CN-119618386-B - Infrared radiation calibration precision inspection method based on Boltzmann constant

CN119618386BCN 119618386 BCN119618386 BCN 119618386BCN-119618386-B

Abstract

The application provides an infrared radiation calibration precision checking method based on a Boltzmann constant, which comprises the steps of cutting a reference blackbody into an infrared camera light path under a satellite on-orbit calibration mode, carrying out full-caliber calibration to obtain parameters such as blackbody temperature, platinum resistance state and the like, collecting calibration data such as gain, bias and the like issued by calibration responsibility units, calculating blackbody radiation brightness according to Planckian radiation law, calculating radiation brightness according to the calibration parameters, pixel DN values and the like, constructing a precision checking variable S1, calculating the Boltzmann constant value under inversion specific conditions according to the blackbody temperature, wavelength, radiation brightness and the like, constructing a precision checking variable S2, further calculating data such as variance, deviation, sensitivity and the like on the basis of S1 and S2, and finely checking and judging calibration precision.

Inventors

CHE XIAOLING
WU MENGXI
WANG MINFENG
SHEN ZHIQIANG
CHEN CHENXIN
LI SHUAI
MENG JING
LI XIYUAN
WU SIYANG
GUO DING

Assignees

航天东方红卫星有限公司
中国空间技术研究院

Dates

Publication Date: 20260508
Application Date: 20241206

Claims (9)

1. An infrared radiation calibration accuracy test method based on boltzmann constants, comprising the following steps: m1, cutting in an imaging light path of an infrared radiation imaging system by an on-board reference black body under an on-orbit calibration working mode of a satellite, heating the on-board reference black body to a set black body temperature T, and detecting infrared radiation emitted by the on-board reference black body by a detector of the infrared radiation imaging system; m2, inverting the spectral radiance of the black body based on the temperature T of the black body according to the Planckian law of the radiation of the black body to obtain the spectral radiance L (lambda, T) of the black body, and obtaining the spectral radiance L λ at the entrance pupil by a detector of an infrared radiation imaging system; M3 constructing a first precision check variable ; M4, inversely calculating a Boltzmann value k T at the blackbody temperature T based on the spectral radiance L λ at the entrance pupil, and constructing a second precision test variable S2, wherein the second precision test variable S2 is the difference between the Boltzmann value k T and the Boltzmann constant theoretical value k; M5, counting a first precision test variable S1 at different blackbody temperatures T, counting deviation, variance and relative error of a second precision test variable S2 at different blackbody temperatures T, taking the deviation, variance and relative error as indexes for infrared radiation calibration precision test, Wherein, step M5 includes: m51, judging that the infrared radiation calibration precision is not qualified if any one of the first precision check variables S1 at different blackbody temperatures T is larger than or equal to a first set threshold value, and ending the checking method, if the first precision check variables S1 at different blackbody temperatures T are smaller than the first set threshold value, performing a step M52; And M52, judging the infrared radiation calibration precision by using a second precision check variable S2, wherein the method comprises the steps of judging that the infrared radiation calibration precision is unqualified if any one of the deviation, variance and relative error of the second precision check variable S2 at different blackbody temperatures T is larger than or equal to a second set threshold value, and judging that the infrared radiation calibration precision is qualified if the deviation, variance and relative error of the second precision check variable S2 at different blackbody temperatures T are smaller than the second set threshold value.
2. The method of claim 1, wherein, The value range of the first set threshold is 5-10%, and the value range of the second set threshold is 0.1-1%.
3. The method of claim 1, wherein, The black body temperature T is obtained by measuring a platinum temperature measuring resistor embedded in the satellite reference black body.
4. The method of claim 1, wherein, The infrared radiation imaging system comprises a satellite-borne infrared camera and a spectrum imaging system, and comprises a lens, a detector and an electronic system.
5. The method of claim 1, wherein, In the step M1, the on-board reference blackbody is cut into an imaging light path of the infrared radiation imaging system in a full-caliber and full-view field.
6. The method of claim 1, wherein, The step of obtaining the spectral radiance L λ at the entrance pupil from the detector of the infrared radiation imaging system in step M2 includes: After imaging by the infrared radiation imaging system, according to a formula L λ ＝DN λ ·g λ +Lo λ , converting the gray value of the detector pixel of each wave band of the medium-length wave infrared channel into spectral radiance L λ at the entrance pupil of the detector, wherein L λ is the spectral radiance at the center wavelength lambda, the unit is w.m -2 ·sr -1 ·μm -1 ,DN λ is the gray value of the detector pixel at the wavelength lambda, g λ is the gain at the center wavelength lambda, and Lo λ is the offset at the center wavelength lambda.
7. The method of claim 1, wherein, In step M4, boltzmann value k T at blackbody temperature T is calculated based on the following inversion: , where h is the Planck constant, c is the vacuum light velocity, and λ is the center wavelength.
8. The method of claim 1, wherein, In the step M5 of the process, Through type Calculating the deviation of the second precision test variable S2; Through type Calculating the variance of the second precision test variable S2; Through type Calculating the relative error of the second precision test variable S2; Where k Ti is the different boltzmann values at the plurality of temperature points Ti.
9. A computer readable storage medium having stored thereon software instructions which, when executed, implement the method according to any of claims 1-8.

Description

Infrared radiation calibration precision inspection method based on Boltzmann constant Technical Field The invention belongs to the technical field of aerospace quantitative remote sensing, and relates to an on-orbit infrared band temperature measurement and calibration method. Background The on-orbit earth observation satellite payload calibration is generally divided into four aspects of ground simulation space environment calibration, space on-orbit calibration, site on-orbit calibration and satellite cross calibration, and the first two are keys of space remote sensor calibration. Before a spacecraft carrying a space reference blackbody source emits and enters a track, a calibration physical model of the blackbody source is established, and after long-term on-track operation, blackbody emissivity, platinum resistance temperature measurement characteristics, infrared remote sensing load detector characteristics and the like are changed, so that remote sensing data are deviated. Therefore, the data and model parameters measured in a laboratory before the remote sensor is transmitted can be further produced into advanced data products after on-orbit calibration and calibration, and the method has important significance for improving the quantification level of the space remote sensor, keeping the long-term effectiveness of the magnitude value and carrying out multi-source data coordination detection and consistency processing. After the space remote sensor is in orbit, the space remote sensor is in a space environment with high vacuum, low gravity and strong radiation, and through a large amount of experiments and data accumulation, the space remote sensor is considered to have unchanged common physical and chemical constants (such as light velocity, charge, boltzmann constant and the like), unchanged atomic transition frequency and unchanged emission spectrum, and other characteristics related to equipment such as emissivity, resistance, responsivity and the like can be changed. The space remote sensor working in the infrared band generally carries a space reference blackbody to realize on-orbit calibration, and platinum resistors are arranged in the blackbody to measure the temperature. The on-orbit platinum resistance thermometer is affected by impact, vibration and natural aging, and the drift of the magnitude can reduce the measurement accuracy of the temperature and enlarge the uncertainty in the calibration process. In order to meet the effectiveness of key magnitude tracing during the on-orbit period, the platinum resistance thermometer needs to be calibrated periodically and re-metered, and the common practice is to add a miniature phase change fixed point device on a blackbody, and the shell is internally packaged with a phase change material, and the phase change point presents a standard temperature value. Because the phase change material is sealed, the phase change material is little influenced by the external environment. The method mainly has the following defects that 1) the complexity of design and maintenance of the on-board blackbody is increased by the phase change fixed point, the blackbody radiation characteristic is influenced to a certain extent, 2) a plurality of platinum resistance sensors are required to be arranged, the development cost is increased, 3) in the actual space use process, the operation flow is complicated, more uncertain parameters can be introduced, and a certain difficulty is brought to the repeated measurement operation. Disclosure of Invention In order to overcome the defects of the prior art, the invention provides the infrared radiation calibration precision inspection method based on the Boltzmann constant, which judges the range of the calibration parameter change and the attenuation degree through the radiation brightness comparison and Boltzmann constant change analysis, further judges whether the radiation calibration data meets the use requirement, and provides a judgment basis for the accuracy of the follow-up quantitative inversion parameters. The application provides an infrared radiation calibration precision inspection method based on a Boltzmann constant, which comprises the following steps: m1, cutting in an imaging light path of an infrared radiation imaging system by an on-board reference black body under an on-orbit calibration working mode of a satellite, heating the on-board reference black body to a set black body temperature T, and detecting infrared radiation emitted by the on-board reference black body by a detector of the infrared radiation imaging system; m2, inverting the spectral radiance of the black body based on the temperature T of the black body according to the Planckian law of the radiation of the black body to obtain the spectral radiance L (lambda, T) of the black body, and obtaining the spectral radiance L λ at the entrance pupil by a detector of an infrared radiation imaging system; M3 constructing a first precision check