Study On New Types Of Spectral Radiance Calibration Source

In the last decade or two,with the promotion of environmental science,solar physics,atmospheric physics,climatology,and meteorology,high-precision solar/atmospheric quantitative spectral remote sensing technology has developed rapidly.The accuracy of the space quantitative spectral remote sensing data depends to a large extent on the radiometric calibration accuracy of the remote sensing instrument.The so-called radiometric calibration of remote sensing instruments refers to the establishment of quantitative correspondence between the instrument output electrical signals and the detection target physical quantities.At present,the accuracy of spectroradiometric calibration of the international mainstream space optical remote sensing instruments is high and can reach 0.2%-2%.At the same time,the development of the research fields such as ground remote sensing,aviation remote sensing,plasma physics and quantitative spectroscopy also raises higher and higher requirements to radiometric calibration accuracy.At present,the radiometric calibration methods of spectral radiance responsivity of the instrument in the ultraviolet to shortwave infrared spectral bands are mainly through broad-band light source and narrow-band light source formed by integrating sphere light source irradiated by tunable monochromatic laser.The spectral radiance of the tunable monochromatic laser irradiation integrating sphere narrow-band light source is calibrated by a trap detector which is calibrated by a cryogenic absolute radiometer.The calibration accuracy of the narrow-band light source is high and itsspectral radiance uncertainty can be as small as 0.1%.However,the system is large and complex,and thetime of the whole spectral band calibration process is long.The broad-band light source is usually a light source formed by a diffuser plaque irradiated by a standard spectral irradiance lamp,or a light source formed by an integrating sphere illuminated by a broad-band lamp.The spectral irradiance of the standard spectral irradiance lamp or the spectral radiance or the integrating sphere light source is usually determined by high-temperature black body standard.The broad-band light source has the advantages of compact structure,convenient use and quick calibration process,but the calibration accuracy is relatively low,and it will decay with the increase of the use of time,requiring frequent retest.Therefore,it is necessary to develop a new type of spectral radiance calibration source that can combine the advantages of the above two kinds of calibration sources.In this thesis,firstly,based on the summarization of the research and development status of new-type spectral radiance calibration sources at home and abroad,a new type of self-calibration standard spectral radiant source with narrow-band and broad-band working modes is proposed,and the system integration,experimental test and and the system analysis of self-calibration source are also conducted and presented;Then based on the self-calibration source,a high-stability spectral radiance calibration source using spectral tunable filter technology and a supercontinuum fiber laser source is studied,the design of the high-stability source system and the experimental prototype setup are completed,and the signal intensity,the spectral bandwidth and the stability of the high-stability source are experimentally tested and studied;Finally,to verify the validity and applicability of the designed high-stability source system,stability test of the visible channel prototype of the solar irradiance spectrometer is completed based on the high-stability source experimental prototype built.The first part of this thesis mainly introduces the research background of the project,the main methods of remote sensing instruments radiometric calibration,and the related research progress of new types of spectral radiance calibration light sources at home and abroad.The main content of the second part is the study on the overall technical plan for designing a self-calibration standard spectral radiant light source,including the second and the third chapter of the thesis.The overall technical plan for the self-calibration standard spectral radiant light source is introduced in the second chapter.First of all,a clear research goal:to develop a set of spectrally tunable standard radiant light source based on standard detectors,to complete the study of its radiometric calibration method,and finally to provide a spectrally tunable uniform spectral radiant light source system with low spectral radiance uncertainty and good long-term stability.Based on this,the overall design scheme of the self-calibration source system is first proposed:the self-calibration source system should have two working modes of narrow-band mode and broad-band mode;In the narrow-band mode,the standard detector is used to calibrate the self-calibration source,and in the broadband mode the self-calibration source is used to calibrate the remote sensing instrument.The mutual conversion of the two working modes can be achieved through spectral tuning technique.Then the components of the self-calibration source system are specifically designed,and the design and working principle of each component are introduced in detail.The radiometric calibration model of the self-calibration????????tunable radiant source system and the spectral radiance conversion algorithm from narrow-band mode to broad-band mode are finally studied.This chapter mainly completes the working principle design of the self-calibration spectrally tunable source and the study of the radiometric calibration method,thereby provides the basis for future prototype construction,calibration and testing.The third chapter mainly completes the related experiment and analysis research of radiometric calibration and performance test of the self-calibration source system.Firstly,according to the design of the self-calibration source,the system integration of the self-calibration source prototype is completed,and a platform for experimental test is built.Then according to the radiometric calibration method of the self-calibration source,the radiometric calibration of the prototype is performed,and the uncertainty of the output spectral radiance of the self-calibration source is analyzed.Finally,the test and analysis results of the spectral resolution,stability and repeatability test for the self-calibration source are completed.The content of this chapter verifies the system design and the radiometric calibration principle of the self-calibration source by experimental method,presents the performance index of the self-calibration source prototype,and provides the basis for the future analysis and improvement of the self-calibration source design scheme.In the third part,based on the research results of the self-calibration standard spectral radiant light source,a high-stability spectral radiant calibration light source is proposed.Firstly,the principle and the design scheme of the high-stability spectral radiant calibration light source are studied and presented;Then an experimental prototype is built according to the design scheme,and its output spectral radiance,spectral bandwidth and stability are tested;finally,the stability of the visible channel prototype of the solar irradiance spectrometer is studied based on the high-stability spectral radiant calibration light source prototype built.The content of this chapter has completed the principle research,the experimental prototype construction and some application experiment and performance test of the designed high-stability spectral radiant calibration light source,providing some technical basis for related research work in the future.Finally,the last part of the thesis summarizes the research result of the full text,concludes the innovation points of this thesis,analyzes the deficiency and forecasts the possible research direction in the future.