test step before formal measurement is a safeguard measure. Those skilled in the art should understand that, in practical applications, the self-test step can be omitted or simplified, or other equivalent alternatives can be used to confirm the status of the measuring device, depending on the site conditions and actual needs. These self-test steps are not essential technical features for achieving the purpose of this invention and should not limit the scope of protection of this invention.

[0056] It is worth noting that the comprehensive measurement method for infrared radiation characteristics of typical plateau landforms of the present invention can also be used for the comprehensive measurement of infrared radiation characteristics of typical plateau landforms such as plateau permafrost landforms or plateau meadow landforms. The setup, self-test, radiation characteristic measurement steps, and data processing flow of the measurement device are the same as those in the above embodiments, and will not be repeated here.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that not every embodiment contains only one independent technical solution, and in the absence of conflict between solutions, the various technical features mentioned in each embodiment can be combined in any way to form other implementation methods that can be understood by those skilled in the art.

[0058] Furthermore, without departing from the scope of the present invention, modifications to the technical solutions described in the foregoing embodiments, or equivalent substitutions of some of the technical features, shall not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A comprehensive measurement method for infrared radiation characteristics of typical landforms in plateau environments, characterized in that, Includes the following steps: Step 1: In a plateau environment, select an open area of ​​the typical landform to be tested as the test site; Step 2: Set up a measuring device at the test point. The measuring device includes a tripod, a two-dimensional turntable mounted on the tripod, and a mid-wave thermal imager, a long-wave thermal imager, and an emissivity measuring instrument, all mounted on the two-dimensional turntable. The optical axes of the mid-wave thermal imager, the long-wave thermal imager, and the emissivity measuring instrument are made parallel to each other. Step 3: Perform radiation characteristic measurements, including the following sub-steps performed simultaneously: Scanning measurement sub-step: Control the two-dimensional turntable to scan with the test point as the center according to multiple preset azimuth angles. At each azimuth angle, use the medium-wave thermal imager and the long-wave thermal imager to collect typical landform infrared images of preset duration at preset frequencies. Gazing measurement sub-step: Control the two-dimensional turntable to be fixed at a preset azimuth angle, and use the mid-wave thermal imager and long-wave thermal imager to continuously collect infrared images of typical landforms; Auxiliary measurement sub-steps: During the measurement process, in-situ meteorological parameters are acquired synchronously using a meteorological measuring instrument; Step 4: Process the measurement data, including: Based on infrared images collected from various azimuth angles, the radiance values ​​of typical landforms are obtained. Using the in-situ meteorological parameters, atmospheric correction is applied to the radiance value to obtain the corrected radiance value; From the data obtained by the emissivity measuring instrument, obtain the band emissivity corresponding to the working band of the medium-wave thermal imager or the long-wave thermal imager; Based on the corrected radiance value and the emissivity of the band, the radiant temperature of a typical landform is calculated.

2. The method according to claim 1, characterized in that, Step three further includes: placing a standard plate within the field of view of the measured terrain during the measurement process; the standard plate has a known emissivity and is used as a reference benchmark for calculating atmospheric downdraft radiation and / or verifying the accuracy of emissivity measurements in the data processing of step four.

3. The method according to claim 1, characterized in that, In the scanning measurement sub-step of step three, the preset multiple azimuth angles are: Multiple azimuth angles are set at 15° intervals within a fan-shaped area centered on the test point, with azimuth angles ranging from -60° to 60°; or Multiple azimuth angles are set at 45° intervals when performing a 360° circular scan with the test point as the center.

4. The method according to claim 1, characterized in that: In the scanning measurement sub-step, the preset frequency is not less than 10Hz, and the preset duration is not less than 1 minute; and / or In the gaze measurement sub-step, the frequency of continuous acquisition is no greater than 0.1 Hz.

5. The method according to claim 1, characterized in that: In step three, when the two-dimensional turntable is controlled to rotate, the medium-wave thermal imager, the long-wave thermal imager, and the emissivity measuring instrument rotate synchronously.

6. The method according to claim 1, characterized in that, In step two: The measurement band of the medium-wave thermal imager is 3.7μm to 4.8μm, the measurement band of the long-wave thermal imager is 7.7μm to 9.3μm, and the measurement band of the emissivity meter covers 2μm to 14μm.

7. The method according to claim 1, characterized in that, Step four specifically includes: Export infrared images acquired at various azimuth angles; Select a typical region in each frame of the image and calculate the average gray value of the pixels in that region. The average gray value is converted into a radiance value using a preset calibration coefficient; Using the in-situ meteorological parameters, atmospheric transmittance and atmospheric path radiation are calculated through an atmospheric transport model, and atmospheric correction is applied to the radiance values ​​to obtain corrected radiance values. From the data obtained by the emissivity measuring instrument, the emissivity spectrum curve of a typical landform is derived, and the band emissivity corresponding to the working band of the medium-wave thermal imager or long-wave thermal imager is calculated. Based on the corrected radiance value and the emissivity of the band, and combined with Planck's formula, the radiant temperature of a typical landform is calculated.

8. The method according to claim 7, characterized in that, The typical region is an N×N pixel region with a relatively uniform center position in the image; the scaling coefficients include gain coefficients. and bias coefficient The average gray value Convert to radiance value The formula is: The formula for atmospheric correction is: in, This is the corrected radiance value. Atmospheric transmittance, This is atmospheric path radiation.

9. A comprehensive measurement device for infrared radiation characteristics of typical landforms in plateau environments, characterized in that, The apparatus for implementing the method according to any one of claims 1 to 8 comprises: The support and positioning module includes a tripod and a two-dimensional turntable mounted on the tripod; The infrared radiation measurement module includes a mid-wave thermal imager and a long-wave thermal imager, both mounted on the two-dimensional turntable. The emissivity measurement module includes an emissivity measuring instrument also mounted on the two-dimensional turntable; Environmental parameter measurement module, including meteorological measuring instrument; The control and data processing module includes a data acquisition and control unit and a computer. The data acquisition and control unit is electrically connected to the two-dimensional turntable, the medium-wave thermal imager, the long-wave thermal imager, and the emissivity measuring instrument, respectively, and is used to transmit control commands and acquire data. The computer is used to execute the operation control of the measuring device, data acquisition and storage, and data processing.

10. The apparatus according to claim 9, characterized in that, The medium-wave thermal imager, long-wave thermal imager, and emissivity meter are all mounted on the two-dimensional turntable via an adapter plate.

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