1. A method for high accuracy estimation of a ground target temperature, the method comprising the steps of:

selecting a thermal radiation brightness measuring instrument and a ground target;

selecting heat radiation brightness data measuring time and environment;

step (3) calculating the down-going radiation heat radiation brightness function L of the atmosphere_atm↓(λ)；

Step (4) measuring the thermal infrared radiance function L of the ground target_s(λ,T)；

Determining an estimated range value of the ground target temperature;

step (6) calculating an absolute blackbody thermal infrared radiance function B (lambda, T) of the wavelength corresponding to the ground target temperature estimated value obtained in the step (5);

step (7) according to the atmospheric downlink thermal infrared radiance function L obtained in the step (3)_atm↓(lambda) and the ground target thermal infrared radiation brightness data L obtained in the step (4)_s(lambda, T), and calculating an absolute blackbody thermal infrared radiance function B (lambda, T) of the ground target temperature estimated value corresponding to the wavelength obtained in the step (6) to obtain emissivity epsilon (lambda, T) of the ground target under different temperature estimated values;

step (8) of calculating smoothness function WJH (epsilon, T) of emissivity epsilon (lambda, T) curve of the ground target obtained in the step (7) under different temperature estimation values_i,T)；

Step (9) of calculating a smoothness function WJH (epsilon) of the emissivity curve of the ground target obtained in the step (8) under different temperature estimations_jT) and obtaining a smoothness graph of the emissivity curve of the sample under different temperature estimation;

and (10) determining the optimal temperature value of the ground target according to the smoothness graph of the emissivity curve of the sample obtained in the step (9) under different temperature estimation.

2. A high accuracy estimation method for ground target temperature according to claim 1, characterized by: the thermal radiation brightness measuring instrument in the step (1) selects a thermal infrared spectrometer; selecting a ground target object with the height less than 1 meter and the diameter more than 2 centimeters.

3. A high accuracy estimation method for ground target temperature according to claim 2, characterized by: the step (3) specifically comprises the following steps:

step (3.1) of calculating the thermal infrared radiance function B (lambda, T) of the absolute black body_g)；

Step (3.2) according to the thermal infrared radiance function B (lambda, T) obtained by calculation in the step (3.1)_g) Calculating the down-going thermal infrared radiance function L of the atmosphere_atm↓(λ)。

4. A high accuracy estimation method suitable for ground target temperature according to claim 3 characterized by: the thermal infrared radiance function of the absolute black body in the step (3.1)

5. A high-precision estimation method suitable for the ground target temperature according to claim 4, characterized in that: the atmospheric downlink thermal infrared radiance function L in the step (3.2)_atm↓(λ)＝(L_g(λ，T_g)-(1-R)×B(λ，T_g))/R。

6. A high-precision estimation method suitable for the ground target temperature according to claim 5, characterized in that: in the step (4), a thermal infrared spectrometer is used for measuring to obtain a ground target thermal infrared radiance function L_s(lambda, T), the specific measurement steps are as follows: measuring a temperature value T of a sample using a contact point thermometer_sThe sample is placed at the same height position when the thermal infrared spectrometer is used for measuring the thermal infrared radiation brightness data of the diffuse reflection gold plate, namely, the thermal infrared radiation brightness function L which changes along with the wavelength lambda when the temperature T of the sample is measured_s(λ,T)。

7. The method of claim 6A high-precision estimation method suitable for ground target temperature is characterized by comprising the following steps: the specific steps of the step (5) are as follows: measuring the temperature value T of the sample by the contact point thermometer in the step (4)_sIs an initial value of the sample temperature, based on which a temperature distribution range T is generated at intervals of 0.01 ℃ temperature difference_s-10℃～T_s+10 ℃ is the estimated value range of the ground target temperature.

8. A method for estimating a ground target temperature with high accuracy as claimed in claim 7, wherein: the absolute black body thermal infrared radiance function in the step (6)

9. A method for estimating a ground target temperature with high accuracy as claimed in claim 8, wherein: the emission rate value of the ground target in the step (7) under different temperature estimation values

10. A method for estimating a ground target temperature with high accuracy as claimed in claim 9, wherein: the smoothness function WJH (ε) in step (8)_j,T)＝COV(ε(v_i+1,T)/ε(v_i,T))。

11. A method for high accuracy estimation of a ground target temperature as claimed in claim 10 wherein: the specific steps of the step (9) are as follows: calculating log base 2 of the smoothness function of the emissivity curve of the sample under different temperature estimates obtained in step (8)₂(WJH(ε_iT)), the samples are differentiatedAnd taking the temperature estimation values as an X axis, taking the smoothness logarithm value of the emissivity curve corresponding to each temperature estimation value as a Y axis, and obtaining the smoothness logarithm diagram of the emissivity curve of the sample under different temperature estimation.

12. A method for high accuracy estimation of a ground target temperature as claimed in claim 11 wherein: the specific steps of the step (10) are as follows: and (4) acquiring a temperature value corresponding to the smoothness minimum value of the Y-axis emissivity curve from the emissivity smoothness log under different temperature estimation obtained in the step (9), namely obtaining the optimal temperature estimation value of the ground target.

Background

Infrared radiation is the most widely occurring thermal radiation in nature and can be acquired by thermal infrared detection instruments. As long as the skin temperature of the object is above absolute zero, it will continuously radiate energy outwards. At present, instruments capable of directly acquiring temperature information of a ground target include a thermal imager, a temperature measuring instrument and the like, although the equipment can directly display the temperature information of the ground target, initially measured information is not temperature information but thermal radiation brightness data, and then the temperature information is calculated by assuming a target emissivity value. However, ground target emissivity values are often difficult to estimate accurately, and when the emissivity values differ by 0.02, the temperature estimates will differ by 1.5 ℃. In addition, the instrument has low spectral resolution, and only one waveband exists in a thermal infrared spectral band, so that the accuracy of target temperature information estimation is greatly limited. Therefore, the instrument cannot be applied to high-precision temperature information extraction.

Besides the thermal infrared device for direct temperature measurement, ground infrared detection devices such as a portable Fourier transform thermal infrared spectrometer (called as a 102F thermal infrared spectrometer for short) and a BOMEN high-precision spectrum radiometer can also acquire ground target thermal radiance data, particularly the spectral resolution of the 102F thermal infrared spectrometer can reach 1 nanometer, and the thermal radiance values of ground targets in different thermal infrared bands can be accurately measured. However, the measured value of the target heat radiation intensity is the result of coupling of the emissivity and the temperature, and an equation has two unknowns, so that a corresponding technical method needs to be developed to estimate the target temperature value. In addition, in daily application, whether tiny temperature abnormality exists or not is detected to be used as an important mark for judging whether equipment such as instrument equipment and the like normally operate or not. Therefore, it is necessary to develop a high-precision estimation method suitable for the temperature of the ground target, and the method has a very important significance for accurately obtaining high-precision temperature information of the ground target and carrying out target temperature weak anomaly detection.

Disclosure of Invention

The invention aims to solve the technical problem that the prior art method is insufficient, and provides a high-precision estimation method suitable for the temperature of a ground target.

In order to solve the technical problem, the invention provides a high-precision estimation method suitable for ground target temperature, which comprises the following steps:

selecting a thermal radiation brightness measuring instrument and a ground target;

selecting heat radiation brightness data measuring time and environment;

step (3) calculating the down-going radiation heat radiation brightness function L of the atmosphere_atm↓(λ)；

Step (4) measuring the thermal infrared radiance function L of the ground target_s(λ,T)；

Determining an estimated range value of the ground target temperature;

step (6) calculating an absolute blackbody thermal infrared radiance function B (lambda, T) of the wavelength corresponding to the ground target temperature estimated value obtained in the step (5);

step (7) according to the atmospheric downlink thermal infrared radiance function L obtained in the step (3)_atm↓(lambda) and the ground target thermal infrared radiation brightness data L obtained in the step (4)_s(lambda, T), and calculating an absolute blackbody thermal infrared radiance function B (lambda, T) of the ground target temperature estimated value corresponding to the wavelength obtained in the step (6) to obtain emissivity epsilon (lambda, T) of the ground target under different temperature estimated values;

step (8) of calculating smoothness function WJH (epsilon, T) of emissivity epsilon (lambda, T) curve of the ground target obtained in the step (7) under different temperature estimation values_i,T)；

Step (9) of calculating a smoothness function WJH (epsilon) of the emissivity curve of the ground target obtained in the step (8) under different temperature estimations_jT) and obtaining a smoothness graph of the emissivity curve of the sample under different temperature estimation;

and (10) determining the optimal temperature value of the ground target according to the smoothness graph of the emissivity curve of the sample obtained in the step (9) under different temperature estimation.

The thermal radiation brightness measuring instrument in the step (1) selects a thermal infrared spectrometer; selecting a ground target object with the height less than 1 meter and the diameter more than 2 centimeters.

The step (3) specifically comprises the following steps:

step (3.1) of calculating the thermal infrared radiance function B (lambda, T) of the absolute black body_g)；

Step (3.2) according to the thermal infrared radiance function B (lambda, T) obtained by calculation in the step (3.1)_g) Calculating the down-going thermal infrared radiance function L of the atmosphere_atm↓(λ)。

The thermal infrared radiance function of the absolute black body in the step (3.1)

The atmospheric downlink thermal infrared radiance function L in the step (3.2)_atm↓(λ)＝(L_g(λ，T_g)-(1-R)×B(λ，T_g))/R。

In the step (4), a thermal infrared spectrometer is used for measuring to obtain a ground target thermal infrared radiance function L_s(lambda, T), the specific measurement steps are as follows: measuring a temperature value T of a sample using a contact point thermometer_sThe sample is placed at the same height position when the thermal infrared spectrometer measures the thermal infrared radiation brightness data of the diffuse reflection gold plate, namely, the thermal infrared radiation brightness function L which changes along with the wavelength lambda when the temperature T of the sample is measured_s(λ,T)。

The specific steps of the step (5) are as follows: measuring the temperature value T of the sample by the contact point thermometer in the step (4)_sIs an initial value of the sample temperature, based on which a temperature distribution range T is generated at intervals of 0.01 ℃ temperature difference_s-10℃～T_s+10 ℃ is the estimated value range of the ground target temperature.

The absolute black body thermal infrared radiance function in the step (6)

The steps are(7) Emission rate values of the ground target at different temperature estimates

The smoothness function WJH (ε) in step (8)_j,T)＝COV(ε(v_i+1,T)/ε(v_i,T))。

The specific steps of the step (9) are as follows: calculating log base 2 of the smoothness function of the emissivity curve of the sample under different temperature estimates obtained in step (8)₂(WJH(ε_iAnd T)), taking different temperature estimated values of the sample as an X axis, taking the smoothness logarithm value of the emissivity curve corresponding to each temperature estimated value as a Y axis, and obtaining a smoothness logarithm diagram of the emissivity curve of the sample under different temperature estimation.

The specific steps of the step (10) are as follows: and (4) acquiring a temperature value corresponding to the smoothness minimum value of the Y-axis emissivity curve from the emissivity smoothness log under different temperature estimation obtained in the step (9), namely obtaining the optimal temperature estimation value of the ground target.

The invention has the beneficial technical effects that:

(1) the high-precision temperature estimation method suitable for the ground target can acquire high-precision temperature information of instrument equipment, study and judge the temperature difference of the instrument in different running times, and play an important role in analyzing whether the running of the instrument is abnormal or not so as to detect and overhaul in advance and ensure the normal work of the equipment.

(2) The high-precision temperature estimation method suitable for the ground target can acquire high-precision temperature information of an electronic circuit board and provides an important basis for researching and judging whether the circuit board has breakpoints and short-circuit problems in advance.

(3) The high-precision temperature estimation method suitable for the ground target can obtain temperature information of ground rocks at different time, further estimate the thermal inertia of the rocks, identify the abnormal thermal inertia, and provide important basis for developing potential prediction of energy minerals such as uranium ores and petroleum.

(4) The high-precision temperature estimation method applicable to the ground target can be extended and applied to large-range rapid ground temperature information extraction of aviation/aerospace thermal infrared remote sensing technology, and provides important reference for developing research and development of related temperature estimation methods.

Drawings

Fig. 1 is a schematic diagram of a high-precision temperature estimation result, which is developed by using the high-precision temperature estimation method suitable for the ground target and takes a rock solid sample as an example.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

The invention provides a high-precision estimation method suitable for ground target temperature, which comprises the following steps:

and (1) selecting a heat radiation brightness measuring instrument and a ground target.

The thermal radiance measuring instrument selects a 102F thermal infrared spectrometer and is used for measuring the thermal radiance data of the ground target; selecting a ground object suitable for measuring heat radiation brightness data by a 102F thermal infrared spectrometer as a ground target experiment sample, wherein the ground target object is required to be less than 1 meter in height and more than 2 centimeters in diameter.

In this example, the selected ground target test sample is a rock solid sample, the height of the rock solid sample is 0.15 m, and the diameter of the rock solid sample is 0.10 m.

And (2) selecting the measuring time and environment of the heat radiation brightness data.

The measurement time of the thermal radiance data is selected from the time in the morning or the afternoon to the evening, and the measurement is carried out in the thermal radiance data measurement environment at the time and place where the weather conditions are stable, the outdoor open area without wind and rain and other outdoor environment temperature is stable and the influence of surrounding ground objects is small.

Step (3) calculating an infrared radiance function L of atmospheric downlink radiant heat_atm↓(λ)。

Step (3.1) of calculating the thermal infrared radiance function B (lambda, T) of the absolute black body_g)；

Measuring diffuse reflection by using contact point thermometer with measurement accuracy higher than 0.5 DEG CTemperature value T of metal-spraying plate_gWhen in measurement, the diffuse reflection gold plate is kept clean; calculating the absolute blackbody temperature as T_gThermal infrared radiance function B (lambda, T) varying with time at wavelength lambda_g) The specific calculation formula is as follows:(in the formula, B (. lamda., T)_g) Is absolute black body at temperature T_gThermal infrared radiance function varying with wavelength lambda in W.m^-2·μm^-1·sr^-1，T_gIs the thermodynamic temperature of the black body in K, and lambda is the thermal infrared spectrum band wavelength in mum; c. C_l＝1.12×10^-16W·m²，c₂＝14388μm·K。

Step (3.2) according to the thermal infrared radiance function B (lambda, T) obtained by calculation in the step (3.1)_g) Calculating the down-going thermal infrared radiance function L of the atmosphere_atm↓(λ)

Carrying out cold and hot black body calibration on a 102F thermal infrared spectrometer, adjusting an optical lens of a measuring instrument to a vertical distance of less than 1 m from a diffuse reflection gold plate, and measuring the temperature T of the diffuse reflection gold plate_gThermal infrared radiance function L as a function of wavelength λ_g(λ，T_g) Calculating the down-air thermal infrared radiance function L with lambda as variable_atm↓(λ)＝(L_g(λ，T_g)-(1-R)×B(λ，T_g) R) in the formula, L_atm↓(λ) is the function of the thermal infrared radiance in the atmosphere with wavelength λ as a variable, L_g(λ，T_g) Is a diffuse reflection gold plate at a temperature T_gThe thermal infrared radiance function, B (lambda, T), as a function of the wavelength lambda_g) Is absolute black body at temperature T_gThe thermal infrared radiance function of time variation with wavelength lambda, R is the reflectivity of the known diffuse reflection gold plate.

Step (4) measuring the thermal infrared radiance function L of the ground target_s(λ,T)。

Measuring a temperature value T of a sample using a contact point thermometer_sWhen the sample is placed on a 102F thermal infrared spectrometer to measure the thermal infrared radiation brightness data of the diffuse reflection gold plateThe position with equal height (the same vertical distance with the optical lens of the measuring instrument and less than 1 meter) is measured to obtain the thermal infrared radiance function L of the sample along with the change of the wavelength lambda at the temperature T_s(λ,T)。

And (5) determining an estimated range value of the ground target temperature.

Measuring the temperature value T of the sample by the contact point thermometer in the step (4)_sIs an initial value of the temperature of the sample, on the basis of which a temperature distribution range (T) is generated at intervals of a temperature difference of 0.01 DEG C_s-10℃～T_s+10 ℃ C, the temperature distribution range (T)_s-10℃～T_sAnd +10 ℃) is the estimated range value of the ground target temperature. Wherein, T_s-10 ℃ is the minimum temperature, T_s+10 ℃ is the maximum temperature. E.g. temperature value T_sAt 20 deg.C, an estimated range of temperatures (10 deg.C, 10.01 deg.C, 10.02 deg.C, 10.03 deg.C-29.97 deg.C, 29.98 deg.C, 29.99 deg.C, 30 deg.C) is generated at intervals of 0.01 deg.C.

And (6) calculating an absolute blackbody thermal infrared radiance function B (lambda, T) of the corresponding wavelength of the ground target temperature estimation range value obtained in the step (5).

Calculating the temperature difference interval of the sample at 0.01 ℃ by T_s-10 ℃ is the minimum temperature, T_s+10 ℃ is a blackbody thermal infrared radiance function B (lambda, T) of the wavelength corresponding to each temperature estimated value in the temperature maximum value range, and the specific calculation formula is as follows:(wherein B (λ, T) is a thermal infrared radiance function of the absolute black body varying with wavelength λ at temperature T, and has a unit of W.m^-2·μm^-1·sr^-1T is the estimated thermodynamic temperature in K, and λ is the thermal infrared spectral band wavelength in μm; c. C_l＝1.12×10^-16W·m²，c₂＝14388μm·K。

Step (7) according to the atmospheric downlink thermal infrared radiance function L obtained in the step (3)_atm↓(lambda) and the ground target thermal infrared radiance function L obtained in the step (4)_s(lambda, T), stepAnd (4) calculating an absolute blackbody thermal infrared radiance function B (lambda, T) of the ground target temperature estimated value corresponding to the wavelength obtained in the step (6) to obtain emissivity epsilon (lambda, T) of the ground target under different temperature estimated values.

Atmospheric downlink thermal infrared radiance function L obtained in step (3)_atm↓(lambda) the ground target thermal infrared radiance function L obtained in the step (4)_s(lambda, T) and substituting the absolute blackbody thermal infrared radiance function B (lambda, T) of the wavelength corresponding to the ground target temperature estimated value obtained in the step (6) into the following formula to calculate and obtain the sample in the temperature distribution range (T)_s-10℃～T_sEmissivity epsilon (lambda, T) corresponding to each temperature estimated value in +10 ℃ is calculated by the following formula:

step (8) of calculating smoothness function WJH (epsilon, T) of emissivity epsilon (lambda, T) curve of the ground target obtained in the step (7) under different temperature estimation values_j,T)。

Calculating the temperature difference interval of the sample at 0.01 ℃ by T_s-10 ℃ is the minimum temperature, T_s+10 ℃ is the smoothness function WJH (ε) of the corresponding emissivity curve for each temperature value in the temperature maximum range_jT) the formula is as follows: WJH (ε_j,T)＝COV(ε(v_i+1,T)/ε(v_i,T))。

Where i denotes the i-th band of the emissivity curve, v_i+1Refers to the i +1 th wave band, v, of the jth emissivity curve_iRefers to the ith wave band, epsilon (v) of the jth emissivity curve_iT) is the emissivity value of the ith wave band of the jth emissivity curve when the sample temperature estimated value is T; epsilon (v)_i+1T) is the emissivity value of the i +1 wave band of the jth emissivity curve when the sample temperature estimated value is T; j refers to the jth emissivity curve, ε j refers to the emissivity value of the jth emissivity curve, WJH (ε_jT) is the smoothness value of the jth emissivity curve when the sample temperature estimated value is T; COV represents the covariance calculation.

Step (9) calculating the emissivity of the ground target obtained in the step (8) under different temperature estimationsCurve smoothness function WJH (ε_jT) and obtaining a smoothness map of the emissivity curve of the sample at different temperature estimates.

Calculating log base 2 of the smoothness function of the emissivity curve of the sample under different temperature estimates obtained in step (8)₂(WJH(ε_iT)). And taking different temperature estimated values of the sample as an X axis, and taking the smoothness logarithm value of the emissivity curve corresponding to each temperature estimated value as a Y axis, thereby obtaining the smoothness logarithm diagram of the emissivity curve of the sample under different temperature estimation.

And (10) determining the optimal temperature value of the ground target according to the smoothness graph of the emissivity curve of the sample obtained in the step (9) under different temperature estimation.

And (4) obtaining a temperature value corresponding to the smoothness minimum value of the Y-axis emissivity curve from the emissivity smoothness log under different temperature estimation obtained in the step (9), namely obtaining an optimal temperature estimation value of the ground target sample, wherein the optimal temperature estimation value in the implementation is 28.68 ℃.

The theoretical accuracy of the ground target temperature estimated by the method can reach 0.01 ℃, as shown in figure 1.

By combining the analysis, the method can acquire high-precision temperature data of the ground target, is applied to the fields of abnormal operation detection of instruments, breakpoint detection of electronic circuit boards, rock thermal inertia calculation, abnormal temperature and water discharge detection of nuclear power stations and the like, and lays an important foundation for improving the large-range aerial/aerospace thermal infrared remote sensing and quickly identifying the target temperature precision.

While the embodiments of the present invention have been described in detail, the above embodiments are merely preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present invention.