Research On Remote LIBS And Raman Detection Technology For Mars Application

With the arrival of the next Mars exploration time window,China will implement the "Tianwen-1" Mars exploration program in 2020,which will be equipped with Mar SCo De(Mars Suface Composition Detector),a detector based on laser-induced breakdown spectroscopy technology.In order to ensure the accuracy and interpretability of the on-orbit data of the Mar SCo De,this dissertation combines the practical application problems faced by the Mar SCo De instrument detection to provide theoretical and technical support for China's 2020 Mars exploration project.In addition,we also conducted in-depth research on key technologies related to the composition analysis of Mars surface substances based on the remote LIBS-Raman technology to provide research experience and method support for the subsequent development and application of the composition analysis techniques of Mars surface substances.The main research contents of this dissertation are as follows:In view of the basic conditions of Mar SCo De payloads' working principle,survival problems and scientific goals,in this dissertation,we discusse Mar SCo De's instrument calibration and on-orbit calibration in two aspects.Using the calibrated standard element lamp and standard radiant lamp,the Mar SCo De instrument is calibrated in the laboratory environment for spectral calibration,radiation calibration and other benchmarks.In order to deal with the problems of instrument drift and response changes in orbit applications,a particle swarm optimization automatic spectral on-orbit wavelength calibration algorithm was proposed,and an adaptability evaluation method was innovatively designed.Experimental test results prove that the correction method can effectively improve the efficiency of wavelength calibration.The evaluation method can accurately evaluate the accuracy of spectral calibration.The resulting line error is less than one order of magnitude of the spectral resolution of the three-channel spectrometer of the instrument,which is in line with The Mars on-orbit application conditions.Aiming at the Mars Co De instrument how to effectively analyze the composition of unknown samples,in this dissertation,we focuse on the problem of establishing a ground database and data analysis method based on Mar SCo De's LIBS and VIS-SWIR spectral data.On the one hand,by establishing a qualitative spectrum database and a quantitative analysis database of each oxide,accurate analysis of Mars surface material is achieved.On the other hand,based on the infrared spectroscopy data of Mar SCo De,the subclasses of minerals can be determined,and then the analysis database of subclasses of minerals can be established in combination with LIBS to achieve more accurate quantitative analysis of the content of mineral components.The establishment of analysis models for the content of each end element and oxide in olivine verified that the fusion analysis of these two spectra can effectively improve the accuracy of quantitative analysis.The final results show that the analysis method can effectively combine the characteristics of LIBS and infrared spectroscopy,and realize the accurate analysis of Mars Co De's surface material element composition and mineral information.The above research provides an effective analysis method for accurate analysis of orbital minerals based on Mar SCo De.In order to solve the problem of inaccurate analysis of Mars surface material using LIBS or Raman technology alone,in this dissertation,we have carried out research on the combined technology of LIBS and Raman on Mars.First,the physical principles,scientific significance,and scientific devices involved in detection are discussed in detail.Based on the existing research foundation,a set of Mars environment simulation system and a set of remote LIBS-Raman combined testing system were established respectively,which realized the work of ground analysis method verification and database establishment.The detailed working principle and the experimental system and the key parameters have been analyzed to provide a groundwork for the ground experiments for our country's subsequent spectral detection methods for Mars surface material analysis.In this dissertation,we also mainly studies the verification of the complementary analysis capabilities of typical mineral compositions using LIBS and Raman spectroscopy based on simulated Martian atmospheric environment.In the experiment,using the remote LIBS-Raman combination system and the Mars environment simulation system,eight typical samples were selected to compare the differences in elemental and molecular properties.The final test results show that this system can effectively use the advantages of LIBS and Raman technology,and can achieve comprehensive detection of element and molecular information.Based on this device,a valuable spectral database can be established for the types of minerals on the surface of Mars,possible biomolecules and brine characteristics.