CN105425247A - Method and apparatus for determining surface temperature by use of middle-infrared remote sensing data - Google Patents

Abstract

The invention discloses a method and device for determining the surface temperature by using mid-infrared remote sensing data, comprising: step (A) using the 22nd (3.929μm-3.989μm) and 23rd mid-infrared spectral regions of the medium-resolution imaging spectrometer MODIS data (4.020μm–4.080μm) channel radiance data and atmospheric parameter data, combined with the developed mid-infrared surface two-way reflectance remote sensing inversion method, determine the surface two-way reflectance of the 22nd and 23rd channels; step (B) uses step (A ) to obtain the surface two-way reflectance, combined with the developed surface directional emissivity remote sensing inversion method, determine the surface directional specific emissivity of the 22nd and 23rd channels; step (C) uses step (A) and step (B) to obtain The mid-infrared surface bidirectional reflectance and directional specific emissivity, combined with the developed surface temperature remote sensing inversion method, can determine the surface temperature. The invention effectively realizes the quantitative remote sensing inversion of the mid-infrared data surface temperature.

Description

A method and device for determining surface temperature using mid-infrared remote sensing data

technical field

The invention belongs to the technical field of remote sensing quantitative inversion, in particular to a method and device for determining the surface temperature by using mid-infrared remote sensing data.

Background technique

Surface temperature plays a very important role in the process of land-atmosphere interaction. It is one of the key parameters in the study of global change. It is of great significance to the research of hydrology, ecology, environment and biogeochemistry. Calculation of thermal inertia and other aspects also have important application value. Quantitative remote sensing inversion of surface temperature plays a very important role in promoting drought forecasting and crop water shortage research, crop yield estimation, numerical weather prediction, global climate change, and global carbon balance.

So far, satellite sensors have obtained decades (since 1978) mid-infrared (3-5μm spectral region) remote sensing data, but unfortunately, these data have not been well applied to terrestrial environment research , so that the mid-infrared channel is called the "neglected channel". The main reason is that the composition of the spectral signal in this spectral region is very complex. In the mid-infrared remote sensing data measured by satellites during the day, not only the reflected solar spectrum, but also the emission spectrum of the surface and atmosphere are included. Compared with other atmospheric windows, the mid-infrared spectrum has many characteristics that are different from other atmospheric windows: ① Compared with visible light and near-infrared, mid-infrared is less affected by aerosols; ② Compared with thermal infrared, mid-infrared is less affected by water vapor absorption , almost negligible; ③Compared with the thermal infrared band, the specific emissivity and reflectivity of different objects in the mid-infrared band vary greatly; ⑤ The mid-infrared band is highly sensitive to energy changes; ⑥ The specific emissivity of the mid-infrared band is highly sensitive to changes in vegetation and soil moisture. It can be seen that in the study of terrestrial environment, mid-infrared radiation spectrum has great advantages. Unfortunately, however, daytime satellite-acquired mid-infrared radiation data cannot be well utilized because there is currently no truly physically accurate way to separate reflected and emitted radiation in the mid-infrared.

Since mid-infrared data are less disturbed by atmospheric water vapor, can also penetrate part of haze and smog, and are less affected by emissivity errors, using mid-infrared remote sensing data to retrieve land surface temperature has more advantages than thermal infrared. However, there is currently no method to effectively separate reflected and emitted radiation from mid-infrared remote sensing data during the day, making it very difficult to determine land surface temperature using mid-infrared remote sensing data. Therefore, in order to solve the effective separation of reflected radiation and emitted radiation of mid-infrared remote sensing data during the day, it is the original intention of the present invention to develop a method and device for determining the surface temperature using mid-infrared remote sensing data, and to realize the inversion of mid-infrared remote sensing data for surface temperature where.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a method and device for determining the surface temperature by using mid-infrared remote sensing data.

The technical solution adopted by the present invention to solve the above-mentioned technical problems is: a method for determining the surface temperature using mid-infrared remote sensing data, and the implementation steps are as follows:

Step (A), using the radiance data and atmospheric parameter data of the 22nd (3.929μm–3.989μm) and 23rd (4.020μm–4.080μm) channels in the mid-infrared spectral region of the MODIS data of the medium-resolution imaging spectrometer, combined with the developed mid-infrared Remote sensing inversion method of surface two-way albedo to determine the two-way surface albedo of the 22nd and 23rd channels;

Step (B), using the mid-infrared channel surface bidirectional reflectance obtained in step (A), combined with the developed surface directional emissivity remote sensing inversion method, to determine the surface directional specific emissivity of the 22nd and 23rd channels;

Step (C), using the mid-infrared surface bidirectional reflectance and directional specific emissivity obtained in step (A) and step (B) respectively, combined with the developed surface temperature remote sensing inversion method, to determine the surface temperature.

Wherein, the process of determining the MODIS 22nd and 23rd channel surface two-way reflectivity in the described step (A) is:

A1. According to the theory of atmospheric radiative transfer in the mid-infrared spectral region, under the condition of local thermodynamic equilibrium, the mid-infrared radiative transfer equation can be approximately expressed as:

${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; \&DownArrow;</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; \&DownArrow;</span><span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; \&Up\; Arrow;</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; \&Up\; Arrow;</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; the\; s</span>}}{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

In the formula, B _i (T _i ) is the radiance value measured by the satellite sensor in channel i, τ _i is the total atmospheric transmittance of channel i, R _{atm_i} ↑ and R _{atm_i} ↓ are the uplink and downlink radiation, and are the solar upgoing and downgoing radiation scattered by the atmosphere measured by channel i, respectively, is the direct solar radiation reaching the ground, and these parameters can be calculated through the atmospheric radiative transfer model MODTRAN combined with atmospheric profile data. To determine the surface temperature T _s , it is necessary to invert the surface bidirectional reflectance ρ _bi and the surface directional specific emissivity ε _i ;

A2. The mid-infrared surface bidirectional reflectance ρ _bi of MODIS data can be obtained by the following formula:

${\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

in,

$<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; twenty\; two</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; twenty\; two</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; twenty\; three</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; twenty\; two</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; twenty\; three</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

T _{g_i} represents the surface brightness temperature of channel i, Indicates the surface brightness temperature of the i channel under the condition of no direct solar radiation. a ₁ -a ₃ are the regression coefficients, they are only a function of the solar zenith angle, and have nothing to do with surface parameters and atmospheric conditions.

Wherein, the process of determining MODIS 22nd and 23rd channel surface direction specific emissivity in the described step (B) is:

B1. According to the RossThick-LiSparse-R nuclear drive model, the two-way reflectivity of the surface can be expressed as:

where k _iso is the isotropic scattering coefficient, k _vol is the coefficient of the Roujean volume scattering kernel f _vol , and k _geo is the coefficient of the LiSparse-R geometric surface scattering kernel f _geo . f _vol and f _geo are both observation zenith angle θ _v , solar zenith angle θ _i and relative azimuth The function. Using at least three groups of surface bidirectional reflectances obtained in step (A), the coefficients k _iso , k _vol and k _geo can be fitted;

B2. According to Kirchhoff's law, for non-transparent objects in local thermodynamic equilibrium, the directional specific emissivity can be expressed as:

ε(θ _v )＝1-πk _iso -k _vol If _vol (θ _v )-k _geo If _geo (θ _v )(5)

In the formula, The subscript x of f represents vol and geo. Using the fitting kernel coefficients k _iso , k _vol and k _geo , the specific emissivity of MODIS channels 22 and 23 can be calculated.

Wherein, the process of determining the surface temperature in the step (C) is: according to the mid-infrared atmospheric radiation transfer equation, using the atmospheric parameter data and the radiance data observed by the satellite sensor, and combining the steps (A) and (B) to obtain respectively The mid-infrared channel surface two-way reflectance and the surface directional specific emissivity are retrieved to obtain the surface temperature.

The present invention provides a device for implementing the above method, which includes: a surface two-way reflectivity inversion module, a surface emissivity inversion module and a surface temperature inversion module, wherein:

Surface two-way reflectivity inversion module, the function of this module is: using the preprocessed MODIS mid-infrared channel remote sensing data and atmospheric parameter data, combined with the spectral response functions of the 22nd and 23rd channels, according to the inversion algorithm, to obtain the mid-infrared channel The two-way reflectivity of the surface. Specifically, assuming that the two-way reflectivity of the surface of the 22nd and 23rd channels is equal, and that the surface brightness temperature of the two channels is equal under the condition of no direct solar radiation, according to the regression coefficient a ₁ -a ₃ , in the case of no direct solar radiation, the Surface brightness temperature of channels 22 and 23 below Then calculate the two-way surface reflectance of the 22nd and 23rd channels;

Surface directional specific emissivity inversion module, the function of which is: using at least three sets of acquired mid-infrared surface bidirectional reflectance, according to the nuclear drive model, to fit the isotropic scattering coefficient k _iso , volume scattering coefficient k _vol and Geometric scattering coefficient k _geo , and according to Kirchhoff's law, use the developed nuclear driving coefficient hemispherical integral parameterization model to calculate the surface specific emissivity of the 22nd and 23rd channels;

Surface temperature inversion module, the function of this module is: according to the mid-infrared atmospheric radiation transfer equation, using atmospheric parameter data and radiance data observed by satellite sensors, combined with the inverted mid-infrared channel surface bidirectional reflectance and surface directional specific emissivity, Determine the surface temperature.

The advantage of the present invention compared with prior art is:

(1) Through the steps of the present invention, the effective separation of reflected radiation and emitted radiation in the mid-infrared remote sensing data measured by the sensor during the day is realized, and technical support is provided for the utilization of the mid-infrared remote sensing data.

(2) Through the steps of the present invention, the inversion of the surface temperature in the mid-infrared remote sensing data is realized, which opens up a new way for the remote sensing inversion of the surface temperature.

(3) In the method for determining the surface temperature using mid-infrared remote sensing data proposed by the present invention, only the mid-infrared data measured during the day is used, which effectively reduces the source of error in the quantitative study of remote sensing, and breaks through the previous use of daytime/night data The surface temperature remote sensing inversion method combining , mid-infrared and thermal infrared improves the inversion accuracy and realizes the combination of new technology and innovative research.

(4), the device that the present invention establishes using the mid-infrared remote sensing data to determine the surface temperature is realized by the surface two-way reflectance inversion module, the surface direction specific emissivity inversion module and the surface temperature inversion module, and the modules have simple operation , Strong practicability and strong scalability.

Description of drawings

Fig. 1 is the overall schematic flow chart of determining surface temperature of the present invention;

Fig. 2 is the schematic flow chart of determining the two-way reflectivity of the surface of the mid-infrared data in the present invention;

Fig. 3 is the schematic flow chart of determining the specific emissivity of the surface direction of mid-infrared data in the present invention;

Fig. 4 is a schematic flow chart of determining the surface temperature of mid-infrared data in the present invention.

detailed description

As shown in Figure 1, specific embodiments of the present invention are as follows:

A method for determining the surface temperature using mid-infrared remote sensing data, the implementation steps are as follows:

Step (A), using the radiance data and atmospheric parameter data of the 22nd (3.929μm–3.989μm) and 23rd (4.020μm–4.080μm) channels in the mid-infrared spectral region of the MODIS data of the medium-resolution imaging spectrometer, combined with the mid-infrared surface bidirectional Albedo inversion method to determine the two-way albedo of the surface for channels 22 and 23. This step is mainly realized through the surface two-way reflectivity inversion module, and the implementation method is as follows:

A.1 Surface brightness temperature without contribution from direct solar radiation determination of

Under the assumption that the two-way surface reflectance of the 22nd and 23rd channels of MODIS are equal, and the surface brightness temperature of the two channels is equal in the case of no direct solar radiation, the following formula is developed to calculate the surface brightness temperature without the contribution of direct solar radiation value:

$<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; twenty\; two</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; twenty\; two</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; twenty\; three</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; twenty\; two</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; twenty\; three</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

In the formula, T _{g_22} and T _{g_23} are the brightness temperature values measured on the ground by the 22nd and 23rd channels, respectively. a ₁ -a ₃ are the regression coefficients, they are only a function of the solar zenith angle, and have nothing to do with the surface parameters and atmospheric conditions, the calculation formula is as follows:

a _i =b _1i +b _2i cos(SZA)+b _3i cos ² (SZA)(7)

In the formula, SZA represents the solar zenith angle, and b _1i -b _3i are conversion coefficients (see Table 1 for details).

Table 1. Conversion Factors in Equation (7)

b1 b2 b3 a1 -0.07866 0.37944 -0.88887 a2 -1.32434 -3.36204 1.99923 a3 0.07913 -0.32188 -0.09891

A.2 Determination of mid-infrared surface two-way reflectivity

Using the preprocessed MODIS mid-infrared channel remote sensing data and atmospheric parameter data (including transmittance, atmospheric upward radiation, atmospheric scattered solar upward radiation, atmospheric downward radiation, and ground solar direct radiation), combined with the 22nd and 23rd channels The spectral response function of , according to the following formula:

${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; \&Up\; Arrow;</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; \&Up\; Arrow;</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 8</span>}<span\; class="notranslate">\; )</span>$

Calculate the surface brightness temperature T _{g_i} of the 22nd and 23rd channels, combined with formula (6) to calculate the surface brightness temperature in the case of no direct solar radiation The mid-infrared surface bidirectional reflectance ρ _bi can be calculated according to formula (2).

Step (B), using the mid-infrared surface two-way reflectance obtained in step (A), combined with the developed surface directional emissivity inversion method, to obtain the 22nd and 23rd channels of the surface directional specific emissivity. This step is mainly realized through the inversion module of surface directional specific emissivity, and the implementation method is as follows:

B.1 Determination of nuclear drive model coefficients

According to the RossThick-LiSparse-R nuclear drive model, the two-way reflectivity of the surface can be expressed as;

In the formula, _θi and _θv are the solar zenith angle and the sensor observation zenith angle respectively, is the relative azimuth between the sun and the sensor, k _iso is the isotropic scattering coefficient, k _vol is the coefficient of the Roujean volume scattering kernel f _vol , and k _geo is the coefficient of the LiSparse-R geometric surface scattering kernel f _geo . Among them, f _vol and k _geo are expressed as:

where ξ is the phase angle, θ _i ' and θ _v ' represent the sun's incident zenith angle and the opposite direction of the sensor's observed zenith angle direction, respectively, is the overlapping area of viewing angle shadow and sun incident angle shadow, which can be calculated by the following formula:

In the formula, ${\mathrm{\&theta;}}_v^{\&prime;}={\mathrm{the\; tan}}^{-1}\left(\frac{b}{r}{\mathrm{tan\&theta;}}_v\right),{\mathrm{\&theta;}}_i^{,}={\mathrm{the\; tan}}^{-1}\left(\frac{b}{r}{\mathrm{tan\&theta;}}_i\right),,$ in, h/b and b/r are dimensionless canopy height and shape parameters, respectively.

Using at least three groups of surface two-way reflectance obtained in step (A), according to the formula (9), the coefficients k _iso , k _vol and k _geo are obtained by fitting with the least square method.

B.2 Determination of the specific emissivity of the mid-infrared surface direction

Assuming that the shape of the nuclear-driven model in the mid-infrared region is similar to that in the visible and near-infrared bands, according to Kirchhoff's law, the mid-infrared surface specific emissivity can be expressed as:

ε(θ _v )＝1-πk _iso -k _vol If _vol (θ _v )-k _geo If _geo (θ _v )(13)

In the formula, If _vol (θ _v ) and If _geo (θ _v ) respectively denote the hemispherical integral of the volume kernel f _vol and the geometric kernel f _geo in the sun incident direction, which can be approximately expressed in a parametric way as:

If _vol (θ _v )＝-0.0299+0.0128exp(θ _v /21.4382)(14)

${\mathrm{<span\; class="notranslate">\; If</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}\mathrm{<span\; class="notranslate">\; e</span>}\mathrm{<span\; class="notranslate">\; o</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; v</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2.0112</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 0.3410</span>}\mathrm{<span\; class="notranslate">\; exp</span>}<span\; class="notranslate">\; \&lsqb;</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 2</span>}{<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; v</span>}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 90.95545</span>}}{\mathrm{<span\; class="notranslate">\; 68.8171</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \&rsqb;</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 15</span>}<span\; class="notranslate">\; )</span>$

Therefore, using the fitted coefficients k _iso , k _vol and k _geo , combined with sensor observation of the zenith angle θ _v , the mid-infrared surface directional specific emissivity can be calculated.

Step (C), using the mid-infrared surface bidirectional reflectance and directional specific emissivity of the 22nd and 23rd channels respectively obtained in step (A) and step (B), according to the mid-infrared atmospheric radiation transfer equation, the surface temperature is obtained by inversion . This step is mainly realized through the surface temperature inversion module, and the implementation method is as follows:

On the basis of obtaining the mid-infrared surface bidirectional reflectance and directional specific emissivity, according to the atmospheric radiation transfer equation of the mid-infrared channel, combined with the inverse function of the Planck function, the surface temperature T _s of the mid-infrared channel can be obtained:

${\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; \&lsqb;</span>\frac{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; \&Up\; Arrow;</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; \&Up\; Arrow;</span>}{{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}<span\; class="notranslate">\; -</span>\frac{<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; \&DownArrow;</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; \&DownArrow;</span><span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}{{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}<span\; class="notranslate">\; \&rsqb;</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 16</span>}<span\; class="notranslate">\; )</span>$

In the formula, B ^-1 is expressed as the inverse function of Planck's function. Atmospheric total transmittance τ _i , atmospheric downstroke radiation R _{atm_i} ↓, atmospheric downgoing radiation scattered by the sun Direct solar radiant energy on the ground and atmospheric upward radiation R _{atm_i} ↑ are atmospheric parameters, which can be calculated by the atmospheric radiative transfer model MODTRAN combined with atmospheric profile data. The two-way surface reflectance ρ _bi and the surface directional specific emissivity ε _i can be obtained through the surface two-way reflectance inversion module and the surface directional specific emissivity inversion module.

Parts not described in detail in the present invention belong to the well-known technology in the art.

The above are only some specific implementations of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be covered within the protection scope of the present invention.

Claims (5)

1. A method utilizing mid-infrared remote sensing data to determine surface temperature is characterized in that the method implementation steps are as follows: Step (A), using the radiance data and atmospheric parameter data of the 22nd and 23rd channels in the mid-infrared spectrum region of the MODIS data of the medium-resolution imaging spectrometer, the wavelength range of the 22nd channel is 3.929 μm–3.989 μm, and the wavelength range of the 23rd channel is 4.020 μm–4.080μm, combined with the developed mid-infrared surface two-way reflectance remote sensing inversion method, determine the surface two-way reflectance of the 22nd and 23rd channels; Step (B), using the mid-infrared channel surface bidirectional reflectance obtained in step (A), combined with the developed surface directional emissivity remote sensing inversion method, to determine the surface directional specific emissivity of the 22nd and 23rd channels; Step (C), using the mid-infrared surface bidirectional reflectance and directional specific emissivity obtained in step (A) and step (B) respectively, combined with the developed surface temperature remote sensing inversion method, to determine the surface temperature. 2. a kind of method utilizing mid-infrared remote sensing data to determine surface temperature according to claim 1, is characterized in that, the process of determining the 22nd and 23rd channel surface bidirectional reflectance in the described step (A) is: A1. According to the theory of atmospheric radiative transfer in the mid-infrared spectral region, under the condition of local thermodynamic equilibrium, the mid-infrared radiative transfer equation can be approximately expressed as: ${\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; \&epsiv;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; \&DownArrow;</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; \&DownArrow;</span><span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; \&Up\; Arrow;</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; m</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; \&Up\; Arrow;</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}\mathrm{<span\; class="notranslate">\; i</span>}}{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; the\; s</span>}}{\mathrm{<span\; class="notranslate">\; \&tau;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$ In the formula, B _i (T _i ) is the radiance value measured by the satellite sensor in channel i, τ _i is the total atmospheric transmittance of channel i, R _{atm_i} ↑ and R _{atm_i} ↓ are the uplink and downlink radiation, and are the solar upgoing and downgoing radiation scattered by the atmosphere measured by channel i, respectively, is the direct solar radiation reaching the ground, and these parameters can be calculated through the atmospheric radiative transfer model MODTRAN combined with atmospheric profile data. To determine the surface temperature T _s , it is necessary to invert the surface bidirectional reflectance ρ _bi and the surface directional specific emissivity ε _i ; A2. The mid-infrared surface bidirectional reflectance ρ _bi of MODIS data can be obtained by the following formula: ${\mathrm{<span\; class="notranslate">\; \&rho;</span>}}_{\mathrm{<span\; class="notranslate">\; b</span>}\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; B</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}{{\mathrm{<span\; class="notranslate">\; R</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}^{\mathrm{<span\; class="notranslate">\; the\; s</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$ in, $<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}^{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; twenty\; two</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; twenty\; two</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; twenty\; three</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; a</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; twenty\; two</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}<span\; class="notranslate">\; \_</span>\mathrm{<span\; class="notranslate">\; twenty\; three</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$ T _{g_i} represents the surface brightness temperature of channel i, Indicates the surface brightness temperature of channel i under the condition of no direct solar radiation, and a ₁ -a ₃ are regression coefficients, which are only functions of the solar zenith angle and have nothing to do with surface parameters and atmospheric conditions. 3. a kind of method utilizing mid-infrared remote sensing data to determine surface temperature according to claim 1, is characterized in that, the process of determining the 22nd and 23rd channel surface direction specific emissivity of MODIS in the described step (B) is: B1. According to the RossThick-LiSparse-R nuclear drive model, the two-way reflectivity of the surface can be expressed as: In the formula, k _iso is the isotropic scattering coefficient, k _vol is the coefficient of the Roujean volume scattering kernel f _vol , k _geo is the coefficient of the LiSparse-R geometric surface scattering kernel f _geo , f _vol and f _geo are both the observation zenith angle θ _v , solar zenith angle θ _i and relative azimuth function, using at least three groups of surface bidirectional reflectance obtained in step (A), the coefficients k _iso , k _vol and k _geo can be fitted; B2. According to Kirchhoff's law, for non-transparent objects in local thermodynamic equilibrium, the directional specific emissivity can be expressed as: ε(θ _v )＝1-πk _iso -k _vol If _vol (θ _v )-k _geo If _geo (θ _v )(5) In the formula, The subscript x of f represents vol and geo, and using the kernel coefficients k _iso , k _vol and k _geo obtained from the fitting, the surface specific emissivity of the 22nd and 23rd channels of MODIS can be calculated. 4. a kind of method utilizing mid-infrared remote sensing data to determine surface temperature according to claim 1, is characterized in that, the process of determining surface temperature in the described step (C) is: according to mid-infrared atmospheric radiation transfer equation, utilize atmospheric The parameter data and the radiance data observed by the satellite sensor are combined with the mid-infrared channel surface bidirectional reflectance and the surface directional specific emissivity obtained in steps (A) and (B), respectively, to invert to obtain the surface temperature. 5. The device for realizing a method for determining surface temperature using mid-infrared remote sensing data as claimed in claim 1 is characterized in that the device comprises: a two-way surface reflectance inversion module, a surface direction specific emissivity inversion module, and a surface Temperature inversion module, where: The surface two-way reflectivity inversion module has the functions of: using the preprocessed MODIS mid-infrared channel remote sensing data and atmospheric parameter data, combined with the spectral response functions of the 22nd and 23rd channels, according to the inversion algorithm, to obtain The two-way surface reflectance of the mid-infrared channel is specifically: assuming that the two-way surface reflectance of the 22nd and 23rd channels is equal, and the surface brightness temperature of the two channels is equal under the condition of no direct solar radiation, according to the regression coefficient a ₁ -a _3. Obtain the surface brightness temperature of the 22nd and 23rd channels under the condition of no direct solar radiation Then calculate the two-way surface reflectance of the 22nd and 23rd channels; The surface directional specific emissivity inversion module, the function of this module is: use at least three sets of mid-infrared surface bidirectional reflectance obtained, and according to the nuclear drive model, fit the isotropic scattering coefficient k _iso and the volume scattering coefficient k _vol and geometric scattering coefficient k _geo , and according to Kirchhoff's law, use the developed nuclear drive coefficient hemispherical integral parameterization model to calculate the surface specific emissivity of the 22nd and 23rd channels; The surface temperature inversion module has the following functions: according to the mid-infrared atmospheric radiation transfer equation, using atmospheric parameter data and radiance data observed by satellite sensors, combined with the inverted mid-infrared channel surface two-way reflectance and surface direction ratio Emissivity, which determines the surface temperature.